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I realized today that, if the sun went out immedeatly, we would still see light for 8 minutes, but the earth would go out of orbit immedeatly. This means that the force of gravity works faster than the speed of light, and therefore could possibly be used to go faster than light in a spaceship, if the force of gravity could be harnessed. Any thoughts?

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I realized today that, if the sun went out immedeatly, we would still see light for 8 minutes, but the earth would go out of orbit immedeatly. This means that the force of gravity works faster than the speed of light, and therefore could possibly be used to go faster than light in a spaceship, if the force of gravity could be harnessed. Any thoughts?

 

You are mistaken. For one, if the sun just went out, it would not have a change on the Earth gravitationally. For the the other, even if the Sun "went away", the Earth would still feel the effects of its gravity for ~8 min after it vanished. Gravity waves (which are what carry the information of changes in gravity) travel at the speed of light.

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I realized today that, if the sun went out immedeatly, we would still see light for 8 minutes, but the earth would go out of orbit immedeatly. This means that the force of gravity works faster than the speed of light, and therefore could possibly be used to go faster than light in a spaceship, if the force of gravity could be harnessed. Any thoughts?

 

No...

 

We would see the Sun disappear before we felt the effects. Light travels faster than gravitational events. I'm not sure what happens if a Sun goes supernova though. Our Sun "shouldn't" create a black hole if it goes supernova. But some Suns will create a supernova. Therefore, I'm not sure if a supernova will slow (or reverse) light once it goes.

 

 

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No...

 

We would see the Sun disappear before we felt the effects. Light travels faster than gravitational events. I'm not sure what happens if a Sun goes supernova though. Our Sun "shouldn't" create a black hole if it goes supernova. But some Suns will create a supernova. Therefore, I'm not sure if a supernova will slow (or reverse) light once it goes.

 

 

 

The post above yours, by Janus, was correct.

 

We would feel the effects when we saw the the Sun disappear. Both light and gravity are predicted to propagate at c.

 

 

 

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Why does the Earth orbit a point that is exactly where the sun was 8 minutes ago? or is it will be in 8 minutes? I know it's not where we see the sun now...

 

well ask and ye shall receive

 

http://en.wikipedia.org/wiki/Speed_of_gravity

 

In a field equation consistent with special relativity (i.e., a Lorentz invariant equation), the attraction between static charges is always toward the instantaneous position of the charge (in this case, the "gravitational charge" of the Sun), not the time-retarded position of the Sun. When an object is moving at a steady speed, the effect on the orbit is order v2/c2, and the effect preserves energy and angular momentum, so that orbits do not decay. The attraction toward an object moving with a steady velocity is towards its instantaneous position with no delay, for both gravity and electric charge.
Edited by Moontanman
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Im a little confused here though, i always though gravity was a field not a particle or a wave? I would think that if one second you are in a field and another second you are not in a field then you would instantly stop feeling the effects of the field

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Im a little confused here though, i always though gravity was a field not a particle or a wave? I would think that if one second you are in a field and another second you are not in a field then you would instantly stop feeling the effects of the field

 

The field only updates at the speed of light.

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