q_id
stringlengths 5
6
| title
stringlengths 3
301
| selftext
stringlengths 0
39.2k
| document
stringclasses 1
value | subreddit
stringclasses 3
values | url
stringlengths 4
132
| answers
dict | title_urls
list | selftext_urls
list | answers_urls
list |
|---|---|---|---|---|---|---|---|---|---|
550c9n
|
when cooking, why do we mix specific ingredients at a time
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/550c9n/eli5when_cooking_why_do_we_mix_specific/
|
{
"a_id": [
"d86h88w",
"d86hm40",
"d86jj5q"
],
"score": [
5,
4,
2
],
"text": [
"Various reasons. It's easier to mix all the liquids together and all the dry and then mix the two mixes, or there needs to be a specific reaction that takes place between two ingredients, etc. ",
"Like the other guy said, various reasons. For instance, when I prepare my base gravy, I make it a point to not add the main vegetable before the base gravy is fully prepared because I don't want the main vegetable to blend in with the rest of the gravy. I want it standing out so that the gravy serves as a \"sidekick\" to add that extra spicy taste.\n\nTL;DR everything has its own role to play.",
"Cooking is chemistry. When you add things causes different reactions to happen. In some cases it is more for a better mixing. "
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
4z29ub
|
why do we find roller coasters and similar rides enjoyable?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4z29ub/eli5_why_do_we_find_roller_coasters_and_similar/
|
{
"a_id": [
"d6sa9qi",
"d6scqw4"
],
"score": [
2,
2
],
"text": [
"\"Nothing in life is so exhilarating as to be shot at without result.\" - Winston Churchill\n\nDangerous stimuli, such as great heights and fast speeds - both of which are features of rollercoasters, trigger the sympathetic nervous response, which increases heart rate, blood pressure, and parts of the brain associated with an excitatory state. The role of the sympathetic nervous response is to prepare our bodies to fight off or flee from danger. \n\nCoincidentally, the parts of the brain that are activated are similar to ones activated while in a state of mania, which is characterized by happiness, restlessness, and energy. The sympathetic response may also cause the release of pain-killing endorphins from structures in the brain in anticipation of injury. Endorphins are known to have euphoric (happy) effects as well, which suggests that they might have a role into why we find cheating death to be enjoyable.",
"\"We\"? \nDon't include me in this "
]
}
|
[] |
[] |
[
[],
[]
] |
||
tcpc1
|
how we know what everything in space does, and how its formed without actually being there, or witnessing it.
|
IDK, lol I'm not an astronomer, I don't even know how to word the question right. But how is it that we somehow know what, for example, a black hole is, how it got there, and what it does without actually witnessing any of it happen. or did we?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/tcpc1/eli5_how_we_know_what_everything_in_space_does/
|
{
"a_id": [
"c4lhfwz",
"c4lihdq",
"c4lipdm"
],
"score": [
3,
11,
7
],
"text": [
"We can witness a lot of it through telescopes. We know about planets around other stars, for example, by the 'wobble' of the star that we can observe when watching it. The mass of something affects everything else in the universe, so whilst a star holds a planet in its orbit, the mass of the planet also moves the star, just to a much lesser extent.\n\nFirst we make a prediction, and to continue with this example, we assume there might be other planets because our star has planets. Then we try and make an observation that confirms it.\n\nBut there are also things that are inferred through our current understanding of physics. A black hole is implied by modelling mathematically how ultra massive objects might behave, and we predicted blackholes before we ever actually had evidence of them.\n\nThe big bang was later backed up by background radiation that fit the predictions we made when we observed the red shift in galaxies (the red shift is caused by the fact that light is stretched to a different wavelength by something accelerating away, like a doppler effect but with light) and so on. So even things we can't physically see, we can infer and that at least gives us a starting point about where we should start looking.\n\nAll of these are massively over-simplified but you get the idea.",
" > without actually being there, or witnessing it\n\nIf a nuclear bomb went off many miles away, but you were on top of a mountain and saw the cloud, you still witnessed it. Now, if you were farther away and saw it through binoculars, you still witnessed it.\n\nSimilarly, we totally witness things in space via telescopes and other instruments.",
"You're standing in the mountains. Green trees, rocky hill tops, bear crap, the whole nine yards. \n\nSuddenly, you hear a crashing noise off in the distance, You look that direction and you see a large boulder rolling and tumbling down the side of a mountain, as it's going, it's knocking loose other rocks and dirt, and by the end, you see a good chunk of the mountain has slumped down in a rock slide. It's made an interesting hollow shape in the otherwise smooth sided mountain. You look at the mountain next to it, and you can see a similiar depression in its side, but the edges are a little smoother, and the pile of rocks at the bottom is mostly worn away and grown over with shrubs and grass. You look on the other side, and you notice that there is nothing like that on THAT mountain, but you notice a huge boulder precariously balanced up at the top. NOW imagine that instead of seeing that rockslide happen in real time, the whole process of that big rock falling from the top ending in a big pile of rocks and dirt at the bottom was going in super slow mo, and it actually took an hour for that big rock to roll forward an inch.\n\nSo by seeing ONE thing, you can now look around and see where the similiar event has happened before, and where a similiar event will happen again. When we look at our solar system and go \"Our planets formed from accretion discs of material coelescing around a newly formed star, eventually combining into planetoid shapes.\" All we are really saying is \"There's a big pile of crap over there that's forming a new star. And right there, there's two new stars with all this crap still circling around it. Then there's that thing over there that's a star with planets starting to form around it from all that crap....This seems to be a common theme in the universe....hmmm..\"\n\nHas anyone ever WITNESSED a solar system forming together? no. That process takes billions of years and we've only been *really* looking for a few hundred. But we can see BILLIONS of examples of what it looks like immediately after, and some a LONG time after it happened...and some just before it happened, etc. Same thing with black holes. We can't watch a real-time video of a black hole eating a star. But you can take a collage of pictures of people eating a steak dinner, and eventually you can make them into this weird little flip book of this amorphous blob of humanity picking up a fork and a knife, cutting into the steak, and putting that first bite into his/her mouth. "
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
11jjkg
|
Does the Snooze Button Actually Give Us More Rest?
|
I was just wondering if sleeping for an additional 10 or so minutes after being abruptly awoken would actually get us more rest, as opposed to forcing ourselves to get up when the alarm goes for the first time.
There are also people, like myself, who snooze multiple times throughout the morning. Does getting awoken multiple times make us more rested, or is it better to just get out of bed and save ourselves time?
|
askscience
|
http://www.reddit.com/r/askscience/comments/11jjkg/does_the_snooze_button_actually_give_us_more_rest/
|
{
"a_id": [
"c6n5y7r",
"c6n62zm",
"c6n7rn7",
"c6n8fbj",
"c6n8gg6",
"c6n96sc",
"c6n9c71"
],
"score": [
93,
171,
8,
37,
35,
217,
30
],
"text": [
"Ok, follow-up: what would be a good interval for a programmable snooze function on an alarm clock in terms of giving someone actual extra rest?",
"Here are a couple sources that claim that snoozing repeatedly is not a good thing: [1](_URL_1_) [2](_URL_0_)\n\nI was hoping to find some actual research papers, but I didn't turn up too much with a quick search (at least nothing non-paywalled). These articles are also reminding me that I should be asleep, but maybe someone else can track down the original research that's being reported.",
"Would this have something to do with waiting until your circadian rhythm has full come out of REM mode if it went off in the middle of a sleep cycle?",
"Informative responses with sources on [this very similar post](_URL_0_) from 4 month ago.",
"Followup question (which may help get to a better answer for OP):\n\nIf a person wakes up in a \"bad\" place in their sleep cycle, will snoozing help fix the otherwise-inevitable groggyness?",
"Ladies and Gentlemen - may I remind you all that the plural of 'personal anecdote' is not 'evidence', and these kinds of response are not appropriate here in AskScience. \n\nWe're keeping a close eye on this question - hopefully we can get some peer-reviewed goodness in here soon. However, it may be there isn't any. \n\nIn either case, please refrain from making any comments which do not go in accordance with our posting guidelines (in the sidebar -- > ), as otherwise we'll be forced to remove the question rather than struggle to keep a fact-free comment-magnet on the front page.\n\nThank you all for your help in this matter.",
"According to noted sleep authority Professor James Maas, hitting the snooze button is very, very bad for your sleep. He specifically called it \"fragmented sleep\" and said it is not only worse than having slept straight through for the same period, it is probably worse than having gotten up at the first alarm.\n\nSource: Personally attended a Guest Lecture by him"
]
}
|
[] |
[] |
[
[],
[
"http://www.dailymail.co.uk/health/article-2031502/Hands-snooze-button-Wake-tired-Heres-bounce-bed.html",
"http://www.maimonidesmed.org/Main/News/The-Snooze-Button-Friend-or-Foe-236.aspx"
],
[],
[
"http://www.reddit.com/r/askscience/comments/v2zuh/is_there_any_reason_or_advantage_to_desiring_that/"
],
[],
[],
[]
] |
|
711rxp
|
Book about Knights in Medieval Spain
|
Hello,
I'm currently writing a story about an idiot knight and his fake heroics, set in a fictional place similar to Spain.
I'm looking for a book to provide me with some inspiration and historical context.
Who were some of the knights who fought in the Iberian Peninsula? What were some of their feats?
Any period of the Middle Ages would do. In my ignorance, I thought that maybe the warring between Muslims and Christians could give me interesting material to work with.
Searching this subreddit I could find recommended books about knights in England, France and Italy; none for Spain, unfortunately.
Thanks.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/711rxp/book_about_knights_in_medieval_spain/
|
{
"a_id": [
"dn7k19t"
],
"score": [
2
],
"text": [
" > an idiot knight and his fake heroics, set in a fictional place similar to Spain.\n\nNot to put too fine a point on it, but you should probably check out Miguel de Cervantes, *Don Quixote* first."
]
}
|
[] |
[] |
[
[]
] |
|
100wy0
|
[Medicine] Can any cardiologists give a real insight into "Cough Cardiopulmonary Resuscitation" or "Cough CPR" and its effectiveness in assisting someone who is about to go into cardiac arrest?
|
Dear medical staff and cardiology specialists in particular, I wonder if you could shed some insight into the "cough CPR" procedure based on my recent experience below.
Many thanks in advance.
----
Recently, a number of contacts on Facebook have been sharing the following text, accompanied by a stock image of a guy supposedly having a heart attack:
> Please Share...
> HOW TO SURVIVE A HEART ATTACK WHEN ALONE
>
> Let's say it's 6.15pm and you're going home (alone of course),
> after an unusually hard day on the job. You're really tired, upset and frustrated. Suddenly you start experiencing severe pain in your chest that starts to drag out into your arm and up into your jaw. You are only about five miles from the hospital nearest your home. Unfortunately you don't know if you'll be able to make it that far. You have been trained in CPR, but the guy that taught the course did not tell you how to perform it on yourself..!!
>
> NOW HOW TO SURVIVE A HEART ATTACK WHEN ALONE..
>
> Since many people are alone when they suffer a heart attack, without help, the person whose heart is beating improperly and who begins to feel faint, has only about 10 seconds left before losing consciousness.
> However, these victims can help themselves by coughing repeatedly and very vigorously.
> A deep breath should be taken before each cough, and the cough must be deep and prolonged, as when producing sputum from deep inside the chest.
> A breath and a cough must be repeated about every two seconds without let-up until help arrives, or until the heart is felt to be beating normally again.
> Deep breaths get oxygen into the lungs and coughing movements squeeze the heart and keep the blood circulating.
> The squeezing pressure on the heart also helps it regain normal rhythm. In this way, heart attack victims can get to a hospital.
>
> Rather than sharing jokes please.. contribute by Sharing this which can save a person's life
Coming from a family with a history of congenital heart disease and as someone who regularly has his blood pressure and cholesterol levels checked, I was intrigued and did some research. Needless to say, what I discovered wasn't exactly in line with the spammy post. Here are some of the articles I found with a quote from each:
> The American Heart Association does not endorse "cough CPR," a coughing procedure widely publicized on the Internet. As noted in the 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care, “cough CPR” is not useful for unresponsive victims and should not be taught to lay rescuers.
[_URL_3_](_URL_2_)
> The BLS/AED Subcommittee knows of no evidence that, even if a lone patient knew that cardiac arrest had occurred, he or she would be able to maintain sufficient circulation to allow activity, let alone driving to the hospital.
[_URL_4_](_URL_5_)
> “It’s right up there with voodoo as far as I’m concerned,” says Dr. Cary Fishbein, a cardiologist with the Dayton Heart Center.
[_URL_6_](_URL_0_)
> There is a theory circulating from an uncertain source that you can stop yourself from having a heart attack by practising a technique called ‘cough cardiopulmonary resuscitation’. It suggests that coughing vigorously when you think you may be having a heart attack can return the electrical activity of the heart to normal. The British Heart Foundation (BHF) is not aware of any evidence to support this theory and ‘cough CPR’ should never be used as a first aid technique.
[PDF Download from _URL_1_](_URL_7_)
So, I - in hindsight, mistakenly - posted some of the above information to Facebook, warning individuals that it's probably best to get in touch with emergency services and to follow standard CPR procedure in the event of someone having a suspected heart attack, than to attempt the "cough" procedure... Inevitably, someone "knew" better.
Citing "two medic friends", this person argued, ignored the facts, articles and documents I cited and stressed that it was better to do this than "looking on the internet for help".
So, for my own curiosity more than anything else, what's the verdict? Would you recommend doing this if you thought you were on the verge of cardiac arrest? Or is it, as I suspect, something which has spread from email spam to Facebook (Snopes lists the first publication of the text sometime in 1999) just as many other stories have.
Many thanks once again.
|
askscience
|
http://www.reddit.com/r/askscience/comments/100wy0/medicine_can_any_cardiologists_give_a_real/
|
{
"a_id": [
"c69g93h",
"c69j7k9"
],
"score": [
9,
2
],
"text": [
"Anesthesiologist here. Vagal maneuvers (coughing, bearing down) may terminate some tachyarythmias by stimulating the vagal nerve and activating parasympathetics which counteract sympathetic stimulation which initiates the tachyarrhythmia. A myocardial infarction is due to an imbalance between supply and demand of oxygen for the heart. While you could arguethat vagal maneuvers would slow the heart and decrease myocardial demand, i have never seen literature to suggest that this effect would be significant enough to prevent a heart attack, or an arrest in which the heart goes into ventricular fibrillation. Unfortuantely no easy access to journals right now, so i cant provide any references to back this up. \nAs a general rule thoguh, if someone is having a heart attack, or passes out, call for help, call for emergency medical services, find an automated external defibrillator if you are trained, and start cpr if you are trained.",
"So, a Valsalva maneuver?"
]
}
|
[] |
[
"http://mendedhearts.org/resources/about-heart-disease/the-coughing-rumor",
"BritishHeartFoundation.org.uk",
"http://www.heart.org/HEARTORG/Conditions/More/CardiacArrest/Cough-CPR_UCM_432380_Article.jsp#.TvxPIZfw18F",
"Heart.org",
"Resus.org.uk",
"http://www.resus.org.uk/pages/coughCPR.htm",
"MendedHearts.org",
"http://www.bhf.org.uk/plugins/PublicationsSearchResults/DownloadFile.aspx?docid=2010437d-683c-4f58-adf9-b93be2bed9d5&version=-1&title=Cardiac+Arrest&resource=IS98"
] |
[
[],
[]
] |
|
1xctps
|
Is there any evidence that people would purposefully lame blacksmiths because their skills were too essential for a village to lose?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1xctps/is_there_any_evidence_that_people_would/
|
{
"a_id": [
"cfabs1o"
],
"score": [
13
],
"text": [
"Just out of curiosity, where did you hear this? I've never heard it before."
]
}
|
[] |
[] |
[
[]
] |
||
2dsczl
|
Does a submerged object placed in a vessel of water (or other liquid) change the total overall weight of that vessel?
|
Suppose I have a 20 gallon fish tank. I fill it with 15 gallons of water and weigh the tank. I then submerge a 5 pound object in the tank, which does not touch the bottom but rather stays suspended in the liquid. If I weigh the tank again, does the weight change? What if I used another liquid besides water?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2dsczl/does_a_submerged_object_placed_in_a_vessel_of/
|
{
"a_id": [
"cjskk14",
"cjsknj2"
],
"score": [
8,
4
],
"text": [
"Dit will weight 5 pound more than before. The object dies not need to touch the tank. His own weight is transmitted through water. It would be the same with an other liquid. \nTo recap: the object is 'pushing' on the water which is 'pushing' on the tank with it's own weight and the weight of the object",
"Yes. \n\nObviously, if the object touches the bottom, it exerts a force due to its mass and a scale would measure the whole system as 5 pounds heavier than the tank and liquid alone.\n\nIf the object floats, either on the surface or at some depth above the bottom of the tank, that object's weight is being balanced by bouyancy *but it still exerts the same amount of force*.\n\nAn analogy: \n\n > Imagine you have a scale big enough to put a mattress on. Take a measurement of the weight of the mattress alone. Now climb on top of the mattress. You probably sink slightly into the matress but you don't drop through to the scale, right? And it shouldn't surprise you to find that the scale registers the combined weight of the mattress and your body. \n\nThe mattress is certainly much denser than most liquids you'll likely be able to fill a 20 gallon tank with but it transfers forces in essentially the same way."
]
}
|
[] |
[] |
[
[],
[]
] |
|
a5d9o3
|
In a vacuum, all objects, regardless of mass, fall at the same rate. However, since objects with less mass have less inertia and therefore they are affected more by the same amount of force, why don't object with less mass fall at a greater rate in a vacuum than more massive objects?
|
askscience
|
https://www.reddit.com/r/askscience/comments/a5d9o3/in_a_vacuum_all_objects_regardless_of_mass_fall/
|
{
"a_id": [
"ebmgvvw",
"ebmicew",
"ebmk119",
"ebmwsz5"
],
"score": [
29,
5,
6,
2
],
"text": [
"The force of classical gravity is proportional to the masses of *both* objects in a gravitational interact. The formula is F=GMm/r^(2), where M is the mass of one object, and m is the mass of the other object. By Newton's third law, this is actually the same force experienced by *both* objects, although in opposite directions.\n\nSo if you consider the interaction between, say, a penny and the Earth, they are both pulling each other with the same force. The penny pulls the Earth up, and the Earth pulls the penny down. If you double the mass of the penny (e.g. taping two pennies together), then the double-penny feels twice as much force as the single penny, and the Earth feels twice as much force too.\n\nHowever, this is *force*, and we need to divide by the mass of an object to get the acceleration. So, while the Earth and the penny have the same magnitude of force, the penny has a much larger acceleration because its mass is much smaller.\n\nSo this gets to the heart of your question: to get the force, we had to multiply by the mass of both objects. But to get the acceleration, we had to divide by the mass of the accelerated object. This cancels out one of the masses, and means that the acceleration *only* depends on the mass of the \"source\" of gravity. So, any object will fall at the same rate.\n\nIf it seems like a bit of an odd coincidence that the mass just happens to cancel out, then this is what bugged Einstein as well. This led him to develop General Relativity. Here, gravity is no longer a force, but an effect caused by the distortion of space-time. This distortion causes objects to change their velocity through space - basically, they are accelerating. Because this is just caused by space-time itself, it's not a force and we don't need to divide by mass to get the acceleration - all objects will take the same path through space-time, provided they're not so massive that they distort space-time a lot themselves.\n\nWe still actually use classical gravity through, because it's incredibly accurate in all but the most extreme of situations, and it's *far* easier to calculate. It's an approximation that gives the right answer almost all of the time, so it's important to be able to understand the theory in terms of this common abstraction. But it's also important to know that the reason *why* classical gravity works out that way does come from a deeper theory of gravity.",
"think of it this way. if you drop one bowling ball in a vacuum, or two bowling balls side by side, or two bowling balls glued together, would you expect one bowling ball to fall faster than either one of two? if not, why do you expect one to fall faster than two glued together?",
"The Newtonian model explains this pretty well. \n\nForce due to Gravity:\nF = G.M.m / r² \n\nNewton’s Second Law:\nF = ma\n\nSo we can combine them and write:\n\nma = G.M.m / r² \n\nNotice the mass of our object (m) appears on both sides? So they cancel out:\n\na = G.M / r²\n\nSo the acceleration due to gravity (a) does not depend on the mass of the object (m). \n\n(Note: this is basically the algebraic version of the excellent explanation from u/Astrokiwi )",
"To answer this, we really need to think about *why* things fall in the first place. We're so used to gravity making things fall that people often forget about it.\n\nThe curious thing about gravity is that the *force* it provides is *stronger* the more mass (i.e., the more inertia) an object has. And it just so happens that the amount the gravitational force increases by is just exactly the right amount to counter the inertia of a heavier object, giving it the same acceleration of a lighter object.\n\nHowever, if we were subjecting objects to a different force, like a spring, the strength of the force *does not* increase with an increasing mass. So if you have two masses on the same spring in vacuum, the heavier mass will accelerate slower than the lighter mass. In fact, this can actually be used to measure the mass of objects when a traditional scale won't work, like in orbit."
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
||
dda4o7
|
[WW2] What was the proportion of Luftwaffe casualties between Eastern and Western fronts? What Germans themselves thought of different opponents?
|
The question is very interesting to me as a Russian since information I've managed to gather is very confusing and self-contradicting. When we talk about overall tank and human losses of the Third Reich, it's pretty clear that majority of them were inflicted in the East. When we talk about naval losses, it's obvious that overwhelming majority of them were inflicted by the Allies.
But I've met very different perspectives about German air war experience, both in Russian and English. Many Russian historians still argue about how many Germans were shot down during war with the Soviet Union and how big their kill ratio might be (no one denies it was much better than their Soviet adversaries but I've seen estimates wobbling around between 1:2 and 1:4 and even up to 1:10, although the last one seems kind of ludicrious), including different years (some Russian historians argue it was extremely bad for the Red Air Force even in 1945, and that's quite a claim).
Estimates of destroyed/heavily damaged Luftwaffe planes vary from as low as 9 000 or 10 000 (Beshanov) to up to 22 000+ (Anokhin), and I'm not sure which figure is correct. Many authors claim they check different German sources, someone named Ghoeler is often brought up, but some sites in English cite him as unreliable, so I have no idea who is biased and who is not. Moreover, there is still no consensus about the degree of Soviet air success even if we don't count casualties since some find it to be "pretty good" while others find it's performance to be awful till the last day of WW2 (Beshanov claiming Eastern Front was much softer in comparison with the West IIRC).
TLl;DR: What was the distribution of German air casualties by WESTERN point of view? How many German aces died in the East? What Germans themselves thought of the Soviet air forces in 1941-1945? Was Eastern Front really as humble in comparison to the Allied air battles as I'm often told to believe?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/dda4o7/ww2_what_was_the_proportion_of_luftwaffe/
|
{
"a_id": [
"f2g9qh0"
],
"score": [
10
],
"text": [
"It's an interesting question, as it tests our faith in documents and implications of bias. However, German military documents - at least those not doctored for public consumption - have proven mostly accurate to the German military situation, at least until late 1944. So let's do some data analysis.\n\nRüdiger Overmans, one of Germany's leading military historians and probably the most distinguished academic in the specific field of German casualties, has a German-language essay called *Menschenverluste der Wehrmacht an der „Ostfront“*.\n\nFor those members of the interested audience that are able to read German, [here](_URL_0_) is the direct link. Even for those who don't understand the language might find the tables full of data useful.\n\nOvermans makes comments in the introduction referring to the popular imagination of mass casualties on the Ostfront (this is addressed in datapoints in Table 5, p. 13), as well as a reference to the contradictory data sets.\n\nPage 3-4 has Table 1, listing Wehrmacht casualties at the Eastern Front by months, broken down by branches of service. The Luftwaffe is listed separately. I'll copy over those specific data points into a table for the readers' convenience. If the table is unreadable to any fellow dark mode users, make sure to turn off the subreddit's theme on the right sidebar.\n\n\nMonth | LW Casualties\n-----|--------------------\n06 1941 | 692\n07 1941 | 952\n08 1941 | 536\n09 1941 | 1.294\n10 1941 | 934\n11 1941 | 597\n12 1941 | 310\n01 1942 | 474\n02 1942 | 497\n03 1942 | 947\n04 1942 | 811\n05 1942 | 1.195\n06 1942 | 1.475\n07 1942 | 1.584\n08 1942 | 1.266\n09 1942 | 1.173\n10 1942 | 609\n11 1942 | 434\n12 1942 | 1.259\n01 1943 | 1.275\n02 1943 | 553\n03 1943 | 707\n04 1943 | 545\n05 1943 | 982\n06 1943 | 1.026\n07 1943 | 1.503\n08 1943 | 971\n09 1943 | 797\n10 1943 | 453\n11 1943 | 208\n12 1943 | 182\n01 1944 | 323\n02 1944 | 379\n03 1944 | 320\n04 1944 | 2.068\n05 1944 | 2.321\n06 1944 | 2.785\n07 1944 | 2.460\n08 1944 | 3.667\n09 1944 | 13.774\n10 1944 | 6.529\n11 1944 | 12.742\n12 1944 | 8.755\n\nThis makes for an overall number of casualties of 82,364 between June 1941 and December 1944. Of these, 26,516 were suffered in the just the two bloodiest months of the campaign, September and November 1944. In September 1944 alone, Germany suffered a total of 426,159 - the strength of an entire army group.\n\nIf we use the rule of thumb that Germany suffered about a quarter of its casualties during the year 1945 (see Table 6, p. 15: Overmans sums up all casualties in 1945 as *Endkämpfe*), we could slap another tentative modifier of x1.33 on there and estimate the overall number of casualties, including 1945, to be 109,544. That would be a rather conservative estimate, since you see the tendency of casualties drastically rise in the last few months of recording, but it's the best we have for Overmans. Schramm puts the number at 138,596 - a lot higher than a 109,000 estimate.\n\nOvermans points out that the reason his dataset ends at December 1944 is mainly that the different fronts started to lose their meaning in 1945, as they started merging with each other as Germany crumbled. In his argument, trying to gather the losses of specific fronts in 1945 is a completely futile endeavor. As German units started surrendering in large numbers in 1945, the PoW number exploded towards casualty rates of 100%.\n\nSome important notes.\n\n1. This is overall casualties of the Luftwaffe service branch, not just combat pilots. The German Luftwaffe, paradoxically, also fielded infantry units in the form of Luftwaffen-Feld-Divisionen. These were assembled in late 1942 and transferred to the army over the course of early 1944. Overmans specifically mentions this on page 10. Furthermore, the list will contain support, ground and logistics personnel.\n\n2. Overmans acknowledges in the introduction the varied definition of \"casualty\", and in his script uses specifically the sum of KiA, MiA, PoW, and a subset of those WiA whose injuries were too severe for quick recovery.\n\n3. These casualties, by the nature of their sourcing, only include those reported through the way of proper Wehrmacht bureaucracy, either by the IIb or the IVb paths of communication. The former were the summed reports made by subordinate military staffs to superior military staffs, whereas the latter were medical officers' reports via the medical bureaucracy within the Wehrmacht. The IVb reports usually were way under the IIb reports, as the medics were not fully informed of each casualty in the field. Although the IIb estimates were more accurate, the IVb reports were often used in the considerations of military planners, simply because they were faster.\n\n4. Casualties that weren't reported or reported too late will not show up in this statistic.\n\n5. Casualty numbers get increasingly unreliable starting in late 1944.\n\n6. Units that were completely destroyed had no one left who even could report their casualties.\n\nThe reports that came in too late or were for some other reason not in the original reports Overmans tried to compensate for in Table 2 on page 6, but here, it is not divided by branch, so it doesn't exactly help us with our question. 570,164 casualties failed to show up in Wehrmacht statistics on time by December 1944. With the Luftwaffe suffering less than a hundreth of the army (see Table 1, \"Durchschnitt\" ('average')), this could statistically indicate maybe 5,000 overall Luftwaffe casualties that went unreported.\n\n---\n\nSo much for human casualties. The German air force, over the course of the entire war, lost 71,965 military aircraft [43,000 destroyed] (Schramm Vol. 4/1 p. 971), including combat and non-combat losses. Now, while we have established that the Eastern Front made up the overwhelming casualties for Germany, the main weight of Soviet bullets was carried by the German army, not the air force. The average German airman was far less likely to die in combat against the Red Army than the average German infantryman, as about 95.9% of Ostfront casualties were suffered by the army and only 3.7% by the air force and 0.4% by the navy (see Overmans p. 10). Soldiers of the Ostheer, including Waffen-SS, suffered 87% of all Wehrmacht casualties that had occured by July 1944 (see p. 12). That's *all* theaters and *all* branches of service, by the way. Army casualties in the east were the absolute majority of casualties even taking into acount all branches and all fronts.\n\nThis indicates that the casualties inflicted on the air force, particularly in terms of air planes, would have been higher in the west than the casualties inflicted on the army.\n\nIf we zoom in on *aircraft losses* specifically, attempting to divide up those 71,000 aircraft cited by Schramm, then we can looks at Williamson Murray's *Strategy for Defeat: The Luftwaffe 1933-1945* for some breakdowns by year and frontline.\n\nMurray cites the overall aircraft losses, not segregated by frontline but subdivided by combat and non-combat losses, in six month periods as follows (p. 304):\n\nPeriod | Combat Losses | Non-Combat Losses\n------|-------------|-----------------\n05-12 1940 | 2572 | 1379\n01-06 1941 | 1189 | 954\n07-12 1941 | 1909 | 1248\n01-06 1942 | 1816 | 1480\n07-12 1942 | 2496 | 1726\n01-07 1943 | 3117 | 2589\n07-12 1943 | 4302 | 3475\n01-06 1944 | 8259 | 3608\n\nThe eastern front breakdown of this, including combat and non-combat: 741 average monthly losses/damages (which isn't the exact same statistic as the others, so harder to compare) June-November 1941 (p. 89), 341 average monthly losses June-December 1942 (p. 114), 315 average monthly losses January-November 1943 (p. 148).\n\nSadly, Murray doesn't provide breakdowns by theater for all time frames, but it is notable that, while the Eastern Front provides the majority of aircraft losses during late 1942 (p. 114), the eastern casualties start flattening off by 1943, when more and more Luftwaffe units are needed against western air defenses. After May 1943, when Western Air Defense, Eastern Front and Mediterranean theater are almost an an equilibrium (333, 331, 331 losses respectively), the Eastern theater falls behind in all months but July and August, when it is barely ahead of West Defense and Mediterranean respectively. In October, the Luftwaffe loses 530 aircraft in the west, 285 in the Mediterranean, and 279 in the east. In November, the losses are 529, 194 and 180 respectively, again with the eastern front at the very back.\n\n---\n\nIn conclusion, I can't comment on the kill ratios you mention, as I simply lack the underlying Red Air Force casualties.\n\nBut in regards to the \"humble\" nature of the Red Air Force, its performance is lesser than that of the Red Army, as the army vs army comparison between Germany and the Soviet Union was certainly a lot more favorable for the USSR than the comparison air force vs air force.\n\nBut it is debatable if that should be accounted to a lower level of accomplishment or military valor by the Red Air Force compared to the Red Army or simply to the contributions of the western allies. The western forces were a lot more defensive when it came to putting boots on the ground between 1941 and 1943/44, whereas the USAAF and RAF started messing up the Germans from 1942 onwards. As a result, the Luftwaffe dedicated itself far more to western defense than by comparison the Heer did.\n\nBut it remains to be debated whether such comparative exercises are actually worth it. The Red Air Force looks \"humbled\" not because of its own insufficiency, but because of the different approaches to warfare between the USSR and the Anglo-American coalition in the west. The USSR could not afford to dedicate itself to aerial warfare to the point where it would be a detriment to Soviet ground forces, whereas the Anglo-Americans had the advantage of being able to invest in aerial commitments, because they had massive bodies of water shielding them from the German ground advance."
