Two blobs alone in the Universe

[bland]

In this thought experiment we place two 100 kg spheres of gold 10 billion light years distance from each other in an otherwise empty universe devoid of particles of any kind as far as is possible, then let them go and we disappear from the experiment leaving just those two spheres alone in the empty void. Will they, given enough time, mutually attract each other. If so what would be their velocity upon colliding?

 

[A.T.]

You can use energy conservation to find the collision velocities. For duration see the links here:
https://www.physicsforums.com/threa...e-two-planets-to-collide.852330/#post-5345029