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Astrophysicists Puzzle over Webb’s New Universe

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Re: Astrophysicists Puzzle over Webb’s New Universe

#121

Post by api »

windsurfer wrote: post #100
pmontra wrote: post #30

Earlier quoted context omitted.

Of course if we had a black hole in a lab (or one in a convenient orbit) we could run all sort of experiments, but which experiments exactly? We will start by throwing things at it and watch, obviously, but that's unimaginative. What are the smart experiments?

If you had a small black hole in a lab you could generate power from the hawking radiation, likely enough to power the entire world. A 1,000,000 ton black hole would last over a thousand years without feeding it more mass and produce about 300 TW of energy (increasing over time, so you better keep feeding it). You'd also need some pretty good sunglasses to be able to watch things being thrown into it. Also I'm not su…

Unfortunately when your power source black hole got smaller it would get hotter, finally reaching runaway at the end and detonating with hundreds of times the power of the Tsar Bomba.

Re: Astrophysicists Puzzle over Webb’s New Universe

#122

Post by andrewflnr »

AtlasBarfed wrote: post #103
windsurfer wrote: post #100

Earlier quoted context omitted.

If you had a small black hole in a lab you could generate power from the hawking radiation, likely enough to power the entire world. A 1,000,000 ton black hole would last over a thousand years without feeding it more mass and produce about 300 TW of energy (increasing over time, so you better keep feeding it). You'd also need some pretty good sunglasses to be able to watch things being thrown into it. Also I'm not su…

So the hawking radiation is so strong that it impedes matter falling into the hole? And can you charge the hole with enough of a charge to use electromagnetism to move and contain it?

Do note that that's a bit speculative. We haven't actually observed hawking radiation. And Hawking radiation definitely isn't what slows feeding in astronomical black holes, but radiation from the gas heating up as it falls.

Re: Astrophysicists Puzzle over Webb’s New Universe

#123

Post by theodorejb »

cogman10 wrote: post #83
theodorejb wrote: post #39

Instead of questioning whether the Big Bang assumption is true, astrophysicists prefer to perform endless "gymnastics" to try to make the mounting contrary data fit their theory about how the universe began.

Are you kidding? An astrophysicist that could come up with a new model that explains the current data would win a Nobel prize and earth shattering levels of notoriety. The data found doesn't contradict the big bang in any shape or form. It does challenge beliefs around black hole formation. The reason for the big bang model is because based on all our measurements of all the visible universe, it appears that everythi…

The Big Bang is an almost infinitely malleable story, contorted to comport with almost anything we observe. But how is this useful? The predictions of this theory continually fail. The farther we look, the more we see stars, galaxies, black holes, and other structures that shouldn't exist according to this model.

What if the universe doesn't have a naturalistic origin, but was created by God? How much greater would our understanding of the world be if more scientists focused on studying present phenomena rather than trying to fit stories about the past with observed data?

Re: Astrophysicists Puzzle over Webb’s New Universe

#124

Post by rolph »

consensus1 wrote: post #73
api wrote: post #22

The most exciting idea to me that JWST has bolstered is primordial black holes. Many models already predict them but JWST has provided the first good indirect evidence in the form of too-early galaxies. The models that predict PBHs predict that. If they exist, they would not be constrained to stellar mass and above. There could be a population of little black holes floating around. Anything under the mass of a decent…

How certain is the evaporation? Obviously Hawking radiation has never been observed, but is it tied in enough to other known physics that we can be reasonably certain it exists?

hawking radiation is a postulated mechanism for tempurature of a black hole.

the whole thing started with information paradox, leading to the suggestion that a black hole would have to be associated with entropy, thus would have a temperature, but required an escape hatch to allow radiation, the thought experiment came to a thought solution when particle-antiparticle pair dissociation at the event horizon was postulated.

We Knew Black Holes Have a Temperature. It Turns out They Also Have a Pressure[2021]:

https://www.universetoday.com/articles/we-knew-black-holes-h...

Black hole thermodynamics:

https://en.wikipedia.org/wiki/Black_hole_thermodynamics

Re: Astrophysicists Puzzle over Webb’s New Universe

#125

Post by muvlon »

technotony wrote: post #114
stouset wrote: post #113

Earlier quoted context omitted.

Yep, it’s a super cool concept. A black hole of a given size has a finite amount of matter that it can ingest over a period of time. Trying to stuff more matter into it causes an outward pressure from essentially the friction of the swirling mass of material falling in. This radiation pressure could in theory be great enough to start fusion as would happen in a stellar core. Also fun is that this puts a limit on the…

Couldn't those large black holes merge though to get bigger ones?

Yes, exactly. Black hole mergers are the one thing exempt from the Eddington Limit, because there is no friction there.

Re: Astrophysicists Puzzle over Webb’s New Universe

#126

Post by muvlon »

cholmdomsky wrote: post #95
typeofhuman wrote: post #33

Earlier quoted context omitted.

I'm not sure anything after the event horizon right? Since no light == no information.