]
}
|
[] |
[] |
[
[
"https://www.stsg.de/cms/sites/default/files/dateien/texte/Overmans.pdf"
]
] |
|
1etdls
|
How soon after the advent of agriculture did humans start hybridizing crops? (selecting desired traits)
|
Also can anyone recommend a book about agriculture through history?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1etdls/how_soon_after_the_advent_of_agriculture_did/
|
{
"a_id": [
"ca3lhre"
],
"score": [
2
],
"text": [
"Its worth noting that selecting desired traits does not have to include hybridizing. Plants such as Vitis vinifera (wine grapes) can have somatic mutations that require cloning (growing a cutting) to preserve and select the desirable trait. I can't speak to crops in general but selection among Vitis vinifera goes back to at least 3500 BC. Wild grapes require male and female plants for reproduction with rare hermaphrodites. Around 3500 BC (or maybe earlier) humans began selecting hermaphrodite vines and propagating them via cuttings because they produced grapes easier. Further selection via cuttings would be done to increase yield and mature fruit sugar content. "
]
}
|
[] |
[] |
[
[]
] |
|
6qqs42
|
How did countries with an established private healthcare system transition into a public healthcare system?
|
How did the various countries that have a somewhat to entirely public healthcare system transition from what was previously private healthcare?
I know many of the posters here have a specialty in specific countries and regions, so hopefully leaving this question open ended will allow for a diverse collection of answers based on the different areas.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/6qqs42/how_did_countries_with_an_established_private/
|
{
"a_id": [
"dkzexbj"
],
"score": [
27
],
"text": [
"What is interesting here is that the very notion of state-sponsored healthcare, as a component of the liberal states in the 19th century, was in part driven by a desire to strengthen the state against rival structures. It can be said that the nationalization of healthcare was a long process that developed concurrently with the expansion of the modern state. \n\nIn pre-unification Italy especially, welfare, healthcare, and education had been in many places either devolved to private associations or handed off to the catholic church. Prof. Vera Negri-Zamagni has edited a volume narrating the transformation of healthcare in Italy which contains a useful essay by Stuart Wolof titled “The “Transformation” of Charity in Italy, 18th-19th Centuries.” (Bologna: Il Mulino, 2000) in addition to series of other papers examining the state's gradual appropriation of welfare. \n\nThe earliest healthcare systems in Europe were insurance funds run by professional associations collecting artisans in similar trades, the direct descendants of the welfare systems managed by the old medieval guilds. In Italy, some professional categories, like Doctors and Lawyers, still get their insurance this way. However, it would be during the Second World War and its increased industrial employment that made it necessary and desirable to oblige employers to run similar kinds of insurance funds for their employees, even though because the war took a turn for the worse, the plan was only implemented in 1947. In 1977, the management of these funds was handed over to the INPS, the newly-founded national welfare authority. The pre-World War II ideation of near-universal healthcare is actually ahead of the trend for the rest of Europe, with France and the United Kingdom only adopting a universal system after the war, influenced by the \"Beveridge Report,\" an influential investigation by the British Health Ministry. \n"
]
}
|
[] |
[] |
[
[]
] |
|
3u4f6a
|
if a company is hacked and user name and passwords are compromised, why doesn't the company immediately disable all of the accounts and require a new password upon next log on?
|
Saw a post that Amazon was hacked. Wouldn't it be easier to lock out the entirety of usernames and passwords and require a new password upon next log in?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3u4f6a/eli5_if_a_company_is_hacked_and_user_name_and/
|
{
"a_id": [
"cxbsnnf",
"cxbtcj4"
],
"score": [
5,
3
],
"text": [
"If it is a very serious breach they will require users to get a new password at some point. Most data breaches are not very severe though, as even if you can access password data it is usually hashed and salted and sometimes even encrypted, which means hackers have close to 0% chance to actually find out passwords of users.",
"Well that only stops one of the problems. Most people reuse their login information across many services. So even if Amazon makes you change your password, the hacker could use the information they got to get into other sites."
]
}
|
[] |
[] |
[
[],
[]
] |
|
8y64nt
|
how do women who have been on birth control pills their whole life have menopause?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/8y64nt/eli5_how_do_women_who_have_been_on_birth_control/
|
{
"a_id": [
"e28hew5",
"e28hl0l",
"e28hyg0",
"e28tegm"
],
"score": [
15,
3,
3,
3
],
"text": [
"Menopause has more to do with active hormone cycles than the actual egg. The endocrine system has more say of when menopause begins rather than actual fertility. \n\nThe pill only introduces 1-3 hormones which control ovulation. However there are a slew of other hormones that drive reproductive function. The decrease of naturally produced estrogens and increase of testosterones is a more sure sign of menopause, rather than \"how many eggs are left\".",
"Sure, but in the womb, a female fetus has millions of eggs, by birth there are about a million or two. By puberty at age 12 it’s half a million. At menopause there are still a couple thousand left. \n\nThey eggs saved are nothing compared to those a female starts with vs ends with. The eggs lost to a period is nothing. That’s like 500-1000 for 30 years of menstruation. ",
"Egg reserves deplete due to the natural aging process, the lack of ovulation while taking birth control does not protect the eggs from aging.\n\nBirth control can mask menopause for women who continue to take it into their 50’s because they contain synthetic estrogen and progesterone which the ovaries stop producing with age as well, this doesn’t mean that they can get pregnant though because the egg reserves have aged too much. As soon as they stop taking birth control they will experience all the symptoms of menopause. ",
"Women start out with tons of potential eggs, however every cycle a batch of them develop, but only one becomes a fully fledged egg. During the follicular phase of the menstrual cycle, the baby egg cells develop but only the biggest cell gets ovulated, the rest atrophy away. Ovulation requires specific hormones to happen, otherwise the egg cell will just sit there and eventually atrophy like the smaller cells did. Most hormonal birth control effectively blocks the production of the hormone required to induce ovulation, thus causing the egg to atrophy, and thus using up your egg reserves.\nSome forms of birth control affect the uterine environment to make the implantation of an ovulated egg unlikely (eg.copper IUD), which doesn't stop you from producing eggs but just stops the fertilized egg from implanting into the uterus and developping.\nMost forms of birth control have some effect on both of these."
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
||
22k9wx
|
the difference between 100s and short cigarettes
|
Aside from them being different length, what makes them different... Why would there not be a difference in price if there is more or less contained in the cigarettes?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/22k9wx/eli5_the_difference_between_100s_and_short/
|
{
"a_id": [
"cgnnmp2",
"cgnntpx"
],
"score": [
2,
2
],
"text": [
"The 100s contain more filter, same amount of tobacco I believe. ",
"This appears to be summed up quite well at _URL_0_"
]
}
|
[] |
[] |
[
[],
[
"http://www.thesmokingstore.com/cigarette-sizes/"
]
] |
|
3e0q2b
|
how has donald trump gained such front-running status so quickly?
|
How has he had such a blitz in poll numbers? Do people know nothing about him or are these poll numbers skewed or should I just lose hope in humanity?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/3e0q2b/eli5_how_has_donald_trump_gained_such/
|
{
"a_id": [
"ctaf82a",
"ctamk6b"
],
"score": [
2,
2
],
"text": [
"Keep in mind he is only polling at 15%, and that is just among Republicans. He is going off name recognition mostly. That and the fact that nobody likes any of the candidates that are running. ",
"Have you ever heard of the phrase \"there's no such thing as bad publicity\"? He's pretty much took that and ran with it. The news loves reporting about him because he's always doing something interesting, even if it is pants on head retarded, so the viewers hear about him more than anybody else and so he's in the front of their minds more often. It's an interesting phenomena for sure."
]
}
|
[] |
[] |
[
[],
[]
] |
|
aen7ws
|
how does a vickrey auction work?
|
_URL_0_
It says that the highest bidder wins, but they pays the amount bid by the second-highest bidder. Am I interpreting this wrong? Why can't you just bid a billion dollars, because you never pay your bidded amount?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/aen7ws/eli5_how_does_a_vickrey_auction_work/
|
{
"a_id": [
"edqseu9",
"edquivd"
],
"score": [
2,
4
],
"text": [
"Because it’s a sealed bid auction, you don’t know what other people have bid. \n\nYou could put a ridiculous bid, but so could someone else, forcing you or them to actually pay it. \n\nThe idea behind them is to make you bid what you believe it’s actually worth. ",
"I think what you’re missing is the purpose of auch auctions. The purpose of this auction as a buyer is to buy a product of unknown price for about as much as it is worth to you. \nYou don’t bid in an auction to win (usually) but to buy a product of limited availability for the price you are willing to pay. The problem is, that you as a bidder don’t know, what everyone else is bidding. You might be willing to pay 1000$ for it, but when the second highest bidder just wants to pay 10$ you effectively wasted 990$. \nSo you guess, that other people are just willing to pay around 10$ for it, so you bid 20$. But let’s now say your guess was wrong, and someone else bid actually 21$. You lost, despite the fact, that you were willing to pay 50 times as much, if it were necessary.\n \nThis kind of auction fixes this. Now you can actually bid your 1000$ you are willing to pay, full knowing, that you won’t waste any unnecessary dollars. \n \nTo answer your question: you don’t simply bid 1 billion $, because it’s not about winning, but it’s about buying a product for a reasonable price. \nAnd if you’re not willing to pay more than 500$ you shouldn’t be sad if anyone else wins paying 750$, because you wouldn’t want it for that much anyways."
]
}
|
[] |
[
"https://en.wikipedia.org/wiki/Vickrey_auction"
] |
[
[],
[]
] |
|
1pn1fz
|
What did students in the early united states learn in school if there even was school?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1pn1fz/what_did_students_in_the_early_united_states/
|
{
"a_id": [
"cd428px",
"cd4482g"
],
"score": [
3,
3
],
"text": [
"Boston Latin School is the first public school and oldest existing school in the United States. It was founded in 1635. Boston itself was only founded in 1629. The school taught Latin, Greek, Religion, and Oration.\n\nOf course, this was a school for older pupils, and it was and still is an elite school with competitive entrance.\n\n",
"I misread your question and wrote about education in the colonies. Sorry about that, but you may find the information useful anyway.\n\nIt depends a great deal on where and when students were living and learning and how well off they were. Education in New England was based on the catechism—ideally, at least—and took place mostly in the home and church, even after the “Old Deluder Satan” law was passed in Massachusetts in 1647. This law required towns of fifty families or more to hire a teacher and towns of 100 families or more to establish a public school, but many towns evaded the law and public school teachers were often little more than temporarily unemployed recent university graduates awaiting their first ministerial appointment. From this barely adequate base in the mid-seventeenth century, public education in New England declined in the latter part of the century for a variety of reasons including Indian warfare, geographic, religious, and demographic expansion. Even after public education was strengthened again in the mid-eighteenth century, perhaps as few as 1 in 10 children attended school at any one time. \nLiteracy was the most important goal of these New England schools. After the Bible, texts like Edmund Coote's [*The English School-Maister*](_URL_1_), John Cotton's [*Spiritual Milk for American Babes*](_URL_2_), and, perhaps most importantly, [*The New England Primer*](_URL_0_) were popular in New England classrooms. The most privileged students would begin their education in the home and church, then, learning the catechism, just like their poorer counterparts; next they would enter a public school around age seven, where they would be exposed to the types of texts linked above and taught writing; they would then enter a Latin grammar school, where both Latin, Greek, and Hebrew were taught (some, after the mid-eighteenth century, may have chosen instead to attend a “writing” school geared toward penmanship, mathematics, accounting, and other “practical” education); successful students—and, again, only the sons of privilege in most cases—would finally gain admission to a university like Harvard or Yale. \nEducation in the southern colonies, where greater religious, political, and demographic diversity was more commonplace, was not nearly as robust. There were no public schools in most southern colonies, and education was only compulsory for orphans and indentured servants; masters of these young people were required to enroll them as apprentices in Virginia, for example, after laws were passed beginning in 1705 for boys and 1751 for girls. Southern education was thus almost exclusively carried out in homes and churches using the Bible, various catechetical texts, and whatever else was available. Almost eighty percent of boys and thirty-five percent of girls in Perquimans County, North Carolina were literate by 1776, nonetheless—to cite just one well-studied example—which demonstrates the relative success of these types of education in the southern and middle colonies. "
]
}
|
[] |
[] |
[
[],
[
"http://www.sacred-texts.com/chr/nep/1777/index.htm",
"http://www.library.utoronto.ca/utel/ret/coote/coote.html",
"http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1018&context=etas"
]
] |
||
1bbiuj
|
Question regarding the technology used in 3D televisions that do not require polarized glasses
|
My understanding of 3D technology is that the 3D effect is caused by sending two slightly different images to each of a person's eyes. Newer 3D TV's have managed to accomplish this without the use of polarized glasses, which must mean the screen itself is sending different images at different angles.
Is there a limitation with current technology on how wide this angle can be? Would it be possible to create a screen that sends two different images, approximately 45 degrees apart, essentially allowing two viewers to see completely different images? And could this be expanded to more than two images/viewers?
Long story short, ignoring the sound aspect, is current 3DTV technology capable of allowing multiple viewers to view completely different images?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1bbiuj/question_regarding_the_technology_used_in_3d/
|
{
"a_id": [
"c95gu8a"
],
"score": [
3
],
"text": [
"[The cover article on the March 21 issue of *Nature* discusses this exact topic](_URL_2_). \n\nAs I understand it, there are a number of current technologies, but most of them rely on having neighboring pixels displaying pieces of the two different pictures needed for depth-perception, and then either using barriers (called parallax barriers) or lens (called lenticular lens) to send the two images to the two eyes. But with both of these, the viewer needs to place his nose in the middle of the two images, or the 3-D effect won't work.\n\nThe article focuses on a new technology that would allow you to look at the display from many more angles by using a diffraction grating to send different images to each eye.\n\nFor those of you who can access *Nature*, [this article has some good pictures that explain the concept behind 3D without glasses](_URL_1_).\n\n[This is the main article](_URL_0_)."
]
}
|
[] |
[] |
[
[
"http://www.nature.com/nature/journal/v495/n7441/full/nature11972.html",
"http://www.nature.com/nature/journal/v495/n7441/full/495316a.html",
"http://www.nature.com/news/hologram-lite-idea-for-3d-phone-displays-1.12647#/b2"
]
] |
|
1rt3a5
|
Why is it that serial computer connections like USB are more used/faster than parallel ones today?
|
As I understand it, serial communication is basically one wire of communication, parallel is more than one. Most newer ports (USB, ethernet, FireWire) are serial, right? Why not parallel? Intuitively, it feels like many parallel connections going as fast as a modern serial connection could be much more efficient.
|
askscience
|
http://www.reddit.com/r/askscience/comments/1rt3a5/why_is_it_that_serial_computer_connections_like/
|
{
"a_id": [
"cdqt6r0"
],
"score": [
3
],
"text": [
"1. Timing. If there is too much timing skew, then bits of data that should belong to one time slice end up in the other one, and you have errors. \n\n2. More wires means more power consumption.\n\n3. When wires are close together, signals that should belong to one wire end up in the other wire. This is called crosstalk and it can cause errors as well. Such errors pop up in Ethernet connections that have cable runs that are too long. "
]
}
|
[] |
[] |
[
[]
] |
|
1quzsd
|
Why aren't Higgs bosons everywhere? (And a few other related questions.)
|
The Higgs field permeates all space, and all fermions in the universe (that we know of) (I think) have mass, so where are all of the Higgs bosons to maintain that field?
And on a related note, since Higgs bosons *aren't* everywhere, are there possible unintended consequences of smashing particles together to make one?
Finally, do we know (or think) that the Higgs field extends throughout the entire universe, or are there potentially Higgs-free zones where particles lack mass?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1quzsd/why_arent_higgs_bosons_everywhere_and_a_few_other/
|
{
"a_id": [
"cdgzde9",
"cdgzisl",
"cdh0x0p"
],
"score": [
9,
5,
5
],
"text": [
"Higgs bosons don't maintain the Higgs field, nor do photons maintain the electromagnetic field, etc. These particles are excitations of their respective fields. The fields exist whether there's a particle there or not. \n\nNot really. We have a pretty solid idea of what the Higgs boson is like. We could, of course, be wrong about something or have yet to discover something new about it, but that's unlikely. \n\nThe Higgs field is an all-permeating field. That description was redundant, though; a field, by definition, exists in all space and time. There's no escaping it. ",
"To add to owl's comment, The Higgs boson is unstable. It decays *very* quickly compared to human detectable timescales.\n\nBroadly speaking, the LHC deduces the existence of the Higgs (and many other unstable particles) by examining the decay products very carefully over a large number of collisions.",
"Be careful when you say the Higgs boson \"maintains\" the Higgs field. This isn't really a good description of what the Higgs is or does.\n\nLike others have mentioned, the Higgs boson is just an *excitation* of the Higgs field. Similarly, there are other gauge bosons which mediate their respective forces. However, and this is the important part, particles do not need to interact with Higgs boson to interact with the Higgs *field itself*.\n\nIn the standard model, all the fundamental forces are *mediated* by the gauge bosons which \"carry\" their respective force, but that is different from the Higgs interaction, which gives most particles mass because the Higgs field has a non-zero expectation value. "
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
113589
|
was william jennings bryan the greatest orator in american history?
|
i know this is a matter of opinion, but would it be a credible opinion to hold?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/113589/was_william_jennings_bryan_the_greatest_orator_in/
|
{
"a_id": [
"c6ivufm",
"c6izsp0",
"c6j0mk1"
],
"score": [
5,
4,
2
],
"text": [
"Undoubtedly many have equalled or exceeded him. I do think, however, that to be America's \"greatest\" orator is about having successfully and with great impact captured something deeply buried at the heart of crisis and/or identity. When Jennings spoke of the cross of gold, he did just this. Furthermore, Jennings spectacular failure at the Scopes trial gives him a rise/fall that lends itself to narrative and memory. He was undoubtedly one of the greatest, a distinction helped by factors other than the consistent quality of his turn of phrase and delivery.",
"By virtue of cross of gold I don't think anyone would laugh you out of the room for holding that opinion but I don't think it would be a popular one either. I'd also say that whenever you do a 'greatest of' in a subjective category like this it helps to have a couple of qualifiers as to what would define the 'best American orator' and how that stands out from a merely great orator. I'd personally put my money on Martin Luther King Jr but even here there is the inherent advantage of me being able to hear recordings of him. We can only go off written accounts of older presidents and activists.",
"Despite his great skills, three presidential elections and the Scopes trial automatically disqualify him for the nod."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
1pw5dp
|
Prior to the 22nd Amendment/FDR, had any presidents ever considered breaking Washington's 2-term precedent?
|
More specifically, is there proof of any president wanting to/possibly considering running for a third term? This is also barring Teddy Roosevelt in the 1912 election.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1pw5dp/prior_to_the_22nd_amendmentfdr_had_any_presidents/
|
{
"a_id": [
"cd6unjc"
],
"score": [
2
],
"text": [
"Teddy Roosevelt wanted another term. His first one was technically William McKinley's but Roosevelt said after his election in 1904 that he considered the first term to be HIS first term and would not run again in 1912. Well..he ran again in 1916. "
]
}
|
[] |
[] |
[
[]
] |
|
7csgz6
|
what happens to profits after a company becomes closed or defunct?
|
Such as buying a game after the developer goes defunct, a song after the record company closes, etc. Does money always make it's way to someone involved, or does the publisher/retailer keep the profit from that point?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/7csgz6/eli5_what_happens_to_profits_after_a_company/
|
{
"a_id": [
"dpsbykz",
"dpsc4j9"
],
"score": [
6,
2
],
"text": [
"When a store gets a physical good, such as a game or a CD, they pay for it. At that point, the company that produced it has made their profit. It doesn't matter if the product sells tomorrow or 5 years from now or gets thrown in the trash - profits have been made.\n\nFurthermore, few businesses ever simply shut their doors & walk away from everything. They generally sell all their assets - including intellectual property rights - to some other company so they can pay off outstanding debts or let the owners cash out of the business. Whoever buys these rights then has the ability to produce new copies & profit from them.\n\nSometimes, with creative works like books & music, the rights revert to the band/author and they're able to find a new publisher and start selling new copies.",
"For intellectual property, the assets will be liquidated, and another company or an investor will likely buy the rights to those properties, and any royalties or additional profits will go back to them."
]
}
|
[] |
[] |
[
[],
[]
] |
|
4wcl6u
|
How did pirates such as Blackbeard, Bartholomew Roberts, and Jack Rackham get their own flag designs?
|
[deleted]
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/4wcl6u/how_did_pirates_such_as_blackbeard_bartholomew/
|
{
"a_id": [
"d664ykl"
],
"score": [
17
],
"text": [
"Might I suggest crossposting to /r/vexillology? It's a fine community of flag historians"
]
}
|
[] |
[] |
[
[]
] |
|
4k3brc
|
what is the purpose of information technology infrastructure library(itil)?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4k3brc/eli5what_is_the_purpose_of_information_technology/
|
{
"a_id": [
"d3bscd7",
"d3bxl4f"
],
"score": [
5,
4
],
"text": [
"At its most basic level, ITIL is really a set of best practices for IT Service Management - without a methodical approach, Service Management can be something that's done on a fairly ad-hoc basis without any specific direction to it.\n\nAlthough ITIL doesn't seek to specifically set in stone how things should be done, as a framework it provides a useful toolset to build a company's IT Service Management organisation and practices on.",
"Just one example of ITIL practices is the concept of a \"Help Desk\". With a Help Desk, any consumer of technology calls a single number no matter what the issue is. This Help Desk then routes the issue to the appropriate team to perform the fix.\n\nWithout a Help Desk, the technology consumer would need to have a huge list of numbers to call the specific group that handles the specific issue they are having. Or, they'd get re-routed multiple times in order to get in touch with the correct group."
]
}
|
[] |
[] |
[
[],
[]
] |
||
8wa9f9
|
why is the book of mormon in so many hotel rooms even though it isn’t a major religion?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/8wa9f9/eli5_why_is_the_book_of_mormon_in_so_many_hotel/
|
{
"a_id": [
"e1tvkmm"
],
"score": [
3
],
"text": [
"The founder of Marriott was a Mormon. All their hotels (Fairfield Inn, Marriott, Courtyard, Renaissance etc) will have the Book of Mormon. They just bought Starwood hotels (Sheraton, W, Westin, etc) so likely their hotels will soon have them as well. I don't know if LDS donates the books like Gideons though."
]
}
|
[] |
[] |
[
[]
] |
||
3skz4z
|
Why didn't China actively try to conquer the north?
|
Most non-academic history book I've read say something about the land is mostly grass, not suitable for agriculture. In my university biology class, it says the land north is the best biome for agriculture, same biome as the one in mid US and Ukraine. Is there any limitation such as technology that made Chinese think it is infertile?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/3skz4z/why_didnt_china_actively_try_to_conquer_the_north/
|
{
"a_id": [
"cwyq69j"
],
"score": [
2
],
"text": [
"Instead of why they couldn't, I think this question is asking why they didn't care to. Short and simple, the answer is Chinese elitism. Much like ancient Greeks (save Alexander who was Macedonian anyway) the Chinese considered themselves the apex of human civilization. Surrounding territories were barbaric, underdeveloped, and wouldn't benefit them a whole lot. I think most people will remember the hubbub a few years ago about claims of the Chinese \"discovering\" North America before Columbus. Without getting into that specifically, the Chinese launched a massive exploratory expedition that sailed all around Southeast Asia and as far as West Africa. Paraphrasing and simplifying, the general consensus was \"Giraffes are pretty cool but really we don't give a shit.\" Yes this one singular event, and yes it was one that happened much later in Chinese dynastic history, but it is indicative of ancient Chinese views vis-a-vis their neighbors. China's name, for instance, translated literally means \"central country\" highlighting just how self-important (though, largely because of good reasons) they were. Instead of thinking about conquering nearby people, the Chinese were significantly more interested in keeping them out.\n\nIt is important to note that two major Chinese dynasties were ruled by northern invaders so there are significant periods of time where China proper was attached to much more northern provinces. These invaders always ended up taking Chinese customs however largely abandoning/modifying their tribal identities."
]
}
|
[] |
[] |
[
[]
] |
|
23krq0
|
why is primary and secondary education free and considered essential for everyone but not university?
|
All children must enroll at primary school because that is considered basic education and that isn't enough either so they have to go to high school. But then the line is drawn at college and universitiy around the age of 17,18 where they are highly selective and expensive.
Is it because our society has simply not developed to the point where everyone can go to university or because it is an admission that not everyone has the academic ability or "brain power" to learn in college?
