Does gravity attract instantaneously?

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In summary, changes in gravity propagate at the speed of light and are called gravitational waves. This means that any sudden changes in mass, such as an explosion, will take time to be felt as the effects of the change travel at the speed of light. This is supported by the theory of general relativity, which includes conservation of energy and momentum. Gravitational waves are also related to the hypothetical concept of an acubierre drive and are different from constant fluctuations in the structure of space-time.
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jadrian
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for example, if a star theoretically came into existence 10 light minutes away, would we feel its pull instantaneously? or would it take 10 minutes for us to feel its pull?
 
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It would take 10 minutes for us to feel the pull. Changes in gravity propagate at the speed of light. The easiest way to see this is by linearizing Einstein's equations of general relativity, so that the metric is a flat metric plus a small perturbation. Then it's easy to show that such perturbations travel at the speed of light and are called gravitational waves.
 
  • #3
Conservation of energy and momentum is an essential ingredient in general relativity. Any question that postulates a mass that suddenly appears or disappears violates the theory, and there is no answer to what will happen as a result.

Sudden changes can occur that conserve energy and momentum, for example the sun could hypothetically (!) explode and split in two, one half going north, the other south. In such a case the change in the gravitational field will propagate at the speed of light, and we will feel the difference with an eight minute delay.
 
  • #4
Is not acubierre drive, though hypothetical, related with gravitational waves. So are gravitational waves not supposed to not have any limit.
Are gravitational waves different from constant fluctuation of structure of space-time continium.
I a novice and have no knowledge even of E.F.E. Let alone solving it. But just ideas.
Forgive me if i am wrong.
 
  • #5
phyzguy said:
It would take 10 minutes for us to feel the pull. Changes in gravity propagate at the speed of light. The easiest way to see this is by linearizing Einstein's equations of general relativity, so that the metric is a flat metric plus a small perturbation. Then it's easy to show that such perturbations travel at the speed of light and are called gravitational waves.

that was my intuition because otherwize mass could propagate info faster than c
 

FAQ: Does gravity attract instantaneously?

What is the concept of instantaneous attraction in gravity?

Instantaneous attraction in gravity refers to the idea that the force of gravity acts immediately between two objects without any delay. This means that as soon as two objects with mass are in each other's presence, they will be attracted to each other without any time delay.

Is gravity an instantaneous force?

According to classical physics, gravity is considered an instantaneous force. However, in modern physics, it is believed that the force of gravity is transmitted through particles called gravitons, which travel at the speed of light. This means that there may be a slight delay in the force of gravity acting between two objects.

How is the concept of instantaneous attraction in gravity different from other forces?

The concept of instantaneous attraction in gravity is different from other forces because most other forces, such as electromagnetism, have a finite speed of propagation. This means that there is a delay in the force acting between two objects, whereas gravity is believed to act instantaneously.

What evidence supports the idea of instantaneous attraction in gravity?

One of the main pieces of evidence that supports the idea of instantaneous attraction in gravity is the observation that the force of gravity between the Earth and the Sun is constantly acting on each other, even though they are millions of miles apart. This suggests that there is no delay in the force of gravity between the two objects.

Are there any theories that challenge the concept of instantaneous attraction in gravity?

Yes, there are some theories, such as general relativity, that challenge the concept of instantaneous attraction in gravity. These theories propose that gravity is not an instantaneous force and that there may be a delay in its effects. However, these theories have not been definitively proven and the concept of instantaneous attraction in gravity is still widely accepted in classical physics.

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