Gravity and the Speed of Light

AdkinsJr

hmmmm, let's say I'm floating about in space, and all of a sudden a giant star magically zaps into existence a few thousand light seconds away. Do I feel the gravity then and there? Or do I have to wait few thousand light seconds for the gravity to "get to me?" Are the effects of gravity limited by the speed of light?

DaleSwanson

Short answer: Yes.
Longer answer:
http://math.ucr.edu/home/baez/physic...rav_speed.html

physalpha

There were many discussions about that matter.
But conclusion is no velocity are over the speed of light.
One of the phenomena related to gravity is supernova explosion.
At that time very big gravity wave is created.
We made a big instrument to detect it.
But, till now we could not detect that wave in the earth.
Many detections were established only by telescope.
The fast gravity disappeance of the far away stars bring about the light intensity variation.

thedeester1

I think you might see it a little after it happened....This is gonna be hard to explain...Ok if your on a vessel traveling at the speed of light....you shine a light forward and you can still measure the speed of light....That should make your light twice the speed of light but it isnt, you will measure your light at the speed of light. In the same way if you come upon a star you wont see the light (forgive the pun) till a little after the light was generated

physalpha

"No velocity are over the speed of light."
From here, the light speed means vacuum speed.
If anyone go to you about 1/2 light speed with a candle, the light speed is same.
At that time, you can see the light whose wave length is more shorter than before.

some one---------------------------------------------------------> you
..............................1/2 light speed
light==================================> you
.............................. vacuum light speed .NOT. 3/2 light speed
When some one is in the rocket with a candle.
The light in the rocket is the same speed of light, and the man feels same feeling.
But the speed difference is 3/2 of the fixed position.
When the light is come out of the rocket, the speed difference is lowered and the light speed would become vacuum speed.
In the air light speed is lower than vacuum.