As far as I know things like rocks, walls, rubber balls, polished tables etc. exert a short range repulsive force on other everyday objects that is responsible for hardness, softness, collisions, friction etc.
Take a pair of electrically neutral solid materials. I am not interested in pairs of magnetic materials or astral bodies. Related to this I have a question:
Are there any such pairs with significantly longer range repulsions? So significant, in fact, that we can observe them repelling each other at large macroscopic scales. Could such materials have applications like anti-gravity?
