What If Dark Matter Is Just Black Holes?

What people said

jraines · 2025-07 · Reference

This PBS Spacetime video pours some cold water on the black holes as dark matter hypothesis: [VIDEO] It’s 4 years old; I don’t know if this JWST finding changes anything. I do know we have finally found some (one?) intermediate-mass black holes in the interim, but I don’t know if that changes it either. The possibility it leaves open for “Planck relics” is interestingly exotic

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nabakin · 2025-04 · Reference

That was my first thought too. A cursory search indicates we would see a lot more gravitational lensing in our observations if that was the case. Found a couple of videos on it too [VIDEO] [LINK]

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ck2 · 2024-09 · Reference

(sorry only available on youtube, they no longer seem to mirror on pbs.org ) If you aren't familiar with Matt, yes he is at least 50% Neanderthal but also brilliant, lol btw I owe @api an apology, apparently black holes could indeed be dark matter, I missed this one from Matt a few years ago (or forgot the lesson) [VIDEO] (actually by the end of that video Matt demonstrates point by point that there aren't enough black holes to be dark matter for several reasons/types, their mass doesn't add up enough, there would have to be more micro-sized black holes than all the stars in the universe and we'd be observing some really strange behaviors if that was the case, like disappearing neutron stars - just a few edge cases are left)

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