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Author Topic: Does gravity only work on moving objects?  (Read 9126 times)

Offline PmbPhy

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Re: Does gravity only work on moving objects?
« Reply #25 on: 23/12/2014 18:37:27 »
Pete said:

"What is what Einstein said? I'm saying that the speed of light varying with position is insufficient to cause light to be deflected. And that is a fact."

This is a very important point. Light being slowed IS insufficient to cause the deflection of light as can be demonstrated by a photon traveling directly away from the centre of gravity. In these circumstances there will be no change of trajectory. It is only by following an angular path to the direction of a gravitational field where we find deflection. The question is do we need tidal forces for this to occur or can it occur in a flat gravitational field?
Not only that but consider a beam of light directed along the x-axis. The potential varies with the distance from the beam so that the speed of light varies with distance from the beam. However if a photon was moving parallel to the beam and in the direction of flow of the energy then it wouldn't be deflected. See
http://home.comcast.net/~peter.m.brown/gr/grav_light.htm
 

The Naked Scientists Forum

Re: Does gravity only work on moving objects?
« Reply #25 on: 23/12/2014 18:37:27 »

 

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