Comment by api
4 days ago
My favorite is that there are probably primordial black holes, which is exciting because they are a good dark matter candidate. They could have other neat implications too, like being common enough that we might some day find one within visiting range. Being able to examine one directly could allow us to “finish physics.”
Note that many if not most variations on the Big Bang and inflation predict them but we have yet to directly see them. What JWST has found is indirect evidence they’re out there.
This PBS Spacetime video pours some cold water on the black holes as dark matter hypothesis:
https://youtu.be/qy8MdewY_TY?si=9jc_a7IAm4qrhfNX
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
Yeah the mass ranges these primordial black holes would need to be mean that it cannot possibly be those little red dots. While the early universe magnifies things, the mass of those little red dots still needs to be close to a small galaxy worth of mass. Tens to hundreds of thousands of star masses absolute minimum. And that's just far, far, incredibly far to high.
I wonder if the time estimates of ~13.8 billion years hold up for the big bang in the future. I remember a physicist talking about time and space being fuzzy in the real early universe.