EDIT: Let’s cool it with the downvotes, dudes. We’re not out to cut funding to your black hole detection chamber or revoke the degrees of chiropractors just because a couple of us don’t believe in it, okay? Chill out, participate with the prompt and continue with having a nice day. I’m sure almost everybody has something to add.
I am curious if the opposite of dark matter could be true; while dark matter inside galaxies would explain galactical motion, couldn’t the same be explained by something repulsive BETWEEN galaxies? If the latter were the case, it would also explain dark energy.
The observations of systems like the Bullet Cluster imply that dark matter is actual material – baryonic matter. Stuff that exists in specific locations and has mass. Modifying the math of the physical laws does not explain these observations without absolutely going into contortions where dark matter explains them quite elegantly.