> Couldn't we just as easily say the same about EM or any of the other forces? We've tested other forces in more regimes than gravity because gravity is so wea

> Couldn't we just as easily say the same about EM or any of the other forces? We've tested other forces in more regimes than gravity because gravity is so weak, but in principle, if predictions of those theories mismatched observations to the same extent as gravity, then we absolutely should be questioning those theories too. > They keep having to add parameters to MOND to make it fit what we see and currently attribute to dark matter, like the bullet cluster. I don't know why people keep saying this like cold dark matter model doesn't do this. LCDM has been refuted many times if this is your criterion. The review paper I cited shows numerous examples of parameterization and curve fitting for LCDM.