I knew a student in high school who was taking university courses at 16. I asked him whether it's free because education for minors under 18 should be free. He said no, he has to pay full tuition because it is a university, it doesn't matter how old the child is.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/23krq0/eli5_why_is_primary_and_secondary_education_free/
|
{
"a_id": [
"cgxz3fa",
"cgxz479",
"cgxz6vc",
"cgxz7lt",
"cgxz89p",
"cgxzjsp",
"cgxzovq",
"cgy0tc1",
"cgy1731",
"cgy1xzr",
"cgy5893"
],
"score": [
44,
2,
27,
4,
40,
2,
2,
2,
4,
2,
2
],
"text": [
"It is free in Denmark.\n\nI guess the reason is that everyone need some basic education but many jobs do not require a university degree. And it is of course a political decision so not a surprise that it isn't free in a country where people don't like to pay tax",
"Typically, university education are also significantly more expensive. I'm not just talking the fraction that the student sees at public universities and colleges, those costs are subsidized, but they still exist.\n\nThanks to the internets though, a huge portion of the university education is available free online to those who seek it.",
"Kids need to be occupied somehow during the day. You can't have a bunch of non-citizens just roaming the streets unsupervised, inflicting havoc on the community. School is a nice compromise between providing education and locking them up. \n\nAfter high school, they can work full hours or be punished as an adult. There's less incentive to spend additional funding on teaching them. Besides, you have to draw the line somewhere. ",
"The basic idea is that primary education prepares you for the basics, then secondary education prepares you for work. You only need university for more specialised forms of work - otherwise you're already prepared except for specific job training. If there's an argument to be made about the development of our society, it's that we've not yet gotten to the stage where 95% of jobs require advanced education in order for them to be done. \n\nMaybe in 100 years time none of our familiar systems will be left, like the replacement of mechanics knowing about the physical workings of car engines with engineers who must understand the computerised parts too. Perhaps most non-creative pursuits will go the same way. In that case we'll need everyone university educated to look after the robots that are doing everything for us...\n\nFor now, most jobs require experience, not university education.",
"When I went to unversity (this was in the UK), I was one of the last to get a grant, before student loans were introduced, and long before students had to pay tuition fees. Essentially, it was free. And yet fewer people went to university. Now, more and more people are going to university, and are being encouraged to do so, even though it's costing them huge amounts of money. The result has been a massive increase in student debt, and also a kind of academic inflation: a BA used to be worth something, but now everyone seems to be getting a bachelor's degree which just means they have to study even longer if they want a degree employers will take any notice of.\n\nBut here's my take on it: We really don't want a nation of brainboxes. When you say this:\n\n > our society has simply not developed to the point where everyone can go to university or because it is an admission that not everyone has the academic ability or \"brain power\" to learn in college\n\nyou're assuming that academic qualifications are somehow better or more desireable than vocational qualifications. And I think this attitude is causing great damage to our society.\n\nThe assumption is that a bricklayer is somehow worth less than an art historian. Oh really? Says who? Train everyone to stare at petri dishes or write sentences in the Proto-Indo-European language, and who's going to fix the plumbing? What possible use is a nation of deskbound office workers?\n\nAcademic excellence is not the only measure of a person's worth. And there's actually a lot of skill and brain power involved in laying the foundations for a house so that the house will stand. We really need to get away from the idea that these vocational skills are worthless or that by failing to get everybody reading Proust we are somehow failing in our duty to provide them with an education. Instead, we should be recognising these jobs as demanding and valuable professions, and the people in those jobs should be respected as the skilled professionals they are. We should be paying them properly, making sure they have access to proper health care and ensuring that we don't look down on them as second-class citizens.",
"It´s easy.\nThe primary school and highschool are considered the minimum education to be productive. After that point (18s) society wants you to be economically profitable, doesn´t matter the way. I mean, by working or paying more studies. ",
"Imagine if you had neither, or only primary. You'd only know how to read and write at a basic level. What are your job prospects? Next to none, as every job nowadays requires you to use a computer or write reports or calculate things, which you can't do unless you've done 12 years of compulsory schooling. So, it is in the government's interest to make sure you can get a job somewhere, otherwise they'll end up paying for your unemployment benefits. Why not tertiary education? Because you can still earn a reasonable wage without having gone to university. ",
"It's not free. It's paid for by taxation.",
"Because taxpayers cover the cost of primary school because it makes for a smarter voting population, lowers crime, and improves the areas tax basis. But college is considered a luxury and therefore the cost is covered by the person attending and not by taxes. ",
"Every society need's a bottom rung. Basic education will (hopefully) make you a functioning enough member of society to pump gas or stock shelves at the supermarket by the time you get through high school. If that's all you want in life, sweet as, but if you want more you have to work for it. And if you're willing to put in the effort and are smart enough it will pay off in the long run. At the very least it will weed out the ones that don't really want to put the effort in. Not everyone can be a doctor or a lawyer, someone has to do the more unpleasant jobs as well.",
"Public primary/secondary isn't free we pay it in the form of taxes and then somtimes school fees"
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[]
] |
|
ediohf
|
why do handbrakes/e-brakes and footbrakes work differently?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/ediohf/eli5_why_do_handbrakesebrakes_and_footbrakes_work/
|
{
"a_id": [
"fbi2uoi",
"fbi37c6"
],
"score": [
6,
4
],
"text": [
"Foot brakes are usually a hydraulic system. You step on the pedal, fluid moves and a caliper compresses the brake shoes. There are many parts here: hydraulic fluid, accumulators, pistons... lots of things that can leak or break.\n\nHand brakes are usually just cables, directly connected to a caliper. You pull the brake, the cable tugs on the caliper and the brake shoes make contact.\n\nHydraulic brakes make it easy to apply a lot of braking quickly, as well as offering you a smooth continuum of incremental braking ability.\n\nHand brakes offer you a robust system with few parts that can break.",
"For safety and because they have radically different intended uses, they are built and behave differently.\n\nThe handbrake is simpler and separate from the footbrake, and generally not intended to take such significant loads. Holding a stopped car stopped takes less pressure than stopping a moving car which is its main purpose, but can still be used in an emergency where the the hydraulic brakes have failed for whatever reason. To this end it often has a much longer throw with less overall pressure, is often cable-connected rather than hydraulic, and has a ratchet system to keep it engaged even when you leave. Of course this varies by car.\n\nThe foot-brake is hydraulically powered with assist from the engine. If the engine shuts down it will not withstand being pressed repeatedly before you lose the assist and you will have to put major pressure on the pedal to get any useful stopping power. However with the asst they usually have more stopping power than the engine can overcome, and flooring the brake will WILL lock up the wheels easily (assuming no ABS)."
]
}
|
[] |
[] |
[
[],
[]
] |
||
1ymdql
|
when the army is called in to handle violent protests, etc why do these men agree to shoot upon their own fellow citizens? what happens if you refuse?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1ymdql/eli5_when_the_army_is_called_in_to_handle_violent/
|
{
"a_id": [
"cfls9i9"
],
"score": [
3
],
"text": [
"Because most of the time, the army isn't called to stop a protest unless it has become a full fledged riot. And rioters are not exerting their right to protest anymore, they have just become a danger to themselves and others and to private and public property, and must be dealt with as such. \n\nIn the case of peaceful protests being attacked by the military. The reasoning (although flawed) is more or less the same: These people are a danger to the country and must be dealt with accordingly. \n\nIf you refuse, you get charged with desertion and will probably face court-martial. "
]
}
|
[] |
[] |
[
[]
] |
||
2ka1lo
|
How much historical evidence is there for a great flood?
|
I've heard that there is evidence aside from the bible to suggest there was some kind of great flood.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2ka1lo/how_much_historical_evidence_is_there_for_a_great/
|
{
"a_id": [
"cljbg9q",
"cljbx78",
"cljcl9v",
"cljhrsr"
],
"score": [
45,
22,
85,
8
],
"text": [
"Usually these arguments are put forth by creationists trying to prove that the Bible is true. They call it *flood geology*; it originated in the early 20th century with Seventh-day Adventist geologist George McCready, but was popularised by Henry M. Morris' book *The Genesis Flood*. This book uses a mix of theology (provided by John Whitcomb) and science (by Morris) to argue that the Earth is less than 10000 years old and that evolution is wrong ('young-earth creationism'). Central to flood geology is the idea that a global flood such as in the Bible could explain many modern geological features, including for example the Grand Canyon. These claims invariably turn out to be contradictory to established scientific explanations (after all, they have to squeeze millions or even billions of years of gradual processes in just a couple thousand years).\n\n----------\nSource: \n\nE.C. Scott, *Evolution vs. Creationism: an Introduction*, Berkeley 2009",
"Glacial erratics, large solitary rocks found in places where they don't appear to belong, [were once believed](_URL_0_) to be the result of bibilical flooding by academic authorities. Charles Lyell is recognized as having provided the now accepted explanation in 1830, that they were the product of massive glaciers from the last ice age. Incidentally Darwin studied them during his Beagle voyage. This phenomenon has had a very strong impact in the history of sciences and was instrumental in our understanding of the geological history of Earth. \n\nBut what I find the most interesting about it is that common people living in the European alps had figured out the real reason for the rocks, unlike the savants who were still influenced by the biblical narrative at the turn of the 18th century. I heard of a couple examples such as [this one](_URL_1_) dated 1815 and reported in 1845:\n\n > In August 1815, a geologist was coming back from a long trek on the glaciers at the bottom of the Lourtier valley (...) He spent the night in the hut of a chamois hunter named Jean-Pierre Perraudin who was to be his guide the next day. (...) They eventually talked about those huge granite blocks that are often found a great distance away from the cliffs they had split from. The geologist took great pain to explain how the savants had proven through profound computations how those erratic blocks had been transported in ancient times by water currents. Perraudin could not respond to all this, but he nodded doubtfully. \"Seems to me that our glaciers used to be much larger than they are today. Our whole valley up to a great height over the Durrance torrent was filled by a large glacier that flowed down to Martigny, as shown by the the blocks you can find around the town, and they are way too big for water to have dragged them there.\" Speaking thusly, Perraudin could not imagine having made a great discovery and solved, with just common sense, a problem that the combined genius of the most famous geologists, armed with all the resources of science, had tried to conquer without success.\n\nThere's another one from the late 18th century but I can't seem to find it. Might even have been in Lyell's book. \n\nAn interesting question to ask is, how did these people figure it out? A dubious hypothesis is that of oral history spanning milleniums, one that is commonly put forth when prehistoric flooding events are hypothesised to be the basis for the biblical flood. Most likely, if they had seen extant glaciers over years, they might have figured out that they moved, however slowly, and they also might have simply noticed how they carry large rocks. ",
"There is the [Black Sea Deluge Hypothesis](_URL_0_), which basically posits that at the end of the latest Ice Age, as the sea levels rose as a result of glacial melting, an area of land separating the ocean from the Black Sea gave way, causing a massive migration of water over that break and into the Black Sea. To any human witnesses, this would have been a mind-blowing event that would almost certainly be told generation to generation, being *embellished* along the way.\n\nThere is a lot of evidence that [this event happened](_URL_1_), including the discovery of a shoreline 400' feet below water level. Of course it would not be a world-wide event, but to the primitive viewer it would certainly have been epic in proportion. \n\nThe question that will probably remain unanswered is whether or not early settlements in that area were witness to this event and subsequently morphed that event into the myth of a world-wide flood and, eventually, the flood stories that we know from the Epic of Gilgamesh and, eventually, the ~~Talmud~~ Torah.",
"There is Zero evidence for a \"Global Flood\" ever happening. There were many ice dam breach floods that occurred at the end of the last Ice Age. The flood myths probably arise from ancient witnesses passing down the information as oral history, until someone wrote it down and made it a holy story.\n\nSee this USGS paper for more information on large historical floods. (This is a direct download link)\nThe world's largest floods, past and present: _URL_4_\n\nCheck out the references in the two Wikipedia articles below, there are some papers specifically about the Black Sea flood, and the mega-flood that made Brittan an island.\n_URL_3_, \n_URL_2_, \n_URL_5_, \n\nHere is a direct download link to a issue of the Ice Age Flood Institutes newsletter that compares the Missoula flood to the Kuray mega-flood in Russia.\n_URL_0_\n_URL_1_\n "
]
}
|
[] |
[] |
[
[],
[
"http://en.wikipedia.org/wiki/Glacial_erratic#History",
"http://fr.wikisource.org/wiki/Recherches_sur_la_p%C3%A9riode_glaciaire_et_l%E2%80%99ancienne_extension_des_glaciers_du_Mont-Blanc_depuis_les_Alpes_jusqu%E2%80%99au_Jura"
],
[
"http://en.wikipedia.org/wiki/Black_Sea_deluge_hypothesis",
"http://abcnews.go.com/2020/video/noahs-biblical-flood-evidence-suggests-happened-18041950"
],
[
"http://www.iafi.org/newsletters/iafi_news_mar_2007.pdf",
"http://www.iceagefloodsinstitute.org/",
"http://en.wikipedia.org/wiki/Outburst_flood",
"http://en.wikipedia.org/wiki/Missoula_Floods",
"http://pubs.usgs.gov/circ/2004/circ1254/pdf/circ1254.pdf",
"http://news.bbc.co.uk/2/hi/science/nature/6904675.stm"
]
] |
|
76sgxp
|
Why Does Space Smell Like Burning Metal?
|
In his recent AMA [Scott Kelly said](_URL_0_) that space smells like burning metal. What would cause this?
|
askscience
|
https://www.reddit.com/r/askscience/comments/76sgxp/why_does_space_smell_like_burning_metal/
|
{
"a_id": [
"doh5vuv"
],
"score": [
19
],
"text": [
"Hydrocarbons! Space is mostly empty, but there's a lot of 'dust' out there. Astronauts also report \"Burnt Steak\" smell sticking to spacesuits when coming back from a spacewalk. \"Metallic\" smells are actually caused by the breakdown of substances on the surface of the metal due to ions on the metal surface. Same reason some metals are \"self disinfecting\" by tearing apart cell membranes. The metal itself doesn't release into the air. You may notice a cleaned coin doesn't really smell, but if you rub a penny between your fingers you can smell \"copper\"."
]
}
|
[] |
[
"https://www.reddit.com/r/IAmA/comments/76rrh0/i_am_scott_kelly_former_nasa_astronaut_and_author/dog80cs/"
] |
[
[]
] |
|
1jsqaz
|
How did Egyptian Hieroglyphics work?
|
Was there a single picture representing each thing? Did they have what we consider to be synonyms? Did they modify each character or did they use strings of words to create bigger meanings, like full-fledged adjectives?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1jsqaz/how_did_egyptian_hieroglyphics_work/
|
{
"a_id": [
"cbi2p06"
],
"score": [
3
],
"text": [
" > Was there a single picture representing each thing? Did they modify each character or did they use strings of words to create bigger meanings, like full-fledged adjectives?\n\nThere are 5 stages of hieroglyphs - Old, Middle, or Late Egyptian, then Demotic and finally Coptic. This is excluding the archaic version (we don't have enough inscriptions to do any meaningful analysis). They start out as hieroglyphic, but as time goes on, they evolve into hieratic and demotic scripts, which are the scribal cursive ways of doing hieroglyphs and are much easier to write - think of them as day to day hieroglyphs. Hieratic lasts until about 600BC when Demotic takes over.\n\nMore confusingly, the Egyptian writing system has 3 major types of signs, which perform different functions. For example, **Logograms** are complete words [and look a bit like this](_URL_0_) and depict the physical item they represent, or what is known in the trade as 'iconic' - they are icons that depict what they represent. That evolved into a more developed system where it could also represent a concept - so in the images above, the image depicting the sun could also represent 'day'. The logogram for 'to come' was a glyph of a pair of legs - depending on which way it was facing, it could also mean 'to go'. It's not very helpful though, because you need 1 image/word you want to use and doesn't reflect ambiguity well, so it's suggested that it developed into phonograms. \n\n**Phonograms** are where a glyph represents a sound and could be joined with another glyph to represent something else: the logogram for 'mouth' which is an 'r' sound, could be put together with the 'n' logogram to make the word 'rn' - or 'name'. This is the same as a [rebus](_URL_2_).\n\nSo hieroglyphs become primarily phonographic with determinatives added on to help the meaning. **Determinatives** are lines or glyphs used to help understand whether we're dealing with a logogram or something else. There are a lot of different determinatives so I won't go into them as it's probably not very interesting, but it's good to know they exist to help bring out the subtleties and nuances of language.\n\n\n > Did they have what we consider to be synonyms? \n\n[Knock yourself](_URL_3_) out and [have a look :)](_URL_1_). You'll see that sometimes the same concept in English has multiple options in the Egyptian."
]
}
|
[] |
[] |
[
[
"http://csmt.uchicago.edu/glossary2004/hieroglyphics/hieroglyphics1.gif",
"http://archive.org/details/egyptianhierogly01budguoft",
"http://en.wikipedia.org/wiki/Rebus",
"http://www.jimloy.com/hiero/e-dict.htm"
]
] |
|
2dw6r6
|
What Happens to the Kinetic Energy in Positron Annihilation?
|
As a Physics graduate (I work in Radiotherapy), I should be able to answer this, but it's got me stumped.
To create an electron-positron pair requires at least a photon with at least 1.022MeV of energy (pair production). Hence when an annihilation events occurs, 2 511keV photons are produced. Makes sense.
But what happens when the positron/electron have a decent amount of kinetic energy?
Let's imagine a 10MeV photon produces an electron-positron pair. They will each have about 4.5MeV of kinetic energy, but the when the positron meets another electron (say from a neighbouring atom) it will annihilate. Are 511keV photons always produced, or does the energy produce more energetic radiation? Does the extra energy produce more mass instead?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2dw6r6/what_happens_to_the_kinetic_energy_in_positron/
|
{
"a_id": [
"cjtnol8",
"cjtntqw",
"cjttic9"
],
"score": [
7,
4,
3
],
"text": [
"The photons will have more energy than just the rest mass of the electrons, to account for the electrons' kinetic energy. Other particles can also form, if the energy is high enough. CERN ran a very high energy electron-positron collider where the LHC is now.",
"Mass-energy is conserved in annihilation/creation events. If two photons collide to make an electron-positron pair, and the photons have more energy than the equivalent mass of the electron and positron, the extra energy of the photons will become kinetic energy of the electron and positron, or perhaps even more particles will be created.\n\nSimilarly, when an electron and a positron with significant kinetic energy meet and annihilate, the resulting photons will have more energy than that produced by an electron and positron at rest that annihilate. \n\nThis has important implications in radiotherapy. For instance, a Positron Emission Tomography (PET) scan works by measuring the photons created by positron/electron annihilation events in the patient's body. The detector must be set to register a small range of photon energies and photon angles to account for conservation of mass/energy and conservation of momentum applied to electrons to electrons and positrons that are not exactly at rest in the patient's body.\n\nIf two particles colliding have very high kinetic energy, they can create a whole shower of new particles. This is the case in particle accelerators and with cosmic rays.",
"There's an easy trick to get around the complications you're worried about:\n\nShift your inertial reference frame until the net momentum of the two particles is zero. That is to say, if you've got an electron at rest, and a positron incoming at, say, 0.2c, don't look at that system. Instead, shift your reference frame so that both are coming towards each other at 0.1c.\n\nOnce you do that, the problem becomes quite simple. You look at the energy of the system beforehand, which consists of the mass-energy of the two particles plus their respective kinetic energies, and you divide that in half to determine the energy of each photon.\n\nThen once you're done, *don't forget to shift your reference frame back!* That means the two photons will have different frequencies. In this sort of problem, where you have to conserve both energy and momentum, life gets much easier if you deal with a system that has zero net momentum.\n\nSo yeah, the short answer is the photons are more energetic to account for the missing energy."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
2qw7jp
|
before electronic currency, how did central banks, e.g the fed, pay for the production of legal tender (bills/coins)?
|
It costs money to print money.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2qw7jp/eli5_before_electronic_currency_how_did_central/
|
{
"a_id": [
"cna4ini"
],
"score": [
3
],
"text": [
"Electronic bookkeeping was not the first time balances were written down rather than represented with physical objects. Did you think that when I deposited $50 in a bank in 1950, that exact $50 bill was kept in the vault until I asked for it back? No, they took the bill, added it to their stash, and added 50 to the number next to my name. Did you think that, to give my son money for college in 1970, I would have to literally drive across the country with $1000 in a suitcase and hand it to the Bursar? You do know that checks predate electronics, right?\n\nAll the Fed had to do back in the day was take the materials that were to be used to print the money, and pay for them with a debit on their account, and a credit on their supplier's account. Same with the laborers. Tim Berners-Lee did a lot of great things, but he didn't invent writing down numbers. "
]
}
|
[] |
[] |
[
[]
] |
|
3q11ss
|
what happens to a company when it's stock reaches zero?
|
Does the company go bankrupt? I know the stock market is largely based on faith in a company, but can't a company run without people having faith in it?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3q11ss/eli5_what_happens_to_a_company_when_its_stock/
|
{
"a_id": [
"cwb4wcq",
"cwb6588"
],
"score": [
5,
2
],
"text": [
"The company won't go bankrupt just because its stock price has collapsed, but the stock price probably collapsed because of other problems which are about to lead to the company going bankrupt.\n\nLet's assume that the company is in fact trading quite happily but the stock market has just lost all faith in it for some reason. Perhaps they appear to be in serious trouble but actually have a great new contract or invention on the way which they can't announce yet. The main problem with the stock price being very low would then be the risk of a hostile takeover. If the stock price is pennies and a competitor wants to buy the company, the directors will struggle to convince the shareholders not to sell.",
"The question is how a stock price would reach actual 0 - sure, it may get to the point where someone would be willing to unload a billion shares for a decent sandwich, but actual $0.000000000 means that someone would rather give away the company rather than hold on to it. \n\nThe way a corporation works is that the shareholder has almost no risk, other than the money they have spent on shares. If I buy Coca Cola shares, and the CEO is revealed to have been murdering children as part of their business strategy, and they're sued for a trillion dollars and they lose... the only thing a shareholder can lose is the total value of the shares. \n\nSo now Coca Cola's shares drop to $0.000001 each. Someone could buy the whole company for a few grand, which may be risky depending on how bad the real damage is. But why would they drop to $0? Someone could literally take it over with no risk at all, not a penny (outside of administrative fees to actually do so). Someone else may say \"well this is worth $100 to me!\" And thus, the share price isn't $0. \n\nAgain though - why would someone sell at that point? If I bought $10 000 in shares, and they dropped to $0.000001 in value, why would I sell? It's not worth me calling someone to make the trade happen. Everyone would just sit on them, and hope the price rises again. "
]
}
|
[] |
[] |
[
[],
[]
] |
|
runpa
|
Why don't we use hydrogen balloons for first stage space deployment rather than rockets
|
I was watching a video about the highest skydives and it included video of an astronaut jumping from above the troposphere. His jump platform was a modified weather balloon. I got to thinking, why do we waste the resources burning fuel to get through the atmosphere when we could get most of the way through using the hydrogen as a balloon and then burning it as fuel once we can't get any higher.
|
askscience
|
http://www.reddit.com/r/askscience/comments/runpa/why_dont_we_use_hydrogen_balloons_for_first_stage/
|
{
"a_id": [
"c48seee",
"c48sjx5",
"c48tqeg"
],
"score": [
2,
4,
5
],
"text": [
"Those balloons that reach orbit are not actually in orbit. They are still held aloft by the buoyancy of the balloon on the atmosphere. If you removed that balloon, the whole thing would fall down.\n\nIf you want to get something \"orbiting\" around the Earth fast enough to stay at altitude, you need tangential velocity. The rocket goes up, but then it starts turning parallel to the Earth's surface to gain the speed necessary to stay at whatever height.\n\nEdit: A balloon likely wouldn't be large enough to power a rocket once you're up there. Not enough gaseous Hydrogen would fit in a balloon(s). That's why we use liquid hydrogen.",
"I'm going to ignore temperature and the change in pressure as you rise, just for ease of calculation here.\n\nHydrogen is lighter than air, obviously, so you can use it to lift. The approximate buoyant force is about 1.204 kg/m^3 ([source](_URL_2_)). Weight of the rocket is about ~400,000 lb with no fuel tanks or SRB's attached ([source](_URL_0_)). That means, after conversions, you would need approximately 150,700 m^3 of hydrogen. To put that in perspective, the Kermit the Frog balloon from the Macy's Thanksgiving Day Parade in NYC has only 312 m^3 of helium in it, so imagine how large that balloon would be ([source](_URL_1_)). \n\nAlso, another big problem would be the hydrogen itself. Most balloons are made up of helium because, as the Hindenburg disaster shows, hydrogen can burn very easily, whereas helium cannot. Helium is twice as heavy as hydrogen, but this means it loses only 7.4% of its lifting power, so its not that big a difference ([Source](_URL_2_)). The biggest obstacle would just be the loss of fuel to the shuttle as well as the immense size of the balloon needed.\n\nI'm sure there are other problems as you go up in the atmosphere with the gases expanding or something, but I am not sure on that, so I won't speculate. Perhaps someone who knows better will be able to.",
"Most of the shuttle's fuel goes into forward velocity, not getting the shuttle at orbital altitudes. If my memory serves me correctly, only about 10% of the fuel is used for lifting the shuttle and the rest is used for acceleration, so you wouldn't gain that much of an advantage by launching it from a balloon. The negligible advantage of starting launch at altitude is grossly outweighed by the engineering complexity of trying to launch from a balloon. Not only do you have to make the balloon large enough to lift the vehicle, but it also has to lift all of the support structures."
]
}
|
[] |
[] |
[
[],
[
"http://www.boeing.com/defense-space/space/hsfe_shuttle/facts.html",
"http://muppet.wikia.com/wiki/Macy's_Thanksgiving_Day_Parade",
"http://mysite.du.edu/~jcalvert/phys/hydrogen.htm"
],
[]
] |
|
1c5xw9
|
what is wall street
|
Explain (like I'm 5) what is walstreet? And what is occupy walstreet?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1c5xw9/eli5_what_is_wall_street/
|
{
"a_id": [
"c9dd5ih",
"c9de9p6",
"c9dfbba"
],
"score": [
3,
7,
2
],
"text": [
"Wall Street is a place where people buy and sell shares of companies. ",
"Wall Street is a famous street in New York with many Banks and trading places. The trading places don't sell goods, they sell shares in big companies and shares in big deals, like oil.\n\nThis is important to pay for big things, like whole ships full of oil to keep our cars going, and new businesses to create new jobs.\n\nSometimes, things don't work out - shares in a company get sold and then the company goes down, and the people who bought the shares loose their money and are very unhappy.\n\nOr someone borrows money from the bank where many people saved it, and looses it with a bad deal. The bank gets in trouble and needs to ask the government for money so people don't loose their savings. But the people still have to pay, because they pay the taxes to help the bank, while the people who profited from the bad deals get to keep the money.\n\nOccupy Wall Street is a group of some people, who feel they have to do something against this, so they protest against and sometimes disturb banking and trading of this kind.\n\nThey often think there are better solutions than allowing traders to do such deals, and they usually believe the government has to do more to control things, so that nothing bad happens.\n\nMany even want very big changes in the way money is handled, which puts them in conflict with governments and traders who say that the trading is necessary to keep things going well for us.\n\nSo sometimes, they clash with police who try to keep them from disturbing the banks and trading places too much.",
"Many hundreds of years ago Wall St was where the northern wall of the Dutch Colony of New Amsterdam stood. The name apparently stuck over time and at some point banks and other financial firms started calling that street and the streets around it home. The term Wall Street has come to mean the entire banking/finance industry in the US."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
c9r7nk
|
I'm interested to know how the political attitude in Germany changed after WW2 from what appeared to be predominantly nationalist and anti-semitic facism to the democracy we know today.
|
I got thinking about this due to current world events and the worrying rise of national populism. I see history repeating itself to lesser extent but it's still worrying nonetheless.
Wondered how long it took the majority of the German population to see the error of its ways and reverse its thinking?
I hope this isn't a stupid question.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/c9r7nk/im_interested_to_know_how_the_political_attitude/
|
{
"a_id": [
"et28sjg"
],
"score": [
125
],
"text": [
"There are lots of answers in many threads on Denazification in this sub what will likely provide lots of answers to this question I think. For instance.\n\n - [What effects did Denazification have on the German and Austrian society?](_URL_0_)\n - [How quick of a process was the denazification of Germany after the end of WWII?](_URL_3_)\n - [What was done to make sure Germans didn't become Nazis again?](_URL_1_)\n - [In what ways and to what extent did DeNazification fail to change Germany in the post-war period?](_URL_2_)"
]
}
|
[] |
[] |
[
[
"https://www.reddit.com/r/AskHistorians/comments/ahyjds/what_effects_did_denazification_have_on_the/",
"https://www.reddit.com/r/AskHistorians/comments/843xmv/what_was_done_to_make_sure_germans_didnt_become/",
"https://www.reddit.com/r/AskHistorians/comments/6ufxkq/in_what_ways_and_to_what_extent_did/",
"https://www.reddit.com/r/AskHistorians/comments/7x8p6e/how_quick_of_a_process_was_the_denazification_of/"
]
] |
|
1kdgir
|
what's the deal with the holy trinity? why is it still monotheistic?
|
I understand the concept of God and Jesus, but what is the Holy Spirit? And how does Christianity remain monotheistic? I'm asking this with a respectful curiosity.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1kdgir/eli5_whats_the_deal_with_the_holy_trinity_why_is/
|
{
"a_id": [
"cbnsv0j",
"cbnw1g9",
"cbo2zdk",
"cbo31md",
"cbo6331"
],
"score": [
6,
12,
6,
2,
2
],
"text": [
"The idea is that even though there are three parts they are the same thing.\n\nBelievers might describe it as parts of the body. While your arm is obviously different from your head, it's all you.",
"The Trinity distinguishes between persons and beings, or in layman terms one what and three who's.\n\nGod is one what (being) with three who's (persons). Each person is 100% God, co-equal (of equal power) and co-eternal (having existed forever). One person is not 1/3 of God because God is infinite and it is impossible to divide infinity into 3.\n\nThe three persons are the Father, the Son, and the Holy Spirit. The Father is unseen in heaven, the Son is the image of the Father, and the Holy Spirit works among believers.\n\nThere is no appropriate analogy because God is unique and thus there is nothing in creation which can accurately describe him.\n\n",
"[Here's a good visual on the Trinity](_URL_0_). I haven't seen any better than this and it has no obvious errors as far as I can tell.",
"Jesus is God\n\nThe Father is God\n\nThe Holy Spirit is God\n\nJesus is not the Father or the Spirit\n\nThe Father is not Jesus or the Spirit\n\nThe Spirit is not Jesus or the Father\n\n\nAll three the same singular God. Existing at the same time, through all time, above time, in perfect unity. ",
"[1 John 5:7](_URL_0_): \"For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one.\"\n\nGod the Father is God seated in heaven, God the Word is Jesus Christ (God manifested in the flesh) and God the Holy Ghost is God manifested in spirit within the believer (the true church).\n\nThese are three aspects of the same God, therefore the trinity is monotheistic."
