Does gravity affect a distant object instantly, or, like light, does it take a certain time to reach it?

Question

In other words, can gravity propagate instantaneously, or does it travel at or close to c, the speed of light? If it's faster than c, then Einstein was wrong. But the only way it can even reach c is if it's a form of electromagnetic radiation--which most scientists believe it's not. So... is gravity <, > or = c??

Answer 1

As far as we know, it travels at the speed of light. There are some very sensitive ongoing experiments to try to detect gravitational waves. That will answer some questions.

Some string theorists think membrane intersections at the higher dimensions of the 11-dimensional space would allow gravity (and only gravity) to 'move' instantaneously across an arbitrary distance. This is still only a conjecture, with no evidence whatsoever.

Gravity is not a form of electromagnetic radiation.

Answer 2

The acceleration is instantaneous. When two fields converge they form a cener line. A central force. It's almost like a tether. It reminds me of two vacuum cleaners and the larger one sucks the other one down. Gravity has a light component. Can anything be faster than light? I wouldn't think so. So constant instantaneous acceleration would be time-delayed for distant objects? That would indicate flow? I would think it would take a lot of power to swing a moon around. I know they say gravity is a weak force but with enough mass like black holes it even sucks in light. Doesn't sound so weak to me.

Answer 3

In general relativity, the effects of gravitation are ascribed to the curvature of spacetime, instead of being a force. Simplistically, these curvatures cause a free falling object to deviate from its geodesic [which is the notion of a "straight line" to curved spacetime; i.e. the world line of particle free from all external force is a particular type of geodesic]. The situation is analogous to setting a bowling ball on a bed; the heavy ball depresses a nearby region of the bed's surface. If you then roll a marble across this "depression" it feels the curvature created by the massive body. The marble thrown onto the bed moves toward the bowling ball. Because its motion is not along a line and its velocity changes, the marble is now accelerating. Therefore it does not matter whether light has mass in order for it to "bend". Now, onto your question. If you look at gravitation as a result of spacetime curvatures and not a force, you'll realize that light can influence a gravitational field since it possesses momentum and energy [by the equation: E^2 = m^2c^4 + p^2c^2]. They're probably not the only reasons, however. Edit: I was wrong, which I realized after reading the above posts. Thanks for the question anyway, made me learn a bit.

Answer 4

Gravity propagates at the speed of light. If the sun suddenly vanished, it would be about 8 minutes before the earth flew out of orbit. This comes from the general theory of relativity.

For more information see http://math.ucr.edu/home/baez/physics/Relativity/GR/grav_speed.html
and
http://www.newscientist.com/article.ns?id=dn3232

Answer 5

I think you want to update your penguin book of science!
Most scientists think gravity is a like a depression in the fabric of space, and like a depression anything entering the well will gradually fall towards the centre.
NOT LIKE A LIGHT, shining out!
All mass has gravity, the larger the mass the larger the gravity.
Even YOU have a gravitational field!

Answer 6

If a tree falls in the forest and nobody hears it, does it make any sound? If you cannot perceive the gravitational effect at anything faster than the speed of light, how can you know? But then again, does handedness in quarks defy the Uncertainty Principle or c or both?

Answer 7

good question!

as far as i know,
The scientific community dosen't know what gravity really is eventhough it's effect are totally predictible by newtonian physics. The problem with your question is that in order to measure "response time" or speed of gravity you need to create or destroy mass. The only way we know how to do that is by nuclear Fission or by nuclear fusion. And the mass involved are so small that i doubt it can be measured. A way to convert a lot of mass into energy would be to blow up a nuke but your little experiment setup would melt ;)

Answer 8

Using the Black Hole theory
Gravity is a strong force and the strongest in the universe.
Light cannot even escape the gravitational pull.