title
stringlengths 1
149
⌀ | section
stringlengths 1
1.9k
⌀ | text
stringlengths 13
73.5k
|
|---|---|---|
Space architecture
|
Etymology
|
There is some debate over the terminology of space architecture. Some consider the field to be a specialty within architecture that applies architectural principles to space applications. Others such as Ted Hall of the University of Michigan see space architects as generalists, with what is traditionally considered architecture (Earth-bound or terrestrial architecture) being a subset of a broader space architecture. Any structures that fly in space will likely remain for some time highly dependent on Earth-based infrastructure and personnel for financing, development, construction, launch, and operation. Therefore, it is a matter of discussion how much of these earthly assets are to be considered part of space architecture. The technicalities of the term space architecture are open to some level of interpretation.
|
Space architecture
|
Origins
|
Ideas of people traveling to space were first published in science fiction stories, like Jules Verne's 1865 From the Earth to the Moon. In this story several details of the mission (crew of three, spacecraft dimensions, Florida launch site) bear striking similarity to the Apollo Moon landings that took place more than 100 years later. Verne's aluminum capsule had shelves stocked with equipment needed for the journey such as a collapsing telescope, pickaxes and shovels, firearms, oxygen generators, and even trees to plant. A curved sofa was built into the floor and walls and windows near the tip of the spacecraft were accessible by ladder. The projectile was shaped like a bullet because it was gun-launched from the ground, a method infeasible for transporting man to space due to the high acceleration forces produced. It would take rocketry to get humans to the cosmos.
|
Space architecture
|
Origins
|
The first serious theoretical work published on space travel by means of rocket power was by Konstantin Tsiolkovsky in 1903. Besides being the father of astronautics he conceived such ideas as the space elevator (inspired by the Eiffel Tower), a rotating space station that created artificial gravity along the outer circumference, airlocks, space suits for extra-vehicular activity (EVA), closed ecosystems to provide food and oxygen, and solar power in space. Tsiolkovsky believed human occupation of space was the inevitable path for our species. In 1952 Wernher von Braun published his own inhabited space station concept in a series of magazine articles. His design was an upgrade of earlier concepts, but he took the unique step in going directly to the public with it. The spinning space station would have three decks and was to function as a navigational aid, meteorological station, Earth observatory, military platform, and way point for further exploration missions to outer space. It is said that the space station depicted in the 1968 film 2001: A Space Odyssey traces its design heritage to Von Braun's work. Wernher von Braun went on to devise mission schemes to the Moon and Mars, each time publishing his grand plans in Collier's Weekly.
|
Space architecture
|
Origins
|
The flight of Yuri Gagarin on April 12, 1961, was humanity's maiden spaceflight. While the mission was a necessary first step, Gagarin was more or less confined to a chair with a small view port from which to observe the cosmos – a far cry from the possibilities of life in space. Following space missions gradually improved living conditions and quality of life in low Earth orbit. Expanding room for movement, physical exercise regimens, sanitation facilities, improved food quality, and recreational activities all accompanied longer mission durations. Architectural involvement in space was realized in 1968 when a group of architects and industrial designers led by Raymond Loewy, over objections from engineers, prevailed in convincing NASA to include an observation window in the Skylab orbital laboratory. This milestone represents the introduction of the human psychological dimension to spacecraft design. Space architecture was born.
|
Space architecture
|
Theory
|
The subject of architectural theory has much application in space architecture. Some considerations, though, will be unique to the space context.
|
Space architecture
|
Theory
|
Ideology of building In the first century BC, the Roman architect Vitruvius said all buildings should have three things: strength, utility, and beauty. Vitruvius's work De Architectura, the only surviving work on the subject from classical antiquity, would have profound influence on architectural theory for thousands of years to come. Even in space architecture these are some of the first things we consider. However, the tremendous challenge of living in space has led to habitat design based largely on functional necessity with little or no applied ornament. In this sense space architecture as we know it shares the form follows function principle with modern architecture.
|
Space architecture
|
Theory
|
Some theorists link different elements of the Vitruvian triad. Walter Gropius writes: 'Beauty' is based on the perfect mastery of all the scientific, technological and formal prerequisites of the task ... The approach of Functionalism means to design the objects organically on the basis of their own contemporary postulates, without any romantic embellishment or jesting.
As space architecture continues to mature as a discipline, dialogue on architectural design values will open up just as it has for Earth.
|
Space architecture
|
Theory
|
Analogs A starting point for space architecture theory is the search for extreme environments in terrestrial settings where humans have lived, and the formation of analogs between these environments and space. For example, humans have lived in submarines deep in the ocean, in bunkers beneath the Earth's surface, and on Antarctica, and have safely entered burning buildings, radioactively contaminated zones, and the stratosphere with the help of technology. Aerial refueling enables Air Force One to stay airborne virtually indefinitely. Nuclear powered submarines generate oxygen using electrolysis and can stay submerged for months at a time. Many of these analogs can be very useful design references for space systems. In fact space station life support systems and astronaut survival gear for emergency landings bear striking similarity to submarine life support systems and military pilot survival kits, respectively.
|
Space architecture
|
Theory
|
Space missions, especially human ones, require extensive preparation. In addition to terrestrial analogs providing design insight, the analogous environments can serve as testbeds to further develop technologies for space applications and train astronaut crews. The Flashline Mars Arctic Research Station is a simulated Mars base, maintained by the Mars Society, on Canada's remote Devon Island. The project aims to create conditions as similar as possible to a real Mars mission and attempts to establish ideal crew size, test equipment "in the field", and determine the best extra-vehicular activity suits and procedures. To train for EVAs in microgravity, space agencies make broad use of underwater and simulator training. The Neutral Buoyancy Laboratory, NASA's underwater training facility, contains full-scale mockups of the Space Shuttle cargo bay and International Space Station modules. Technology development and astronaut training in space-analogous environments are essential to making living in space possible.
|
Space architecture
|
Theory
|
In space Fundamental to space architecture is designing for physical and psychological wellness in space. What often is taken for granted on Earth – air, water, food, trash disposal – must be designed for in fastidious detail. Rigorous exercise regimens are required to alleviate muscular atrophy and other effects of space on the body. That space missions are (optimally) fixed in duration can lead to stress from isolation. This problem is not unlike that faced in remote research stations or military tours of duty, although non-standard gravity conditions can exacerbate feelings of unfamiliarity and homesickness. Furthermore, confinement in limited and unchanging physical spaces appears to magnify interpersonal tensions in small crews and contribute to other negative psychological effects. These stresses can be mitigated by establishing regular contact with family and friends on Earth, maintaining health, incorporating recreational activities, and bringing along familiar items such as photographs and green plants. The importance of these psychological measures can be appreciated in the 1968 Soviet 'DLB Lunar Base' design: ...it was planned that the units on the Moon would have a false window, showing scenes of the Earth countryside that would change to correspond with the season back in Moscow. The exercise bicycle was equipped with a synchronized film projector, that allowed the cosmonaut to take a 'ride' out of Moscow with return.
|
Space architecture
|
Theory
|
The challenge of getting anything at all to space, due to launch constraints, has had a profound effect on the physical shapes of space architecture. All space habitats to date have used modular architecture design. Payload fairing dimensions (typically the width but also the height) of modern launch vehicles limit the size of rigid components launched into space. This approach to building large scale structures in space involves launching multiple modules separately and then manually assembling them afterward. Modular architecture results in a layout similar to a tunnel system where passage through several modules is often required to reach any particular destination. It also tends to standardize the internal diameter or width of pressurized rooms, with machinery and furniture placed along the circumference. These types of space stations and surface bases can generally only grow by adding additional modules in one or more direction. Finding adequate working and living space is often a major challenge with modular architecture. As a solution, flexible furniture (collapsible tables, curtains on rails, deployable beds) can be used to transform interiors for different functions and change the partitioning between private and group space. For more discussion of the factors that influence shape in space architecture, see the Varieties section.
|
Space architecture
|
Theory
|
Eugène Viollet-le-Duc advocated different architectural forms for different materials. This is especially important in space architecture. The mass constraints with launching push engineers to find ever lighter materials with adequate material properties. Moreover, challenges unique to the orbital space environment, such as rapid thermal expansion due to abrupt changes in solar exposure, and corrosion caused by particle and atomic oxygen bombardment, require unique materials solutions. Just as the industrial age produced new materials and opened up new architectural possibilities, advances in materials technology will change the prospects of space architecture. Carbon-fiber is already being incorporated into space hardware because of its high strength-to-weight ratio. Investigations are underway to see whether carbon-fiber or other composite materials will be adopted for major structural components in space. The architectural principle that champions using the most appropriate materials and leaving their nature unadorned is called truth to materials.
|
Space architecture
|
Theory
|
A notable difference between the orbital context of space architecture and Earth-based architecture is that structures in orbit do not need to support their own weight. This is possible because of the microgravity condition of objects in free fall. In fact much space hardware, such as the Space Shuttle 's robotic arm, is designed only to function in orbit and would not be able to lift its own weight on the Earth's surface. Microgravity also allows an astronaut to move an object of practically any mass, albeit slowly, provided he or she is adequately constrained to another object. Therefore, structural considerations for the orbital environment are dramatically different from those of terrestrial buildings, and the biggest challenge to holding a space station together is usually launching and assembling the components intact. Construction on extraterrestrial surfaces still needs to be designed to support its own weight, but its weight will depend on the strength of the local gravitational field.
