Dynamic theory of gravity: Difference between revisions

Revision as of 08:17, 7 December 2006

Revision as of 20:22, 17 January 2007

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{{Merge| Nikola Tesla|date=December 2006}}

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Tesla allegedly said that his theory explained [[gravitation]] as a mixture of [[transverse wave|transverse]] and [[longitudinal wave|longitudinal]] electromagnetic waves.

For comparison, in the language of mainstream physics, [[electromagnetic wave]]s as treated in [[Maxwell's theory of electromagnetism]] are said to be ''spin-one'' and ''purely transverse'', while in [[general relativity]], [[gravitational wave]]s are said to be ''spin-two'' and ''purely transverse''. Thus, in Maxwell's theory there are no longitudinal electromagnetic waves, while in general relativity, despite some useful conceptual similarities, the gravitational field effect (of a mass deforming spacetime) is distinct from electromagnetic radiation. Also, while in Maxwell's theory the effects of the electromagnetic field on charged test particles is treated by the [[Lorentz force law]], in general relativity the effects of the gravitational field on test particles is treated very differently: the kinematical history of a test particle is represented by a [[timelike]] [[geodesic]] in a [[Lorentzian manifold]], while, roughly speaking, the kinematical history of a photon is represented by a [[null geodesic]].

==Tesla's views on special and general relativity==

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:''... Supposing that the bodies act upon the surrounding space causing curving of the same, it appears to my simple mind that the curved spaces must react on the bodies, and producing the opposite effects, straightening out the curves. Since action and reaction are coexistent, it follows that the supposed curvature of space is entirely impossible - But even if it existed it would not explain the [[Celestial mechanics|motions of the bodies]], as observed.'' <small>^[1]</small>

This statement appears to reflect misconceptions concerning [[Albert Einstein]]'s theory of gravitation:

*General relativity does give a self-consistent description of the motion of celestial bodies.

*In 1937, Einstein, Infeld, and Hoffman argued that description in terms of geodesics of the motion of massive objects immersed in a gravitation field follows from the [[Einstein field equation]] of general relativity. To be fair, these arguments are not easy, and physicists to this day continue to try to improve them. However, they are generally regarded as essentially correct and can be supported.

Tesla's 1937 announcement appears to have made little or no impression upon contemporary physicists, perhaps because his statement appears to have been too vague to guess very much about the nature of his alleged theory, and appears to have been couched in language which was already receding into the distant past.

Extensive experimental testing of general relativity did not begin until about [[1960]]; furthermore, essential theoretical features of general relativity were not well understood until about this time. (See [[Golden age of general relativity]] for more information about events in the period 1960-1975 which firmly established general relativity as our gold standard theory of gravitation.) Therefore, in 1937 general relativity had not quite so solid an experimental footing as it has today. By 1937 most astronomers and physicists had long accepted that general relativity gives an accurate description of solar system dynamics to within the accuracy of observation and experiment. Tesla's murky description of his unified field theory could perhaps have been described as ''fringe science'' in 1937. Today it could only be described as ''[[not even wrong]]''.

== See also ==