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Nuclear Pulse Propulsion
Nuclear pulse propulsion or external pulsed plasma propulsion is a hypothetical method of spacecraft propulsion that uses nuclear explosions for thrust. It originated as Project ''Orion'' with support from DARPA, after a suggestion by Stanislaw Ulam in 1947. Newer designs using inertial confinement fusion have been the baseline for most later designs, including Project ''Daedalus'' and Project ''Longshot''. History Los Alamos Calculations for a potential use of this technology were made at the laboratory from and toward the close of the 1940s to the mid-1950s. Project Orion Project Orion was the first serious attempt to design a nuclear pulse rocket. A design was formed at General Atomics during the late 1950s and early 1960s, with the idea of reacting small directional nuclear explosives utilizing a variant of the Teller–Ulam two-stage bomb design against a large steel pusher plate attached to the spacecraft with shock absorbers. Efficient directional explosives maxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partial Test Ban Treaty
The Partial Test Ban Treaty (PTBT), formally known as the 1963 Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water, prohibited all nuclear weapons testing, test detonations of nuclear weapons except for those conducted underground nuclear weapons testing, underground. It is also abbreviated as the Limited Test Ban Treaty (LTBT) and Nuclear Test Ban Treaty (NTBT), though the latter may also refer to the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which succeeded the PTBT for ratifying parties. Negotiations initially focused on a comprehensive ban, but that was abandoned because of technical questions surrounding the detection of underground tests and Soviet concerns over the intrusiveness of proposed verification methods. The impetus for the test ban was provided by rising public anxiety over the magnitude of nuclear tests, particularly tests of new thermonuclear weapons (hydrogen bombs), and the resulting nuclear fallout. A test ban was also se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alan Bond (engineer)
Alan Bond (born 1944) is a British mechanical and aerospace engineer, who served as Managing Director of Reaction Engines Ltd and associated with Project Daedalus, Blue Streak missile, HOTOL, Reaction Engines Skylon and the Reaction Engines A2 hypersonic passenger aircraft. Career Alan Bond is an engineer, with a degree in Mechanical Engineering. He worked on liquid rocket engines, principally the RZ.2 (liquid oxygen / kerosene) and the RZ.20 (liquid oxygen / liquid hydrogen) at Rolls-Royce under the tutelage of Val Cleaver, and he was also involved with flight trials of the Blue Streak at Woomera. He then worked for about 20 years at UK Atomic Energy Authority's Culham Laboratory on nuclear fusion, on the JET and RFX nuclear research projects. He was engaged in studies for the application of fusion to interplanetary space travel. He is the leading author of the report on the Project Daedalus interstellar, fusion powered starship concept, published by the Briti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Interplanetary Society
The British Interplanetary Society (BIS), founded in Liverpool in 1933 by Philip E. Cleator, is the oldest existing space advocacy organisation in the world. Its aim is exclusively to support and promote astronautics and space exploration. Structure It is a non-profit organisation with headquarters in London and is financed by members' contributions. It is situated on South Lambeth Road ( A203) near Vauxhall station. History The BIS was only preceded in astronautics by the American Interplanetary Society (founded 1930), the German VfR (founded 1927), and Soviet Society for Studies of Interplanetary Travel (founded 1924), but unlike those it never became absorbed into a national industry. Thus it is now the world's oldest existing space advocacy body. When originally formed in October 1933, the BIS aimed not only to promote and raise the public profile of astronautics, but also to undertake practical experimentation into rocketry along similar lines to the organisations ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freeman Dyson
Freeman John Dyson (15 December 1923 – 28 February 2020) was a British-American theoretical physics, theoretical physicist and mathematician known for his works in quantum field theory, astrophysics, random matrix, random matrices, mathematical formulation of quantum mechanics, condensed matter physics, nuclear physics, and nuclear engineering, engineering. He was professor emeritus in the Institute for Advanced Study in Princeton, New Jersey, Princeton and a member of the board of sponsors of the ''Bulletin of the Atomic Scientists''. Dyson originated several concepts that bear his name, such as Dyson's transform, a fundamental technique in additive number theory, which he developed as part of his proof of Mann's theorem; the Dyson tree, a hypothetical genetic engineering, genetically engineered plant capable of growing in a comet; the Dyson series, a Perturbation theory (quantum mechanics), perturbative series where each term is represented by Feynman diagrams; the Dys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinetic Energy
In physics, the kinetic energy of an object is the form of energy that it possesses due to its motion. In classical mechanics, the kinetic energy of a non-rotating object of mass ''m'' traveling at a speed ''v'' is \fracmv^2.Resnick, Robert and Halliday, David (1960) ''Physics'', Section 7-5, Wiley International Edition The kinetic energy of an object is equal to the work, or force ( F) in the direction of motion times its displacement ( s), needed to accelerate the object from rest to its given speed. The same amount of work is done by the object when decelerating from its current speed to a state of rest. The SI unit of energy is the joule, while the English unit of energy is the foot-pound. In relativistic mechanics, \fracmv^2 is a good approximation of kinetic energy only when ''v'' is much less than the speed of light. History and etymology The adjective ''kinetic'' has its roots in the Greek word κίνησις ''kinesis'', meaning "motion". The dichoto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deep Impact (film)
