The gravity of the molecules of the ruler will definitely NOT be insignificant, if you're in a void where there are no other forces acting on the ruler. think about it... there's nothing to pull the molecules away from each other. In this imaginary void, there is no gravity other than that of the molecules. The only forces in this scenario are gravity between molecules, electromagnetic forces, and the weak and strong interactions of particles. Unless one or more of these forces start pushing away from each other, or some imaginary wind blows through, there will be no other force to cause the particles to move away from each other. Even if the space between the molecules is "expanded" so you've got a ruler perfectly blown up 2x... the only forces are the ones pulling the particles together. Even if you expand everything to the point that particle A is so far away from particle B that the electromagnetic, gravitational, weak and strong forces between them cannot affect them.... what force would cause them to do anything other than stand where they are?
victor809 wrote: