Black holes the size of an atom that contain the mass of an asteroid may fly through the inner solar system about once a decade, scientists say. Theoretically created just after the big bang, these examples of so-called primordial black holes could explain the missing dark matter thought to dominate our universe. And if they sneak by the moon or Mars, scientists should be able to detect them, a new study shows.
If dark matter is fully explained by such black holes, their most likely mass, according to some theories, would range from 1017 to 1023 grams—or about that of a large asteroid.
In case this doesn’t tell you a lot, 1017 grams is half the weight of Mount Everest, and 1023 grams is 4x the weight of the Antarctic ice shield.
The earth is estimated to “weigh” 13,170,000,000,000,000,000,000,000 pounds. (That is weird when you think about it. The weight of the earth being based on what something weighs on earth, I mean.)
Mt. Everest is only about 357,000,000,000,000 pounds and is just a tiny fraction of the mass of the earth.
So. My point is that we need a better way to portray scale of things in the universe. AUs work to a point but then we have to quickly move to parsecs. Parsecs quickly give way to light years. (Or vice-versa, depending on how you visualize things better.) Light years kinda work, but only for between 14-26 billion years. Even after all of that, I can hardly still fathom the size of Mt. Everest. (This was a rant, but not an angry rant.)
I thought these were disproved by lack of gravitational microlensing?
The main way you’d see that kind of microlensing is if they aggregated.
But given the way gravity works, they should aggregate, otherwise why call them black holes?
If they were relatively evenly distributed would that counteract lensing?
Yes, it would just be surprising because, gravity should make them not be evenly distributed.
The whole thing with dark matter is that it’s this magic stuff that causes gravity but isn’t affected by it, which… is not how gravity normally works.
Though there is still room for it, we just need a better framework other than “I added 3 and 5 and got 12, so obviously I must mean to add 3 and 5 and 4 too”.
You’re mistaken. Dark matter, whatever it is, isn’t affected by anything except gravity. It interacts with gravity just like “normal” matter.
The evidence is also significantly better than you’re describing
Then it should also coelescce, particularly since it doesn’t have the em force to keep it repelled, the universe should be dominated by massive dark matter black holes.
Yes, there’s math that explains part of the distribution, but also there is 0 force opposing any collapse we’d have a lot more neutron stars and other degenerate matter catalyzed by dark matter.
We have hypotheses like this when our observations don’t make sense and we need to explain them, it’s definitely a possibility but we still have room to understand the large scale physics at play.
You don’t need a force to prevent collapse if there’s no drag force to slow things down. It would actually be almost impossible for a cloud of dark matter to collapse since any individual particle has momentum and no way to slow down, so they’ll all be in some sort of mutual orbit
