(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 bril

(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) https://www.youtube.com/watch?v=qy8MdewY_TY https://www.youtube.com/watch?v=qy8MdewY_TY (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)