]
}
|
[] |
[] |
[
[],
[],
[
"http://i.imgur.com/u9wZMUT.jpg"
],
[],
[
"http://www.biblegateway.com/passage/?search=1%20john%205:7&version=KJV"
]
] |
|
5dd2s9
|
how do compression stockings help to prevent blood clots?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5dd2s9/eli5_how_do_compression_stockings_help_to_prevent/
|
{
"a_id": [
"da3ms5d"
],
"score": [
14
],
"text": [
"Blood clots tend to form when blood is sitting stagnant. The compression increases blood pressure in the area and pushes blood out of the area, back into circulation."
]
}
|
[] |
[] |
[
[]
] |
||
s3nft
|
When we break a bone, is it nerve receptors in the bone that register the pain, or receptors in the muscles around the bone?
|
I got to thinking about this today, and realized I'm not sure!
|
askscience
|
http://www.reddit.com/r/askscience/comments/s3nft/when_we_break_a_bone_is_it_nerve_receptors_in_the/
|
{
"a_id": [
"c4avr12",
"c4awz8b",
"c4b18ob"
],
"score": [
15,
4,
2
],
"text": [
"Bones are covered by a membrane called the periosteum, which is very sensitive to pain.",
"Injuries cause the body to release a cocktail of signaling molecules and other factors that lead to inflammation. Inflammation is another source of pain that may arise in the surrounding tissues as well. You often have to take a systems approach if you want to understand things like pain.",
"DVM/PhD here. There are no neurons in the calcified bone, what most people think of when they think bone. Instead, the periosteum mentioned by langfan is highly innervated, as is the endosteum (which is the membrane in the center of the long bones that have a marrow cavity...think thigh bone, rib, etc). When a break happens, those two membranes are stretched/torn, which registers as pain, blood, etc from the marrow flows out causing pressure in the surrounding tissue, inflammation causes more pressure, all of which will register as pain once a certain threshold is reached, and then immune cells will enter the area, called there by cytokines (chemical signals of damage), and release more cytokines that cause more inflammation and swelling. And all that swelling causes pain too."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
2w9q94
|
how is it that software can crash, but restarting and trying a second time doesn't always yield the same results?
|
I mean, I've always thought computers are so logical, they are literally repeating the same steps and routines. This is strange because sometimes a program can do something wrong and crash, but if you reopen and do the same thing, it'll work the second time around.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2w9q94/eli5_how_is_it_that_software_can_crash_but/
|
{
"a_id": [
"cooueu3"
],
"score": [
2
],
"text": [
"A lot of programs are doing a number of things simultaneously. It could easily be something \"under the covers\" that causes the crash. The actions you're found may only cause a problem if a number of other things were done first. Or, even tougher to find and fix, the problem may only occur when a few things under the covers conflict, and nothing you do may have caused the failure."
]
}
|
[] |
[] |
[
[]
] |
|
g05p2
|
Why aren't plants more intelligent?
|
I understand the lack of nervous systems etc, but why doesn't evolution shape them to become more self aware like animals?
|
askscience
|
http://www.reddit.com/r/askscience/comments/g05p2/why_arent_plants_more_intelligent/
|
{
"a_id": [
"c1jxvrs",
"c1jxyux",
"c1jy2wf",
"c1jy74y",
"c1jyq09",
"c1jyrxn",
"c1jywz2"
],
"score": [
21,
5,
33,
16,
2,
3,
10
],
"text": [
"What good would it do them as they are?\n\nMost importantly, evolution is not a pointed or goal oriented system.\n",
"As MrsWormwood and AluminumFalcon3 correctly point out, evolution has no goal, and intelligence is not an inevitable outcome.\n\nAlso, intelligence doesn't have any utility if you can't act upon the understanding it gives you; to attack, run away, seek new habitats and food sources, or manipulate the world, etc. \n\nImagine a poor intelligent plant, quite literally rooted to the spot, doomed to thinking its plaintive thoughts; 'I'm being eaten by a cow - great', 'Oh crap, the light is so much better on the other side of the field', 'FFS - here comes a chainsaw - aaarrrggghhh!!!' ...",
"Evolution isn't a guy leveling up in an RPG.",
"I think most people in this thread have covered the \"why\", but let's go a little bit into the how.\n\nNervous systems, in addition to various other cell types, are energetically very expensive. Many animals, in addition to reproduction, have fitness that is highly correlated to efficient energy consumption and therefore many have specific niches or strategies in order to not starve. \n\nPlants, for the most part (with the exception of carnivorous plants who only gain a small fraction of energy by eating bugs), rely on sunlight for energy. While this is great because they don't have to go out and forage all the time, the amount of energy gained from this is astronomically low compared to eating other animals. Unless plants can get over this energy barrier then developing these types of cells will never be advantageous.",
"Plants wouldn't benefit from intelligence. ",
"I think you might enjoy this TED talk: [Stefano Mancuso: The roots of plant intelligence](_URL_0_)",
"Plants are aware of their environment, and can work together, on a rudimentary level, to attack aggressors. \n\nIt happened in 1992 in South Africa, a bunch of Acacia trees essentially ganged up on the local livestock (some type of deer/antelope) and killed off a whole shitload of them.\n\nThere was a particularly bad drought going on, so a lot of the plant life was dying off. The livestock decided to start eating the Acacia leaves. Acacia's develop tannin's, which are toxic, but these livestock have enzymes to counteract the toxicity of the tannin's. Then something interesting happened, because of the drought and the livestock eating the leaves, the Acacia's started developing 4x the normal amount of tannin's, this caused fermentation in the livestock's stomachs to come to a halt, effectively starving them to death. \n\nAfter the livestock would munch on the Acacia's a bit, the Acacia's would start to emit ethylene gas, which would notify nearby Acacia's that they were under-attack, and to start developing more tannin's themselves.\n\nIt kept going on and on until some farmers alerted the Gov't, which sent in biologists and plant scientists etc... to figure out what was happening, they eventually did, and the farmers had to keep their livestock away from the Acacia trees.\n\nIt's almost like the Happening, but without the shitty acting."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[
"http://www.ted.com/talks/stefano_mancuso_the_roots_of_plant_intelligence.html"
],
[]
] |
|
430n3i
|
einstein podolsky rosen paradox
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/430n3i/eli5_einstein_podolsky_rosen_paradox/
|
{
"a_id": [
"czem8s7"
],
"score": [
12
],
"text": [
"This is actually not terribly hard to do.\n\nHeisenberg's Uncertainty Principle states that certain properties of quantum mechanical systems can't be precisely known simultaneously (why this is the case doesn't matter too much for an ELI5-level understanding of the EPR argument). Among such properties are position and momentum: the more precisely you know one, the less certain you can be about the other. Quantum mechanics also (usually) purports to be a \"complete\" theory of quantum systems: it tells you everything there is to know about the system, with nothing left out. EPR tried to show that these two assumptions are incompatible with one another, generating a paradox. \n\nHere's the original setup. Suppose, EPR said, we have two particles A and B that are allowed to become entangled with one another so that their positions and momentums are correlated, then the particles are separated. We can imagine this as something like allowing two billiard balls to roll down a track toward each other, strike together, and then bounce off in opposite directions along the track. We let the particles drift apart for a while without disturbing them until they're separated by a substantial distance.\n\nNow, Heisenberg states that we can't know both the position and momentum of either particle with perfect precision. But suppose, EPR said, we do the following. We first measure the position of Particle A. Since we know how particle A is correlated with Particle B, this lets us deduce the position of Particle B as well. But we could equally well have chosen to measure the *momentum* of Particle A. Again, because we know how the two are correlated, this would have let us deduce the momentum of Particle B. Since Particles A and B are far apart from one another, there's no way for Particle A to \"tell\" Particle B whether we've chosen to measure position or momentum, and since we could make either a measurement that would let us know Particle B's position or Particle B's momentum with certainty, Particle B must have had both a particular position and particular momentum all along. This violates Heisenberg's Uncertainty Principle, generating a paradox. EPR concludes, then, that the starting assumption that quantum mechanics was complete must be false. There must be properties about Particle B that have real values, but which quantum mechanics doesn't cover. Einstein suggested that this paradox was best resolved by positing what's called \"local hidden variables:\" features of quantum mechanical systems that are concrete, real, and spatially localized but which are inaccessible to measurement.\n\nOf course, there are a number of problematic assumptions in their setup that eventually turned out to be false. Most significantly, they assumed that given sufficient spatial separation, Particle A and Particle B could be prevented from interacting with one another, despite being part of an entangled pair. They justified this assumption by pointing out that otherwise, Particle A would have to exert an influence on Particle B instantaneously, which seems to violate Special Relativity's prohibition on faster-than-light information exchange. This was what Einstein called \"spooky action at a distance.\" If you assume that Particle A and B can interact even when spatially separated, the EPR argument falls apart.\n\nEventually (in 1964), John Bell [proved](_URL_0_) that the experimentally observed statistical behavior of entangled particles *could not* be explained by such local hidden variables; the numbers just failed to add up. His result, Bell's Theorem, is a proof (in the strongest possible sense) that any theory of quantum mechanics that reproduces the observed behavior of quantum systems *has to be* non-local in at least some sense (either by permitting action at a distance *or* by positing *global* hidden variables that aren't unique to individual particles). The EPR paradox was thus resolved by showing that one of their assumptions--locality--was false."
]
}
|
[] |
[] |
[
[
"http://plato.stanford.edu/entries/bell-theorem/"
]
] |
||
3aaq7l
|
Why is New Horizons not flying closer than 7750 miles from Pluto's surface?
|
Wouldn't flying closer yield more/better data/pictures?
|
askscience
|
http://www.reddit.com/r/askscience/comments/3aaq7l/why_is_new_horizons_not_flying_closer_than_7750/
|
{
"a_id": [
"csblfkf"
],
"score": [
14
],
"text": [
"because 7750 miles is extremly close for a planetary flyby. there is the chance that any closer would cause the ship to go of course due to the gravity of the planet, or that a slight miscalculation would place the ship closer than expected. the windows of tolerence would then be smaler as to not allow the craft to acutally hit the surface. there may also be dust, or other debris. But one of the main reasons is that New Horizons is going really fast. it's only doing a flyby. it will not go into orbit. so if the flyby was too close you would have a very small field of view. possibly too small to do anything useful because the surface will pass the craft by so fast."
]
}
|
[] |
[] |
[
[]
] |
|
1yjok6
|
can somebody please help me to understand the political structure in india and how this influences the citizens?
|
This is something I've been trying to wrap my head around recently and I cannot seem to find a simple answer. From what I understand so far is that they employ both a president and prime minister and that they have different purposes, but I'm not entirely sure how it all works.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1yjok6/eli5_can_somebody_please_help_me_to_understand/
|
{
"a_id": [
"cfl7nli"
],
"score": [
6
],
"text": [
"Okay, I'll bite since I'm Indian.\n\nIndia does have both a president and a prime minister. The real power though rests with the Prime Minister (Dr. Manmohan Singh) while the President (Pranab Mukherjee) is only a ceremonial head. India inherited this system from the UK and the President essentially fulfills the role of the monarch. \n\n**Who elects the PM?** Technically, the PM isn't elected, but chosen by the party/coalition that has a simple majority in the lower house of the Parliament. The lower house (Lok Sabha) has Members of Parliament (MPs) who represent as many as 543 constituencies covering the whole country. The MPs in the Lok Sabha are elected by the people in a General Election that takes place once every five years. \n\n**Who elects the President?** The President is elected by the MPs of both the lower and upper house (Rajya Sabha) as well as the Members of the Legislative Assemblies (MLAs) of the different states of the country. A Legislative Assembly is the state equivalent of the Lok Sabha. The President is almost always somebody who enjoys good support from whichever party is in the majority at the time of the election, making them nothing more than puppets. \n\n**Who elects the Rajya Sabha MPs?** They're not elected, rather nominated by state legislative assemblies. On paper, they are supposed to be experts from different fields, but only rarely does this happen. A Rajya Sabha MP's term lasts for six years. The incumbent PM is a member of the Rajya Sabha.\n\nQuestions?"
]
}
|
[] |
[] |
[
[]
] |
|
26p2bj
|
the purpose of developing self driving cars.
|
I'm wondering why so much research effort and finance is going into developing self driving cars.
Edit: Another reason I'm asking this is because I'm thinking of that Henry Ford quote ("If I had asked people what they wanted, they would have said faster horses."). Maybe it's not a driverless car that we need - maybe it's something else that none of us have imagined or innovated yet. I.e. What will be the "motorcar" of the 21st century? (Maybe that's a question for another post).
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/26p2bj/eli5the_purpose_of_developing_self_driving_cars/
|
{
"a_id": [
"cht3q41",
"cht3r47",
"cht4jzd",
"cht7brh",
"chtnyjv"
],
"score": [
7,
10,
3,
2,
2
],
"text": [
"Because nearly every traffic accident is caused by driver error AND nearly every traffic jam is caused by driver over-reaction. If we eliminate those two issues, our roads become exponentially safer and more efficient.\n\nFactor in all the fuel savings by removing the driver, and we're heading into a sunny future.",
"Many people spend a significant amount of time driving, especially their daily commute due to their job. Many people spend well over an hour driving to and from work. \n\nI would pay a significant premium on a vehicle if it were capable of driving itself, which would free up that hour each day for me to just sit back and read, or play games, or just take a nap. I sleep about 8 hours per day, I work about 8 hours per day, that leaves me only 8 hours for all the other stuff I'd like to get done. If a self driving car would free up one of those scarce hours, sign me up. \n\nThere's also a zillion other more business oriented reasons. How much would Walmart save in costs if their trucks drove themselves, and they didn't have to hire thousands of drivers to ship products across the country?\n\n",
"Here's 3 reasons, there are plenty more too.\n\nSafety - human drivers are prone to errors. When you make an error while driving a car, it often doesn't end well.\n\n\nEfficiency - human drivers have to be cautious so they don't crash, this causes traffic build ups. Self driving cars could drive faster and closer to one another, and at constant speeds, reducing travel time and fuel costs.\n\n\nComfort - you can have a nap, read a book etc while traveling, instead of having to focus on the road. And you don't have to use public transport, which is often not ideal, for various reasons.\n\n",
"A self driving car will result in significant cost reductions across industries and will grant greater freedom and comfort to the passengers in the car.\n\nSelf driving cars never speed, and traffic violations will be reduced to only cars that are manually operated. Traffic enforcement departments will evaporate as a dedicated workforce will become outmodded. Local police can pick up the slack, which will be minimal. That's an entire branch of your local law enforcement that doesn't need to be financially maintained. That money can be diverted to anything else more important.\n\nTraffic congestion will be greatly reduced, as most congestion occurs because of human piloting of vehicles. Intersections become more efficient as cars can negotiate traversal order. Traffic lights become outmodded. Did you know crosswalk buttons are placebos? Almost none in the US are wired up to actually do anything. Now, with traffic signals no longer necessary, the only signaling in an intersection will be to disrupt traffic so pedestrians can cross.\n\nThe cars can drive under extremely tight margins, bumper to bumper, for more efficient use of space. They can drive in groups to maximize aerodynamic efficiency, they can brake in unison, should they need.\n\nCars will communicate with each other in local, ad-hoc style mesh networks with whoever else is in range. They can coordinate speeds, passing, braking, lane changes, group configurations, and intersections faster and more efficiently than humans can. All this comes down to better use of road space, greater fuel economy, reduced travel time, and increased safety.\n\nSpeeds can increase as automated cars are safer.\n\nAnd automated cars never speed, and never drive aggressively, or drunk, and they don't do stupid risky things. Insurance on an automated car will be down through the floor, as insurance becomes a factor of the car and not the driver.\n\nAutomated cars can operate like taxis, they can show up when and where you need them and take you where you want to go. In fact, if the whole US fleet were automated, it seems unnecessary to even own a personal car. Perhaps a subscription model or an optional pay-per-use would be more effective. Cars would always be out and about so you could hail one and get a quick response, or schedule ahead of time and know it will be there and for you, and others can't snatch your ride.\n\nIf this is how cars operate, then your children can utilize cars themselves. Damn kids want to go to the mall? Don't want to take them? They can get themselves there.\n\nNow that no one has to manually operate the vehicle, you don't have to worry about drunks, or the fatigued falling asleep behind the wheel. No more driver distractions. You can arrange the seats to face inward and converse with your neighbors, do homework, get work done, take a nap, or have a cocktail.",
"Can't believe no one touched on this. The reason GOOGLE is developing self driving cars is to free up the one individual that, in their current state, cannot pump their main revenue engine (advertising) - the driver. 96% of Google's revenue is derived from advertising and since their advertising platform is basically ubiquitous across the internet, the basic fact is, the more time you spend on the internet, the more money they stand to make. I don't have the calculations on hand, however I've worked out what freeing up all driving hours in the US could generate in advertising revenue and it is significant. "
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[]
] |
|
3xwrip
|
why does comcast charge me *less* to provide tv internet than internet alone?
|
I was paying $80/month for Internet alone. Called up, they offered me the same Internet service plus basic TV for $60/month with a one-year contract. How is this a better deal for them?
When I lived another place, the local provider there did the same thing, so it's not just Comcast either.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3xwrip/eli5_why_does_comcast_charge_me_less_to_provide/
|
{
"a_id": [
"cy8h8el",
"cy8hk9x",
"cy8hqm1",
"cy8ncgi"
],
"score": [
10,
2,
3,
2
],
"text": [
"This is likely some promotional rate, which will increase in 12-24 months above what you were paying for a single service.",
"They bundle it up. The thing is though after your promo is over it will be a lot higher and they will hope u don't go back to just Internet. ",
"They are not charging less for tv+internet. They are charge more for only internet. If they charged less for internet - lets say 40$ - you would use that. A logical person would think charging twice the reasonable price for internet would make them lose customers but in reality they just \"force\" you to buy the TV subscribtion too by making it seem like you are paying less. A further question can be \"then why do they have an internet option?\". First, if someone somehow gets the internet only option the company earns more money. Second, if there wasn't an internet only option you would question it and demand to get a discount by not getting the tv of tv+internet and they would either lose money or look bad publically. ",
"i work in telecom so this is what the marketing folks actually want from consumer.\n\nthey want the user to signed up to their services.\n\neven with 60/mth, they are earning quite a bit from you. the analogy is that when you have service with them, there is a chance that you will upgrade your services or continue to spend on their services rather then not having any of their service.\n\nmeaning to say, you might 1 day be jolly and subscribe a new channel from the paid tv section and to them, it is an opportunity. \n\ni hope this clarify your doubt.\n\nto be honest, if you think that no one would add services that is totally not true, there are many people in this world would pay for nothing. the data of profit shows exactly my sentiment because many people would just be like \"oh it is just a 1.99 only\".\n\n"
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
|
88jb60
|
Examples of Autocrats who were loved by their people
|
Bonus points for the following.
A.) They regularly monitored and executed political opposition.
B.) their policies legitimately improved the well being of their people.
C.) People outside of their dominion saw the people inside as disillusioned about said autocrats competency.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/88jb60/examples_of_autocrats_who_were_loved_by_their/
|
{
"a_id": [
"dwl0baf",
"dwld9si"
],
"score": [
6,
3
],
"text": [
"**Check out this one AMAZING trick that made the Greeks LOVE their tyrants!**\n\nThink of Ancient Greece. Are you thinking of temples and statues, of heroes and philosophers? Are you thinking of democracy?\n\nOf course you are. The Greeks were the first people to introduce democratic government. But they didn't stop there! They also launched another word, which they took from their neighbours: tyranny.\n\nBut surely, you ask, the freedom-loving pro-democratic Greeks would have hated tyrants? Would have risen up and thrown them out? Would have fed them to the dogs?\n\nSure they did. Eventually. When they had learned to stop worrying and love democracy. But that took a while. It had to be invented first, and then perfected, and until that time, what was a Greek city-state to do? There was no fixed idea of what a government should look like. Most places had a couple factions of rich men fighting each other for supremacy. All those laws the Greeks wrote? They were all about trying to channel that violence, trying to give everyone a big enough slice of the cake that they would stop fighting to get more.\n\nNeedless to say, this usually didn't work! The result is that these states were always unstable. They were often in open civil war. Nobody wants civil war, especially when your state is only a couple thousand people. They were desperate for the elite to stop fighting.\n\nOn the other hand, these rich factions often gave nice things to their community to get their support. You know those temples we mentioned, those statues? Most of those were paid for by these same elite men, who tried to get people to think of them as benefactors. You build a statue, people remember you. You fund a festival, people will cheer you on. You build a temple, people will think you love the gods.\n\n*That's not the trick, though!*\n\nHere's the thing. All these factions vying for power - every now and then, one of them *won*. They beat their rivals in the game for influence, and then got rid of the main contenders. Exile or execution was common. And then there was only one man left. They took on the name of \"tyrant\" - a word borrowed from Lydian - to express their supreme power. They were large and in charge.\n\n*And here it is!*\n\nWhen you've violently disposed of all your rivals, there's no civil war anymore!\n\nStates that fell under long-lasting tyrannies tended to prosper simply because they were at peace with themselves. The best tyrants co-opted their remaining rivals by giving them some semblance of power, so that everyone would have a stake in keeping them in the saddle. And then it was just a matter of doing that great public beneficence. With more resources at their disposal than ever, great tyrants like the Kypselids in Corinth or the Peisistratids in Athens built great public works: temples, market squares, public fountains, etc. The great slipway over the Isthmus of Corinth was the work of its tyrant, as was the aquaduct on Samos, an artificial waterway cut through 500m of rock. Once in power, the tyrants made it rain, and the people loved them for it! The reign of the tyrant Peisistratos at Athens was remembered as a Golden Age. The tyrant Periander of Corinth was remembered as one of the Seven Sages of Archaic Greece.\n\nThat is, until they became paranoid and started to attack random people, or until people began to develop the idea that maybe they should have more of a say in things, or until people stopped thinking that the tyrant in charge was the best guy for the job. That's why they ended up thinking about tyranny just like we do.\n\n",
"### Three French generals who seized autocratic power and were loved! #3 will shock you!\n\n[Click here to never spend another penny on food again!](_URL_0_)\n"
]
}
|
[] |
[] |
[
[],
[
"https://www.reddit.com/r/gardening/"
]
] |
|
4dek74
|
when you read news articles about global warming such as "the hottest year on record in 80 years!", why was it so hot 80 years ago?
|
[deleted]
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4dek74/eli5_when_you_read_news_articles_about_global/
|
{
"a_id": [
"d1q8l5v"
],
"score": [
4
],
"text": [
"This year being really hot isn't necessarily indicative of global warming, an article with that title is being sensationalist. If the running average temperature over the last 10 years was getting continuously warmer, that would be a better indication of a trend.\n\nTemperature is affected by a lot of different things so their are years that are extra hot and years that are extra cold. It becomes a (potential) problem when their are a lot more hot years than cold years in a 10, or 50, or 100 year period.\n\n"
]
}
|
[] |
[] |
[
[]
] |
|
2py6qi
|
what exactly happens when an officer gives me a warning instead of a ticket?
|
I just got pulled over for the first time, I was polite and courteous to the officer and he let me off with a warning, I was just curious as to what happens when he goes to his car and looks up my information? Does it get saved that he looked it up, does he mark it as a warning, or speak to a higher up to ask if it should be a warning or ticket? Does it show up on my record?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2py6qi/eli5_what_exactly_happens_when_an_officer_gives/
|
{
"a_id": [
"cn12sv6",
"cn12uyd"
],
"score": [
21,
3
],
"text": [
" > I was just curious as to what happens when he goes to his car and looks up my information?\n\nHe is checking to see if the registration is still current on your car, checking your drivers license to ensure it is still valid, and checking to see if there are any warrants out for your arrest. \n\n > Does it get saved that he looked it up, does he mark it as a warning,\n\nIt depends. If you got a written warning than there is a record of it in that officer's department. Other police departments usually cannot see other departments warnings. If it was just a verbal warning than there is no record of it. \n\n > or speak to a higher up to ask if it should be a warning or ticket?\n\nNo, the cop has full authority to make the decision on a ticket or warning. ",
"It depends on the state, but there is usually a log that states that your information was run and the reason why. It won't show up on background checks or anything like that, but it can show up when you get pulled over again so the next officer will know that, for example, your window tint was too dark and you were told to take it off but refused to listen so they will issue a ticket. Replace window tint with busted light, speeding, etc.\n\nUsually they won't talk to a super to be told to give a warning. It is more along the lines of your record came back clear, or you seem to be a reasonable person, or you are cute or just that the cop is in a good mood. In most cases it will be a combination of the first two."
]
}
|
[] |
[] |
[
[],
[]
] |
|
5cjgb3
|
Is it true that Saint Patrick never drove snakes out of ireland but instead drove out African Twa Pygmies?
|
Someone told me that Saint Patrick never drove out snakes from Ireland, that there were no snakes there in the first place to be driven out.
Instead, he drove out metaphorical snakes meaning sinful things. Apparently a group of african twa pygmies travelled to Ireland, where when they couldn't be converted, Saint Patrick had them killed. Making him the saint who drove the snakes out of ireland.
Is this true? Seems like bullshit
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/5cjgb3/is_it_true_that_saint_patrick_never_drove_snakes/
|
{
"a_id": [
"d9wyul7",
"d9x61mx"
],
"score": [
9,
9
],
"text": [
"It's bullshit. There was no direct contact between sub-Saharan Africa and Europe until the 15th century, except by way of Jerusalem during the Crusades.\n\nSome scholars have tried to place Coptic Christian missionaries from Egypt in early medieval Ireland, but this theory is no longer taken seriously.\n\nIn these cases, furthermore, contact was *positive*. Spain attempted to forge marriage alliances (non succeeded); the Ethiopians sent monk-ambassadors to Rome and established a Church there; the Kingdom of Kongo adopted the insignia and titles of the Portuguese heirs to the Knights Templar.\n\nThere is a whole lot of yucky treatment of non-European/non-Christian/non-\"orthodox\" ('heresy' is a slippery thing)/non-male people in the Middle Ages, but this story is bullshit.",
"Let's underscore the assessment of /u/sunagainstgold - this is a lame if not contemptible fabrication (this story provides just a little bit of a racist edge to St. Patrick). But it is worth exploring this just a bit further.\n\nOn snakes: there were no indigenous snakes in Ireland before St. Patrick. The legend giving him the role of expelling the snakes was an after-the-fact explanation for this gap in the Irish ecosystem. Snakes were simply not able to get there because there wasn't a land bridge at the right time to allow snakes to achieve that sort of diffusion.\n\nMore importantly, the idea that there was an indigenous population of small people in Ireland is a common attempt to explain the persistent belief that the fairies - the Irish sidhe or \"wee\" folk. The belief that there must be some truth behind every legend is just that: it is a bit of modern folklore with nothing to substantiate it. Legends exist without necessarily having anything valid behind them, but the folk belief persists (and accounts for many of the questions in this subreddit!).\n\nThe idea that there must have been a smallish indigenous population living in Ireland before the arrival of the Irish has persisted as a way of explaining the widespread belief in diminutive fairies. But if that sort of explanation were needed for Ireland, then we would need it throughout Northern Europe because the idea of these supernatural beings, often living underground and often diminutive, is ubiquitous. There is simply no archaeological or other evidence to support the idea that these sorts of people lived there.\n\nBut for those who seek these sorts of explanations, the next task has always been to find the small people who might have been there at some early point in prehistory. It is easy to connect the dots - even though the dots cannot realistically be connected - so that a group like an African population must have in Ireland. But in fact there is no evidence of Africans or anyone else in Ireland or elsewhere who were small and then who were part of some persistent folk memory that turned them into fairies. Legends are not necessarily based on some phantom truth."
