Does Gravity Travel at the Speed of Light?

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Discussion Overview

The discussion revolves around the question of whether gravity travels at the speed of light, exploring implications of this idea in various scenarios, including theoretical and conceptual considerations related to general relativity.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant questions whether the effects of gravity are instantaneous or if they are limited by the speed of light, suggesting a scenario involving a star appearing suddenly in space.
  • Another participant asserts that the effects of gravity are indeed limited by the speed of light, providing a link to further information.
  • A different viewpoint mentions that no velocity exceeds the speed of light, referencing phenomena such as gravitational waves created by supernovae, which have not yet been detected on Earth.
  • One participant proposes an analogy involving light traveling at the speed of light, suggesting that one would not perceive the effects of a star appearing until after the light from that event reaches them.
  • Another participant discusses the constancy of light speed in different frames of reference, indicating that light emitted from a moving source still travels at the speed of light relative to an observer.

Areas of Agreement / Disagreement

Participants express differing views on whether gravity's effects are limited by the speed of light, with some asserting this limitation while others provide counterarguments or analogies that complicate the discussion. The conversation remains unresolved.

Contextual Notes

Participants reference various scenarios and analogies that may depend on specific assumptions about relativity and the nature of light and gravity, but these assumptions are not fully articulated or agreed upon.

AdkinsJr
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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?
 
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AdkinsJr said:
Are the effects of gravity limited by the speed of light?

Short answer: Yes.
Longer answer:
http://math.ucr.edu/home/baez/physics/Relativity/GR/grav_speed.html"
 
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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.
 
I think you might see it a little after it happened...This is going to 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 won't see the light (forgive the pun) till a little after the light was generated
 
"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.
 
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