Heaviside
Poincare
Feynman and Einstein
Heaviside |
Poincare |
Feynman and Einstein |
In 1893, self-taught physicist, engineer and mathematician Oliver Heaviside speculated that gravitational radiation could exist, based on analogy between the classical Maxwell equations for electromagnetism and the classical Newtonian theory of gravity represented in field form. A similar argument was made by mathematician Henri Poincare in 1905. Einstein himself was not certain that his 1915 equations for gravity admitted a physical solution for a radiation field. In the 1930s he tried to publish a paper showing that gravitational radiation does not exist. This paper contained a mathematical error and was rejected by the journal Physical Review. In the late 1950s and early 1960s, Richard Feynman attended conferences on then-current work on Einstein's theory of gravity. He wrote to his wife that the people at one conference were mainly "a lot of dopes." But at a 1957 conference, he presented a thought-experiment, the "sticky bead experiment," with which he demonstrated that gravitational radiation was in principle observable, and argued that people should work on the technology necessary to detect it. The first indirect evidence that gravitational radiation does exist came from 1974 observations of close binary stars... the systems lost total energy at a rate corresponding to the amount of the gravitational radiation the systems should be emitting based on calculations using Einstein's theory of gravity. Various physicists advocated using laser interferometers to detect gravitational radiation, and the first operating interferometers with enough sensitivity to detect gravitational radiation came on-line in 2015, only a decade ago... when a collision between two black holes was quickly seen. Since then, a world-wide network of interferometers has seen around 100 bursts of gravitational waves, from black hole collisions, neutron star collisions and neutron star-black hole collisions.
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