|
Space architecture
|
Ground infrastructure
|
Human spaceflight currently requires a great deal of supporting infrastructure on Earth. All human orbital missions to date have been government-orchestrated. The organizational body that manages space missions is typically a national space agency, NASA in the case of the United States and Roscosmos for Russia. These agencies are funded at the federal level. At NASA, flight controllers are responsible for real-time mission operations and work onsite at NASA Centers. Most engineering development work involved with space vehicles is contracted-out to private companies, who in turn may employ subcontractors of their own, while fundamental research and conceptual design is often done in academia through research funding.
|
Space architecture
|
Varieties
|
Suborbital Structures that cross the boundary of space but do not reach orbital speeds are considered suborbital architecture. For spaceplanes, the architecture has much in common with airliner architecture, especially those of small business jets.
|
Space architecture
|
Varieties
|
SpaceShip On June 21, 2004, Mike Melvill reached space funded entirely by private means. The vehicle, SpaceShipOne, was developed by Scaled Composites as an experimental precursor to a privately operated fleet of spaceplanes for suborbital space tourism. The operational spaceplane model, SpaceShipTwo (SS2), will be carried to an altitude of about 15 kilometers by a B-29 Superfortress-sized carrier aircraft, WhiteKnightTwo. From there SS2 will detach and fire its rocket motor to bring the craft to its apogee of approximately 110 kilometers. Because SS2 is not designed to go into orbit around the Earth, it is an example of suborbital or aerospace architecture.The architecture of the SpaceShipTwo vehicle is somewhat different from what is common in previous space vehicles. Unlike the cluttered interiors with protruding machinery and many obscure switches of previous vehicles, this cabin looks more like something out of science fiction than a modern spacecraft. Both SS2 and the carrier aircraft are being built from lightweight composite materials instead of metal. When the time for weightlessness has arrived on a SS2 flight, the rocket motor will be turned off, ending the noise and vibration. Passengers will be able to see the curvature of the Earth. Numerous double-paned windows that encircle the cabin will offer views in nearly all directions. Cushioned seats will recline flat into the floor to maximize room for floating. An always-pressurized interior will be designed to eliminate the need for space suits.
|
Space architecture
|
Varieties
|
Orbital Orbital architecture is the architecture of structures designed to orbit around the Earth or another astronomical object. Examples of currently-operational orbital architecture are the International Space Station and the re-entry vehicles Space Shuttle, Soyuz spacecraft, and Shenzhou spacecraft. Historical craft include the Mir space station, Skylab, and the Apollo spacecraft. Orbital architecture usually addresses the condition of weightlessness, a lack of atmospheric and magnetospheric protection from solar and cosmic radiation, rapid day/night cycles, and possibly risk of orbital debris collision. In addition, re-entry vehicles must also be adapted both to weightlessness and to the high temperatures and accelerations experienced during atmospheric reentry.
|
Space architecture
|
Varieties
|
International Space Station The International Space Station (ISS) is the only permanently inhabited structure currently in space. It is the size of an American football field and has a crew of six. With a living volume of 358 m³, it has more interior room than the cargo beds of two American 18-wheeler trucks. However, because of the microgravity environment of the space station, there are not always well-defined walls, floors, and ceilings and all pressurized areas can be utilized as living and working space. The International Space Station is still under construction. Modules were primarily launched using the Space Shuttle until its deactivation and were assembled by its crew with the help of the working crew on board the space station. ISS modules were often designed and built to barely fit inside the shuttle's payload bay, which is cylindrical with a 4.6 meter diameter.Life aboard the space station is distinct from terrestrial life in some very interesting ways. Astronauts commonly "float" objects to one another; for example they will give a clipboard an initial nudge and it will coast to its receiver across the room. In fact, an astronaut can become so accustomed to this habit that they forget that it doesn't work anymore when they return to Earth. The diet of ISS spacefarers is a combination of participating nations' space food. Each astronaut selects a personalized menu before flight. Many food choices reflect the cultural differences of the astronauts, such as bacon and eggs vs. fish products for breakfast (for the United States and Russia, respectively). More recently such delicacies as Japanense beef curry, kimchi, and swordfish (Riviera style) have been featured on the orbiting outpost. As much of ISS food is dehydrated or sealed in pouches MRE-style, astronauts are quite excited to get relatively fresh food from shuttle and Progress resupply missions. Food is stored in packages that facilitate eating in microgravity by keeping the food constrained to the table. Spent packaging and trash must be collected to load into an available spacecraft for disposal. Waste management is not nearly as straight forward as it is on Earth. The ISS has many windows for observing Earth and space, one of the astronauts' favorite leisure activities. Since the Sun rises every 90 minutes, the windows are covered at "night" to help maintain the 24-hour sleep cycle.
|
Space architecture
|
Varieties
|
When a shuttle is operating in low Earth orbit, the ISS serves as a safety refuge in case of emergency. The inability to fall back on the safety of the ISS during the latest Hubble Space Telescope Servicing Mission (because of different orbital inclinations) was the reason a backup shuttle was summoned to the launch pad. So, ISS astronauts operate with the mindset that they may be called upon to give sanctuary to a Shuttle crew should something happen to compromise a mission. The International Space Station is a colossal cooperative project between many nations. The prevailing atmosphere on board is one of diversity and tolerance. This does not mean that it is perfectly harmonious. Astronauts experience the same frustrations and interpersonal quarrels as their Earth-based counterparts.
|
Space architecture
|
Varieties
|
A typical day on the station might start with wakeup at 6:00 am inside a private soundproof booth in the crew quarters. Astronauts would probably find their sleeping bags in an upright position tied to the wall, because orientation does not matter in space. The astronaut's thighs would be lifted about 50 degrees off the vertical. This is the neutral body posture in weightlessness – it would be excessively tiring to "sit" or "stand" as is common on Earth. Crawling out of his booth, an astronaut may chat with other astronauts about the day's science experiments, mission control conferences, interviews with Earthlings, and perhaps even a space walk or space shuttle arrival.
|
Space architecture
|
Varieties
|
Bigelow Aerospace Bigelow Aerospace took the unique step in securing two patents NASA held from development of the Transhab concept in regard to inflatable space structures. The company now has sole rights to commercial development of the inflatable module technology. On July 12, 2006, the Genesis I experimental space habitat was launched into low Earth orbit. Genesis I demonstrated the basic viability of inflatable space structures, even carrying a payload of life science experiments. The second module, Genesis II, was launched into orbit on June 28, 2007, and tested out several improvements over its predecessor. Among these are reaction wheel assemblies, a precision measurement system for guidance, nine additional cameras, improved gas control for module inflation, and an improved on-board sensor suite.While Bigelow architecture is still modular, the inflatable configuration allows for much more interior volume than rigid modules. The BA-330, Bigelow's full-scale production model, has more than twice the volume of the largest module on the ISS. Inflatable modules can be docked to rigid modules and are especially well suited for crew living and working quarters. In 2009 NASA began considering attaching a Bigelow module to the ISS, after abandoning the Transhab concept more than a decade before. The modules will likely have a solid inner core for structural support. Surrounding usable space could be partitioned into different rooms and floors. The Bigelow Expandable Activity Module (BEAM) was transported to ISS arriving on April 10, 2016, inside the unpressurized cargo trunk of a SpaceX Dragon during the SpaceX CRS-8 cargo mission.Bigelow Aerospace may choose to launch many of their modules independently, leasing their use to a wide variety of companies, organizations, and countries that can't afford their own space programs. Possible uses of this space include microgravity research and space manufacturing. Or we may see a private space hotel composed of numerous Bigelow modules for rooms, observatories, or even a recreational padded gymnasium. There is the option of using such modules for habitation quarters on long-term space missions in the Solar System. One amazing aspect of spaceflight is that once a craft leaves an atmosphere, aerodynamic shape is a non-issue. For instance it's possible to apply a Trans Lunar Injection to an entire space station and send it to fly by the Moon. Bigelow has expressed the possibility of their modules being modified for lunar and Martian surface systems as well. However, it is out of business since March 2020.
|
Space architecture
|
Varieties
|
Lunar Lunar architecture exists both in theory and in practice. Today the archeological artifacts of temporary human outposts lay untouched on the surface of the Moon. Five Apollo Lunar Module descent stages stand upright in various locations across the equatorial region of the Near Side, hinting at the extraterrestrial endeavors of mankind. The leading hypothesis on the origin of the Moon did not gain its current status until after lunar rock samples were analysed. The Moon is the furthest any humans have ever ventured from their home, and space architecture is what kept them alive and allowed them to function as humans.
|
Space architecture
|
Varieties
|
Apollo On the cruise to the Moon, Apollo astronauts had two "rooms" to choose from – the Command Module (CM) or the Lunar Module (LM). This can be seen in the film Apollo 13 where the three astronauts were forced to use the LM as an emergency life boat. Passage between the two modules was possible through a pressurized docking tunnel, a major advantage over the Soviet design, which required donning a spacesuit to switch modules. The Command Module featured five windows made of three thick panes of glass. The two inner panes, made of aluminosilicate, ensured no cabin air leaked into space. The outer pane served as a debris shield and part of the heat shield needed for atmospheric reentry. The CM was a sophisticated spacecraft with all the systems required for successful flight but with an interior volume of 6.17 m3 could be considered cramped for three astronauts. It had its design weaknesses such as no toilet (astronauts used much-hated 'relief tubes' and fecal bags). The coming of the space station would bring effective life support systems with waste management and water reclamation technologies.