]
}
|
[] |
[] |
[
[],
[]
] |
|
6ywxkv
|
what is the difference between all types of soap. i.e. shampoo, hand wash. body wash, bar soap, dish soap, detergent etc...
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6ywxkv/eli5_what_is_the_difference_between_all_types_of/
|
{
"a_id": [
"dmqwm2q",
"dmqy1xp",
"dmr8h7s",
"dmr8iqt",
"dmrbsu8",
"dmrbz36",
"dmrd9gv",
"dmrev7r",
"dmrhb2u",
"dmri7lx",
"dmrindp",
"dmrj1im",
"dmrj55i",
"dmrlroo",
"dmrmp04",
"dmrnpj0"
],
"score": [
1814,
33,
21537,
41,
13,
4,
25,
29,
3,
8,
2,
5,
2,
8,
5,
2
],
"text": [
"Actually, soap isn't soap. Kinda.\n\nDepending on what sort of saponificator you use, you get two very different types of soap. Lye will produce a hard soap, like what you get in bars. Potash produces a liquid soap.\n\nThe type of fat you use also matters. Lard make a very, very hard and dry bar of soap, while olive oil makes a very soft soap. Other fats have all sorts of other things that can be added. Then, you add different scents and colors and stuff.\n\nSo, soap for your hands will be made with lye and will generally be less \"harsh\" than powdered laundry soap, which doesn't have to worry about potentially drying your skin out. Shampoo is potash soap with lots of water and fragrances and magical chemicals that companies say repair damage. Liquid detergent is a potash soap that's designed to be \"tougher\" on grease.\n\nSoap for the body tends to have more fat in it compared to soap for other things. This is why \"dish hands\" used to be a thing. A high-quality body soap will leave fat on your skin, which is why it feels soft and smooth afterwards. Yes, that's either plant or animal fat that's covering your skin. Enjoy!",
"Great answers so far about soap. Detergent differs from soap by actually destroying and killing bacteria. Essentially it rips them apart whereas soap carts it away. Detergent is quite harsh to use on your skin for this reason, which is why we tend to use soaps to clean ourselves. ",
"Most modern liquid \"soaps\" are not technically soaps at all, which is to say they're not produced from mixing vegetable or animal fats with a strongly alkaline solution such as lye or potash. Instead they're a blend of (usually) petroleum-derived surfactants such as sodium lauryl sulfate with other chemicals to produce a detergent that matches the desired use. \n\nShampoo is designed to be gentle on the keratin which forms hair, have strong foaming properties to be more easily worked through the fine strands, remove common hairstyling products, and - especially for those of us with more than a couple inches of hair - have specific effects on the texture of the hair. It has a fairly low concentration of surfactants so that it rinses out quickly and you're not in the shower forever trying to get it all out of your hair.\n\nHand and body wash is usually formulated with a mild surfactant to avoid skin irritation, plus various ingredients that can moisturize the skin, add scent, improve lather, etc. Lathering agents are generally surfactants as well, so there's a careful balance here between getting a nice lather and not drying out skin. Hand washes are usually less foamy since they don't need to cover much surface area and are used frequently throughout the day, while body washes tend towards more foam since they need to cover a lot more surface area and are used less frequently. They're both a bit more concentrated than shampoo, since it's easier to rinse soap off of skin than hair, and in the case of body wash, most consumers pour it onto a sponge/pouf/washcloth/etc. before applying it to the skin, which spreads it out thinner than applying it directly. Face washes are their own magical category and can include all sorts of fun chemistry like ceramides and multivesicular emulsions, alpha hydroxy acids, benzoyl peroxide or salicylic acid, etc. - and as an acne sufferer, it _definitely_ makes a difference. \n\nBar soaps are one area where true soaps are still relatively common. Moisturizing ingredients can also be added, and the naturally occurring glycerine is also somewhat moisturizing. However, traditional soaps also have a lot of limitations. They have a fairly narrow range of environments in which they're effective, needing hot water with a low mineral content to function, and must be rinsed a second time with clean water to avoid deposits. \n\nLaundry detergents are commonly formulated these days with specific surfactants designed to work well with cold and hard water, both of which decrease the effectiveness of traditional soaps. They're also highly concentrated, since they're going to be diluted by the large volume of wash-water, which is why just a few drops of liquid detergent on your hands will take much longer to rinse off than an equal amount of hand soap. This is also why ideally you should fill the washer with soap and water so they can mix, then add the clothes.\n\nDishwasher detergents aren't worried about gentleness, since they don't come in contact with skin or organic fibers, so they can use harsher detergents and often include abrasives, but do rely on hot water to be effective. For similar reasons to laundry detergents, they're highly concentrated, but they use surfactants that are more effective on metal and ceramic. \n\nDish detergents meant for hand-washing dishes have to balance removing grease, starches, sugars, etc. from food with not completely stripping the natural oils from skin, which is a bit tricky - the oils that keep your skin nice and pliable aren't any different from the oils of any other animal, chemically speaking. They're also pretty highly concentrated for that \"grease-fighting\" effect, and so that your washcloth/sponge/etc. doesn't need more soap on it after every dish you wash.\n\nEdit: Added some information on surfactant concentration that I forgot to include when I typed this up last night.",
"My question is can a bar of soap get dirty?",
"About handmade/homemade soaps... Sodium hydroxide lye is used for making solid soap bars, while potassium hydroxide lye is be used for making liquid soaps which usually need additives to prevent mold growth. Detergent for laundry is generally a blend of washing soda (works better in cold water), Borax (works better in hot water), and grated soap with a higher lye content.",
"shaving soap specifically has high amounts of stearic acid in it. It's what makes the lather stable",
"If we are talking about traditional soap, than the differance between a hard bar of soap and liquid soap would simply be the type of oils/fats used and the type of lye used. Sodium Hydroxide or Potassium Hydroxide for example.\n\nThe differance between liquid soap and foam soap depends on the dispensing device itself and how watered down the liquid is.\n\nBrands like Zest, Dove, Lever 2000, etc, aren't actually soap. They are a detergent bar. \n\nShampoo is just a liquid soap with a lye discount and differant oils used to protect and nourish your hair and scalp. Like tea tree oil and argan oil.\n\nDish soap is just liquid soap with added chemicals to help further degrease the food grime.\n\nEdit: I don't think a great many people realise this industry is heavily regulated, atleast in Canada. Everything from the ingrediants used to the size and font used on the packaging. In order for a product to be considered soap, fairtrade, vegen, etc, it has to meet the criteria. Anything else could land the Soaper into a lot of trouble. \n\nAnother thing most people don't understand is that these products fall under the Weights and Measures Act of Canada and these products have to be sold by weight in order to be considered legal. A lot of Soapers selling their products at fixed values at craft shows are breaking federal laws.",
"There was an amazing AMA about this a while back. One of the best Ive read in a while. \n\n_URL_0_",
"It's all marketing fluff, plain and simple.\n\n\nThe \"beard cleanser\" which I've received as a gift is the same crap that you'd otherwise see in body wash containers 2x the size, except that this \"specially formulated\" beard soap probably has 10x the markup on it. Same with all these other soaps.",
"So what about those 3 in 1 shampoo + conditioner + body wash things?",
"What's the difference between conditioner and shampoo?",
"How different is toothpaste? It performs a similar *function,* but I'm sure is vastly different *chemically.* ",
"No wonder my scalp and body itch so much! All the surfactants and chemical compounds reek havoc on my skin regardless of where on my body. So I have to use shampoos without SLS and alcohol of any kind. Otherwise, I will claw and scratch til I bleed. It's not fun. Most shampoo and conditioner I can use are without these ingredients and don't exactly smell like \"GEE YOUR HAIR SMELLS TERRIFIC\". Kudos to all those who gave such detailed response as it was very helpful for me. Thank you OP for the post. ",
"There are some pretty good answers here so I'll keep it short:\n\nFirstly, Soaps are made from animal or vegitable fat while detergents are manufactured synthetically using petroleum products.\n\nBoth clean using molecules called surfactants which have a water loving loving (hydrophilic) and a water repelling part (hydrophobic).\n\nDetergents became popular after Germany manufacturered them during world War 2 as they had issues with trading soap and precursors to soap production.\n\nBasically, more or less all liquid Soaps, detergents, shampoos, dish washing liquid etc nowadays are detergents based on SLS (sodium laurel sulfate) but people are finding alternatives as this is bad for the environment (see eutrification).\n\nBack in the day the trouble was that detergent was harsh on the hands (so is soap btw but not as much) so companies added ingredients to mitigate these effects. This is why gloves were so much more important while washing dishes back in the day. Industrial detergent is still harsh on the hands and skin. \n\nTo answer your question, fundamentally all of the detergent based cleaners are the same. The difference is the additives to make it more suitable for application. Eg. Shampoo additives have chemicals that make it less harsh on hair and skin. Similarly dishwahsers will enzymes to break down tough greases and stains. But at the detergent level, it's all the same.\n\nFun fact: frothing agents are added to make lather and foam when washing, especially in shampoos. This is just for show and has nothing to do with the cleaning abilities of the shampoo, body wash etc. ",
"All of these products have a simple formula: two parts linked together, one for sticking to grease (and everything grease-like) and one for sticking into water. The former glues onto what you want to wash off, and the latter takes the former into what you wash with (water). \n\nThe two halves can be tweaked like say with a car: you might want a Toyota with a bigger engine to haul things, or you might want a regular Toyota but with a differently looking bumper. The reason for this is that if you have soaps, you want something that doesn't degrade the skin too much, but if you want a detergent, you don't have to worry about skin. With shampoo you want to worry about skin and hair at the same time. For some of these you add another substance besides the one intended to do the washing, to \"condition\" the skin or the hair.",
"Major variations are changes in the types of oils used and the other additives added such as chelating agents and moisturizers. Changes in oil can make a big difference on weather a soap will work well with very oily substances..."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[],
[
"https://amp.reddit.com/r/science/comments/3ofxf8/science_ama_series_we_are_dr_curtis_schwartz_and/"
],
[],
[],
[],
[],
[],
[],
[],
[]
] |
||
1i1gde
|
Did Romans marry in the same sense that we do today? What were their pre-Christian marriage rituals like?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1i1gde/did_romans_marry_in_the_same_sense_that_we_do/
|
{
"a_id": [
"cb02f4s"
],
"score": [
71
],
"text": [
"The Romans had both marriage and weddings that would be very familiar to you. From the engagement ring (iron, not gold) to the veil (red, not white), we have inherited a lot of our wedding traditions from the Romans.\n\n(Everything I describe will only apply to the upper classes of Rome, and even then can vary depending on when and where and who.)\n\nAn engagement was arranged between the families of bride and groom, with thought for family status. Love between the bride and groom was at best an afterthought. Political alliances were formed and broken in marriage pacts. Technically the couple had to consent to the union, but in reality they had no choice.\n\nThe wedding ceremony was a religious ritual. Its date was chosen with traditional superstition and it was held in relative privacy. In the morning the bride gave away her girl's locket and her childish possessions if she was a first-time bride and dressed up for the occasion. (The boy will have parted with his boy's locket years ago, in part because his becoming a man was not tied to marriage and in part because he was always at least somewhat older than her.) A sacrifice was made to the Gods (animal and cake both have a history) and the bride spoke the words, \"Where you are Gaius, I am Gaia\".\n\nThe wedding spilled over to the streets, where they made quite a procession out of it. This terminated at their home, where the couple may be showered in nuts (which are probably better for the birds than rice, if the urban legends are true^1 ). The husband carried the wife in through the doorway.\n\nThe ceremony had religious and social significance, but no real legal significance. It was not strictly required and it did not affect which of the multiple legal classes of marriages you fell into under Roman law, which were mostly based on social status.\n\nDivorce was not uncommon and was not particularly stigmatized. Remarriage for both men and women was allowed. \n\nThe emperors Nero and Elagabalus are famous for marrying men. This had no legal significance and does not seem to be taken to have any bearing on their legally-valid marriages to women. (Both emperors had multiple marriages to women, with some oddness to them. Nero's first wife seems to have been the love of his life and he mourned hard for her death. His second wife started as his lover until her husband died under odd circumstances, ostensibly suicide. Nero's second husband was a man who he had castrated then called by his first wife's name. Elagabalus, I must tell you, was significantly crazier than Nero...his most famous and by far most scandalous wedding was not to a man, but to a Vestal Virgin.)\n\n^1 They're not."
]
}
|
[] |
[] |
[
[]
] |
||
4l7tnj
|
Why did the planes that dropped the nuclear bombs during World War II have such weird names?
|
_URL_0_
_URL_1_
It seems like a big joke. Why would they make it seem so informal?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/4l7tnj/why_did_the_planes_that_dropped_the_nuclear_bombs/
|
{
"a_id": [
"d3l2g46"
],
"score": [
8
],
"text": [
"Crews were allowed to make up their own names for their plane and there was a painter who would come and paint images on the plane's side that were thematically appropriate. Enola Gay was the name of the mother of Paul Tibbets, the plane's pilot.\n\nBockscar was named after Captain Frederick C. Bock, the commander of the plane. His crew ended up not being the one to fly the plane to Nagasaki, it was the crew of a different plane that ended up flying the mission. So the name sounds more puzzling if you hear the name of the crew, whereas it would have an obvious origin if it had been flown by its normal crew.\n\nFlying bombing missions was a frightening and deadly task, and a significant percentage of the young men flying these planes would end up dying in these planes. They picked the names to raise their spirits or laugh in the face of death or remind them of loved ones they might never see again. For example, Louis Zamperini, recently profiled in the biopic Unbroken, flew a plane that he and his crew named \"Superman\". Almost all of the names of these planes have been forgotten and were never historically relevant. But the two planes that carried the nuclear bombs will likely be remembered until the end of human history, due to the historical significance of their missions. The planes' names thus have a significance that was never suspected or intended by the namers at the time the planes were first named. Perhaps they would have chosen different names, perhaps not. Tibbets' mother is now immortalized, while Bock will be remembered as a footnote forever because of the name of a plane that flew a mission he wasn't a part of."
]
}
|
[] |
[
"https://en.wikipedia.org/wiki/Bockscar",
"https://en.wikipedia.org/wiki/Enola_Gay"
] |
[
[]
] |
|
64n8io
|
how/why do names become considered "old fashioned"?
|
[deleted]
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/64n8io/eli5_howwhy_do_names_become_considered_old/
|
{
"a_id": [
"dg3ivel",
"dg3lqgo"
],
"score": [
2,
3
],
"text": [
"The how: over time things get older such as clothes, Home-goods, vehicles, tools, etc. People then give those items a time frame in which it was used. ex: hand saw, is very \"old fashioned\" by today's standards since we have electric saws that make jobs easier now. \n\nThe why: since new things are constantly being made when something \"goes out of date\" the populous will eventually get said new thing and refer to the old thing as \"classic, old fashioned, etc\" when it reaches a certain point in time. such as a 1950s ford, 1970s washing machine, or even a 1990 cell phone. \n\nThis is my take on it so please don't crucify me for not being super smarticles. I kinda am mentally 5 lol.. ",
"I read that the usual trend in baby names is that first a new name is used by the rich. Then the middle class copy them because it's seen as a bit of an aspirational name, then the poor copy the middle class. Then the rich and middle class stop using it because it's become a poor people name. Then the poor stop using it and it becomes old-fashioned. Then at some point the rich pick it up again and the cycle repeats."
]
}
|
[] |
[] |
[
[],
[]
] |
|
2zqvd1
|
why do corporations have to defend their trademarks even if the allegation that a competitor is infringing is extremely weak.
|
There are plenty of lawsuits wherein one party sues another for trademark infringement when it's pretty clear to almost everyone that both products are sufficiently distinct. Often times it seems the plaintiffs themselves don't even feel threatened by the competitor. As I understand it there is some legal reason why a trademark holder has to defend their trademarks even if they don't feel threatened by competing products or that there is any confusion at all. Is this true? If so, why?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2zqvd1/eli5_why_do_corporations_have_to_defend_their/
|
{
"a_id": [
"cplgmer",
"cplgmkw",
"cplixsh"
],
"score": [
3,
2,
2
],
"text": [
"If you don't enforce the trademark it can be argued that it's no longer distinctive enough to merit that status. So you have to enforce to avoid the risk of losing it. ",
"Because not defending in one case may (a) encourage other, more egregious infringers and (b) be used as a defense by future infringers.",
"If enough incidences of failure to enforce become known, then when they do go after someone who risks both confusing and/or diluting the trademark, the infringer could defend themselves by citing the common use and claim that it's become a generic term.\n\nSo part of having and keeping a trademark is a duty to enforce."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
4d3owx
|
Why is my sense of touch regarding moisture wonky when it is cold/chilly?
|
For my family, I am the laundry engineer and have issues sometimes telling when items are "really" dry out of the dryer or off the clothing line. I have THE WORST time telling if textiles are still damp when they are slightly cold. Why is this? It seems like cold/chilly temps are cryptonite for my sense of touch regarding moisture.
|
askscience
|
https://www.reddit.com/r/askscience/comments/4d3owx/why_is_my_sense_of_touch_regarding_moisture_wonky/
|
{
"a_id": [
"d1nqcwb"
],
"score": [
4
],
"text": [
"This has to do with the way we feel temperature. We don't just feel if a thing is hot or cold, we can actually feel the rate that an object drains heat from us (the rate of heating and conductance). \n\nFor instance metal feels colder than a plastic at the same temperature or much hotter depending on the head differential between the substrate and your hand. This is also the reason why staying in water that feels warm can lead to hypothermia, you lose heat up to 32x faster. Again this depends on the difference in temp between you and the water."
]
}
|
[] |
[] |
[
[]
] |
|
2letje
|
if i use my credit card for all my monthly expenses and then pay my balance in full, why would my cc company value me as a customer if they don't make any interest off me and i just rack up free points?
|
I missed a payment on my CC (oops) and I called them up to see if I could get it waived. Except for this month, I've always paid my balance on time and in full. I also used the card to pay about $12k in 6 months.
If they never make any money off me in interest and I get money from them in cash back points, why would they waive the late fee (i.e. the only money they really got from me) and why would I be a valued customer?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2letje/eli5_if_i_use_my_credit_card_for_all_my_monthly/
|
{
"a_id": [
"clu3iwa",
"clu3j6l",
"clu49bo",
"clu4cxf",
"clu57k2",
"clu5hr9",
"clu5nnc",
"clu62dw",
"clu6gs2",
"clu6uau",
"clu76n6",
"clu8d5y",
"clubmxt",
"clucm0h",
"clucw4b",
"cluczwb",
"clud4ch",
"clulil9",
"clum46b"
],
"score": [
127,
9,
6,
2,
8,
2,
8,
2,
2,
85,
3,
5,
3,
2,
2,
2,
3,
2,
22
],
"text": [
"Everytime you use your credit card, the merchant (store, person, whoever) has to pay a fee. Generally, it's around 1.5%.",
"The credit card company still charges the store for the transaction processing, so they still get something.",
"Plus, for many people, it just takes a small financial downturn and you can't pay the whole thing off. Even a small balance month-to-month makes them some juicy interest.",
"The hundreds of thousands of people with maxed out cards make up any shortfall I would imagine...\n\n",
"As said by others, every time you use your credit card the credit card company charges a percentage of the transaction amount to the merchant (company you're paying). As an interesting side note, one reason that sometimes companies will only take visa/mastercard and won't take amex and/or discover is that amex and discover charge higher percentages than visa/mastercard. Discover charges the highest. They are able to give you points/cashback/miles/whatever because they make the money off of those fees.",
"Amex charges up to 5% to the merchants. My boss used to refuse discounts to anyone paying with Amex. ",
"The banks actually appreciate people that pay on time for multiple reasons. First, people that are in financial difficulties can default, and their accounts charge off as a loss. That's not a good thing, which is why a bank's collections department will try and work with customers to set up a payment plan- or a settlement- prior to a charge off. Secondly, the bank makes money off the merchant for each charge via processing fees. That's why, besides fees, rewards cards can actually exist. So, yes, the banks do appreciate a good customer. Most are going to look past a one time late and waive a fee.\n\nOne thing I would do is remember not to let a card go 6 or more months without use. A lot of banks will shut down an account after 6 to 12 months of inactivity. At that point, the closure is automatic and it doesn't matter how good of a customer you've been in the past.",
"Because there's a good chance that at some point in your life you'll be temporarily unemployed...and hey they've got your back right? There's also a decent chance it might take a while to find work again. That's cool though, you've got $20k credit because you've been a customer of theirs for a while.\n\nJust got a job? Cool, we'll keep your payments low so you can get back on your feet again...don't worry about the fact that we've set it up so that it'll take you 80 years to pay off that loan, and that $20k will end up being a million.",
"Because people are irrational and make stupid decisions all the time",
"Banks make money off credit card holders who aren't incurring finance charges. Here are just a few ways...\n\n- Transaction fees charged to merchants for purchases you make\n- \"Sharing\" (selling) your data with their \"partners\" (companies who buy the data). Read the privacy policy, I'd bet it allows this.\n- Cross-selling other products... have they tried to get you to open a checking account? Fed you an ad for a home or car loan? Many do this.\n- Ever gotten a \"bonus\" on certain spending? Like double points for shopping at Best Buy, etc. The merchant is paying your bank for that bonus. AmEx's offers area falls under this category, too... all those coupons are paid placement.\n\nIt's also worth keeping you around in case you do incur fees/interest later.\n\nAnd ultimately, it's a numbers game... for every customer like you, there's a guy they'll make four figures a year in interest off of. No sense throwing out the baby with the bath water.",
"I'm confused by the other responses because there's something that nobody addressed: the bank who issues you credit vs. the credit card company. For the big four, Visa and MasterCard usually partner with banks and other lenders where the latter gives the customer a line of credit. Here, Visa and MasterCard act as the party who handle the transaction but the banks/lenders are the ones who give the customer a line of credit.\n\nTo my knowledge, when you use your credit card, Visa/MasterCard get the transaction fee, not the bank/lender. The bank/lender makes money off of the interests of the late payments.",
"Well if you do a lot of transactions, they get a cut of that from the interchange fees, which adds up.",
"Banker here.\n\nThe issuing bank gets a flat fee per credit card sold, right around $2 at time of purchase. Even of you pay it in full thus avoiding the interest VISA/MC is going to get paid by the merchant. This is called interchange and is usually a percentage of the purchase or a flat fee depending on their plan.\n\nAs usual the business will bear the brunt of the fees. This is why they charge a fee sometimes if it is under a certain amount to offset that cost.",
"It's hidden. Remember, if you get anything for free you're the product.\n\n1. As others have said, they get a cut of each transaction. This is often not visible for you since many businesses will simply roll it into the price of the product/service.\n2. They get a LOT of data on your spending habits. Data mined from this is very valuable to some companies. This spans from general market trends to your own spending habits.\n\nThey do make a ton of money off of interest from those that don't pay on time. But they're not terribly bothered by it if you keep paying consistently.",
"Technical term for a person who pay off his entire balance every month is: transactor.",
"This is how they get you. Nearly everyone starts off with this mentality. Stay responsible.",
"They also make money off the businesses you do business with. The high interest rates are just gravy.",
"In the industry, apparently they call people who pay on time \"deadbeats\" as they incur no fees or revenue for the businesses.\n\nRobert Hammer, an industry consultant, said the legislation might have the broad effect of encouraging card issuers to become ever more reliant on fees from marginal customers as well as creditworthy cardholders — “deadbeats” in industry parlance, because they generate scant fee revenue.\n\n_URL_0_",
"I have worked in the credit card industry for many years.\n\nBanks love cardholders who pay off their balance every month. They are a very important part of the credit card ecosystem.\n\n1) Yes, they make more money from people who carry a balance and pay interest, but those people are a credit risk. Remember that all the debt on a credit card is \"unsecured,\" that is, there are no assets the bank can repossess if you can't pay them back, and therefore extremely high risk.\n\nBanks DO NOT want you to be in debt forever. The risk that you'll default is too high. They would rather you carry some balance, but act responsibly and pay them back over time.\n\n2) The bank's outstanding loans are judged (from a Wall Street sense) based on its cardholders average FICO score (credit score). If you carry a your card's max balance and pay only the minimum, your FICO score goes down. If everyone carried a huge balance and had a low FICO score, the bank's credit card assets would be worth very little, because to an outside investor, it would look like a huge risk that people will default en masse if the economy turns south.\n\n3) Issuing banks make money from each transaction. People who pay off their balances each month oftentimes spend more than a person carrying a balance, so the fees are greater.\n\nLet's take a $100 purchase example. You pay $100 for something at a store. The store has to pay on average a 2.5% fee ($2.50) to its bank for accepting your credit card. The merchant's bank gets to keep about 25 cents for its service. The merchant's bank then passes the transaction to Visa, who figures out which bank you use, and sends the transaction to them. Visa takes another 25 cents for its service. Your bank processes the transaction, and sends the merchant's bank its $98.00, keeping the remaining $2.00 for itself. With that $2.00, it gives you 1% cash back ($1.00), and pockets the leftover $1.00 for itself.\n\nIf you spend $20,000 per year on your credit card and pay it all back each month, your bank makes $200 in profit from you. Multiply that by a few million cardholders, and you've got yourself a business.\n\n4) If you still don't believe that a bank likes people who pay back their balance each month, consider how cards are marketed. Some cards offer 0% balance transfers and low teaser interest rates. These cards are for people who carry a balance. Other cards feature big rewards points, or additional points for spend at common locations, like supermarkets and gas stations. These cards are more for people who will be paying off each month, and therefore the point is to try to entice people to spend more on that particular card. This concept is called \"share of wallet\" - if you're paying off each month, the bank's primary goal is to get you to use their card for all your purchases, in order to generate that 1% profit from your spend.\n\nObviously a significant amount of marketing thought goes into cards for both people who carry a balance, and those who don't. Both are profitable, and in fact banks absolutely need both to maintain a financially healthy portfolio of cardholders."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[
"http://www.nytimes.com/2009/05/19/business/19credit.html?_r=0"
],
[]
] |
|
4qntmw
|
what is the ideology of the larouche movement?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4qntmw/eli5_what_is_the_ideology_of_the_larouche_movement/
|
{
"a_id": [
"d4ukw41"
],
"score": [
3
],
"text": [
"Oof. That's a lot to bite off. I've got a bunch of family that's been all up in their business for ages, so I'll do my best.\n\nBasically their central idea is that intellectuals should run the government, and we should just accept that they know what's best.\n\nEconomic themes are a huge part of their cult (er... political party?). Our lack of manufacturing is going to lead to a lasting depression. Any day know the economy will collapse because we don't actually make things. \n\nThey love their conspiracy theories too. The UK Monarchs have been behind every major assassination in American history. \n\nThey do really love arts and science. They love fission. We'd totally all be driving fission powered cars were Big Oil not so powerful. \n\nI do appreciate their love of art and music though. They love Schopenhauer, who's pretty meh to me, but as long as it's older than say late 1800s they're good with it.\n\nObviously I've got a bit of bias here. I grew up around these guys a lot, and watched as too many sacrificed too much (shoot, my uncle went to jail for them...). Lots of really well meaning people, but IMO they lack respect for individual freedom, and of course are way too quick to buy into crazy conspiracy theories. Lyndon himself is a good speaker, and very charismatic. Plus I do very much believe his intentions are honestly good, which itself seems notable.\n\nThey have a monthly magazine they publish if you're interested. It does always include some good non-political writing, so there's that.\n\nI know this is super rambly and vague. You may get a better answer from someone who hasn't lived through it."
