4 ms·

The minimum mass for a black hole is about 3 times the size of the sun. So we would definitely detect such an object. In fact it would have pretty catastrophic

The minimum mass for a black hole is about 3 times the size of the sun. So we would definitely detect such an object. In fact it would have pretty catastrophic consequences if it entered the solar system...

mr_mitm 4y ago
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/ https://physicsworld.com/a/concerning-primordial-black-holes...
- LatteLazy 4y ago
  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...
  - scotty79 4y 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_mitm 4y 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.
scotty79 4y ago
I did not mean stellar black holes.

mr_mitm 4y ago

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

LatteLazy 4y ago
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...
- scotty79 4y 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_mitm 4y 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.

scotty79 4y ago

I did not mean stellar black holes.