|
Space architecture
|
Varieties
|
The Lunar Module had two stages. A pressurized upper stage, termed the ascent stage, was the first true spaceship as it could only operate in the vacuum of space. The descent stage carried the engine used for descent, landing gear and radar, fuel and consumables, the famous ladder, and the Apollo Lunar Rover during later Apollo missions. The idea behind staging is to reduce mass later in a flight, and is the same strategy used in an Earth-launched multistage rocket. The LM pilot stood up during the descent to the Moon. Landing was achieved via automated control with a manual backup mode. There was no airlock on the LM so the entire cabin had to be evacuated (air vented to space) in order to send an astronaut out to walk on the surface. To stay alive, both astronauts in the LM would have to get in their space suits at this point. The Lunar Module worked well for what it was designed to do. However, a big unknown remained throughout the design process – the effects of lunar dust.
|
Space architecture
|
Varieties
|
Every astronaut who walked on the Moon tracked in lunar dust, contaminating the LM and later the CM during Lunar Orbit Rendezvous. These dust particles can't be brushed away in a vacuum, and have been described by John Young of Apollo 16 as being like tiny razor blades. It was soon realized that for humans to live on the Moon, dust mitigation was one of many issues that had to be taken seriously.
|
Space architecture
|
Varieties
|
Constellation program The Exploration Systems Architecture Study that followed the Vision for Space Exploration of 2004 recommended the development of a new class of vehicles that have similar capabilities to their Apollo predecessors with several key differences. In part to retain some of the Space Shuttle program workforce and ground infrastructure, the launch vehicles were to use Shuttle-derived technologies. Secondly, rather than launching the crew and cargo on the same rocket, the smaller Ares I was to launch the crew with the larger Ares V to handle the heavier cargo. The two payloads were to rendezvous in low Earth orbit and then head to the Moon from there. The Apollo Lunar Module could not carry enough fuel to reach the polar regions of the Moon but the Altair lunar lander was intended to access any part of the Moon. While the Altair and surface systems would have been equally necessary for Constellation program to reach fruition, the focus was on developing the Orion spacecraft to shorten the gap in U.S. access to orbit following the retirement of the Space Shuttle in 2010.
|
Space architecture
|
Varieties
|
Even NASA has described Constellation architecture as 'Apollo on steroids'. Nonetheless, a return to the proven capsule design is a move welcomed by many.
|
Space architecture
|
Varieties
|
Martian Martian architecture is architecture designed to sustain human life on the surface of Mars, and all the supporting systems necessary to make this possible. The direct sampling of water ice on the surface, and evidence for geyser-like water flows within the last decade have made Mars the most likely extraterrestrial environment for finding liquid water, and therefore alien life, in the Solar System. Moreover, some geologic evidence suggests that Mars could have been warm and wet on a global scale in its distant past. Intense geologic activity has reshaped the surface of the Earth, erasing evidence of our earliest history. Martian rocks can be even older than Earth rocks, though, so exploring Mars may help us decipher the story of our own geologic evolution including the origin of life on Earth. Mars has an atmosphere, though its surface pressure is less than 1% of Earth's. Its surface gravity is about 38% of Earth's. Although a human expedition to Mars has not yet taken place, there has been significant work on Martian habitat design. Martian architecture would usually fall into one of two categories: architecture imported from Earth fully assembled and architecture making use of local resources.
|
Space architecture
|
Varieties
|
Von Braun and other early proposals Wernher von Braun was the first to come up with a technically comprehensive proposal for a crewed Mars expedition. Rather than a minimal mission profile like Apollo, von Braun envisioned a crew of 70 astronauts aboard a fleet of ten massive spacecraft. Each vessel would be constructed in low Earth orbit, requiring nearly 100 separate launches before one was fully assembled. Seven of the spacecraft would be for crew while three were designated as cargo ships. There were even designs for small "boats" to shuttle crew and supplies between ships during the cruise to the Red Planet, which was to follow a minimum-energy Hohmann transfer trajectory. This mission plan would involve one-way transit times on the order of eight months and a long stay at Mars, creating the need for long-term living accommodations in space. Upon arrival at the Red Planet, the fleet would brake into Mars orbit and would remain there until the seven human vessels were ready to return to Earth. Only landing gliders, which were stored in the cargo ships, and their associated ascent stages would travel to the surface. Inflatable habitats would be constructed on the surface along with a landing strip to facilitate further glider landings. All necessary propellant and consumables were to be brought from Earth in von Braun's proposal. Some crew remained in the passenger ships during the mission for orbit-based observation of Mars and to maintain the ships. The passenger ships had habitation spheres 20 meters in diameter. Because the average crew member would spend much time in these ships (around 16 months of transit plus rotating shifts in Mars orbit), habitat design for the ships was an integral part of this mission.
|
Space architecture
|
Varieties
|
Von Braun was aware of the threat posed by extended exposure to weightlessness. He suggested either tethering passenger ships together to spin about a common center of mass or including self-rotating, dumbbell-shaped "gravity cells" to drift alongside the flotilla to provide each crew member with a few hours of artificial gravity each day. At the time of von Braun's proposal, little was known of the dangers of solar radiation beyond Earth and it was cosmic radiation that was thought to present the more formidable challenge. The discovery of the Van Allen belts in 1958 demonstrated that the Earth was shielded from high energy solar particles. For the surface portion of the mission, inflatable habitats suggest the desire to maximize living space. It is clear von Braun considered the members of the expedition part of a community with much traffic and interaction between vessels.
|
Space architecture
|
Varieties
|
The Soviet Union conducted studies of human exploration of Mars and came up with slightly less epic mission designs (though not short on exotic technologies) in 1960 and 1969. The first of which used electric propulsion for interplanetary transit and nuclear reactors as the power plants. On spacecraft that combine human crew and nuclear reactors, the reactor is usually placed at a maximum distance from the crew quarters, often at the end of a long pole, for radiation safety. An interesting component of the 1960 mission was the surface architecture. A "train" with wheels for rough terrain was to be assembled of landed research modules, one of which was a crew cabin. The train was to traverse the surface of Mars from south pole to north pole, an extremely ambitious goal even by today's standards. Other Soviet plans such as the TMK eschewed the large costs associated with landing on the Martian surface and advocated piloted (crewed) flybys of Mars. Flyby missions, like the lunar Apollo 8, extend the human presence to other worlds with less risk than landings. Most early Soviet proposals called for launches using the ill-fated N1 rocket. They also usually involved fewer crew than their American counterparts. Early Martian architecture concepts generally featured assembly in low Earth orbit, bringing all needed consumables from Earth, and designated work vs. living areas. The modern outlook on Mars exploration is not the same.
|
Space architecture
|
Varieties
|
Recent initiatives In every serious study of what it would take to land humans on Mars, keep them alive, and then return them to Earth, the total mass required for the mission is simply stunning. The problem lies in that to launch the amount of consumables (oxygen, food and water) even a small crew would go through during a multi-year Mars mission, it would take a very large rocket with the vast majority of its own mass being propellant. This is where multiple launches and assembly in Earth orbit come from. However even if such a ship stocked full of goods could be put together in orbit, it would need an additional (large) supply of propellant to send it to Mars. The delta-v, or change in velocity, required to insert a spacecraft from Earth orbit to a Mars transfer orbit is many kilometers per second. When we think of getting astronauts to the surface of Mars and back home we quickly realize that an enormous amount of propellant is needed if everything is taken from the Earth. This was the conclusion reached in the 1989 '90-Day Study' initiated by NASA in response to the Space Exploration Initiative.
|
Space architecture
|
Varieties
|
Several techniques have changed the outlook on Mars exploration. The most powerful of which is in-situ resource utilization. Using hydrogen imported from Earth and carbon dioxide from the Martian atmosphere, the Sabatier reaction can be used to manufacture methane (for rocket propellant) and water (for drinking and for oxygen production through electrolysis). Another technique to reduce Earth-brought propellant requirements is aerobraking. Aerobraking involves skimming the upper layers of an atmosphere, over many passes, to slow a spacecraft down. It's a time-intensive process that shows most promise in slowing down cargo shipments of food and supplies. NASA's Constellation program does call for landing humans on Mars after a permanent base on the Moon is demonstrated, but details of the base architecture are far from established. It is likely that the first permanent settlement will consist of consecutive crews landing prefabricated habitat modules in the same location and linking them together to form a base.In some of these modern, economy models of the Mars mission, we see the crew size reduced to a minimal 4 or 6. Such a loss in variety of social relationships can lead to challenges in forming balanced social responses and forming a complete sense of identity. It follows that if long-duration missions are to be carried out with very small crews, then intelligent selection of crew is of primary importance. Role assignments is another open issue in Mars mission planning. The primary role of 'pilot' is obsolete when landing takes only a few minutes of a mission lasting hundreds of days, and when that landing will be automated anyway. Assignment of roles will depend heavily on the work to be done on the surface and will require astronauts to assume multiple responsibilities. As for surface architecture inflatable habitats, perhaps even provided by Bigelow Aerospace, remain a possible option for maximizing living space. In later missions, bricks could be made from a Martian regolith mixture for shielding or even primary, airtight structural components. The environment on Mars offers different opportunities for space suit design, even something like the skin-tight Bio-Suit.
