undefined | Better HN

0 pointsmr_mitm3y ago0 comments

You mean stellar black holes, right? Primordial black holes could be much smaller, if they exist.

I just looked up what would happen in that case, and it sounds really bizarre:

> Nevertheless, a PBH would have a notable local impact, Rahvar notes. “The passage of a black hole could melt a cylinder along the interior of the Earth with a radius of almost 10 cm. After a short time, this tunnel would freeze,” he explains. In theory, this would produce a distinct metamorphic fingerprint of the passage in the rock record. But given that we might expect only eight of these to have been produced in the Earth’s lifetime (one on each side of the planet per collision episode), “I would expect that such a geological trace is difficult to detect,” Rahvar concedes.

https://physicsworld.com/a/concerning-primordial-black-holes...

0 comments

3 comments · 1 top-level

LatteLazy3y ago· 2 in thread

The issue with that is you're really just talking about another form of dark matter: something else theoretically not impossible but also never observed despite decades of looking...

scotty793y ago

At least it's never observed in a sense that neutrino was never observed until it was. We just lack powerful enough sensors. The other forms of dark matter were never observed in a sense tachyons were never observed. As in we don't just lack sensors, we lack exact understanding of what we are trying to observe.

mr_mitmOP3y ago

I should point out that primordial black holes are one of the candidates for dark matter. The scientific community seems to be flipflopping about the plausibility of this theory.

j / k navigate · click thread line to collapse