# How soon that a force affect another object?

Imagine this scenario: I have 2 objects in vacuum without any force exerted upon them not even a possible gravitational force between them. Now if one of them gets a gravitational or magnetic force, how long from the moment the object gained this force to the other object to be affected by it? Is it instantaneous? Is it the same as speed of light?

• Good question. A magnetic force would certainly be the speed of light, but the gravitational force, I'm not so sure. Mar 17 '13 at 17:01
• According to wikipedia, the gravitational force would also be the speed of light. I'm not sure why though, so I'll leave it to someone who knows general relativity to explain. Mar 17 '13 at 17:03
• Bosons are particles which carry force. Photons are force carriers of EM field, W and Z bosons for weak force and gluons are carriers of strong force. But this is mere information. I guess the exact answer you seek will be given by someone well versed with these particles. Mar 17 '13 at 17:15
• Possible duplicates: physics.stackexchange.com/q/5456/2451 and links therein. Mar 17 '13 at 17:16
• That question only adresses gravitational force. Is it the same for all kind of forces? Mar 17 '13 at 21:40