]
}
|
[] |
[] |
[
[]
] |
||
qinrv
|
Why is sugar so rewarding?
|
askscience
|
http://www.reddit.com/r/askscience/comments/qinrv/why_is_sugar_so_rewarding/
|
{
"a_id": [
"c3xwfnl",
"c3xz3f2",
"c3xzisa"
],
"score": [
7,
3,
2
],
"text": [
"[Not an evolutionary biologist/psychologist, and this is an evolutionary just-so story, but one which is pretty transparently true]\n\nSugar is a very dense concentration of calories. Energy was hard to come by in the ancestral environment, so we evolved to favour foods with more calories.\n\nThe person with a sweet tooth goes out of their way to get sweet things, even if that means some difficulty (like dealing with bees to get at honey). If you didn't care about sweet things you wouldn't go to that effort, and so you'd miss out on a source of a lot of calories. Generally, given a choice between two foods, one sweet and one not, the sweet one has more calories and is thus more valuable to eat. So the people who like sweet things had better survival chances and had more surviving children, and passed on their genes.\n\nBecause sugar was pretty rare in the ancestral environment, we don't really have any adaptations to deal with a world where sugar can be accessed cheaply in basically unlimited amounts. The same is true of fat and salt. These are nutritionally extremely valuable in small to moderate amounts, and for most of history only small to moderate amounts have ever been available, so we never evolved much of an impulse to dial back. In the ancestral environment, if you find a big pile of fat and sugar you eat as much as you possibly can, because it's only going to go off and you probably won't see a source of calories like that for a long long time, so you stock up. You eat as much as you can, and your body stores the excess in body fat, to keep you going in the harder times which are probably coming. We still have those adaptations, so we seek out sugar and find it rewarding. We have changed the world faster than we are evolving to adapt to it.",
"Can someone answer this question on a biochemical level, i.e. 'How does sweet stuff on the tongue register as rewarding in the brain?'\n",
"In general, highly palatable foods (high in fat and/or sugar) trigger the release of dopamine from the ventral tegmental area, which projects to the nucleus accumbens and to a lesser extent, the prefrontal cortex. This is collectively known at the mesocorticolimbic pathway, and is activated by many natural rewards. Furthermore, there is evidence that sugars activate opioid receptors. These mechanisms are reviewed [here](_URL_0_)."
]
}
|
[] |
[] |
[
[],
[],
[
"http://onlinelibrary.wiley.com/doi/10.1301/nr.2003.may.S5-S9/pdf"
]
] |
||
1eabtv
|
what someone should know about a getting and having a mortgage.
|
I'm in the process of buying a house and I really honestly don't understand a lot of the terminology. Like what the hell is Escrow? How is the interest calculated? What in Gods name are points and why should I buy them?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1eabtv/eli5_what_someone_should_know_about_a_getting_and/
|
{
"a_id": [
"c9ybo6j",
"c9ybp3r",
"c9yfdy0"
],
"score": [
2,
2,
2
],
"text": [
"* Escrow - A bank account jointly held by two parties, that can only be accessed if both agree. It is kind of like a deposit. You use it show you are able to prepay taxes, insurance and other thrid party costs, without handing that money over to the lender.\n* Interest - It is usually calculated on a monthly basis...if you have a 4% rate, the amount you owe will increase by 0.33% each month. You payments are calculated so they pay off all of the interest and some of the principal each month.\n* Point - You can pay extra to reduce the interest rate...each percent reduction is a \"point\". It really only makes sense if you plan on keeping the home and not refinancing for the entire duration of the loan.",
"Escrow is money held on your behalf to pay a third party. For a mortgage, that's typically property taxes: the bank wants to make sure the taxes get paid because if they don't, the county will put a lien on the property. The bank collects property taxes monthly as part of the payment, and then sends that payment to the county.\n\nInterest is typically calculated monthly, so it's 1/12 of the quoted rate (some mortgages use 'simple interest', which is calculated daily). There will also be an \"APR\" which is the *effective* interest rate, taking into fees (like points). There are many 'mortgage calculators' online that will show you the amortization schedule - how much money is going to interest and principle each month, and the resulting loan balance, for the life of the loan.\n\nPoints is really just an up-front fee that you pay. It's called points because it's a percentage of the loan value, so '1 point' means you pay a fee of 1% of the mortgage value. This is a cash payment at closing. The more points you pay (the higher the fee), the lower interest rate you should get. Banks like points because mortgages are often paid off early, and the points are a way to ensure the loan is profitable. \n\nThe way interest works is, you pay 1/12 of the annual rate on the remaining loan balance. Day one, that's the full amount you are borrowing, so the interest payment is very high. As a result, there's not much money left to pay down principle, so the loan balance goes down very slowly. As a result, a 30-year mortgage will eventually cost about double the amount you borrowed. You can save a lot of money in the long run by getting a 15-year mortgage, but the monthly payments will be much higher for the same loan value. That's because you still have to make the same interest payment (a bit less, because you'll get a better rate), but you also need to pay down principle faster.\n\nMake sure there's no prepayment penalty (very rarely is, but you need to be careful), and be aware that a low down payment will require PMI. That's mortgage insurance *for the bank*, to pay them if you don't. You pay the premiums for PMI and it's expensive and does nothing for you. Try to negotiate a loan that does not require PMI. You'll also be required to have homeowners insurance at all times. ",
"Are you keeping the house for 5 or more years? If yes GET A FIXED RATE!!!!! If not then get whatever but I still recommend a fixed rate. Also FHA has changed it's rules. It will no longer Allow you to drop the principal mortgage insurance once you have reached 5 years into your loan and have a loan to value of 80% or less. Basically what that means is they are charging you for all the people that default and now even after you prove yourself worthy you still have to pay for other people's mess. Try and get a conventional loan and out down 20% if possible. "
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
9r0c4h
|
how is 'explosive mail' detected but the person not harmed?
|
The recent news about Obama and Clinton having explosive mail intercepted makes me wonder how it's possible (I know they have a staff to deal with this) to do this. More importantly, what do they do in order to not trigger the device and hurt themselves?
I'm assuming for risks just as with a harmful substance (like anthrax) there is a scanner for explosive materials. But I'm sure it's more involved because now there's a device added to the mix.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9r0c4h/eli5_how_is_explosive_mail_detected_but_the/
|
{
"a_id": [
"e8d1tew",
"e8d2oky",
"e8d90uv"
],
"score": [
29,
57,
8
],
"text": [
"Hillary Clinton 's and Obama's mail is screened, by actual people, before ever being delivered. This is why Soros 's mailbomb was found in his mail but Clinton's was found by screening personel, under the authority of the federal government. Because there are literally people who's job it is is to examine every piece of mail these federally important / formerly federally important people would recieve, beyond normal mail system sorting and detection.",
"Plenty of ways to screen mail without opening it. Most high explosives are organic chemicals with nitrate groups, they can be detected by sniffer devices and dogs. Metal detectors and x-ray shows timers, wiring etc. There are other techniques like neutron activation that can tell the chemical type or the suspected explosive.\n\nNowadays, many manufacturers add tag chemicals to explosives to make them more detectable. Semtex and other explosives often has small amounts of dimetnyldinitrobutane added, dogs are very sensitive to this.\n\n_URL_0_",
"Most explosive devices are not defused like on TV/movies. Bomb squad uses robots and portable xray or backscatter machines, evaluates the bomb trigger if it's safe to move, moves it into a sealed pressure tank and intentionally detonates it. If not safe to move, they move people out of area, then remotely detonate it."
]
}
|
[] |
[] |
[
[],
[
"https://en.m.wikipedia.org/wiki/DMDNB"
],
[]
] |
|
htyqw
|
Is it possible that there are areas of the universe we could be unaware of and unable to see due to light not being able to reach them?
|
This is hypothetical, obviously, as we would never know, but is it possible for light to bot be able to reach areas, or would it travel all the way through the universe?
Edit: Yes, black holes, but I left those out because light obviously does reach them, but it sucked into them. But yes, that is also a valid point. I was not aware of the area behind the black hole, however.
|
askscience
|
http://www.reddit.com/r/askscience/comments/htyqw/is_it_possible_that_there_are_areas_of_the/
|
{
"a_id": [
"c1yceq0",
"c1ychg7"
],
"score": [
15,
26
],
"text": [
"Nothing from inside the event horizon of a black hole can reach us.",
"It's not just possible, but certain. There has been only a finite amount of time since the Big Bang, and light could only have travelled a finite distance since then. The furthest distance we can see is called our particle horizon. Since the Universe looks the same in all directions, and we're pretty confident we're not directly in the center of it with the size exactly equal to the particle horizon (it would be quite a coincidence!) we can be sure that there's more Universe beyond our particle horizon, and probably lots of it.\n\nThere's also the matter of a cosmological event horizon - the farthest distance light can ever travel into the future. As it turns out, our Universe also likely has one of those. Not only are there some places that haven't had time to let us know they exist, there are also places which never will have the time!\n\nInteresting side note: the expansion of the Universe is believed to have been dominated by matter for a long time, and recently dominated by this mysterious \"dark energy.\" During matter domination, the expansion is decelerating, but then during dark energy domination it accelerates. The funny thing is that in a purely matter (or radiation) dominated universe, there's a particle horizon but no event horizon - wait long enough and we'll see the light from a galaxy at any distance - while in a purely dark energy dominated universe, there's no particle horizon (since there's no Big Bang), but there is an event horizon. Since our Universe is a combination of both, it just so happens we get both kinds of horizons!"
]
}
|
[] |
[] |
[
[],
[]
] |
|
6k2gr2
|
when a person loses memory, what exactly do they forget?
|
I mean if they have amnesia, do they forget about the things they've learned at schools like basic math stuff and all? For example, a person can't remember even their parents but can remember a book they read once.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6k2gr2/eli5_when_a_person_loses_memory_what_exactly_do/
|
{
"a_id": [
"djit0k6",
"djj4b0a"
],
"score": [
4,
2
],
"text": [
"Human memory is a very complex system, and we actually don't fully understand it. Truth be told, we barely understand it at all.\n\nHowever, there are different kinds of memories. Things like language, math and other learned skills are stored differently than memories like when you ate a hot dog last Memorial Day. Memories are stored in ways we're still sorting out, but it's believed that when you remember something you're not actually remembering it- you're remembering the last time you remembered it. The actual underlying mechanisms are still a subject of much research.\n\nWhen someone has amnesia the cause is important to consider; was it physical damage or some kind of mental disorder? In the case of the former, it might be that the brain simply cannot activate the proper equipment (so to speak) to fetch memories that may still exist- like a computer unable to access its hard drive, even if it's still functional.\n\nIn the case of the latter, it's more likely that for some reason the person's mental processes are short-circuiting the attempt for any of a number of reasons.\n\nAmnesia is also not typically what you see in movies- it's not like a total blank slate before waking up, at least in almost all cases. It's more common for certain memories within a time frame to be unavailable, or for the person to have problems with specific things like remembering what they see instead of what they hear, etc.\n",
"There are two primary types of amnesia, retrograde and anterograde. A retrograde patient is someone who has lost all memory. An anterograde patient is someone who has all memories in tact, but cannot form new ones. \n \nA classic case is Patient HM, who had undergone brain surgery to cure his seizures. He had suffered severe damage to his hippocampus, which is the major brain component responsible for memory. After the surgery, he developed severe anterograde and limited retrograde amnesia. He could remember certain parts of his life, but not others. Most critically, however, was his complete inability to form new memories. Indeed, this meant that patient HM would wake up every morning, in the hospital, unaware of his own situation. As the years went by, this also meant that the news of his loved ones passing would be a daily, novel ritual. \n \nTo answer your question more directly, patient HM was used as a case study for experimentation. One thing they did was test whether or not they could teach him how to play the piano. Although he claimed that he had no recollection of ever playing, he eventually learned how to play with competence. As he was instructed to play, his ability surprised him. \n \nHM was instrumental in the development of neurological memory theories. The discoveries contributed to many ideas, such as memory being separately localized and distributed as long-term episodic, procedural, short-term and motor skill. Additionally, distinctions were made regarding encoding and retrieval. In this example, his encoding was severely impaired, while his retrieval was less so. \n \nIn conclusion, memory is very complicated, and indeed, a person may forget their parents name, but have little issue performing math tasks, as these two tasks are most likely separately localized."
]
}
|
[] |
[] |
[
[],
[]
] |
|
2266l5
|
Did any country in the Americas ever consider joining the USA?
|
Other than Texas.
I was reading some blog a while back that collected speculations about the future made in the past and it seems like a lot of early 1900's speculators seemed to think that various countries in North America would seek to join the United States over the course of the proceeding decades.
But that obviously didn't happen. Was it ever actually even seriously considered in public discourse in any independent American country?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2266l5/did_any_country_in_the_americas_ever_consider/
|
{
"a_id": [
"cgjrrn9",
"cgjsmwa",
"cgjwg7k",
"cgjxwum"
],
"score": [
18,
29,
5,
2
],
"text": [
"Are you looking for countries that could have been annexed, or countries interested in joining the United States willingly?\n\nFor the former, *The Dominican Republic and the United States:\nFrom Imperialism to Transnationalism* discusses how the United States considered annexing the Dominican Republic in the years after the U.S. Civil War but decided against it for fear of causing instability in the region. \n\nMost countries in Latin America and the Caribbean have been considered for annexation at some point, through means as varied as William Walker's filibustering expeditions and the Spanish-American War.\n\nFor the latter, consider the short-lived Republic of Yucatan, which maintained a tenuous independence from Mexico in the first half of the 19th century. Someone better-informed than I can explain the history of that republic. \n\nIn 1847 and 1848, representatives from the Republic visited Washington, D.C. to request assistance in a nasty three-cornered civil war within the Republic. After their initial requests went unanswered, in desperation, they asked the United States to annex the Republic. \n\nThe U.S. House of Representatives approved a measure granting President James K. Polk permission to take control of the country, but the measure died in the Senate. \n\nThe debates regarding the issue can be found starting on Page 728 of the 30th Congress, 1st session of the Congressional Globe.\n\n",
"Not the USA, but the CSA. The governor of Nuevo Leon and Coahuila, Santiago Vidaurri, asked the Confederacy to annex his northern Mexican state. He was incredibly powerful in northern Mexico, and likely could have also delivered Tamaulipas, Chihuahua and Durango as well. Northern Mexico was more connected economically to Texas than the rest of Mexico, and Vidaurri was wary of Benito Juarez attempting to reduce his near total control of the north.\n\nJefferson Davis turned down the offer as it would have cut off a potential route to export cotton (through Matamoros), leaving it open to union blockade. Also it would piss off the French, preventing a potential European recognition the Confederacy desperately wanted, as Napoleon III was openly preparing to intervene.\n\n[A good NYTimes article about the offer.](_URL_0_)",
"As /r/rumsodomy points out, there was some sentiment for formal secession in northern Mexico, which was never very fond of Mexico City. There were a number of filibusters and rebellions in the region before the U.S. Civil War: the most notable attempted to set up independent republics. The [Republic of the Sierra Madre](_URL_0_) and the [Republic of the Rio Grande](_URL_1_) both failed, but had they managed to gain traction it's possible they could have been annexed to the United States. \n\nThere was a very active annexation movement in Newfoundland in the late 40s, before the referendum that made it a Canadian province. \n\nThe U.S. government made quiet overtures to Denmark in 1946, offering to [buy Greenland](_URL_2_), unsuccessfully. \n\n",
"As someone mentioned in the thread, the Dominican Republic petitioned to join the USA, but the motion died in the Senate. By a single vote, if I remember correctly. \n\nThere was also brief discussion of Newfoundland joining the USA rather than Canada, but I don't think it was taken very seriously. "
]
}
|
[] |
[] |
[
[],
[
"http://opinionator.blogs.nytimes.com/2011/09/01/the-confederate-of-the-sierra-madre/?_php=true&_type=blogs&_r=0"
],
[
"http://www.tshaonline.org/handbook/online/articles/fvi24",
"http://www.tshaonline.org/handbook/online/articles/ngr01",
"http://news.google.com/newspapers?nid=1345&dat=19910502&id=cVlYAAAAIBAJ&sjid=APoDAAAAIBAJ&pg=4674,194417"
],
[]
] |
|
132pc9
|
Why are there bumps when you bring a magnet near ferrofluid? What causes the bumps, and what determines the number and size of them? Why isn't it a sphere?
|
askscience
|
http://www.reddit.com/r/askscience/comments/132pc9/why_are_there_bumps_when_you_bring_a_magnet_near/
|
{
"a_id": [
"c70ik93"
],
"score": [
6
],
"text": [
"Really fascinating question - I've never really thought about it and once I did I didn't have an immediate answer. \n\nI did some research and found the following on wikipedia:\n\nNormal-field instability\nWhen a paramagnetic fluid is subjected to a strong vertical magnetic field, the surface forms a regular pattern of peaks and valleys. This effect is known as the normal-field instability. The instability is driven by the magnetic field; it can be explained by considering which shape of the fluid minimizes the total energy of the system.\n\nFrom the point of view of magnetic energy, peaks and valleys are energetically favorable. In the corrugated configuration, the magnetic field is concentrated in the peaks; since the fluid is more easily magnetized than the air, this lowers the magnetic energy. In consequence the spikes of fluid ride the field lines out into space until there is a balance of the forces involved.\n\nAt the same time the formation of peaks and valleys is resisted by gravity and surface tension. It costs energy to move fluid out of the valleys and up into the spikes, and it costs energy to increase the surface area of the fluid. In summary, the formation of the corrugations increases the surface free energy and the gravitational energy of the liquid, but reduces the magnetic energy. The corrugations will only form above a critical magnetic field strength, when the reduction in magnetic energy outweighs the increase in surface and gravitation energy terms.\n\n_URL_0_\n\nThe paper they reference can be found here (you may need to be at an institution to access it)\n\n_URL_1_"
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Ferrofluid#Normal-field_instability",
"http://pubs.acs.org/doi/pdf/10.1021/jp807770n"
]
] |
||
26vzpl
|
why you shouldn't put sharp knives in the dishwasher.
|
It's just water and soap right? What's different about it than washing them by hand?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/26vzpl/eli5_why_you_shouldnt_put_sharp_knives_in_the/
|
{
"a_id": [
"chuzgu4",
"chuznu2",
"chv0kpb",
"chv2s7s",
"chv8jpn"
],
"score": [
3,
2,
4,
4,
3
],
"text": [
"I believe it's more to do with the fact that in a dishwasher the knife can be pushed around by the water jets and shoved into shelves and other cutlery, possibly dulling it or damaging it.",
"My knives came with this badass warning: \"These knives will not be hurt by washing them in your dishwasher, but they are so sharp that they may damage your dishwasher.\"",
"I think that this warning is more geared toward higher quality knives. Such knives generally have a high concentration of carbon steel, which has a greater tendency to rust. A dishwasher will leave water on such knives long enough for them to start forming rust spots.",
"Dishwasher detergent isn't just soap and water.\n\nIn addition to detergent, the high heat, high humidity and prolonged exposure means rust and depredation on steel edge. Hand washed knife is only exposed to water for a couple of seconds. Not an hour",
"I had wondered this as well and learned recently that its because dishwasher 'soap' contains chemical abrasives and stronger chemicals in order to have water jets work as well as a scrubbie. So you're basically microscopically sandblasting them into dullness and hurting the handles."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[]
] |
|
2dcb5i
|
Do plant's roots steal from other plant's roots?
|
I have what I think are some Coleus, and Hedera helix plants. The Coleus plant is entirely pinkish red, the Hedera helix has small green leaves with pale yellow edges around. These are their colours when they are planted far from each other. I have a few close to each other and the Hedera helix developed leaves that are stained pink on the otherwise pale yellow edges. Are they stealing from the Coleus plant? Is this a common occurrence with other plants?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2dcb5i/do_plants_roots_steal_from_other_plants_roots/
|
{
"a_id": [
"cjoh8a9"
],
"score": [
3
],
"text": [
"As a rule, no. Plant roots from different species do not interact in the soil. Sometimes roots from the same species (or rarely, closely related species) might grow together and start sharing sugars and maybe some hormones. This is called [inosculation](_URL_0_), and cab be relatively commonly seen in above-ground tissues, especially in the same individual. But for the most part root-root intergrowth between individuals doesn't happen, and I've never heard of it happening in annuals like Coleus. Also, there are studies showing that roots can differentiate between roots from the same individual and those of others and don't grow into each other [[1]](_URL_1_). \n\nThat said, I saw a talk a couple of years ago from a lab out of Montreal were tree roots from different species were in fact growing together when they excavated the entire root system. That's a pretty deal if it ends up being true/ common."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Inosculation",
"http://www.pnas.org/content/101/11/3863.short"
]
] |
|
g1wduh
|
Why did the early European colonisers never set up feudal systems in their new colonies? Why were there no Dukes or Counts in the New World?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/g1wduh/why_did_the_early_european_colonisers_never_set/
|
{
"a_id": [
"fnk30iw"
],
"score": [
16
],
"text": [
"In the Spanish America there was a feudal system, and there were titles of nobility. Hernán Cortés was created Marquess of the Valley of Oaxaca, lording over 20,000 vassals, the Moctezumas were given the lordship of Tacuba, Francisco Pizarro was granted a marquisal title too, Columbus was marquess of Jamaica, and these are not the only cases. There is a whole \"Nobiliario de Indias\" were you can see the families that were granted arms and titles in America. \n\nComparatively, though, the titles of nobility were way fewer in number, but in quality they could be far superior to those in the Old World. I mentioned above that Cortés was lord over 20,000 vassals, which was a lot, especially for a noble of new creation. Gonzalo Fernández de Oviedo, in his \"Batallas y Quinquágenas\", comments on the wealth and number of vassals of many noble houses in 1550: the most prominent one was the Duke of Infantado with a yearly income of 60,000 ducats, and lording over 30,000 vassals. Oviedo also notes on a different dialogue of the same book that 5,000 ducats would be the income of a good nobiliary house in Aragon or Castille. The admiral of Valencia, marquess of Guadalest, had an income of 13,000 ducats, which ranked him amongst the richest aristocrats of the Crown of Aragon, being outclassed only by the Duke of Cardona, who in his fief had a monstruously large salt mine, with salt of the finest quality. \n \nHowever, the grant of nobility titles was not nearly close to what it had been in the XIV and XV century in Castille, when an unreasonable percentage of the Crown's estate had been given away to pay for military assistance in the civil wars. A particularly generous monarch was Henry II, known as \"of the mercies\", for he granted many titles to the nobles that had helped him overthrow his brother. These many mercies took a massive toll on the Crown's income and yearly budget, and the Catholic Monarchs knew it. Their successor Charles V knew that as well, hence the comparatively few nobility titles. \n\nEdit: I'll add here a link to the [Nobiliario de Conquistadores de Indias](_URL_0_)"
]
}
|
[] |
[] |
[
[
"http://bdh-rd.bne.es/viewer.vm?id=0000115053&page=1"
]
] |
||
1n5tth
|
how is beef jerky safe to eat?
|
Please explain how drying food preserves it.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1n5tth/eli5how_is_beef_jerky_safe_to_eat/
|
{
"a_id": [
"ccfncyw"
],
"score": [
3
],
"text": [
"One of the cornerstones for life is water.\n\nWithout water there's very little oppertunity for life, which includes all the kinds that involve decomposition and rot, to take hold.\n\nAdding in large amounts of salt will add to this effect as salt likes to bond with water very much and too much salt in water is toxic for most living things."
]
}
|
[] |
[] |
[
[]
] |
|
3c8ac2
|
when shipwreck drivers/archaeologists find new shipwrecks, are they allowed to keep any treasure found?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/3c8ac2/eli5_when_shipwreck_driversarchaeologists_find/
|
{
"a_id": [
"cst53hu",
"cst59o4"
],
"score": [
2,
2
],
"text": [
"If they are found in international waters they are free to be taken if no one else has a claim to it wether it be a nation or a private/corporate intrest. When it is not the caseit depends on local laws and regulations",
"Depends\n\nEach country generally has their own laws but most (all that I am aware of but I'm sure there are some exceptions) are based on the International Convention of Salvage.\n\nIf no-one else has a claim to the salvage (rare) than they can keep what they find\n\nOtherwise they are entitled to a \"fair reward\" for their salvage efforts. Usually this is done by an agreement but they can apply to the relevant court (or the international court if it's in international waters) for a ruling.\n\n\nMore often than not though salvage crews / archaeologists are employed under a contract to find the shipwreck (usually by the owner of the ship or a government with a vested interest in the historical wreck) and the contract determines what their rights are \n\n_URL_0_"
]
}
|
[] |
[] |
[
[],
[
"https://en.wikipedia.org/wiki/Law_of_salvage"
]
] |
||
2r6vpn
|
how is it legal for businesses to offer discounts to women and not men solely because of their sex?
|
I ask this in response to getting my car wash and noticing that women get 10% off on Ladies Day (every Tuesday). [Image](_URL_0_)
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2r6vpn/eli5_how_is_it_legal_for_businesses_to_offer/
|
{
"a_id": [
"cnd0gxd"
],
"score": [
3
],
"text": [
"It is illegal in some states. In California car washes have ladies and men's days"
]
}
|
[] |
[
"http://i.imgur.com/heLQokl.jpg?1"
] |
[
[]
] |
|
8cpu71
|
why does the milk poured into coffee or tea not spoil if left out/not consumed over many hours, while a glass of milk or cream left out would go bad?
|
I poured a (large)cup of coffee before leaving the house and only finished about half of it. When I returned over 12 hours later, the coffee with a significant amount of milk poured in was fine. If I had left milk out on the counter for that long (approx. 77° F/25° C room temperature) it would have spoilt. I've seen the same situation with milk or cream in tea.
Why is the milk okay in the coffee/tea but not by itself?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/8cpu71/eli5_why_does_the_milk_poured_into_coffee_or_tea/
|
{
"a_id": [
"dxgurmr",
"dxgvp3q"
],
"score": [
8,
2
],
"text": [
"Milk has a complex carbohydrate called lactose (this is the same thing that lactose-intolerant people can't digest/breakdown). Some bacteria can't go through aerobic respiration, i.d. taking in oxygen and glucose to make energy for your cells. So these bacteria go through anaerobic respiration which involves fermentation. The byproducts of anaerobic respiration are lactic acid and ethanol. \n\nSo hungry bacteria see that lactose, go through fermentation, create lactic acid, and turn the milk bitter and curdy. But to do all this, the bacteria need a nice pH balanced environment with adequate temperature. Coffee manages to destroy both of these conditions. Coffee is more acidic, so it lowers the pH, and it is usually hot. When you do this to the milk, the bacteria that was on the milk will either die or have its enzymes denatured so it can't ferment the lactose. Caffeine itself is seen as an anti-microbial (because of its acidity and some other stuff that I don't really know about), so this is why it also works with tea. \n\nSo next time you want to make sure your milk lasts a bit longer, either turn it to coffee or tea, or heat it up and cover it so no more nasty bacteria will feed on your hard earned lactose. ",
"Milk does not spoil if left out for a few hours. It doesn't taste great at room temperature, and it'll shorten the shelf life, but milk left out for a few hours is totally fine to drink. "
]
}
|
[] |
[] |
[
[],
[]
] |
|
6pf2s1
|
why can we not achieve efficient and relativity low energy flight the same as birds through the design of a similar winged style flying machine?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6pf2s1/eli5_why_can_we_not_achieve_efficient_and/
|
{
"a_id": [
"dkotipb",
"dkoumjv",
"dkp0vsq"
],
"score": [
4,
12,
5
],
"text": [
"The short answer is weight. Humans are immensely dense relative to birds, so it is not feasible to attach huge wings to us that can then move quick enough to generate and maintain lift.",
"Short answer is we do! We make gliders in a similar way to large marine birds but:\n\nWhen you say birds wings are efficient they are for a bird is doing but aircraft wings are more efficient for what an aircraft is doing and per kg.\n\nLook at an example of probably the best long distance most efficient birds going the Wandering Albatross and it's huge 3.5m wing span and weighing in at 12kg. It can travel 10'000 miles in a single trip and without flapping it's wings much if at all, truly amazing efficient bird! It does this at low altitude using dynamic soaring and averages a speed of..... 35mph.\n\nOk so that's great and really efficient but do you really want to spend 5 or 6 days to get from New York to London? You can sail it in that time!\n\nNow look at an aircraft say A350. It can fly 300+ people totalling about 120ton 10000km in about 11 hours. Cross the Atlantic in 8 hours.\n\nAn aircraft flies fast and high to gain efficiency if it tried to dynamic soar it wouldn't get very far or very quickly. We do make aircraft like that. Gliders. Very light with large broad wings to gain as much lift as possible. We don't make airliners like that as they wouldn't gain from it. \n\nEdit spelling",
"The [square-cube law](_URL_0_) strikes again, the answer to pretty much any question about why we can't do something that tiny animals can.\n\nSpecifically, if you simply scale up the body plan of a bird, it stops working, because at twice the size, its wings will create four times as much lift - but it will weigh *eight times* as much, so its weight-to-lift ratio is actually only half as much. And the same goes for the strength of the bones. \n\nThe only we we can make big flying engines at all is by using far stronger materials and far more powerful sources of energy than nature does."
