Gravitational Fields

[emzz]

When an object is moved away from another object, how do you calculate the time it takes for the stationary object to experience a change in the gravitational force due to the other object?

I know in electric fields we calculate the time taken for an EM wave to travel the distance between the objects to find the time taken for the change in force to occur.

Is there also a wave or something like that being emitted in a gravitational field?

[Jay-qu]

Theoretically there would be a gravitational wave, that also travels at c.

[whipflip15]

Yeah J thats what i thought! Although i was just reading some journal articles and they state that gravitational waves travel atleast 10 orders of magnitudes faster than the speed of light.

[Qfwfq]

Who says that?

[Jay-qu]

Yeah J thats what i thought! Although i was just reading some journal articles and they state that gravitational waves travel atleast 10 orders of magnitudes faster than the speed of light.

where did you read that andy? it doesnt sound very plausible..

 

I can think of a test for the speed of gravity. If light and gravity travel at the same speed then as we rotate the sun we actually rotate the image of the sun, where it was 8 mins ago. This is because the sun is moving about the galactic center.

 

If gravity is faster (perhaps instantaneous) then we would be orbiting about the actual position of the sun while we would see the image of sun lagging behind. This would mean that our orbit would appear off center.

 

Giving this some more thought, apart from being incompatible with relativity, this seems non-nonsensical, it leads to orbits appearing unstable but not being unstable.

 

If there is a flaw in my logic please point it out.

[whipflip15]

I don't think it is plausible either. But i believe a Russian named V.A.Dubrovskiy. There was another article too, which i can't find now. I don't believe it..

[von Faulkenstein]

It seems that the speed of light is only a limit on objects like rockets, baseballs, etc. as they move through space but the movement of space can make the speed of light appear very slow. At the big bang inflation, the outer edge of the cosmos traveled many time faster than light. While objects moving in space are limited by the speed of light, space itself can travel at speeds exceeding this constant and, is continuing to do so, carrying the stars with it. Would it in some time in the future, make the universe appear totally dark?