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Blackett Effect
The Blackett effect, also called gravitational magnetism, is the hypothetical generation of a magnetic field by an uncharged, rotating body. This effect has never been observed. History Gravitational magnetism was proposed by the German-British physicist Arthur Schuster as an explanation for the magnetic field of the Earth, but was found nonexistent in a 1923 experiment by H. A. Wilson. The hypothesis was revived by the British physicist P. M. S. Blackett in 1947 when he proposed that a rotating body should generate a magnetic field proportional to its angular momentum. This was never generally accepted, and by the 1950s even Blackett felt it had been refuted., pp. 39–43 The Blackett effect was used by the science fiction writer James Blish in his series ''Cities in Flight'' (1955–1962) as the basis for his fictional stardrive, the spindizzy ''Cities in Flight'' is a four-volume series of science fiction novels and short stories by American writer James Bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Field
A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to the magnetic field. A permanent magnet's magnetic field pulls on ferromagnetic materials such as iron, and attracts or repels other magnets. In addition, a nonuniform magnetic field exerts minuscule forces on "nonmagnetic" materials by three other magnetic effects: paramagnetism, diamagnetism, and antiferromagnetism, although these forces are usually so small they can only be detected by laboratory equipment. Magnetic fields surround magnetized materials, and are created by electric currents such as those used in electromagnets, and by electric fields varying in time. Since both strength and direction of a magnetic field may vary with location, it is described mathematically by a function assigning a vector to each point of space ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
