Originally Posted by Edge Of Pain
Guys this ISN'T saying that gravity causes you to fall at the speed of light. It means the force caused by the gravitational field takes 1 planck second to travel 1 planck distance (1 planck distance/1planck second = speed of light).
In other words, let's say a large mass suddenly came into existence somewhere. Now let's say you were 1 light year away from that mass. So although the radius of the field permeates all of space, you would only observe the effects of that field 1 year after the mass suddenly came into existence. (Assuming neither you or the mass move relative to one another)
Yep, or reverse it: If the sun were to instantly vanish (unrealistic, but whatever), the earth would continue to "orbit" it as long as we could see it, since the update in gravity (the curvature of space-time) had not reached us yet. Then once we saw that the sun no longer existed (since the lighted had stopped reaching us) we would stop orbiting, since space-time would have reverted to a flat-state. Its cool, but also insane. It means technically speaking, we would orbit NOTHING for about 8 minutes.