|
Space architecture
|
Varieties
|
A number of specific habitat design proposals have been put forward, to varying degrees of architectural and engineering analysis. One recent proposal—and the winner of NASA's 2015 Mars Habitat Competition—is Mars Ice House. The design concept is for a Mars surface habitat, 3d-printed in layers out of water ice on the interior of an Earth-manufactured inflatable pressure-retention membrane. The completed structure would be semi-transparent, absorbing harmful radiation in several wavelengths, while admitting approximately 50 percent of light in the visible spectrum. The habitat is proposed to be entirely set up and built from an autonomous robotic spacecraft and bots, although human habitation with approximately 2–4 inhabitants is envisioned once the habitat is fully built and tested.
|
Space architecture
|
Robotic
|
It is widely accepted that robotic reconnaissance and trail-blazer missions will precede human exploration of other worlds. Making an informed decision on which specific destinations warrant sending human explorers requires more data than what the best Earth-based telescopes can provide. For example, landing site selection for the Apollo Moon landings drew on data from three different robotic programs: the Ranger program, the Lunar Orbiter program, and the Surveyor program. Before a human was sent, robotic spacecraft mapped the lunar surface, proved the feasibility of soft landings, filmed the terrain up close with television cameras, and scooped and analysed the soil.A robotic exploration mission is generally designed to carry a wide variety of scientific instruments, ranging from cameras sensitive to particular wavelengths, telescopes, spectrometers, radar devices, accelerometers, radiometers, and particle detectors to name a few. The function of these instruments is usually to return scientific data but it can also be to give an intuitive "feel" of the state of the spacecraft, allowing a subconscious familiarization with the territory being explored, through telepresence. A good example of this is the inclusion of HDTV cameras on the Japanese lunar orbiter SELENE. While purely scientific instruments could have been brought in their stead, these cameras allow the use of an innate sense to perceive the exploration of the Moon.
|
Space architecture
|
Robotic
|
The modern, balanced approach to exploring an extraterrestrial destination involves several phases of exploration, each of which needs to produce rationale for progressing to the next phase. The phase immediately preceding human exploration can be described as anthropocentric sensing, that is, sensing designed to give humans as realistic a feeling as possible of actually exploring in person. More, the line between a human system and a robotic system in space is not always going to be clear. As a general rule, the more formidable the environment, the more essential robotic technology is. Robotic systems can be broadly considered part of space architecture when their purpose is to facilitate the habitation of space or extend the range of the physiological senses into space.
|
Space architecture
|
Future
|
The future of space architecture hinges on the expansion of human presence in space. Under the historical model of government-orchestrated exploration missions initiated by single political administrations, space structures are likely to be limited to small-scale habitats and orbital modules with design life cycles of only several years or decades. The designs, and thus architecture, will generally be fixed and without real time feedback from the spacefarers themselves. The technology to repair and upgrade existing habitats, a practice widespread on Earth, is not likely to be developed under short term exploration goals. If exploration takes on a multi-administration or international character, the prospects for space architecture development by the inhabitants themselves will be broader. Private space tourism is a way the development of space and a space transportation infrastructure can be accelerated. Virgin Galactic has indicated plans for an orbital craft, SpaceShipThree. The demand for space tourism is one without bound. It is not difficult to imagine lunar parks or cruises by Venus. Another impetus to become a spacefaring species is planetary defense.
|
Space architecture
|
Future
|
The classic space mission is the Earth-colliding asteroid interception mission. Using nuclear detonations to split or deflect the asteroid is risky at best. Such a tactic could actually make the problem worse by increasing the amount of asteroid fragments that do end up hitting the Earth. Robert Zubrin writes: If bombs are to be used as asteroid deflectors, they cannot just be launched willy-nilly. No, before any bombs are detonated, the asteroid will have to be thoroughly explored, its geology assessed, and subsurface bomb placements carefully determined and precisely located on the basis of such knowledge. A human crew, consisting of surveyors, geologists, miners, drillers, and demolition experts, will be needed on the scene to do the job right. If such a crew is to be summoned to a distant asteroid, there may be less risky ways to divert the asteroid. Another promising asteroid mitigation strategy is to land a crew on the asteroid well ahead of its impact date and to begin diverting some its mass into space to slowly alter its trajectory. This is a form of rocket propulsion by virtue of Newton's third law with the asteroid's mass as the propellant. Whether exploding nuclear weapons or diversion of mass is used, a sizable human crew may need to be sent into space for many months if not years to accomplish this mission. Questions such as what the astronauts will live in and what the ship will be like are questions for the space architect.
|
Space architecture
|
Future
|
When motivations to go into space are realized, work on mitigating the most serious threats can begin. One of the biggest threats to astronaut safety in space is sudden radiation events from solar flares. The violent solar storm of August 1972, which occurred between the Apollo 16 and Apollo 17 missions, could have produced fatal consequences had astronauts been caught exposed on the lunar surface. The best known protection against radiation in space is shielding; an especially effective shield is water contained in large tanks surrounding the astronauts. Unfortunately water has a mass of 1000 kilograms per cubic meter. A more practical approach would be to construct solar "storm shelters" that spacefarers can retreat to during peak events. For this to work, however, there would need to be a space weather broadcasting system in place to warn astronauts of upcoming storms, much like a tsunami warning system warns coastal inhabitants of impending danger. Perhaps one day a fleet of robotic spacecraft will orbit close to the Sun, monitoring solar activity and sending precious minutes of warning before waves of dangerous particles arrive at inhabited regions of space.
|
Space architecture
|
Future
|
Nobody knows what the long-term human future in space will be. Perhaps after gaining experience with routine spaceflight by exploring different worlds in the Solar System and deflecting a few asteroids, the possibility of constructing non-modular space habitats and infrastructure will be within capability. Such possibilities include mass drivers on the Moon, which launch payloads into space using only electricity, and spinning space colonies with closed ecological systems. A Mars in the early stages of terraformation, where inhabitants only need simple oxygen masks to walk out on the surface, may be seen. In any case, such futures require space architecture.
|
Cold shrink tubing
|
Cold shrink tubing
|
Cold shrink tubing is an open ended rubber sleeve, made primarily from rubber elastomers with high-performance physical properties, that has been factory expanded or pre-stretched, and assembled onto a supporting removable plastic core. Cold shrink tubing shrinks upon removal of the supporting core during the installation process and the electrician slides the tube over the cable to be jointed, terminated or abandoned and unwinds the core, causing the tube to collapse down, or contract, in place. The following video demonstrates the installation process of using Cold Shrink to abandon power cables.
|
Cold shrink tubing
|
Cold shrink tubing
|
Cold shrink tubing is used to insulate wires, connections, joints and terminals in electrical work. It can also be used to repair wires, bundle wires together, and to protect wires or small parts from minor abrasion.
It needs storage in controlled environments with temperatures not exceeding 43 degrees Celsius.
|
Phenylbutazone
|
Phenylbutazone
|
Phenylbutazone, often referred to as "bute", is a nonsteroidal anti-inflammatory drug (NSAID) for the short-term treatment of pain and fever in animals.
|
Phenylbutazone
|
Phenylbutazone
|
In the United States and United Kingdom, it is no longer approved for human use (except in the United Kingdom for ankylosing spondylitis), as it can cause severe adverse effects such as suppression of white blood cell production and aplastic anemia. This drug was implicated in the 2013 meat adulteration scandal. Positive phenylbutazone tests in horse meat were uncommon in the UK, however.
|
Phenylbutazone
|
Uses
|
In humans Phenylbutazone was originally made available for use in humans for the treatment of rheumatoid arthritis and gout in 1949. However, it is no longer approved, and therefore not marketed, for any human use in the United States. In the UK it is used to treat ankylosing spondylitis, but only when other therapies are unsuitable.
|
Phenylbutazone
|
Uses
|
In horses Phenylbutazone is the most commonly used NSAID for horses in the United States. It is used for the following purposes: Analgesia: It is used for pain relief from infections and musculoskeletal disorders, including sprains, overuse injuries, tendinitis, arthralgias, arthritis, and laminitis. Like other NSAIDs, it acts directly on musculoskeletal tissue to control inflammation, thereby reducing secondary inflammatory damage, alleviating pain, and restoring range of motion. It does not cure musculoskeletal ailments or work well on colic pain.
|
Phenylbutazone
|
Uses
|
Antipyresis: It is used for reduction of fevers. Its antipyretic qualities may mask other symptoms.
|
Phenylbutazone
|
Uses
|
History of phenylbutazone in racing In the 1968 Kentucky Derby, Dancer's Image, the winner of the race, was disqualified after traces of phenylbutazone were allegedly discovered in a post-race urinalysis. Owned by prominent Massachusetts businessman Peter D. Fuller and ridden by jockey Bobby Ussery, Dancer's Image was the first horse to win the Kentucky Derby and then be disqualified. Phenylbutazone was legal on most tracks around the United States in 1968, but had not yet been approved by Churchill Downs.
|
Phenylbutazone
|
Uses
|
Controversy and speculation still surround the incident. In the weeks prior to the race, Fuller had given previous winnings to Coretta Scott King, the widow of slain civil rights activist Martin Luther King Jr., which brought both praise and criticism. The previous year, King held a sit-in against housing discrimination which disrupted Derby week. Forty years later, Fuller still believed Dancer's Image was disqualified due to these events.Although Forward Pass had been named the winner, after many appeals the Kentucky Derby official website lists both Dancer's Image and Forward Pass as the winner. The website's race video commentary states that on the winner's plaque at Churchill Downs, both Dancer's Image and Forward Pass are listed as the 1968 winner of the Kentucky Derby.
