Good to see that the classic "middlebrow dismissal" is still alive and well here on HN. The fact is that dark matter isn't just some half-baked theory that ast

Good to see that the classic "middlebrow dismissal" is still alive and well here on HN. The fact is that dark matter isn't just some half-baked theory that astrophysicists pulled out of their ass. Nor does it represent some lame attempt to just sweep complexity under the rug as if astronomers said "I dunno, probably magic", shrugged, and moved on. Dark matter is a very specific and constrained theory that has withstood the test of decades of observational tests where all other theories have fallen by the wayside. Astrophysicists and cosmologists did not set out trying to force the theory of dark matter on the world, they have tried repeatedly to prove that other explanations could account for observational evidence, but none did. Instead they've had the reality of dark matter thrust upon them. And it's not such a crazy theory either. We know that there are other kinds of weakly interacting massive particles such as neutrinos that exist in the Universe. And we know that our understanding of particle physics, the standard model, is incomplete. It is not a great leap to posit that potentially there are other types of weakly interacting massive particles that we have yet to discover. We know that neutrinos and "hot dark matter" does not make up the majority of the mass of dark matter in our Universe through several lines of observations. We know that baryonic (atomic) matter is also not dark matter as well. Only "cold" (sub-relativistic speeds) WIMPs fit the evidence for dark matter. The evidence gathered from galactic motion studies, gravitational lensing observations, simulations of the evolution of the large scale structure of the Universe, measurements of the cosmic microwave background, and many other experiments. Nothing fits all the data except the cold dark matter theory. That's why scientists believe it. The fact that you are skeptical about it is irrelevant. Educate yourself on the evidence and science of it first, and then you can talk.