]
}
|
[] |
[] |
[
[],
[],
[
"https://en.m.wikipedia.org/wiki/Square%E2%80%93cube_law"
]
] |
||
1xnvwa
|
why do we have to sign things? what gives cursive handwriting more authority than just print?
|
Some forms even require that you sign your name and then print your name. It just seems so trivial.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1xnvwa/why_do_we_have_to_sign_things_what_gives_cursive/
|
{
"a_id": [
"cfd1c22",
"cfd4lnw"
],
"score": [
2,
2
],
"text": [
"You can tell a lot from a signature. A flick of the letters and the presentation can show what kind of person you are. It's somewhat similar to the Rorschach test where the image can reflect upon your personality. \n\nAlso, most people cannot read cursive writing so they stick to block letters for legibility. And most people can forge a block letter signature when it's harder to forge a signature made of cursive elements.\n\nHope it helps :-) \n",
"Legally, contracts can only require you to 'affix your mark and seal' and that could be a simple X if you are illiterate. \n\nYour name is printed because your signature could be illegible, or it could just be a mark like an X if you can't write. You don't have to print the name yourself - it could be printed by your agent or guardian.\n\nYou do have to write the signature or make the mark yourself."
]
}
|
[] |
[] |
[
[],
[]
] |
|
41ml3s
|
if you are convicted of a crime and new evidence later surfaces in your favor, why are you allowed a new trial, while someone who was initially found not guilty can't be tried again if new evidence surfaces against them?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/41ml3s/eli5_if_you_are_convicted_of_a_crime_and_new/
|
{
"a_id": [
"cz3i9p9",
"cz3iift",
"cz3j4dt",
"cz3j9mu",
"cz3ty77"
],
"score": [
22,
14,
7,
2,
2
],
"text": [
"Because the justice system is more concerned with (and wants to avoid) punishing the innocent than it is with letting the guilty go free. ",
"They don't want someone innocent to be tried repeatedly until they're convicted. There's not much reason to worry about it the other way, since if the government *doesn't* want someone convicted, they can just not bother to press charges. Or they can pardon them.",
"If you are in the United States, you are protected from double-jeopardy in the Bill of Rights. This doesn't entirely protect a person from never being tried a second time, but the exceptions are few and far between.\n\nIt requires that the prosecutor be thorough and complete, and that if a reasonable body of evidence and information fails to convict you the first time, that you can not be charged twice for the same crime. It does not protect a suspect from being charged later after being initially cleared prior to a trial. The cases that result in a conviction after an initial \"not guilty\" charge are almost non-existent; if the prosecutor doesn't think they can convict, or that more evidence will come up later, they will usually delay pressing charges rather than botch the trial or may not press charges at all.\n\nIn other countries, the laws differ.",
"In the US we have a thing called \"double jeopardy\" which basically means that once you've been declared innocent of a crime in court you are free. This is because when we were a colony under the British, it wasn't uncommon for the British to keep arresting and prosecuting people for the same crime until they got the guilty verdict they wanted. So because of this the courts have to be vigilant and make sure they're making their best case on their first attempt. Otherwise someone could spend their whole lives repeatedly defending the same case, spending time in jail, spending money on lawyers etc. ",
"It's supposed to safeguard innocents from being tried over and over again with only slightly varying evidence. That said, if a substantial and compelling, entirely new body of evidence comes to light it's entirely possible that the person may then be convicted. A lot of this probably occurred with the advent of fingerprinting and then again with DNA analysis: all those murderers who had previously gotten away with crimes, convicted on the back of the new techniques."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[]
] |
||
7koo7j
|
What is the origin of the misconception that Vikings had horns on their helmets?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/7koo7j/what_is_the_origin_of_the_misconception_that/
|
{
"a_id": [
"drgg6bz",
"drggsa2"
],
"score": [
19,
52
],
"text": [
"I've researched this a bit out of my own curiosity, and it seems there's no academic study on the matter. As the whole 'viking' concept as it's known today is a product of 19th century romanticism, it's a good guess the helmet thing came out of that as well. Andrew Wawn's _The Vikings and the Victorians: Inventing the Old North in Nineteenth-century Britain_ is very detailed on the phenomenon in general, but not so much on the visual representations, and doesn't give an answer on the helmet matter. \n\nFrithiof's Saga by Tegnér was an important work in the whole viking-romanticism movement, both in Scandinavia and Britain. Now the first publications in Swedish (1820) and Stephens' translation to English (1839) didn't have illustrations, but later editions did. [Here's the 1876 Swedish edition](_URL_5_) which had many engravings with many helments, none of which are horned, though. (It does however feature massively anachronistic Bronze Age [lurs](_URL_2_), so one should not doubt their lack of commitment to historical accuracy) \n\nHowever the British reworking _The song of Frithiof_ by G. C. Allen (1890) had illustrations by T. H.Robinson that [prominently featured](_URL_6_) the now-'classic' viking horned-helmet, and seems to have been a quite popular book. Not long after that you have Dicksee's fairly well-known painting [The Funeral of a Viking](_URL_3_) from 1893, which also has horned helmets in it. By 1902 it seems to have reached America where [_Viking Tales_ by Jennie Hall](_URL_0_) is published featuring horned vikings.\n\nMeanwhile in Scandinavia though, Malmström's incomplete monumental painting of [the Battle of Bråvalla](_URL_4_) has no horned helmets, nor do they feature among the ornate helmets in Carl Larsson's [Midvinterblot](_URL_1_) from 1915. (but the lurs are there again) If there are any 19th century Scandinavian artists who depicted horned-helmeted vikings, I've failed to find them. (and I've looked quite a bit, this is just a selection) \n\nSo in short what I've arrived at was that the horned helmet more likely originated in British depictions than Scandinavian ones and no later than 1890. It makes sense really, since Britain's more culturally influential in general and their version of vikings was as well. (again, not to imply the version created by Scandinavian romantics was necessarily any more historically accurate)\n\nFinally, I've seen a lot of people give Wagner credit, but I've been unable to find any images of horned helmets in 19th century Wagnerian costumes. _Winged_ helmets a-plenty, but not horned ones.\n\nObviously it's impossible to go through all 19th century art, so if anyone's found any earlier examples you're welcome to help me out by posting them. ",
"Ok so, depictions of warriors with some sort of attachment on their helmets are pretty damn ubiquitous. Vikings and the fictitious horns are perhaps the most well known example. \n\nHowever as has now entered popular consciousness, the Vikings did not actually attach horns to their helmets.\n\nSo where did this representation come from? Medieval depictions of the Rus, Varangians, Vikings, and any other Scandinavia based group of raiders and conquerors are conspicuously missing them.\n\nArchaeological evidence clearly shows no evidence of horns in helmets from the Norse or other closely related groups such as the Anglo-Saxons. Though literary and archeological sources do show boar crests were certainly sported. Their prevalence in *Beowulf* is also fairly well known.\n\n_URL_1_\n\nI hope the mods will forgive me for the link to wikipedia, but its a pretty good picture....\n\nIt has been proposed that the empty slots in there were filled by horn sheets that have since decayed, which I suppose would make this a \"horn\" helmet, if not a horned helmet in the more traditional sense. \n\nIt is of note though, that despite the common cultural connections, this is not a Viking or Norse helmet, it is definitively Anglo-Saxon. \n\nSo if contemporary depictions do not depict the vikings with horns on their helmets, when does this particular trope start to become prevalent?\n\nAs in most things historically related, it is all the 19th century's fault. Specifically the confluence of opera, nationalism, and artistic license, as well as the conflation of continental history and Scandinavian.\n\nA quick googling of vikings and horns on their helmets will eventually point you in the direction of 19th century opera as the locale where this was entered popular imagination. One of the first results to pop up will lead you to the Economist's article, and the author that they are citing has this to say on the topic.\n\n > For it was not until 1875 that humanist scholarship, misunderstood archae-ological finds, heraldic origin fantasies, and the Great God Wish (whom JacobGrimm was first to name) had worked their magic. A small herd of \"viking\"helmets was now on the move, led by an innocent-looking cow-horn modelcreated that year by Wagner's costume designer, Professor Carl Emil Doepler,for the first Bayreuth production (1876) of the full Ring des Nibelungen. Putting cow-horns on\nNibelungenlied heads was a departure from tradition:until 1878 not a single illustrated version of that courtly south-German poem had depicted such headgear. Wagner's Ring commingled Old Norse and Middle High German motifs, creating an impression, which has endured, that valkyries and norns, Valhalla and the twilight of the gods, were timelessly German. When Doepler supplied Gunther's youthful retinue, Siegfried's funeral cortege, and Hunding himself with horned helmets, a piece of armour long attached to continental \"barbarians\" became part of this heady stew.\n\nThe article that I'm using can be found at _URL_0_, and the quotation I used is from the free trial, but the rest of the article is behind a paywall.\n"
]
}
|
[] |
[] |
[
[
"http://digital.library.upenn.edu/women/hall/viking/viking.html",
"https://upload.wikimedia.org/wikipedia/commons/c/c8/Carl_Larsson_-_Midwinter%27s_Sacrifice_-_Google_Art_Project.jpg",
"https://en.wikipedia.org/wiki/Lur",
"https://uploads3.wikiart.org/images/frank-dicksee/the-funeral-of-a-viking-1893.jpg",
"https://upload.wikimedia.org/wikipedia/commons/4/4e/August_Malmstr%C3%B6m-Br%C3%A5vallaslaget.JPG",
"https://upload.wikimedia.org/wikipedia/commons/6/6a/Fritiofs_saga_%281876%29%2C_titelillustration.png",
"https://images-na.ssl-images-amazon.com/images/I/51%2BfdJNHVRL._SX258_BO1,204,203,200_.jpg"
],
[
"https://www.scribd.com/doc/51267328/Frank-Invention-of-Horned-Helmet",
"https://upload.wikimedia.org/wikipedia/commons/thumb/1/16/Benty_grange_helm_crop.png/800px-Benty_grange_helm_crop.png"
]
] |
||
608hl8
|
equity, mortgages, owning, and selling a home.
|
I searched on this subreddit and I now understand that equity what the "house is worth minus what you owe on it." However I don't understand the advice older people keep giving me - buy a condo/townhouse when I can so that when I sell it again, I was technically living for free. I mean, it was an investment as opposed to throwing money away by renting. Does this advice make sense? Does this only work if the property value went up?
Say I buy a $250,000 home with $40,000 downpayment. Two years later I decide to sell and:
Home is now worth $200,000 - did I lose money? If so, how, since I haven't finished paying it off? Does that mean I owe $50,000 to the bank? What happens to the loan?
Or home is now worth $300,000 - do I get $50,000 that's all mine?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/608hl8/eli5_equity_mortgages_owning_and_selling_a_home/
|
{
"a_id": [
"df4dj57"
],
"score": [
6
],
"text": [
"Property usually increases in value, slowly, over time (a lot of mortgages are 15 or 30 years, that's the time period you're looking at). So you're paying your money to BUY an actual physical thing that will likely keep or increase its value over the years. It's like buying $250k worth of gold, it will likely keep or increase its value over the years.\n\nAs a bonus, you can also live inside the house. You can't live inside the gold, of course.\n\nRenting an apartment, you're paying money to be able to live inside it, and it's like paying giant bills. You're buying, and immediately consuming, a month of shelter at a time (a month of electricity, water, cable TV, etc. cost a lot less than the monthly rent), and after 30 years you'll have your health and your life, but no actual thing that you own or can sell.\n\nYou own the house the moment you sign the sale document that says you'll pay for it. \n\nIf you don't have $250k cash to pay immediately, you have to ask a bank for a loan, and the bank will pay $250k and you sign a contract that says you'll pay back the bank (and they want interest to make a profit, so all in all you'll pay back closer to $350k by the time you're done, 30 years later). \n\nYou're still the owner of the house, but if you don't pay back the bank, the bank can sue you and the judge will transfer ownership of the house from you to the bank.\n\nIf you want to sell the house, buyers will offer you, probably, $250k for it. Since you're the owner, you can decide to sell for that amount, but you must also immediately settle your loan balance with the bank; they'll probably want most of that $250k that you get from the buyer, minus the parts of the loan amount that you've paid already, to settle the balance. \n\nNote that paying back a loan, they put your checks towards the interest first, and only a small amount towards the actual loan amount (the principal), so it's quite possible to pay for several years, say $100k worth of checks, and still owe $200k out of the $250k principal.\n\nBut let's say that you wait your 30 years and sell the house after finishing the mortgage; in that case the buyers will probably still offer you $250k for it, and you paid the bank $350k for the loan, so you've lost $100k over 30 years. It's still better than paying $1000/month rent for 30 years (that's equivalent to \"you 'lose' $360k over 30 years\").\n\nBut if the neighborhood gets better or Trump builds a golf course right next to you, thereby increasing the value of the whole town, then your house may be worth $500k in 30 years, and you end up with a $150k profit when you sell it ($500k - $350k).\n\nSo, to sum it all up, the mortgage is the loan that you've taken to pay for the house. \n\nEquity is the amount that you'd be able to pocket if you sell the house (and settle what's remaining of the loan). Equity would be very small if you sell within 2 years, because the loan amount is still big. As the years pass, however, and the remaining loan gets smaller and smaller, equity increases, and it increases even more if the neighborhood gets better / more popular.\n\nYou're the owner.\n\nAnd selling the home means you must also settle what remains of your mortgage loan with the bank, immediately after the sale."
]
}
|
[] |
[] |
[
[]
] |
|
2tey9c
|
how did chopsticks get their name if they don't do any actual chopping?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2tey9c/eli5_how_did_chopsticks_get_their_name_if_they/
|
{
"a_id": [
"cnye90m",
"cnyeakb",
"cnyeft2"
],
"score": [
4,
10,
3
],
"text": [
"I believe it has something to do with the saying chop chop, as in quickly.",
"\"Chop\" in pidgin English used to mean \"quick\". In Chinese their term translates to \"nimble one\", and so \"chopsticks\" means \"quick sticks\".",
"Man, that was fast. Thanks guys!"
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
4qt5yo
|
Does rain cause a cold front or is it the result of a cold front?
|
askscience
|
https://www.reddit.com/r/askscience/comments/4qt5yo/does_rain_cause_a_cold_front_or_is_it_the_result/
|
{
"a_id": [
"d4wcon9"
],
"score": [
4
],
"text": [
"My understanding is that it is a symptom of a cold front meeting a warm front. If I had to classify it in a chicken or egg kind of way, I would say that the cold front comes first.\n\n_URL_0_\n\n_URL_1_"
]
}
|
[] |
[] |
[
[
"http://apollo.lsc.vsc.edu/classes/met130/notes/chapter11/graphics/cf_xsect.jpg",
"http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/af/frnts/cfrnt/prcp.rxml"
]
] |
||
fgsxh
|
What do you think will be the first major vindication/discovery of the LHC in CERN?
|
Creation of a mini black hole? Uncover a Higgs particle? Who decides what experiments are going to be done using the facility? Is it a for profit entity where you can pay to use the collider or what?
|
askscience
|
http://www.reddit.com/r/askscience/comments/fgsxh/what_do_you_think_will_be_the_first_major/
|
{
"a_id": [
"c1fu5sz"
],
"score": [
3
],
"text": [
" > Creation of a mini black hole? \n\nNo.\n\n > Uncover a Higgs particle?\n\nMaybe.\n\n > Who decides what experiments are going to be done using the facility?\n\nThere are two experiments that they do proton-proton collisions and gold-gold collisions. When you say that two different scientists are doing two different experiments with with the LHC that means that they are looking at the same data but looking for different things in the data, eg The higgs or black holes. However, they do have to decide how much time to spend on protons an how much time to spend on gold, I think the decision is made by the director of the CERN laboratory.\n\n > Is it a for profit entity where you can pay to use the Collider or what?\n\nNo, CERN is an international interjurisdictional entity created by the governments of several European nations. It would be really expensive to pay for anything the LHC does and it would be of little commercial value.\n\n"
]
}
|
[] |
[] |
[
[]
] |
|
1pkp9b
|
Can suns, planets, or other bodies escape the gravitational pull of a galaxy during a collision between two galaxies?
|
How high likely is it for our Sun or even Earth to be flung out into space between galaxies if and when the Milky Way and Andromeda galaxies collide?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1pkp9b/can_suns_planets_or_other_bodies_escape_the/
|
{
"a_id": [
"cd3d57m"
],
"score": [
2
],
"text": [
"Definitely. When galaxies collide, they often produce [tidal tails](_URL_0_) of material that has been ejected into intergalactic space. These tails are composed of galaxy-stuff: stars, gas, and dust. \n\nThe planets are tightly gravitationally bound to the Sun, so whatever happens to it happens to them. There is nothing so violent in a galaxy collision that would rip the planets away from the sun, even if the sun gets ejected.\n\nHow likely? That's hard to estimate accurately, but probably in the 10% range or so."
]
}
|
[] |
[] |
[
[
"http://ontariostargazing.ca/wp-content/uploads/2013/05/Antennae-galaxies.jpg"
]
] |
|
adsnin
|
In WW2, were staffing positions at concentration camps considered sought after or desirable for members of the German military?
|
[deleted]
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/adsnin/in_ww2_were_staffing_positions_at_concentration/
|
{
"a_id": [
"edn0cvk"
],
"score": [
2
],
"text": [
"Most scholars agree with Christopher Browning and Daniel Goldhagen that there were not significant punishments for those who refused to partisipate in the Holocaust. In short, they had a choice. Even local collaborators such as the Ukrainian Volksdeutsche guards at Sobibor, or the Lithuanian partisans who assisted the Einsatzgruppen, had a choice. The camps were considered an \"easy\" assignment, an easy way to avoid combat and to gain wealth. \n\nThe guards and staff did not face the squalid conditions the prisoners did and both lived in fairly comfortable housing and most guards got significant wealth through theft of goods from the prisoners sent to be killed. The commandant of Auschwitz, Rudolf Hoess lived essentially in the camp, but in a different world. He and his family (including his children) lived in luxury. In fact many of the commandants lived in or directly next to the camps, in quite luxurious homes. The guards and staff lived in comfort, having access to comfortable living conditions, good food, unimaginable amounts of loot, and often to women who were forced into sexual slavery. The extermination camps extracted huge amounts of wealth from the people they killed. Jewish prisoners of the kanadakommando (camp esperanto for the workers in the barracks where personal belongings were kept before being shipped to Germany) have testified to the fact that many guards stole jewelry and other valuables, and that most could be bribed for better food with the contents of the hundreds of thousands of suitcases. \n\nMany of the staff of death camps were volunteers, others were offered (offered rather than ordered) their positions as a promotion from working in Operation T4 or in a concentration camp, or as a promotion after fighting on the Eastern Front (in the case of Josef Mengele for example). Franz Stangl, for example, worked first in Operation T4, killing disabled people in Germany, then was promoted by Himmler to be the first commandant of Sobibor, then was promoted again by Odilo Globocnik to be the commandant of the larger death camp of Treblinka. It was seen as a good career path, to work in a death camp. \n\nThe question of why they would choose to work as full time murderers and torturers is one of the hardest questions of the Holocaust, and unfortunately I don't have answers that satisfy me. Most of the guards and staff were not violent criminals before the war, though some were, and most were not after the war either. For the most part these were just normal people influenced by hatred, prejudice, and greed."
]
}
|
[] |
[] |
[
[]
] |
|
31i9b0
|
What is the smallest amount of atoms it would take to form something barely visible to the naked eye?
|
askscience
|
http://www.reddit.com/r/askscience/comments/31i9b0/what_is_the_smallest_amount_of_atoms_it_would/
|
{
"a_id": [
"cq1xxe5",
"cq21q02",
"cq2cb5q"
],
"score": [
5,
27,
2
],
"text": [
"We could maybe see something 50 to 100 microns wide. If it is a sphere and the atoms are two angstoms apart, this is about 15 quadrillion atoms.",
"The human eye is very sensitive but can we see a single photon? The answer is that the sensors in the retina can respond to a single photon. However, neural filters only allow a signal to pass to the brain to trigger a conscious response when at least about five to nine arrive within less than 100 ms. If we could consciously see single photons we would experience too much visual \"noise\" in very low light, so this filter is a necessary adaptation, not a weakness.\n\nSome people have said that single photons can be seen and quote the fact that faint flashes from radioactive materials (for example) can be seen. This is an incorrect argument. Such flashes produce a large number of photons. It is also not possible to determine sensitivity from the ability of amateur astronomers to see faint stars with the naked eye. They are limited by background light before the true limits are reached. To test visual sensitivity a more careful experiment must be performed.\n\nThe retina at the back of the human eye has two types of receptors, known as cones and rods. The cones are responsible for colour vision, but are much less sensitive to low light than the rods. In bright light the cones are active and the iris is stopped down. This is called photopic vision. When we enter a dark room, the eyes first adapt by opening up the iris to allow more light in. Over a period of about 30 minutes, there are other chemical adaptations that make the rods become sensitive to light at about a 10,000th of the level needed for the cones to work. After this time we see much better in the dark, but we have very little colour vision. This is known as scotopic vision.\n\nThe active substance in the rods is rhodopsin. A single photon can be absorbed by a single molecule that changes shape and chemically triggers a signal that is transmitted to the optic nerve. Vitamin A aldehyde also plays an essential role as a light-absorbing pigment. A symptom of vitamin A deficiency is night blindness because of the failure of scotopic vision.\n\nIt is possible to test our visual sensitivity by using a very low level light source in a dark room. The experiment was first done successfully by Hecht, Schlaer and Pirenne in 1942. They concluded that the rods can respond to a single photon during scotopic vision.\n\nIn their experiment they allowed human subjects to have 30 minutes to get used to the dark. They positioned a controlled light source 20 degrees to the left of the point on which the subject's eyes were fixed, so that the light would fall on the region of the retina with the highest concentration of rods. The light source was a disk that subtended an angle of 10 minutes of arc and emitted a faint flash of 1 millisecond to avoid too much spatial or temporal spreading of the light. The wavelength used was about 510 nm (green light). The subjects were asked to respond \"yes\" or \"no\" to say whether or not they thought they had seen a flash. The light was gradually reduced in intensity until the subjects could only guess the answer.\n\nThey found that about 90 photons had to enter the eye for a 60% success rate in responding. Since only about 10% of photons arriving at the eye actually reach the retina, this means that about 9 photons were actually required at the receptors. Since the photons would have been spread over about 350 rods, the experimenters were able to conclude statistically that the rods must be responding to single photons, even if the subjects were not able to see such photons when they arrived too infrequently.\n\nIn 1979 Baylor, Lamb and Yau were able to use toads' rods placed into electrodes to show directly that they respond to single photons.\n\nFrom: _URL_0_\nPlease understand that cells responding doesn't always mean conscious perception ",
"Since you want the fewest atoms possible, let's use the largest stable atoms we can get: Caesium. The radius of a caesium atom is 244 picometers, or 244x10^(-12) meters. The smallest thing resolvable by the human eye is about 100 microns, or 100x10^(-6) meters. So you'd need a sphere with a diameter of 409836 caesium atoms, which works out to about 36 quadrillion atoms."
]
}
|
[] |
[] |
[
[],
[
"http://math.ucr.edu/home/baez/physics/Quantum/see_a_photon.html"
],
[]
] |
||
6x6z1m
|
why are trailer tractors so boxy and non-aerodynamic?
|
So, first of all, there's a shape difference between tractors in Europe and the ones in the US. EU ones are pretty much a flat surface slamming against the wind at 100+km/h. US tractors have a front mounted engine, which gives them a seemingly more aerodynamic shape. However, when brought together together in the same plane, the engine and the windshield have roughly about the same surface area, with both surfaces being mostly flat. I don't know if the US trucks are more aerodynamic or not, so some input on this would be nice, as well.
The overall question, however, remains: how come aerodynamics doesn't play a role in truck development? Considering the fuel costs, the large front surface area and the speed they cruise at, you'd think aerodynamics would be something truck manufacturers should be all over.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6x6z1m/eli5_why_are_trailer_tractors_so_boxy_and/
|
{
"a_id": [
"dmdk9qu",
"dmdl6wt",
"dmdlij3",
"dmdmpns",
"dmdmxf2",
"dmdvyp4"
],
"score": [
33,
2,
9,
2,
6,
15
],
"text": [
"EU tractors generally have their passenger cabins mounted on top of the engine instead of having the engine be in front of the cab. This makes the tractor look much boxier than American styles but it also makes them shorter. Being shorter is much more important in Europe because many cities have small roads with tight corners that aren't as common as in America.",
"Aerodynamics are very much a part of truck design. Here in Europe we already have a lot of haulage firms implementing aerodynamic trailers that look [like this](_URL_2_) though the flat boxy type are still the greater majority at the moment.\n\nWhen it comes to the actual cab and tractor (Herein referred to as the \"truck\") there is a slight difference in design concept between the US and Europe because of a number of factors.\n\nFirstly, US roads tend to be bigger and wider than European roads. Because of this, truck designs over here tend to be more compact than the traditional Peterbilt inspired design of US trucks. This saves weight, less weight means less fuel used against the downside of increased air resistance.\n\nAs you pointed out, traditional slab sided peterbilt style trucks do appear to be more aerodynamic initially, but ultimately they tend to have the same surface area meeting the windstream head on. For that reason they tend not to offer any great improvement in terms of aerodynamic performance and because they are heavier, tend to use more fuel.\n\nThat might be about to change though, thanks to [this design](_URL_1_), and [this concept one](_URL_0_).\n\nWhile the importance of aerodynamics has always been understood, previously making a truck aerodynamic often meant increasing its weight and size as it required additional materials. With newer materials like carbon fibre much of this extra weight can be minimised. The downside of course, is that fancy aerodynamic truck is probably going to cost a bit more.",
"A reson for the difference in max length.\nIn continental Europe the max length is 18.57 m, 40 ton and 24-25.25m, 60 ton in Scandinavia (the reason is that the extra length make it possible to have 3 instead of 2 cut to length stack of timber because the forest industry is important in Scandinavia). It is economical to have a cab over engine design to maximize the amount of cargo space\n\nI the US there are no federal max length but there are weight limitations of 36 ton so there is no incentive to make it compact the same way\n\nWith those limitation is it not strange that the designs are different. I is liley the case that increasing aerodynamics would reduce capacity and be non economic. \n\nA flat front is not that bad for aerodynamics. A flat back is worse \nLook at how [aircraft wheel covers looks like](_URL_0_[5]-1784-p.jpg). They are quite bulky at the front and pointier at the back. That design are that way for a reason\n",
"this is more about the trailers, but I have noticed many trucks in America will have one or both of these addons, I'm guessing for reducing drag... I'd love any insight on what the practical benefits are vs how long they take to pay for themselves \n\n_URL_0_\n\n_URL_1_",
"As much as it looks like things aren't aerodynamic these things tend to be heavily engineered towards being as fluid as possible while considering other handling characteristics. Many others have pointed out about the size restrictions so I'll leave that unsaid as other commnets seem to be more than enough for that. \n\nWhat I will say is take for example the Volvo FH16 truck. You look at it and you think it's very poor for aerodynamics but when you start looking into it you'll notice subtle things about it's design aimed at improving the CD (coefficient of drag) rating of the vehicle.\n\nTake a look at this image;\n\n_URL_0_\n\nLooks like a massive flat wall with a slight curve at the very edge of the cab doesn't it. Now look at the plan overview of the truck and what do you notice. \n\n_URL_1_\n\nI bet you should be able to see that there's a very slight curve to the entire front of the vehicle. The figures I've found is that most Cab over Engine trucks in Europe have C^D around 0.55-0.70, Most mainstream modern cars are around a value of 0.20-0.35. Now when you consider how much larger of a profile a truck has, then you soon can see that the figures are pretty impressive as an FH12 is from the figures I can find about 3 times the size of most cars in terms of cross sectional area (I've looked up a few common European models). \n\nIt's also worth adding that a lot of the parts on a truck (or other vehicle) are designed to be for aerodynamics not just in terms of the coefficient of drag but also to aid grip for the tyres, improve road holding and other performance metrics beyond being a fluid shape. Making a vehicle perfectly aerodynamic is possibly a great idea if you plan to use it in a straight line on perfectly dry roads with no wind or weather influences. For real world use you have to deal with pushing them into the road surface to press through rain to combat aquaplaning, to work against strong winds to prevent roll overs and many other things. ",
"I'm an aerospace engineering grad so can provide some insight into this. The default, most aerodynamic shape is a tear drop (fat end into the air). A lot of people think a knife edge is more aerodynamic because that's what they see on fighter jets. \n\nBut take a look at this fighter from 1945:\n\n_URL_0_\n\nIt has a rounded nose, just like a modern commercial airliner. Sharper noses only came in when people wanted to go super-sonic where aerodynamic rules get really different.\n\nAnyways. If a teardrop is the best shape, how far off that shape is the front end of a truck and how could we improve it? It turns out, when you start to consider the stuff you need in the front of the truck (and where it has to be places so that you are good with local highway axel loading rules), you just don't have much wiggle room. You could improve things a bit, but not that much.\n\nThe interesting thing is that the BIG aerodynamic savings are to be had at the back of the truck. That flat surface deviates significantly from the tapered end of a teardrop and creates all sorts of excess drag. The problem is, that;s where stuff gets loaded in and out of the truck, and a giant spike sticking out the back of a truck isn't a safe idea."