|
Phenylbutazone
|
Uses
|
In dogs Phenylbutazone is occasionally used in dogs for the longer-term management of chronic pain, particularly due to osteoarthritis. About 20% of adult dogs are affected with osteoarthritis, which makes the management of musculoskeletal pain a major component of companion animal practice. The margin of safety for all NSAIDs is narrow in the dog, and other NSAIDs are more commonly used (etodolac, and carprofen). Gastrointestinal-protectant drugs, such as misoprostol, cimetidine, omeprazole, ranitidine, or sucralfate, are frequently included as a part of treatment with any NSAID. Dogs receiving chronic phenylbutazone therapy should be followed with regular blood work and renal monitoring.Side effects of phenylbutazone in dogs include gastrointestinal (GI) ulceration, bone marrow depression, rashes, malaise, blood dyscrasias, and diminished renal blood flow.
|
Phenylbutazone
|
Dosage and administration in horses
|
Phenylbutazone has a plasma elimination half-life of 4–8 hours, however the inflammatory exudate half life is 24 hours, so single daily dosing can be sufficient, although it is often used twice per day. The drug is considered fairly non-toxic when given at appropriate doses (2.2-4.4 mg/kg/day), even when used repeatedly. This dose has been doubled for diseases that cause severe pain, such as laminitis, but is toxic if repeated long-term, and exceptionally high doses (15 mg/kg/d or higher) can kill the animal in less than a week.Phenylbutazone can be administered orally (via paste, powder or feed-in) or intravenously. It should not be given intramuscularly or injected in any place other than a vein, as it can cause tissue damage. Tissue damage and edema may also occur if the drug is injected repetitively into the same vein.
|
Phenylbutazone
|
Side effects and disadvantages
|
Side effects of phenylbutazone are similar to those of other NSAIDs. Overdose or prolonged use can cause gastrointestinal ulcers, blood dyscrasia, kidney damage (primarily dose-dependant renal papillary necrosis), oral lesions if given by mouth, and internal hemorrhage. This is especially pronounced in young, ill, or stressed horses which are less able to metabolize the drug. Effects of gastrointestinal damage include edema of the legs and belly secondary to leakage of blood proteins into the intestines, resulting in decreased appetite, excessive thirst, weight loss, weakness, and in advanced stages, kidney failure and death. Phenylbutazone can also cause agranulocytosis.
|
Phenylbutazone
|
Side effects and disadvantages
|
Phenylbutazone amplifies the anticoagulant effect of vitamin K antagonists such as warfarin or phenprocoumon. Phenylbutazone displaces warfarin from plasma binding sites, and toxic blood levels leading to haemorrhage can occur. It may aggravate kidney or liver problems.
Phenylbutazone may be toxic to the embryo and can be transferred via the umbilical cord and by milk.
Phenylbutazone can be used in foals. Premature foals, septicemic foals, foals with questionable kidney or liver function and foals with diarrhea require careful monitoring. Drugs to protect the GI tract such as omeprazole, cimetidine, and sucralfate are frequently used with phenylbutazone.
High doses of phenylbutazone may be considered a rules violation under some equestrian organizations, as the drug may remain in the bloodstream four to five days after administration.
The International Agency for Research on Cancer places it in Group 3; i.e., "not classifiable as to its carcinogenicity to humans".
Use in horses is limited to those not intended for food. Metabolites of phenylbutazone can cause aplastic anaemia in humans.
|
Phenylbutazone
|
Investigations into potential carcinogenicity
|
Opinions are conflicting regarding the carcinogenicity of phenylbutazone in animals; no evidence indicates it causes cancer in humans at therapeutic doses. Maekawa et al. (1987) found no increased cancer incidence in DONRYU rats fed a diet containing 0.125% or 0.25% phenylbutazone over two years. On the other hand, Kari et al. (1995) found a rare type of kidney cancer in rats (13 of 100) and an increased rate of liver cancer in male rats fed 150 and 300 mg/kg body weight of phenylbutazone for two years. Tennant (1993) listed phenylbutazone as a non-mutagenic carcinogen. Kirkland and Fowler (2010) acknowledged that, while phenylbutazone is not predicted to be a mutagen by computer software that simulates the chemicals interaction with DNA, one laboratory study indicated phenylbutazone subtly altered the structure of chromosomes of bone marrow cells of mice. Kirkland and Fowler (2010) furthermore explained that the theoretical carcinogenic effects of phenylbutazone in humans cannot be studied because patients prescribed the drug were given doses far below the level any effect may become apparent (<1 mM). The World Health Organization's International Agency For Research On Cancer (IARC) stated in 1987 that there was inadequate evidence for a carcinogenic effect in humans.
|
Phenylbutazone
|
Interactions
|
Other anti-inflammatory drugs that tend to cause GI ulcers, such as corticosteroids and other NSAIDs, can potentiate the bleeding risk. Combination with anticoagulant drugs, particularly coumarin derivatives, also increases the risk of bleeding. Avoid combining with other hepatotoxic drugs.
Phenylbutazone may affect blood levels and duration of action of phenytoin, valproic acid, sulfonamides, sulfonylurea antidiabetic agents, barbiturates, promethazine, rifampicin, chlorpheniramine, diphenhydramine, and penicillin G.
|
Phenylbutazone
|
Overdose
|
Overdoses of phenylbutazone can cause kidney failure, liver injury, bone marrow suppression, and gastric ulceration or perforation. Early signs of toxicity include loss of appetite, and depression.
|
Phenylbutazone
|
Chemistry
|
Phenylbutazone is a crystalline substance. It is obtained by condensation of diethyl n-butylmalonate with hydrazobenzene in the presence of base. In effect, this represents the formation of the heterocyclic system by simple lactamization.
Oxyphenbutazone, the major metabolite of phenylbutazone, differs only in the para location of one of its phenyl groups, where a hydrogen atom is replaced by a hydroxyl group (making it 4-butyl-1-(4-hydroxyphenyl)-2-phenyl-3,5-pyrazolidinedione).
|
Hang Ten
|
Hang Ten
|
"hang ten" is a nickname for any of several maneuvers used in sports, especially surfing, wherein all ten toes or fingers are used to accomplish the maneuver.
surfing: the surfer stands and hangs all their toes over the nose of the board. Usually this can only be done on a heavy longboard.
basketball: the basketball player dunks the ball and hangs onto the hoop.
BMX: a flatland move.
Jiu Jitsu: any of an infinite number, of grips, chokes, escapes, or maneuvers where play involves all toes touching the mat or all ten fingers gripping Gi or swimming to some void somewhere to create or escape a dominant position. Gripping Gi skateboarding: a nose manual named after the surfing maneuver.
|
Windows Media Services
|
Windows Media Services
|
Windows Media Services (WMS) is streaming media server software from Microsoft that allows a Windows Server administrator to generate streaming media (audio/video). Only Windows Media, JPEG, and MP3 formats are supported. WMS is the successor of NetShow Services.In addition to streaming, WMS also has the ability to cache and record streams, enforce authentication, impose various connection limits, restrict access, use multiple protocols, generate usage statistics, and apply forward error correction (FEC). It can also handle a high number of concurrent connections making it suitable for content providers. Streams can also be distributed between servers as part of a distribution network where each server ultimately feeds a different network/audience. Both unicast and multicast streams are supported (multicast streams also use a proprietary and partially encrypted Windows Media Station (*.nsc) file for use by a player.) Typically, Windows Media Player is used to decode and watch/listen to the streams, but other players are also capable of playing unencrypted Windows Media content (Microsoft Silverlight, VLC, MPlayer, etc.) 64-bit versions of Windows Media Services are also available for increased scalability. The Scalable Networking Pack for Windows Server 2003 adds support for network acceleration and hardware-based offloading, which boosts Windows Media server performance. The newest version, Windows Media Services 2008, for Windows Server 2008, includes a built-in WMS Cache/Proxy plug-in which can be used to configure a Windows Media server either as a cache/proxy server or as a reverse proxy server so that it can provide caching and proxy support to other Windows Media servers. Microsoft claims that these offloading technologies nearly double the scalability, making Windows Media Services, according to the claim, the industry's most powerful streaming media server.Windows Media Services 2008 is no longer included with the setup files for the Windows Server 2008 operating system, but is available as a free download. It is also not supported on Windows Server 2012, having been replaced with IIS Media Services.
|
Windows Media Services
|
Releases
|
NetShow Server 3.0 (Windows NT 4.0) NetShow Services 4.0 (Windows NT 4.0 SP3 or later) Windows Media Services 4.1 (Included in Windows 2000 Server family and downloadable for previous Windows versions) Windows Media Services 9 Series (Included in Windows Server 2003, works with IIS 6) Windows Media Services 2008 (Downloadable for Windows Server 2008, works with IIS 7)
|
Tai chi
|
Tai chi
|
Tai chi (simplified Chinese: 太极拳; traditional Chinese: 太極拳; lit. 'Grand Ultimate Boxing') is an internal Chinese martial art practiced for self-defense and health. Known for its slow, intentional movements, Tai chi has practitioners worldwide and is particularly popular as a form of gentle exercise and moving meditation, with benefits to mental and physical health.
|
Tai chi
|
Tai chi
|
Many forms of tai chi are practiced, both traditional and modern. While the precise origins are not known, the earliest documented practice is from Chen Village, Henan. Most modern styles trace their development to the five traditional schools: Chen, Yang, Wu (Hao), Wu, and Sun. Practitioners such as Yang Chengfu and Sun Lutang in the early 20th century promoted the art for its health benefits. Tai chi was included in the UNESCO List of Intangible Cultural Heritage of Humanity in 2020.