Can magnetic fields escape, if their lines intersect the event horizon of a black hole?

No, a classic GR black hole does not have its own magnetic field. It can have electric charge, along with mass and spin, but that's it.

There is a somewhat fringe alternative idea called a MECO, which can have a magnetic field. Unlike some of the other fringe black hole alternatives, this one at least produces falsifiable predictions.

Re: Astrophysicists Puzzle over Webb’s New Universe

#127

Post by pndy »

theodorejb wrote: post #123
cogman10 wrote: post #83

Earlier quoted context omitted.

Are you kidding? An astrophysicist that could come up with a new model that explains the current data would win a Nobel prize and earth shattering levels of notoriety. The data found doesn't contradict the big bang in any shape or form. It does challenge beliefs around black hole formation. The reason for the big bang model is because based on all our measurements of all the visible universe, it appears that everythi…

The Big Bang is an almost infinitely malleable story, contorted to comport with almost anything we observe. But how is this useful? The predictions of this theory continually fail. The farther we look, the more we see stars, galaxies, black holes, and other structures that shouldn't exist according to this model. What if the universe doesn't have a naturalistic origin, but was created by God? How much greater would o…

https://en.wikipedia.org/wiki/Calculating_God?useskin=vector have fun

Re: Astrophysicists Puzzle over Webb’s New Universe

#128

Post by fractaled »

JumpCrisscross wrote: post #107
sulam wrote: post #97

I thought I read somewhere that many of these little red dots are turning out to be nothing more than bog-standard brown dwarfs in our own galaxy that are confusing the signal. These days we have some pretty powerful agents who can read these things faster than I can, so I went and found the paper: https://arxiv.org/abs/2506.04004 It turns out that brown dwarfs are actually corrected for, so my remembrance is correct…

> many of these little red dots are turning out to be nothing more than bog-standard brown dwarfs Your own paper estimates 5 to 25% may be brown dwarfs, and says nothing about whether they might be in our galaxy or not.

Pretty sure we can't resolve brown dwarfs farther than a few 10k ly (well inside the confines of our galaxy).

Re: Astrophysicists Puzzle over Webb’s New Universe

#129

Post by cogman10 »

theodorejb wrote: post #123
cogman10 wrote: post #83

Earlier quoted context omitted.

Are you kidding? An astrophysicist that could come up with a new model that explains the current data would win a Nobel prize and earth shattering levels of notoriety. The data found doesn't contradict the big bang in any shape or form. It does challenge beliefs around black hole formation. The reason for the big bang model is because based on all our measurements of all the visible universe, it appears that everythi…

The Big Bang is an almost infinitely malleable story, contorted to comport with almost anything we observe. But how is this useful? The predictions of this theory continually fail. The farther we look, the more we see stars, galaxies, black holes, and other structures that shouldn't exist according to this model. What if the universe doesn't have a naturalistic origin, but was created by God? How much greater would o…

> The predictions of this theory continually fail.

No they don't. There are surprising and unexplained aspect (why is the expansion currently accelerating? That's an unknown afaik). But the baseline prediction and observation that the universe is expanding have yet to see any sort of contradicting evidence.

> The farther we look, the more we see stars, galaxies, black holes, and other structures that shouldn't exist according to this model.

That's just hogwash from answers in genesis. Name an example of a black hole that "shouldn't exist" according to the big bang theory.

> What if the universe doesn't have a naturalistic origin

The big bang says nothing about the origin of the universe. It is merely a description of the current observable universe. We don't know what caused the big bang, if this is the only big bang, or if the universe is actually infinite in size. We don't know if our current observable region is just one in a cosmos of regions.

> but was created by God?

God doesn't exist, so no. But even if I granted god does exist, it could be completely compatible with the big bang as being the ultimate cause of it or some earlier event which triggered it. Certainly god as envisioned through fundamentalist Christianity is incompatible with the big bang, there is a mountain of evidence against that god.

> How much greater would our understanding of the world be if more scientists focused on studying present phenomena rather than trying to fit stories about the past with observed data?

That's what they do. You have a completely false notion of what scientists and astrophysicists are doing. They aren't trying to "fit to the model" they are trying to expand understanding and change the model to match observations. There's no dogma in science and they get the most excited when something unexplained is observed.

Re: Astrophysicists Puzzle over Webb’s New Universe

#130

Post by cholmdomsky »

muvlon wrote: post #126
cholmdomsky wrote: post #95

Earlier quoted context omitted.

Can magnetic fields escape, if their lines intersect the event horizon of a black hole?

No, a classic GR black hole does not have its own magnetic field. It can have electric charge, along with mass and spin, but that's it. There is a somewhat fringe alternative idea called a MECO, which can have a magnetic field. Unlike some of the other fringe black hole alternatives, this one at least produces falsifiable predictions.

I suppose what I meant to have asked was, can an external magnetic field intersect with a black hole's event horizon and then escape?

For instance, with these theoretical tiny black holes, what would happen if you held a powerful magnet close enough for the lines of flux to actually intersect the event horizon?

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