/sci/ - Science & Math

How far can gravity reach?

Is there an upper limit on the distance at which gravity can act? I expect that for the larger distances we've observed, Newton's law of gravitation basically holds. But is there any reason to believe that their could be a limit?

I'm not asking about the time it takes gravity to act at a distance. Assume, for the question, an infinite universe and an infinite amount of time.

It's a naive question, I guess. I imagine that photons, unhindered, can travel forever. But as gravity is a binding force of sorts, I imagine a sort of tension between a mass and the graviton (or whatever type of particle transmits the attraction). Does this tension continuously approach zero at infinite distance, or is there a cutoff of sorts?