Gravity waves?

[espen180]

Main Question or Discussion Point

I heard somewhere that gravity behaves much like waves. That must mean that gravity has a speed, right?

Does that mean that is the sun suddenly dissapeared, the planets in our solar system would continue to move in their previous orbits until the end of the waves reaches them?

Then, if two planets by chance were properly alligned to eachother, then one might start going in a straight live before the other, and the other, who is still moving in an orbit, moves in such a way that the two planets collide with one another or start to go in orbits around eachother?

 

[junglebeast]

I heard somewhere that gravity behaves much like waves. That must mean that gravity has a speed, right?

Yes, the speed of light.

Does that mean that if the sun suddenly dissapeared, the planets in our solar system would continue to move in their previous orbits until the end of the waves reaches them?

Yes, the effects of gravity take time to propagate.

Then, if two planets by chance were properly alligned to eachother, then one might start going in a straight live before the other, and the other, who is still moving in an orbit, moves in such a way that the two planets collide with one another or start to go in orbits around eachother?

It is not apparent to me that this would necessarily be a possible situation if the sun suddenly disappeared, but it's certainly not possible for the sun to disappear, so it's a moot question.

 

[ilocar]

I thought gravitational waves only occur around major events like two black holes colliding or super novae?