]
}
|
[] |
[] |
[
[],
[
"http://exa.com/sites/default/files/media-module/nikola_one.jpg",
"http://gas2.org/wp-content/uploads/2014/01/airflow-bullet-truck-5.jpg",
"http://www.donbur.co.uk/gb-en/images/products/uk-mail-teardrop-trailer.jpg"
],
[
"http://www.bladehobbies.co.uk/ekmps/shops/33fb39/images/e-flite-umx-cessna-182-bnf-as3x-brushless-rc-plane-steerable-nose-wheel-eflu5650-"
],
[
"http://www.ccjdigital.com/wp-content/uploads/sites/10/2010/10/ATDynamics-TrailerTail.jpg",
"https://media-cache-ak0.pinimg.com/736x/39/87/f8/3987f8efc0cdf0b2a6a089cdb1d25bd2.jpg"
],
[
"http://car--reviews.com/images/volvo-fh16/volvo-fh16-12.jpg",
"http://www.volvotrucks.co.uk/content/dam/volvo/volvo-trucks/masters/euro-6/volvo-fh-series/specifications-landing/1000x1000-specifications-landing-volvo-fh-data-sheets.jpg/jcr:content/renditions/[email protected]"
],
[
"https://en.wikipedia.org/wiki/McDonnell_FH_Phantom"
]
] |
|
14e1sb
|
If a student is ill-prepared for a difficult memorization test, is it better to be awake all night and go over the material one more time or get a good night's sleep?
|
askscience
|
http://www.reddit.com/r/askscience/comments/14e1sb/if_a_student_is_illprepared_for_a_difficult/
|
{
"a_id": [
"c7c8009",
"c7c8nuh"
],
"score": [
8,
2
],
"text": [
"Sleep has been proven to help sort and remember information, so getting a good night's sleep is beneficial. Obviously, the student would have to know the information in the first place to perform well. Contrary to popular belief, knowledge osmosis does not occur when sleeping on an open text book.\n\narticle: _URL_0_",
"Honestly, neither. Long term memory is not a function of just information acquisition, but more importantly reinforcement. This is why professors encourage their students to study over the course of the entire semester instead of just cramming at the last minute. With reinforcement your brain's normal neural pruning routines (neural pruning being the act of changing clusters of neurons to better adapt to your day to day needs) will see a consistent set of stimuli being entered into long term memory and optimize them as opposed to removing them. \n\nBecause your brain first has to get those memories into LTM from Short Term Memory (think of it like RAM or temporary files in a computer), that means cramming just encodes the bare minimum into your LTM, which then doesn't get optimized properly. Going to bed is equally pointless on the learning scale because you'll be optimizing that information no matter what. \n\nOn the conscious scale though, it's better to go to bed and wake up refreshed/ready. This isn't related to what you've just crammed, but rather your ability to quickly access prior learned information. If your brain is mostly focusing on going back to bed, you won't be able to access memory stores as easily or quickly. If you're rested however, your ability to access those stored memories more efficiently improves markedly. Unfortunately though, this is more pertinent to individuals who are doing active processing tasks (e.g. tests that require thinking things through), not active retrieval tasks (e.g. tests that are about rote memorization). \n\nFor future reference though, the best memorization involves more than picking up the information, but also knowing how and why you process it in different ways. This is because your brain can contextually recognize errors and unnecessary thought paths and dismiss them without extra effort. \n\n"
]
}
|
[] |
[] |
[
[
"http://www.psychologytoday.com/blog/memory-medic/201103/how-sleep-helps-memory"
],
[]
] |
||
vtm0e
|
If I were floating 100 yards away from the Voyager 1 at its current location, would there be enough light for me to see it?
|
askscience
|
http://www.reddit.com/r/askscience/comments/vtm0e/if_i_were_floating_100_yards_away_from_the/
|
{
"a_id": [
"c57ixji",
"c57j3ni",
"c57jfri",
"c57k4mr"
],
"score": [
37,
947,
212,
8
],
"text": [
"[voyagers current location](_URL_0_)",
"I think the answer is yes.\n\nConsider your ability to see things at night with a full moon out--it's possible to read the big print on a newspaper and you can see objects around you quite clearly.\n\nNow consider the Sun is about 400,000 times the brightness of the full moon here on Earth at one AU. Voyager 1 is now about 120 AUs away from the Sun, which means the Sun is about 1/14400 the brightness it is here on Earth (inverse square law), which is still 28 times the brightness of the full moon (400,000/14400 = 28).\n\nIf you were 100 yards away from Voyager 1 while being illuminated by an object 28 times as bright as the full moon, I'd say you could probably pick it out pretty easily.",
"**TL:DR**- Yes.But you really should read on as I believe science is not just cool facts and figures, but how cool facts and figures can be **obtained** by making good use of existing information.\n\n\nApproach to solving the problem:\n\n > 1. Check the sun's brightness.\n > 2. Check the sun's apparent brightness at the location of the voyager probe.\n > 3. Check if the probe is sufficiently illuminated to be visible.\n\n.\n\n.\n\n**1. Check the sun's brightness.**\n\nThe sun's [absolute magnitude is 4.83](_URL_0_). Absolute magnitude measures a celestial object's brightness.\nAt the Voyager 1, the apparent magnitude of the sun is calculated as:\n\n.\n\n.\n\n**2. Check the sun's apparent brightness at the location of the voyager probe.**\n\nCurrently, the probe is approximately 18,100,000,000 km away from the sun. Conveniently, a [table of apparent magnitudes](_URL_1_) of the sun when seen from different places is available. At Pluto's aphelion (7,311,000,000 km from the sun), the apparently magnitude of the sun is -18.2.\n\nThe brightness of the sun when viewed from Voyager 1 can be determined by using the inverse square law. Let B be the luminosity of the sun when observed from Pluto's aphelion. The brightness when viewed from Voyager 1 is B x 7,311,000,000^2 / 18,100,000,000^2 = 0.16315 B. The luminosity of the sun at Voyager 1's position is merely 16% of the luminosity at Pluto's aphelion.\n\nReturning to the apparent magnitude- the apparent magnitude reduces by 1 for every 2.512 times increase in brightness. The ratio of brightness between the sun's brightness at Pluto and Voyager 1 is 0.16315. Therefore the difference in apparent magnitude is 2.512^M = 0.16315, and M can be calculated from M = log(base 2.512) 0.16315. This gives M = -1.97.\n\nThe sun's apparent magnitude at Voyager 1 is -18.2 + 1.97 = -16.3 (lower brightness means higher magnitude).\n\n.\n\n.\n\n**3. Check if the sun is visible from the location of the voyager probe.**\n\nBased the [table of apparent magnitudes](_URL_1_), the full moon is at apparent magnitude of -12.9. The sun when viewed from Voyager 1 has apparent magnitude of -16.3. Therefore, the sun at Voyager 1 is 3.4 magnitudes brighter than the full moon on earth, corresponding to 2.512^3.4 times the luminosity. This is equivalent to a dark night with 23 full moons in the sky. Way more than enough to see in, as one can see (although slightly clumsily) on a clear full moon night.\n\n.\n\n.\n\n**Therefore,** if you were up close to the Voyager 1 probe at its current location, you will be able to see the probe using weak sunlight. HOWEVER, because light is only coming from the sun (ignoring star light for being too weak to properly light up the probe), only the side facing the sun can be seen.",
"To the OP. The apparent magnitude of the Sun as viewed from a distance similar to the planet Eris (sitting at 97.5 AUs from the sun at it's Aphelion {furthest distance}) is -16.7. The apparent Magnitude of the moon is -12.9 (this shall be our baseline, because I know I can see the length of a football field on a full moonlit night) Now the rest of this is conjecture, so please do not quote me on the numbers. The Apparent Magnitude of the sun at Pluto (48.8 AUs away from the sun at aphelion) is -18.2. If the decay of apparent magnitude is linear with distance, then the apparent magnitude of the sun from Pluto to Eris decays 1.5 points over 49.7 AUs. Since Voyager is @ 120 AUs from the sun, that is only 22.5 AUs from Eris at Aphelion, a smaller distance than Eris to Pluto. If linear, the max magnitude decay would be 1.5 points again, giving us an Apparent magnitude of the sun of -15.2 at 120 AUs (actually this number would most likely be higher, or lower due to the negative sign.) So, since the Full moon has an apparent magnitude of -12.9 and we should be able to see 100 yards, Yes, we should be able to see Voyager 1 at a distance of 100 yards while it is sitting 120 AUs away from the sun, which will have an apparent magnitude of -15.2 at the very least."
]
}
|
[] |
[] |
[
[
"http://voyager.jpl.nasa.gov/where/index.html"
],
[],
[
"http://en.wikipedia.org/wiki/Sun",
"http://en.wikipedia.org/wiki/Apparent_magnitude#Table_of_notable_celestial_objects"
],
[]
] |
||
2h7b89
|
how can youtubers post videos of them singing popular songs without getting their videos taken down, but i can't upload a school video that has "eat it" (which was published in 1984)?
|
I thought that the copyright laws protected people from singing songs from within the last 20 years? In america, that is.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2h7b89/eli5how_can_youtubers_post_videos_of_them_singing/
|
{
"a_id": [
"ckq22i9"
],
"score": [
2
],
"text": [
" > I thought that the copyright laws protected people from singing songs from within the last 20 years?\n\nThat's patent law (which only applies to inventions, product designs and manufacturing processes).\n\nCopyright typically lasts for the entirety of the author's life plus an additional 50-75 years depending on what jurisdiction you live in.\n\nWhen people post themselves singing popular songs on Youtube and it's not taken down, it's usually because the use of that particular song is covered by blanket licensing arrangements Youtube has with record labels, music publishers, and performing rights agencies. \n\nMusic which they haven't licensed in this way and/or which the publisher has specifically asked Youtube to take down (e.g. through YT's content matching system) will be removed shortly after being uploaded."
]
}
|
[] |
[] |
[
[]
] |
|
21n7ji
|
what really happens when country a's leader calls country b's leader, where the language isn't the same?
|
This sounds silly. When they say "Putin calls Obama to discuss Ukraine" what does that mean exactly?
1. Does Putin picks up the phone, makes a long distance call to Obama and they talk person to person?
2. What language do they speak?
3. Or is it something like Obama - > Translator - > phone < - Translator < - Putin
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/21n7ji/eli5_what_really_happens_when_country_as_leader/
|
{
"a_id": [
"cgenpuo",
"cgep9v0",
"cgeqtn7",
"cger58m",
"cger8k0",
"cgerbz2",
"cgerzq5",
"cges3bz",
"cgesjoy",
"cget343",
"cget4jz",
"cgeu2cl",
"cgeuzes",
"cgevoiv",
"cgeycyn",
"cgeydjy"
],
"score": [
760,
88,
58,
30,
68,
78,
4,
17,
5,
4,
332,
3,
3,
3,
2,
10
],
"text": [
"Both leaders have trusted translators who are also on the line. It's a big teleconference.\n\nEdit: It's actually an interpreter instead of a translator. I myself am a big stickler for using the correct term even if the vernacular might allow for others. Corrections accepted.",
"Putin speaks English.",
"Putin: В Крыме нет никаких российских солдат.\n\nObama: What is he saying?\n\nBiden: He's talking about the weather, I think.",
"Luthor, Obama's anger translator to the rescue",
"Why would you need two translators?",
"I know for larger functions, such as the UN, everything is translated from its native language into English, and then into the other language. \n\nExample: Russia wants to ask Italy a question. Russia submits its question to a translator who translates it into English. Then that is translated to Italian, and is given to Italy. \n\nThe reason for this system (instead of a direct translation from Russian to Italian) is because of the sheer amount of translators that would be required.\n\nIf you have 10 countries that all wanted to talk to eachother using direct translations, then you would need 100 (edit: 45 or 90, see /u/the_full_effect's post below) translators, 10 for each language. By using English as a middle ground, you only need 10 translators, each of them need to know English and one other language. So it is much more efficient. ",
"There's a few episodes of the West Wing where they do this with translators on the line",
"I believe world leaders are extremely concerned not just with communicating clearly but coming across as having higher social status. Communicating with another world leader in their native language would be to yield a little bit of status even if it doesn't hinder clear communication.\n\nYou can find pictures online of world leaders shaking hands and \"fighting\" to be the one standing on the right towards the audience which allows for a more open posture that looks more confident.\n\nThat's why I believe there's no way Putin would speak English with Obama in a public setting even if he could speak the language unhindered. If the call is private then maybe I suppose.",
"Well, Putin can speak English...\n\nbut yeah, in general there are translators involved, although 've always wondered how they knew a translator wasn't purposefully lying about what the other said just to cause drama?",
"Everyone speaks English. Even the Vulcans.",
"They have trusted > interpreters < on the phone with them, not \"translators,\" since interpreters deal with the spoken language and translators work with the written language. For Obama that's an interpreter from the U.S. Department of State.\n\nFun Fact: The actual \"Presidential Hotline\" is not a red phone, or a phone at all, it's a data link that produces text, and hence requires translators, not interpreters. It's also officially called the Direct Communications Link (Liniya Pryamoy Svyazi in Russian).\n\nSource: I'm a former Presidential Hotline translator.\n\nEdit: Putin does not speak English (well enough to conduct negotiations). Even if he did, he would never deign to speak to Obama in English because there's still a great deal of nationalistic pride associated with the language, especially for Putin, to say nothing of the complexity and sensitivity of the discussions, which would really require him to be bilingual.\n\nEven at G-8 meetings where the leaders share a common language they actually almost never use that common language. All the interpreters are just out of camera range when all those photos are taken.\n\n2nd Edit: Correction: Yes, Putin \"speaks English\" but not remotely close enough to the level to conduct serious negotiation (I should have said -- \"Putin does not speak English well enough.\") He is, of course, a former KGB agent, where English was taught quite extensively, but was so meek and ineffectual in the KGB when he was first starting out that he was referred by other agents as \"the moth.\"\n\n",
"Other than that, I think most leaders are fluent in english but using translators make sure nothing is misunderrstood.",
"Each has a translator, even when it is someone like Reagan and Gorbachev. We know Gorbachev could speak English when he wanted to. \n\nSo could Arafat\n\nKing Hussain of Jordan, also.\n\nThere were times when both of those would ditch the translators. \n\nAlso, Churchill, when dealing with the Americans would bounce most of what he planned to say off his American friends just to make sure there was none of this \"Divided by a common language\" stuff that can still crop up occasionally. ",
"They laugh and joke about how the masses really believe they are arguing with each other. Probably the same sort of stuff the Hulkster and Roddy Piper or Randy Savage used to joke about with each other when the fans really got into the act.",
"Both people on the phone would just say \"yes\" alot in english to fool whoever is in the room with them. Then get off the phone and say \"the call was very constructive and we are on the same page\"",
"The world leaders communicate through South African sign language interpreter"
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[]
] |
|
1f6f0v
|
Was Julius Caesar truly afraid of cats?
|
I see this claim time and time again also followed by other famous leaders such as Mussolini and Napoleon but I have found no evidence to back up these claims. This surprises me considering the few documents that account for Julius Ceasar's life.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1f6f0v/was_julius_caesar_truly_afraid_of_cats/
|
{
"a_id": [
"ca79o09"
],
"score": [
3
],
"text": [
"It is said that Caesar was afraid of cats and banished them from the Imperial Palace, which is funny because I am not to sure if there was one during his time. It is brought up a lot but it's just claims. There are no writings from the day about it. Caesar spent a lot of time in Egypt and cats are deeply rooted in their culture. Also Caesars 13th legion's symbol was a lion. I think it is more of a rumor, like you listed a lot of other famous leaders were terrified, or so they say, of cats including Genghis Khan and Hitler. "
]
}
|
[] |
[] |
[
[]
] |
|
3a3pmz
|
why, on an evolutionary perspective, are humans hyper-evolving? we've grown in height just in the past few thousand years, and have much less hair than predecessors.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/3a3pmz/eli5_why_on_an_evolutionary_perspective_are/
|
{
"a_id": [
"cs8zlt1"
],
"score": [
7
],
"text": [
"Height can be attributed to improved nutrition, look at NK/SK. NK are much shorter than SK even though they were the same people up until very recently. The hair thing requires a citation."
]
}
|
[] |
[] |
[
[]
] |
||
9dvhct
|
electric force, electric field, coulomb’s law and gauss’s law
|
What are these and how do they apply to physics? Any examples regarding them?
Background info: been sick lately and unable to go to class, so I don’t really understand these subjects much apart from their formulas.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9dvhct/eli5_electric_force_electric_field_coulombs_law/
|
{
"a_id": [
"e5ked1b",
"e5khwbd"
],
"score": [
3,
2
],
"text": [
"Physics is, in a broad sense, the study of what things in the universe *are*, how they *move*, and how they *interact*.\n\nCharged objects generate a so-called \"electric field\" around themselves, similar in some ways to how a lightbulb gives off light. Other charged objects \"see\" that field from a distance, and know from the \"color\" (sign) and \"brightness\" (magnitude) how they should react relative to their own charge. This \"reaction\" to the field uses the same math as pushing an object, so people lumped them together as \"forces\". Since this force is related to electricity, they call it the electric force.\n\nCoulomb's law explains that F=ma=k*q*q/r^2, so doubling the distance makes the force weaker by 4 times, and doubling the charge of one object \"only\" doubles the force.\n\nIt was also found that if you drew an imaginary ball (or, it turns out, any closed shape) around a bunch of charged objects, you only need to know the net charge to determine how a charge outside that sphere will react. They called this the Gauss Law, and it's used often to make complex situations easier to calculate. For example, you don't need to know where every rock on earth is and how much mass they have: just how much mass the Earth has in total and how far you are from the center. (Fun fact: mass and electric charge are *really* similar in surprising ways.)",
"Assuming you're taking a physics course, your best bet is to read the relevant explanations in the textbook then go hunting around Youtube or Khan Academy for lectures on these topics. [Here's Khan Academy's basic electric force bit](_URL_2_). If you're in a college level course and know Calculus, you can go to MIT's open course site _URL_3_ and grab the relevant lecture videos under one of the Physics II courses. It may also be helpful to review Stokes' and Greene's Theorems which can be found [here at Khan Academy.](_URL_7_) For basic intuition explained quick and dirty you might look at the Crash Course series who have a video on [electric charge here](_URL_5_) and [electric fields here](_URL_6_). I'd also point out that the Giancoli and Feynman Lecture books in the background of the Crash Course videos are great books that describe exactly what you're asking about.\n\nThe electric field is a vector field. It's just saying that space is filled with invisible arrows (vectors) everywhere that have a direction and size. These arrows are caused by electric charges. [Relevant picture.](_URL_4_) Positive charges have arrows pointing out and negatives have them pointing in. One way of visualizing electric fields is to connect the arrows from source to destination, and draw more lines for stronger charges [like so](_URL_0_).\n\nAny time a charged particle is placed in a position where it can 'feel' the electric field from another particle, it experiences a force. Like charges repel and opposite charges attract. The is electric force. Coulomb's Law is just the expression of how much this force happens with math. [Here's the full equation with explanations of the constants involved.](_URL_1_) The basic gist is that the force is proportional to the strength of both charges multiplied together, then divided by the square of the distance between them: F ∝ (q_1 * q_2) / r^2\n\nGauss's Law asks you to place an imaginary, closed of bubble (like an inflated balloon) somewhere in space, then draw all of the electric field lines from any charges nearby. If the bubble has charges inside of it, then field lines will go through the bubble. If the charges are outside the bubble, then any field lines that go into the bubble will go back out again. A better and fuller explanation is probably not ELI5 appropriate, which is why I referenced the things at the beginning as good sources to go to to learn about this stuff."
]
}
|
[] |
[] |
[
[],
[
"https://upload.wikimedia.org/wikipedia/commons/thumb/e/ed/VFPt_charges_plus_minus_thumb.svg/220px-VFPt_charges_plus_minus_thumb.svg.png",
"http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elefor.html",
"https://www.khanacademy.org/science/physics/electric-charge-electric-force-and-voltage",
"https://ocw.mit.edu/courses/physics/",
"https://www.physicsclassroom.com/Class/circuits/u9l1a2.gif",
"https://www.youtube.com/watch?v=TFlVWf8JX4A",
"https://www.youtube.com/watch?v=mdulzEfQXDE",
"https://www.khanacademy.org/math/multivariable-calculus/greens-theorem-and-stokes-theorem/stokes-theorem/v/stokes-theorem-intuition"
]
] |
|
1o6ofw
|
why do people with adhd/add not feel the "high" feeling that adderal and other amphetamine based medications give those without it?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1o6ofw/eli5_why_do_people_with_adhdadd_not_feel_the_high/
|
{
"a_id": [
"ccp91v8",
"ccpallu",
"ccpawbh",
"ccpgod6"
],
"score": [
13,
14,
3,
2
],
"text": [
"People with add/adhd have a chemical imbalance in the prefrontal lob. Basically their dopamine levels are lower then average, so when they take drugs that raise dopamine it their dopamine levels go to the average. Whereas those who don't it would have a surplus levels of dopamine that creates the high.",
"I was diagnosed with ADD and amphetamines got me high as shit if I took them at recreational doses. However, 1) people diagnosed with ADD generally take fairly small doses of stimulants, and 2) low doses of stimulants serve to make anyone more industrious and focused, not just people diagnosed with ADD. I've always doubted the premise that stimulants somehow affect people with ADD differently, although if anyone has a decent study that shows otherwise I'd love to read it.",
"The theory that it affects ADHD brains differently is controversial. It's probably at least partly because people with ADHD are using that medication under the supervision of a doctor and begin with a very, very small does (much less than what would get anyone high). They usually wait around a month before trying a higher does, so that the effect can be clearly judged, until the right dose is eventually found. It is still way less that what is needed to get high. ",
"I was diagnosed with ADD and the medicine they put me one DEFINITELY made me feel fucked up and weird. I took it for 2 weeks then never touched the stuff again. It's just not good."
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
||
6zpkfr
|
what is a state comptroller?
|
Pretty much as simple as that, my state has an office called "the office of the comptroller" and I don't really understand what that person does.
Thanks!
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6zpkfr/eli5_what_is_a_state_comptroller/
|
{
"a_id": [
"dmx28q3",
"dmx2dby",
"dmx3esg"
],
"score": [
9,
2,
3
],
"text": [
"They're basically a chief accountant/financial officer for the state. They oversee things like state budgets, government spending, government contracts, and paying state employees. ",
"They are like the state's treasurer (or work directly under the treasurer), overseeing the money that comes into the state and gets paid out. Like making sure the tax revenues are in the correct accounts to make payroll for state employees.",
"My dad is a comptroller for the Federal government. He checks out banks, makes sure they follow laws and have a good track record before they open or merge with other banks. "
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
1jyi9r
|
Why do many moons like Europa and our own have one side that permanently faces their planets?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1jyi9r/why_do_many_moons_like_europa_and_our_own_have/
|
{
"a_id": [
"cbjj80j"
],
"score": [
4
],
"text": [
"[Tidal locking. ](_URL_0_)\n\nIn essence, the moons bulge where the planet's gravity tugs on them, making it slightly oval. As the moon rotates, these bulges move out of alignment.\n\nAt this point, bulge A (near the planet) and B (far from the planet)seek to move back into alignment, and exert torque on one another. But A, being closer to the planet, has more force to exert on B. Thus, over time the net result is to force B into synchronization with its orbit, which is tidal locking."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Tidal_locking"
]
] |
||
2wze14
|
Did the Soviet Union have any sort of Internet presence before it fell apart?
|
I realize that the overlapping period of time between the fall of the Soviet Union and the rise of the Internet as a social phenomenon in the mid-90s is small to nonexistent, but did the Soviet government at least experiment with global computer networking?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2wze14/did_the_soviet_union_have_any_sort_of_internet/
|
{
"a_id": [
"covo3pf",
"covsqam",
"covt2mf"
],
"score": [
7,
7,
3
],
"text": [
"Their was a famous 'kremvax' hoax in 1984, but apparently their was a real VAX system in moscow in 1991 _URL_0_",
"There were a few websites, I think mostly relating to universities. They used the .su domain name, which has a lot more web pages registered to it than you would think. Apparently Russia kept using .su for a little bit after the collapse of the Soviet Union, before they switched to .ru in 1994.\n\nI don't really have a source for this besides wikipedia, though. You could probably just visit some of these sites yourself! \n\n_URL_0_",
"In 1990 they were assigned the .su country code top-level domain but dissolved fourteen months later. Up until that point most internet activity was done by the military and universities. One of the earliest domestic software networking companies still active in Russia, [Demos](_URL_1_), was founded in 1989. If you'd like to know more, someone asked [a similar question](_URL_0_) a while ago."
]
}
|
[] |
[] |
[
[
"https://stuff.mit.edu/afs/sipb/user/marthag/text/humor/april_fools/kremvax"
],
[
"https://en.wikipedia.org/wiki/.su"
],
[
"http://www.reddit.com/r/AskHistorians/comments/1apczm/what_was_the_internet_like_in_the_soviet_union/",
"http://demos.ru/about/internet/"
]
] |
|
c2d7oi
|
Since Hitler was technically Austrian, what steps did he have to undergo in order to enter German society as an immigrant? Did he do that correctly or would he be considered an illegal immigrant?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/c2d7oi/since_hitler_was_technically_austrian_what_steps/
|
{
"a_id": [
"erjo0xx",
"es4q98b"
],
"score": [
35,
2
],
"text": [
"Without trying to diminish newer answers, /u/kielowskifans already explained this in [another thread](_URL_0_).\n\n > Hitler's Austrian background was not that much of a problem for him as there was a sizable number of Germans in the 1920s and 30s that considered German-speaking Austrians to be ethnically German.",
"I see that this has been answered with a link to a somewhat related post, but I'd like to try and give you a more concise answer to what you're looking for. \n\nWhile Hitler was an Austrian-born man, there are a certain set of circumstances that surround the scope of this question. After the assassination of the Archduke, Austria and Germany knew that it was a given that war was coming soon. Hitler, during the four or so years leading up to the war, had spent a lot of time in Vienna. Vienna is where Hitler did the majority of his learning, growth, and development as a person and the city deeply shaped his political views. While Hitler was an Austrian, he had a fascination with the German people and the German country. Though one could make the argument that Austrians are Germans, Hitler saw the Austrians, though powerful, as slightly weaker than the German people due to the types of individuals that held government positions and positions of power in Austria (Jews, immigrants, etc.) \n\nWhen WWI broke out, Hitler was called in for a physical examination to see if he would be drafted into the Austrian army. Many historians contend that he failed his examination intentionally so that he could instead volunteer for the German army. Regardless of the facts surrounding his failure at the drafting exam, Hitler did relocate to Bavaria, Germany where he volunteered for the army. \n\nWhile military service in the present era has the potential to earn a person citizenship, this wasn't the case for Hitler. Hitler, throughout the war, served with distinction, was injured and almost killed on multiple occasions, and even earned the German Iron Cross First and Second class! Though he only made the rank of corporal, primarily because he turned down promotions that would take him from the action, he put his life on the line for the German people and the Kaiser, but after the war he was mostly tossed aside. \n\nFollowing WWI, Hitler was made into a spy for the Weimar military. His job had him spying on political parties that were deemed radical and potentially dangerous. Essentially, he was there to decide whether or not a group posed an actual threat to the very shaky stability that existed. It was here that he found the Germany Workers Party (DAP). \n\nAfter years of building the party and other circumstances, Hitler's hand was forced and the infamous Beer Hall Putsch occurred. The Putsch was a planned revolution that was supposed to sweep Germany to take the government by force. \n\nThough the Putsch failed, something interesting occurred. Hitler was put on trial and he was convicted of treason in 1924. Hitler, however, wouldn't gain German citizenship until 8 years later in 1932. His citizenship came about a whole one year before he was elected Chancellor of Germany. This begs an interesting question as to how a person without citizenship could be convicted of treason. This factor alone was, ironically enough, one of the reasons Hitler even gained his citizenship in the first place. \n\nMy information comes from various books, but a great source for this information and the life of Hitler in general is: Hitler- A Biography by Ian Kershaw."
]
}
|
[] |
[] |
[
[
"https://www.reddit.com/r/AskHistorians/comments/75zam6/why_did_the_german_people_embrace_hitler_a/doa47ea/"
],
[]
] |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.