''Deep Impact'' is a 1998 American science fiction disaster film directed by Mimi Leder, written by Bruce Joel Rubin and Michael Tolkin, and starring Robert Duvall, Téa Leoni, Elijah Wood, Vanessa Redgrave, Maximilian Schell, and Morgan Freeman. Steven Spielberg served as an executive producer of this film. It was released by Paramount Pictures in North America and by DreamWorks Pictures internationally on May 8, 1998. The film depicts humanity's attempts to prepare for and destroy a wide comet set to collide with Earth and cause a mass extinction. ''Deep Impact'' was released in the same summer as the similarly themed '' Armageddon'', which fared better at the box office, while astronomers described ''Deep Impact'' as being more accurate. ''Deep Impact'' was slightly better received critically than ''Armageddon'', although both ultimately received mixed reviews. ''Deep Impact'' grossed over $349.5 million worldwide on an $80 million production budget, becoming th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dirty Bomb
A dirty bomb or radiological dispersal device is a radiological weapon that combines radioactive material with conventional explosives. The purpose of the weapon is to contaminate the area around the dispersal agent/conventional explosion with radioactive material, serving primarily as an area denial device against civilians. It is not to be confused with a nuclear explosion, such as a fission bomb, which produces blast effects far in excess of what is achievable by the use of conventional explosives. Unlike the rain of radioactive material from a typical fission bomb, a dirty bomb's radiation can be dispersed only within a few hundred meters or a few miles of the explosion. Dirty bombs have never been used, only tested. They are designed to disperse radioactive material over a certain area. They act through the effects of radioactive contamination on the environment and related health effects of radiation poisoning in the affected populations. The containment and decont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Weapon Design
Nuclear weapons design are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three existing basic design types: # Pure fission weapons are the simplest, least technically demanding, were the first nuclear weapons built, and so far the only type ever used in warfare, by the United States on Empire of Japan, Japan in World War II. # Boosted fission weapons are fission weapons that use nuclear fusion reactions to generate high-energy neutrons that accelerate the fission chain reaction and increase its efficiency. Boosting can more than double the weapon's fission energy yield. # Staged thermonuclear weapons are arrangements of two or more "stages", most usually two, where the weapon derives a significant fraction of its energy from nuclear fusion (as well as, usually, nuclear fission), . The first stage is typically a boosted fission weapon (except for the earliest thermonuclear weapons, which used a pure fission ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hormesis
Hormesis is a two-phased dose-response relationship to an environmental agent whereby low-dose amounts have a beneficial effect and high-dose amounts are either inhibitory to function or toxic. Within the hormetic zone, the biological response to low-dose amounts of some stressors is generally favorable. An example is the breathing of oxygen, which is required in low amounts (in air) via respiration in living animals, but can be toxic in high amounts, even in a managed clinical setting. In toxicology, hormesis is a dose-response phenomenon to xenobiotics or other stressors. In physiology and nutrition, hormesis has regions extending from low-dose deficiencies to homeostasis, and potential toxicity at high levels. Physiological concentrations of an agent above or below homeostasis may adversely affect an organism, where the hormetic zone is a region of homeostasis of balanced nutrition. In pharmacology, the hormetic zone is similar to the therapeutic window. In the context of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fallout
Nuclear fallout is residual radioactive material that is created by the reactions producing a nuclear explosion. It is initially present in the radioactive cloud created by the explosion, and "falls out" of the cloud as it is moved by the atmosphere in the minutes, hours, and days after the explosion. The bulk of the radioactivity from nuclear fallout comes from fission products, which are created by the nuclear fission reactions of the nuclear device. Un-fissioned bomb fuel (such as plutonium and uranium), and radioactive isotopes created by neutron activation, make up a smaller amount of the radioactive content of fallout. The amount of fallout and its distribution is dependent on several factors, including the overall yield of the weapon, the fission yield of the weapon, the height of burst of the weapon, and meteorological conditions. Fallout can have serious human health consequences on both short- and long-term time scales, and can cause radioactive contamination far ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear No-threshold Model
The linear no-threshold model (LNT) is a dose-response model used in radiation protection to estimate stochastic health effects such as radiation-induced cancer, genetic mutations and teratogenic effects on the human body due to exposure to ionizing radiation. The model assumes a linear relationship between dose and health effects, even for very low doses where biological effects are more difficult to observe. The LNT model implies that all exposure to ionizing radiation is harmful, regardless of how low the dose is, and that the effect is cumulative over lifetime. The LNT model is commonly used by regulatory bodies as a basis for formulating public health policies that set regulatory dose limits to protect against the effects of radiation. The validity of the LNT model, however, is disputed, and other models exist: the threshold model, which assumes that very small exposures are harmless, the radiation hormesis model, which says that radiation at very small doses can be bene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
