Gravity according to Newton moves instanteously whereas non-gravity forces move with the speed of light. With such a wide variation in the speed of application, there may not be a canonical basis for their unification. While trying to unify the fundamental forces, are we assuming that gravity force also moves with the speed of light? If so, what is the proof for that assumption?
2006-07-12 19:58:30 · 4 answers · asked by gulfarazahmed 1 in Science & Mathematics ➔ Physics
A gravitational wave or gravity potential field are known to move with the speed of light but are these not different from the force of gravity? Is there a wider understanding and agreement about the speed of gravity?
2006-07-12 20:45:43 · update #1
Newton's theory of gravity is basically wrong about it being instantaneous. We now know that Einstein is right, and that gravity's influence is also limited to the speed of light.
But to answer your question, yes, gravity and the other forces, strong, weak, and EM, can be unified. One such theory is Superstring Theory.
As for how to measure the speed of gravity, it is understood that while current observations do not yet provide a direct model-independent measurement of the speed of gravity, a test within the framework of general relativity can be made by observing a binary pulsar. The orbit of this type of binary system is gradually decaying, and this behavior is attributed to the loss of energy due to escaping gravitational radiation. In any field theory, radiation is intimately related to the finite velocity of field propagation, and the orbital changes due to gravitational radiation can equivalently be viewed as damping caused by the finite propagation speed.
The rate of this damping can be computed, and one finds that it depends sensitively on the speed of gravity. The fact that gravitational damping is measured at all is a strong indication that the propagation speed of gravity is not infinite. If the calculational framework of general relativity is accepted, the damping can be used to calculate the speed, and the actual measurement confirms that the speed of gravity is equal to the speed of light to within 1%. (Measurements of at 2 binary pulsar systems have confirmed this result.)
Are there future prospects for a direct measurement of the speed of gravity? One possibility would involve detection of gravitational waves from a supernova. The detection of gravitational radiation in the same time frame as a neutrino burst, followed by a later visual identification of a supernova, would be considered strong experimental evidence for the speed of gravity being equal to the speed of light. However, unless a very nearby supernova occurs soon, it will be some time before gravitational wave detectors are expected to be sensitive enough to perform such a test.
2006-07-12 20:04:06 · answer #1 · answered by PhysicsDude 7 · 0⤊ 0⤋
Perhaps Newton suggested the possibility that gravity force also moves at speeds equal to the speed of light. I suggest further reading of Newton.
2006-07-13 03:05:16 · answer #2 · answered by Anonymous · 0⤊ 0⤋
It turns out that gravity travels at the speed of light..check the source. My uncle Al was right AGAIN!
2006-07-13 03:04:03 · answer #3 · answered by sleeplessinslo 2 · 0⤊ 0⤋
without trying to pretend to know more than I really do,
this *might* be one of those instances where asking the question means that more study is required before any 'correct' answer would be understood.
2006-07-13 03:09:12 · answer #4 · answered by atheistforthebirthofjesus 6 · 0⤊ 0⤋