How fast is gravity?
how fast does gravity work? Is it instentanious or does it work at the speed of light?
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It is a constant force so it would have an instantaneous effect.
In the classical Newtonion view of gravity, it was an instantanious phenomena. Einstein’s general relativity however, predicts that gravity, or rather changes in the gravitational field, travel at the speed of light.
You can read more about this here: http://en.wikipedia.org/wiki/Gravitational_radiation
Gravity does not have a speed. It is all around us and everything that exists on planet earth. If it were an energy it would travel at 186,000 miles per second. But I think it is more like being in a gigantic bowl of jello chilled to different temperatures depending on the depth. It is an applied force that pushes down on the earth because of its rotation.
The process is instantaneous. Gravity and the spin of the earth on its axis is what keeps our feet on the ground.
Welcome to Fluther.
It’s an interesting question, and whether you believe this or not, I was wondering the exact same thing two days ago and thinking of asking it myself.
The effect of gravity is lessened when the presense of light is within it.
Without light then it would instataneous.
Since Instaneous is a descriptive word relative to time,
It may be better to actually say that its effect is always there, while never there.
According to general relativity, gravity goes at the speed of light.
This might not be true at the quantum scale. But it’s the best answer we have right now.
The correct answer is the speed of light.
If the Sun suddenly vanished, we would remain in orbit of the location where the Sun was for 8 minutes, or the time it takes light to reach us from the Sun.
It’s speed varies depending on what you dropped and how breakable the object is and how expensive it is to replace…..
Surely gravity does not travel.
Your question’s a little ambiguous, but the answer you may be looking for is that the acceleration of gravity, on Earth, is approximately 9.81 meters per second, per second (9.81 m/s^2). See the Wikipedia article “Gravity of Earth”.
@Jeruba – I believe that’s the theory, assuming you could instantly add or subtract mass from something, the change in it’s gravitational force would need to travel.
I had a hard time wrapping my head around it until I thought of it in other terms. If you have a electromagnet and flip the switch to pass electricity through it, you’re essentially upping the force exerted by the magnet and it would make sense that it may take a moment for that force to reach anything that would be affected by it.
So gravity travels just like a shock wave, light, sound, or any other force. We just perceive it to be constant because the only massive object that really effects us in a noticeable way (the Earth) is constant.
Changes in gravity travel at the speed of light. Just look up Gravity Waves.
@Jeruba
Physics tends to fly in the face of what we think of as obvious.
Gravity travels at the speed of light. If the sun were to disappear, we wouldn’t know about it for 9 minutes.
@Jeruba, other forces travel; they work through “force carrier” particles called bosons. Photons are bosons; they are the force-carrier particles for the electromagnetic work. Photons travel at the speed of light.
We haven’t identified a “graviton” particle as the force carrier for gravity. Gravity may not even work through particles like the other three forces. But relativity has shown that it, too, travels at the speed of light, so it’s consistent in that respect.
Ah, well, even though I recently read Hawking and Mlodinow’s The Grand Design, I’m still just an editor with a degree in English.
@Rarebear Great answer! Wish I said that!
oh, wait. I did about 7 answers earlier
@filmfann No need to be snarky, I just missed it. Sorry.
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