If you've got the time, these YouTube videos are a nice counterpoint to a lot of popular communication and discussion on dark matter: Dark matter is not a theo

If you've got the time, these YouTube videos are a nice counterpoint to a lot of popular communication and discussion on dark matter: Dark matter is not a theory: https://www.youtube.com/watch?v=PbmJkMhmrVI https://www.youtube.com/watch?v=PbmJkMhmrVI That dark matter video aged like milk: https://www.youtube.com/watch?v=qS34oV-jv_A https://www.youtube.com/watch?v=qS34oV-jv_A the tl;dr is that "dark matter" is a bit of a misnomer. (But also a fun name so it's probably here to stay through sheer memetic momentum.) Dark matter is not actually a hypothesized kind of matter. Dark matter is just an unresolved discrepancy between theory and observation. I'll say that again: "dark matter" is not an attempt at explaining the discrepancy; dark matter is the discrepancy. There are some hypotheses that postulate some kind of as-yet-unobserved matter that could resolve the discrepancy, but these hypotheses are not the actual problem that we call "dark matter". And not all hypotheses postulate unobserved or exotic matter. Some of them suggest alternative physics, others suggest measurement error.