181–190 of 318 posts
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Actually, they can shoot out relativistic jets at the poles. https://www.nustar.caltech.edu/page/relativistic-jets
But there, the black hole is ejecting other mass near it, not its own.
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But the universe isn’t spherical. I’m not sure I understand this hypothesis as explained.
But the observable universe roughly is.
In other words, your observable universe is different than mine and that's both spheres we're in the middle of. That suggests the universe itself probably isn't a sphere.
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I don't think it is infinite - each universe can only have that mass/energy that fell into the outer black hole in the parent universe. At some level you'll inevitably have black holes with universes that do not have enough mass to form another inner black hole.
How much mass is required to form a black hole in a new universe with perhaps different physical constants? It could be that 'ability to make black holes' is a prerequisite for successful universes in the way way that good genes are a prerequisite for successful organisms. The universes that fail to spawn black holes are 'dead ends' so any life is statistically likely to find itself in a black hole spawning universe.…
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How does that follow? I imagine there was already a preferred spin of gases immediately after the big bang, just due to random chance, so why wouldn’t that be preserved more or less?
That's the thing, we don't know any reason for a preferred spin and assumed it would be equally distributed. So this is an interesting fact.
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But there, the black hole is ejecting other mass near it, not its own.
Mm, I didn't correctly interpret their comment. You're absolutely correct.
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I don't understand how the 1e-16 Hz rotation of the Milky Way affects how we perceive other spiral galaxies' orientations.
Relative motion to the center. 230 km/s is fast.
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A 50/50 matter/anti-matter system could still house stable local pockets of mostly matter or anti-matter. The problem is, from what I understand, that the universe seems to have sprung into existence with way more matter than anti-matter, and we don't know why.
Could it be that the observable universe is one of these stable local pockets and the antimatter to balance it out is simply not observable to us?
If you flip 2n fair coins, you expect n+δ heads and n-δ tails, where δ is (IIRC) sqrt(n/2). Going much away from that becomes infintessimally unlikely.
Probability is a subject famously easy to get wrong, so be careful with what I'm about to suggest: I *think* you could argue that in the moment prior to the inflation epoch spreading everything out just enough that pair production stops*, any given particle in our horizon is a coin toss of matter or antimatter.
Number of observed atoms in the universe is about 6e79 (http://www.wolframalpha.com/input/?i=how%20many%20atoms%20in...), so 6e79 = sqrt(n/2) -> n = 7.2e159 due to protons, and the same again for electrons; as we don't see significant signs of antimatter, any around must have annihilated a long time ago, so in this scenario we should expect to see ~7e159 (red-shifted) photons from the supermajority of particles which have annihilated.
It's outside my field to know how that compares to cosmologist's observations.
* won't that be at different times for protons/neutrons and electrons?
I can't get good answers on the expectations for either "why are protons and electrons counts the same" or "what is the observable consequence if they're not?"