|
Tai chi
|
Etymology
|
The name "tai chi", the most common English spelling, is not a standard romanization of the Chinese name for the art (simplified Chinese: 太极拳; traditional Chinese: 太極拳; lit. 'Taiji boxing'). The Chinese name was first commonly written in English using the Wade–Giles system as "tʻai chi chʻüan". But English speakers abbreviated it to "tʻai chi" and dropped the mark of aspiration. Since the late twentieth century, pinyin has replaced Wade–Giles as the most popular system for romanizing Chinese. In pinyin, tai chi is spelled taijiquan (tàijíquán). In English, tai chi is sometimes referred to as "shadowboxing".
|
Tai chi
|
Etymology
|
The etymology of tai chi's Chinese name is somewhat uncertain because of the lack of a record of spoken usage. Before the mid-nineteenth century, it appears that outsiders generically described the art as zhanquan (沾拳, "touch boxing"), "Long Boxing"(長拳), mianquan ("Soft/Cotton/Neutralizing Boxing"; 軟/棉/化拳) or shisan shi (十三式, "the thirteen techniques"). In the mid-nineteenth century, the art began to be associated with the philosophy of taiji (see Conceptual background). This association may have originated in the writings of the founders of Wu (Hao)-style tai chi, perhaps inspired by a tai chi classic attributed to the semi-mythical Wang Zongyue that begins with the words "Taiji is born from Wuji; it is the mother of Yin and Yang". However, as the Wu (Hao) founders had no financial need to promote their art, their contributions to the "tai chi classics" were not distributed widely for many years. The first public association between taiji and the art was a poem by Imperial Court scholar Weng Tonghe describing a tai chi performance by Yang Luchan. It is not clear whether Weng was making a new connection or whether the new name was already in use. Written evidence for the Yang family's adoption of the name taiji first appeared in a later text, possibly completed in 1875 by Yang Luchan's son, Yang Banhou, or no later than the first decade of the twentieth century by one or more of Yang Banhou's disciples. By the second decade of the twentieth century, Yang Chengfu's disciples and Sun Lutang were using the term taijiquan in their publications, including in the titles of some of the tai chi classics. It then appeared in a book by a Chen family member, Chen Xin, published after he died in 1929.
|
Tai chi
|
Philosophical background
|
Chinese philosophy, particularly Taoist and Confucian thought, forms the conceptual background to tai chi. Early tai chi texts include embedded quotations from early Chinese classics like the I Ching, Great Learning, Book of Documents, Records of the Grand Historian, and Zhuangzi, as well as from famous Chinese thinkers like Zhu Xi, Zhou Dunyi, and Mencius.Early tai chi sources are grounded in Taiji cosmology. Taiji cosmology appears in both Taoist and Confucian philosophy, where it represents the single source or mother of yin and yang (represented by the taijitu symbol ). Tai chi also draws on Chinese theories of the body, particularly Taoist neidan (internal alchemy) teachings on qi (vital energy) and on the three dantian. Cheng Man-ch'ing emphasizes the Taoist background of tai chi and states that it "enables us to reach the stage of undifferentiated pure yang, which is exactly the same as Laozi's 'concentrating the qi and developing softness'".As such, tai chi considers itself an "internal" (neijia) martial art focused on developing qi. In China, tai chi is categorized under the Wudang group of Chinese martial arts—that is, arts applied with internal power. Although the term Wudang suggests these arts originated in the Wudang Mountains, it is used only to distinguish the skills, theories, and applications of neijia from those of the Shaolin grouping, or waijia (hard/external styles).Tai chi also adopts the Taoist ideals of softness overcoming hardness, of wu wei (effortless action), and of yielding into its martial art technique while also retaining Taoist ideas of spiritual self-cultivation.Tai chi's path is one of developing naturalness by relaxing, attending inward, and slowing mind, body, and breath. This allows the practitioner to become less tense, to drop conditioned habits, to let go of thoughts, to allow qi to flow smoothly, and thus to flow with the Tao. It is thus a kind of moving meditation that allows us to let go of the self and experience no-mind (wuxin) and spontaneity (ziran).A key aspect of tai chi philosophy is to work with the flow of yin (softness) and yang (hardness) elements. When two forces push each other with equal force, neither side moves. Motion cannot occur until one side yields. Therefore, a key principle in tai chi is to avoid using force directly against force (hardness against hardness). Laozi provided the archetype for this in the Tao Te Ching when he wrote, "The soft and the pliable will defeat the hard and strong." Conversely, when in possession of leverage, one may want to use hardness to force the opponent to become soft. Traditionally, tai chi uses both soft and hard. Yin is said to be the mother of Yang, using soft power to create hard power.
|
Tai chi
|
Philosophical background
|
Traditional schools also emphasize that one is expected to show wude ("martial virtue/heroism"), to protect the defenseless, and to show mercy to one's opponents.In December 2020, the 15th regular session of the UNESCO Intergovernmental Committee for the Safeguarding of the Intangible Cultural Heritage included tai chi in the UNESCO Representative List of the Intangible Cultural Heritage of Humanity.
|
Tai chi
|
Practice
|
Traditionally, the foundational tai chi practice consists of learning and practicing a specific solo forms or routines (taolu). This entails learning a routine sequence of movements that emphasize a straight spine, abdominal breathing and a natural range of motion. Tai chi relies on knowing the appropriate change in response to outside forces, as well as on yielding to and redirecting an attack, rather than meeting it with opposing force. Physical fitness is also seen as an important step towards effective self-defense.
|
Tai chi
|
Practice
|
Tai chi movements were inspired by animals, "particularly...birds and" leopards.There are also numerous other supporting solo practices such as: Sitting meditation: The empty, focus and calm the mind and aid in opening the microcosmic orbit.
|
Tai chi
|
Practice
|
Standing meditation (zhan zhuang) to raise the yang qi Qigong to mobilize the qi Acupressure massage to develop awareness of qi channels Traditional Chinese medicine is taught to advanced students in some traditional schools.Further training entails learning tuishou (push hands drills), sanshou (striking techniques), free sparring, grappling training, and weapons training.In the "tai chi classics", writings by tai chi masters, it is noted that the physiological and kinesiological aspects of the body's movements are characterized by the circular motion and rotation of the pelvis, based on the metaphors of the pelvis as the hub and the arms and feet as the spokes of a wheel. Furthermore, the respiration of breath is coordinated with the physical movements in a state of deep relaxation, rather than muscular tension, in order to guide the practitioners to a state of homeostasis.
|
Tai chi
|
Practice
|
Tai chi is a complete martial art system with a full range of bare-hand movement sets and weapon forms, such as tai chi sword and tai chi spear, which are based on the dynamic relationship between yin and yang. While tai chi is typified by its slow movements, many styles (including the three most popular: Yang, Wu, and Chen) have secondary, faster-paced forms. Some traditional schools teach martial applications of the postures of different forms (taolu).
|
Tai chi
|
Practice
|
Solo practices Taolu (solo "forms") are choreographed sets of movements practiced alone or in unison as a group. Tai chi is often characterized by slow movements in Taolu practice, and one of the reasons is to develop body awareness. Accurate, repeated practice of the solo routine is said to retrain posture, encourage circulation throughout students' bodies, maintain flexibility, and familiarize students with the martial sequences implied by the forms. Usually performed standing, solo forms have also been adapted for seated practice.
|
Tai chi
|
Practice
|
Weapon practice Tai chi practices involving weapons also exist. Weapons training and fencing applications often employ: the jian, a straight double-edged sword, practiced as taijijian; the dao, a heavier curved saber, sometimes called a broadsword; the tieshan, a folding fan, also called shan and practiced as taijishan; the gun, a 2 m long wooden staff and practiced as taijigun; the qiang, a 2 m long spear or a 4 m long lance.More exotic weapons include: the large dadao and podao sabres; the ji, or halberd; the cane; the sheng biao, or rope dart; the sanjiegun, or three sectional staff; the feng huo lun, or wind and fire wheels; the lasso; the whip, chain whip and steel whip.
|
Tai chi
|
History
|
Early development Tai chi's formative influences came from practices undertaken in Taoist and Buddhist monasteries, such as Wudang, Shaolin and The Thousand Year Temple in Henan. The early development of tai chi proper is connected with Henan's Thousand Year Temple and a nexus of nearby villages: Chen Village, Tang Village, Wangbao Village, and Zhaobao Town. These villages were closely connected, shared an interest in the martial arts and many went to study at Thousand Year Temple (which was a syncretic temple with elements from the three teachings). New documents from these villages, mostly dating to the 17th century, are some of the earliest sources for the practice of tai chi.Some traditionalists claim that tai chi is a purely Chinese art that comes from ancient Taoism and Confucianism. These schools believe that tai chi theory and practice were formulated by Taoist monk Zhang Sanfeng in the 12th century. These stories are often filled with legendary and hagiographical content and lack historical support.Modern historians pointing out that the earliest reference indicating a connection between Zhang Sanfeng and martial arts is actually a 17th-century piece called Epitaph for Wang Zhengnan (1669), composed by Huang Zongxi (1610–1695). Aside from this single source, the other claims of connections between tai chi and Zhang Sanfeng appeared no earlier than the 19th century. According to Douglas Wile, "there is no record of a Zhang Sanfeng in the Song Dynasty (960–1279), and there is no mention in the Ming (1368–1644) histories or hagiographies of Zhang Sanfeng of any connection between the immortal and the material arts."Another common theory for the origin of tai chi is that it was created by Chen Wangting (1580–1660) while living in Chen Village (陳家溝), Henan. The other four contemporary traditional tai chi styles (Yang, Sun, Wu and Wu/Hao) trace their teachings back to Chen village in the early 1800s.Yang Luchan (1799–1872), the founder of the popular Yang style, trained with the Chen family for 18 years before he started to teach in Beijing, which strongly suggests that his work was heavily influenced by the Chen family art. Martial arts historian Xu Zhen claimed that the tai chi of Chen Village was influenced by the Taizu changquan style practiced at nearby Shaolin Monastery, while Tang Hao thought it was derived from a treatise by Ming dynasty general Qi Jiguang, Jixiao Xinshu ("New Treatise on Military Efficiency"), which discussed several martial arts styles including Taizu changquan.
