Every other force attracts and repels, gravity does not. Gravity only attracts. This is assymmetrical. We like to assume things that are not symmetrical are wrong. Why do we not assume this is wrong? Is there any possible way gravity could be repulsive? I know there is staggering amounts of evidence to suggest it isn't, but why not on very small lengths, say planck length, that gravity actually becomes repulsive. Maybe the repulsion is just "gravitons" get so thick in an exchange between two particles it just pushes them away to a very small length until the density of them goes down. Things like this idea would solve the idea of a singularity existing at the center black holes and such. Do we have any experimental data at such small scales? Do we have anything that disproves an idea like this? Just wondering.