gravitational constant G 6.673(10) x 10-11 N*m2/kg2 F = G (M1 * M2)/r^2 solving for r r = (F/(G* M1*m2) ^ 0.5) r = 12.02540008 meters Two Neutrons more than 12 meters apart will not be gravitationally attracted to each other. Could this be right? I was a bit surprised by that figure, so that means much to my surprise that gravitational attraction does add and would extend indefinitely throughout the Universe with sufficient mass to bend the Space Time. Could you check this Trippy please? Please Register or Log in to view the hidden image!