|
Tai chi
|
History
|
Standardization In 1956 the Chinese government sponsored the Chinese Sports Committee (CSC), which brought together four wushu teachers to truncate the Yang family hand form to 24 postures. This was an attempt to standardize tai chi for wushu tournaments as they wanted to create a routine that would be much less difficult to learn than the classical 88 to 108 posture solo hand forms.
|
Tai chi
|
History
|
Another 1950s form is the "97 movements combined tai chi form", which blends Yang, Wu, Sun, Chen, and Fu styles.
|
Tai chi
|
History
|
In 1976, they developed a slightly longer demonstration form that would not require the traditional forms' memory, balance, and coordination. This became the "Combined 48 Forms" that were created by three wushu coaches, headed by Men Hui Feng. The combined forms simplified and combined classical forms from the original Chen, Yang, Wu, and Sun styles. Other competitive forms were designed to be completed within a six-minute time limit.
|
Tai chi
|
History
|
In the late 1980s, CSC standardized more competition forms for the four major styles as well as combined forms. These five sets of forms were created by different teams, and later approved by a committee of wushu coaches in China. These forms were named after their style: the "Chen-style national competition form" is the "56 Forms". The combined forms are "The 42-Form" or simply the "Competition Form".
|
Tai chi
|
History
|
In the 11th Asian Games of 1990, wushu was included as an item for competition for the first time with the 42-Form representing tai chi. The International Wushu Federation (IWUF) applied for wushu to be part of the Olympic games.Tai chi was added to the UNESCO Intangible Cultural Heritage Lists in 2020 for China.
|
Tai chi
|
Styles
|
Chinese origin The five major styles of tai chi are named for the Chinese families who originated them: Chen style (陳氏) of Chen Wangting (1580–1660) Yang style (楊氏) of Yang Luchan (1799–1872) Wu/Hao style (武郝氏) of Wu Yuxiang (1812–1880) and Hao Weizhen (1842–1920) Wu style (吳氏) of Wu Quanyou (1834–1902) and his son Wu Jianquan (1870–1942) Sun style (孫氏) of Sun Lutang (1861–1932)The most popular is Yang, followed by Wu, Chen, Sun, and Wu/Hao. The styles share underlying theory, but their training differs.
|
Tai chi
|
Styles
|
Dozens of new styles, hybrid styles, and offshoots followed, although the family schools are accepted as standard by the international community. Other important styles are Zhaobao tai chi, a close cousin of Chen style, which is recognized by Western practitioners; Fu style, created by Fu Zhensong, which evolved from Chen, Sun and Yang styles, and incorporates movements from baguazhang; and Cheng Man-ch'ing style which simplifies Yang style.
|
Tai chi
|
Styles
|
United States Choy Hok Pang, a disciple of Yang Chengfu, was the first known proponent of tai chi to openly teach in the United States, beginning in 1939. His son and student Choy Kam Man emigrated to San Francisco from Hong Kong in 1949 to teach tai chi in Chinatown. Choy Kam Man taught until he died in 1994.Sophia Delza, a professional dancer and student of Ma Yueliang, performed the first known public demonstration of tai chi in the United States at the New York City Museum of Modern Art in 1954. She wrote the first English language book on tai chi, T'ai-chi ch'üan: Body and Mind in Harmony, in 1961. She taught regular classes at Carnegie Hall, the Actors Studio, and the United Nations.
|
Tai chi
|
Styles
|
Cheng Man-ch'ing, who opened his school Shr Jung tai chi after he moved to New York from Taiwan in 1964. Unlike the older generation of practitioners, Cheng was cultured and educated in American ways, and thus was able to transcribe Yang's dictation into a written manuscript that became the de facto manual for Yang style. Cheng felt Yang's traditional 108-movement form was unnecessarily long and repetitive, which makes it difficult to learn. He thus created a shortened 37-movement version that he taught in his schools. Cheng's form became the dominant form in the eastern United States until other teachers immigrated in larger numbers in the 1990s. He taught until his death in 1975.
|
Tai chi
|
Styles
|
United Kingdom Norwegian Pytt Geddes was the first European to teach tai chi in Britain, holding classes at The Place in London in the early 1960s. She had first encountered tai chi in Shanghai in 1948, and studied with Choy Hok Pang and his son Choy Kam Man (who both also taught in the United States) while living in Hong Kong in the late 1950s.
|
Tai chi
|
Styles
|
Lineage Note: This lineage tree is not comprehensive, but depicts those considered the "gate-keepers" and most recognised individuals in each generation of the respective styles.
Although many styles were passed down to respective descendants of the same family, the lineage focused on is that of the martial art and its main styles, not necessarily that of the families.
Each (coloured) style depicted below has a lineage tree on its respective article page that is focused on that specific style, showing a greater insight into the highly significant individuals in its lineage.
Names denoted by an asterisk are legendary or semi-legendary figures in the lineage; while their involvement in the lineage is accepted by most of the major schools, it is not independently verifiable from known historical records.
Modern forms The Cheng Man-ch'ing (Zheng Manqing) and Chinese Sports Commission short forms are derived from Yang family forms, but neither is recognized as Yang-style tai chi by standard-bearing Yang family teachers. The Chen, Yang, and Wu families promote their own shortened demonstration forms for competitive purposes.
|
Tai chi
|
Benefits
|
The primary purposes of tai chi are health, sport/self-defense and aesthetics benefits.
Practitioners mostly interested in tai chi's health benefits diverged from those who emphasize self-defense, and also those who attracted by its aesthetic appeal (wushu).
More traditional practitioners hold that the two aspects of health and martial arts make up the art's yin and yang. The "family" schools present their teachings in a martial art context, whatever the intention of their students.
|
Tai chi
|
Benefits
|
Health Tai chi's health training concentrates on relieving stress on the body and mind. In the 21st century, tai chi classes that purely emphasize health are popular in hospitals, clinics, community centers and senior centers. Tai chi's low-stress training method for seniors has become better known. Clinical studies exploring tai chi's effect on specific diseases and health conditions exist, though there are not sufficient studies with consistent approaches to generate a comprehensive conclusion.Tai chi has been promoted for treating various ailments, and is supported by the Parkinson's Foundation and Diabetes Australia, among others. However, medical evidence of effectiveness is lacking. A 2017 systematic review found that it decreased falls in older people.A 2011 comprehensive overview of systematic reviews of tai chi recommended tai chi to older people for its physical and psychological benefits. It found possitive results for fall prevention and overall mental health. No conclusive evidence showed benefit for most of the conditions researched, including Parkinson's disease, diabetes, cancer and arthritis.A 2015 systematic review found that tai chi could be performed by those with chronic medical conditions such as chronic obstructive pulmonary disease, heart failure, and osteoarthritis without negative effects, and found favorable effects on functional exercise capacity.In 2015 the Australian Government's Department of Health published the results of a review of alternative therapies that sought to identify any that were suitable for coverage by health insurance. Tai chi was one of 17 therapies evaluated. The study concluded that low-quality evidence suggests that tai chi may have some beneficial health effects when compared to control in a limited number of populations for a limited number of outcomes.A 2020 review of 13 studies found that tai chi had positive effect on the quality of life and depressive symptoms of older adults with chronic conditions who lived in community settings.In 2022, the U.S.A agency the National Institutes of Health published an analysis of various health claims, studies and findings. They concluded the evidence was of low quality, but that it appears to have a small positive effect on quality of life.
|
Tai chi
|
Benefits
|
Sport and self-defense As a martial art, tai chi emphasizes defense over attack and replies to hard with soft. The ability to use tai chi as a form of combat is the test of a student's understanding of the art. This is typically demonstrated via competition with others.
Practitioners test their skills against students from other schools and martial arts styles in tuishou ("pushing hands") and sanshou competition.
|
Yoshinobu Miyake
|
Yoshinobu Miyake
|
Yoshinobu Miyake (三宅 義信, Miyake Yoshinobu, born November 24, 1939) is a retired Japanese weightlifter and Japan Ground Self-Defense Force Lieutenant. He won one silver and two gold medals at the 1960, 1964 and 1968 Olympics and finished fourth in 1972. He also won world titles in 1962, 1963 and 1965–66. Between 1959 and 1969 Miyake set 25 official world records, including 10 consecutive records in the snatch and nine consecutive records in the total. In 1993 he was inducted into the International Weightlifting Federation Hall of Fame.Miyake was known for his signature "frog style" or "Miyake pull" lifting technique, in which he kept his heels together with knees spread outward to about 60 degrees with a wide grip on the bar, resembling a frog.After retiring from competitions Miyake coached the national weightlifting team. His brother Yoshiyuki Miyake and niece Hiromi Miyake also won Olympic medals in weightlifting. All three were shorter than 1.56 m.Miyake took part in the opening ceremony of the 2020 Olympics as one of the flagbearers of the flag of Japan.
|
ISO/IEC 4909
|
ISO/IEC 4909
|
ISO/IEC 4909 is a 2006 international standard produced by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) for Identification cards — Financial transaction cards — Magnetic stripe data content for track 3. It was reviewed in 2018. The original ISO 4909 standard appeared in 1987. It is one of a number of international bank card standards. The standard is used for credit cards.The standard has been adopted in many countries, including (for example) Denmark,Germany,India,Netherlands,New Zealand,Norway,United Kingdom, etc.
|
Arrangement of lines
|
Arrangement of lines
|
In geometry, an arrangement of lines is the subdivision of the plane formed by a collection of lines. Problems of counting the features of arrangements have been studied in discrete geometry, and computational geometers have found algorithms for the efficient construction of arrangements.
|
Arrangement of lines
|
Definition
|
Intuitively, any finite set of lines in the plane cuts the plane into two-dimensional polygons (cells), one-dimensional line segments or rays, and zero-dimensional crossing points. This can be formalized mathematically by classifying the points of the plane according to which side of each line they are on. Each line separates the plane into two open half-planes, and each point of the plane has three possibilities per line: it can be in either one of these two half-planes, or it can be on the line itself. Two points can be considered to be equivalent if they have the same classification with respect to all of the lines. This is an equivalence relation, whose equivalence classes are subsets of equivalent points. These subsets subdivide the plane into shapes of the following three types: The cells or chambers of the arrangement are two-dimensional regions not part of any line. They form the interiors of bounded or unbounded convex polygons. If the plane is cut along all of the lines, these are the connected components of the points that remain uncut.
|
Arrangement of lines
|
Definition
|
The edges or panels of the arrangement are one-dimensional regions belonging to a single line. They are the open line segments and open infinite rays into which each line is partitioned by its crossing points with the other lines. That is, if one of the lines is cut by all the other lines, these are the connected components of its uncut points.
|
Arrangement of lines
|
Definition
|
The vertices of the arrangement are isolated points belonging to two or more lines, where those lines cross each other.The boundary of a cell is the system of edges that touch it, and the boundary of an edge is the set of vertices that touch it (one vertex for a ray and two for a line segment). The system of objects of all three types, linked by this boundary operator, form a cell complex covering the plane. Two arrangements are said to be isomorphic or combinatorially equivalent if there is a one-to-one boundary-preserving correspondence between the objects in their associated cell complexes.The same classification of points, and the same shapes of equivalence classes, can be used for infinite but locally finite arrangements, in which every bounded subset of the plane may be crossed by only finitely many lines, although in this case the unbounded cells may have infinitely many sides.
|
Arrangement of lines
|
Complexity of arrangements
|
The study of arrangements was begun by Jakob Steiner, who proved the first bounds on the maximum number of features of different types that an arrangement may have. The most straightforward features to count are the vertices, edges, and cells: An arrangement with n lines has at most n(n−1)/2 vertices (a triangular number), one per pair of crossing lines. This maximum is achieved for simple arrangements, those in which each two lines cross at a vertex that is disjoint from all the other lines. The number of vertices is smaller when some lines are parallel, or when some vertices are crossed by more than two lines.
|
Arrangement of lines
|
Complexity of arrangements
|
Any arrangement can be rotated to avoid axis-parallel lines, without changing its number of cells. Any arrangement with no axis-parallel lines has n infinite-downward rays, one per line. These rays separate n+1 cells of the arrangement that are unbounded in the downward direction. The remaining cells all have a unique bottommost vertex (again, because there are no axis-parallel lines). For each pair of lines, there can be only one cell where the two lines meet at the bottom vertex, so the number of downward-bounded cells is at most the number of pairs of lines, n(n−1)/2 . Adding the unbounded and bounded cells, the total number of cells in an arrangement can be at most n(n+1)/2+1 . These are the numbers of the lazy caterer's sequence.
|
Arrangement of lines
|
Complexity of arrangements
|
The number of edges of the arrangement is at most n2 , as may be seen either by using the Euler characteristic to calculate it from the numbers of vertices and cells, or by observing that each line is partitioned into at most n edges by the other n−1 lines. Again, this worst-case bound is achieved for simple arrangements.More complex features go by the names of "zones", "levels", and "many faces": The zone of a line ℓ in a line arrangement is the collection of cells having edges belonging to ℓ . The zone theorem states that the total number of edges in the cells of a single zone is linear. More precisely, the total number of edges of the cells belonging to a single side of line ℓ is at most 5n−1 , and the total number of edges of the cells belonging to both sides of ℓ is at most 9.5 n⌋−1 . More generally, the total complexity of the cells of a line arrangement that are intersected by any convex curve is O(nα(n)) , where α denotes the inverse Ackermann function, as may be shown using Davenport–Schinzel sequences. The sum of squares of cell complexities in an arrangement is O(n2) , as can be shown by summing the zones of all lines.
|
Arrangement of lines
|
Complexity of arrangements
|
The k -level of an arrangement is the polygonal chain formed by the edges that have exactly k other lines directly below them. The ≤k -level is the portion of the arrangement below the k -level. Finding matching upper and lower bounds for the complexity of a k -level remains a major open problem in discrete geometry;. The best upper bound is O(nk1/3) , while the best lower bound is log k) . In contrast, the maximum complexity of the ≤k -level is known to be Θ(nk) . A k -level is a special case of a monotone path in an arrangement; that is, a sequence of edges that intersects any vertical line in a single point. However, monotone paths may be much more complicated than k -levels: there exist arrangements and monotone paths in these arrangements where the number of points at which the path changes direction is n2−o(1) Although a single cell in an arrangement may be bounded by all n lines, it is not possible in general for m different cells to all be bounded by n lines. Rather, the total complexity of m cells is at most Θ(m2/3n2/3+n) , almost the same bound as occurs in the Szemerédi–Trotter theorem on point-line incidences in the plane. A simple proof of this follows from the crossing number inequality: if m cells have a total of x+n edges, one can form a graph with m nodes (one per cell) and x edges (one per pair of consecutive cells on the same line). The edges of this graph can be drawn as curves that do not cross within the cells corresponding to their endpoints, and then follow the lines of the arrangement. Therefore, there are O(n2) crossings in this drawing. However, by the crossing number inequality, there are Ω(x3/m2) crossings. In order to satisfy both bounds, x must be O(m2/3n2/3)
|
Arrangement of lines
|
Projective arrangements and projective duality
|
It is often convenient to study line arrangements not in the Euclidean plane but in the projective plane, due to the fact that in projective geometry every pair of lines has a crossing point. In the projective plane, it is not possible to define arrangements using sides of lines, because a line in the projective plane does not separate the plane into two distinct sides. However, one may still define the cells of an arrangement to be the connected components of the points not belonging to any line, the edges to be the connected components of sets of points belonging to a single line, and the vertices to be points where two or more lines cross. A line arrangement in the projective plane differs from its Euclidean counterpart in that the two Euclidean rays at either end of a line are replaced by a single edge in the projective plane that connects the leftmost and rightmost vertices on that line, and in that pairs of unbounded Euclidean cells are replaced in the projective plane by single cells that are crossed by the projective line at infinity.Due to projective duality, many statements about the combinatorial properties of points in the plane may be more easily understood in an equivalent dual form about arrangements of lines. For instance, the Sylvester–Gallai theorem, stating that any non-collinear set of points in the plane has an ordinary line containing exactly two points, transforms under projective duality to the statement that any projective arrangement of finitely many lines with more than one vertex has an ordinary point, a vertex where only two lines cross. The earliest known proof of the Sylvester–Gallai theorem, by Melchior (1940), uses the Euler characteristic to show that such a vertex must always exist.
|
Arrangement of lines
|
Triangles in arrangements
|
An arrangement of lines in the projective plane is said to be simplicial if every cell of the arrangement is bounded by exactly three edges. Simplicial arrangements were first studied by Melchior. Three infinite families of simplicial line arrangements are known: A near-pencil consisting of n−1 lines through a single point, together with a single additional line that does not go through the same point, The family of lines formed by the sides of a regular polygon together with its axes of symmetry, and The sides and axes of symmetry of an even regular polygon, together with the line at infinity.Additionally there are many other examples of sporadic simplicial arrangements that do not fit into any known infinite family.
|
Arrangement of lines
|
Triangles in arrangements
|
As Branko Grünbaum writes, simplicial arrangements "appear as examples or counterexamples in many contexts of combinatorial geometry and its applications." For instance, Artés, Grünbaum & Llibre (1998) use simplicial arrangements to construct counterexamples to a conjecture on the relation between the degree of a set of differential equations and the number of invariant lines the equations may have. The two known counterexamples to the Dirac–Motzkin conjecture (which states that any n -line arrangement has at least n/2 ordinary points) are both simplicial.The dual graph of a line arrangement has one node per cell and one edge linking any pair of cells that share an edge of the arrangement. These graphs are partial cubes, graphs in which the nodes can be labeled by bitvectors in such a way that the graph distance equals the Hamming distance between labels. In the case of a line arrangement, each coordinate of the labeling assigns 0 to nodes on one side of one of the lines and 1 to nodes on the other side. Dual graphs of simplicial arrangements have been used to construct infinite families of 3-regular partial cubes, isomorphic to the graphs of simple zonohedra.
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.