१७ मार्च, २०२२

"The prediction of bald, featureless black holes has been nicknamed the 'no-hair theorem' since the 1970s."

"[Xavier] Calmet and his collaborators think the black hole is more complex – or hairy. As matter collapses into a black hole, they suggest, it leaves a faint imprint in its gravitational field. This imprint is referred to as 'quantum hair' and, the authors say, would provide the mechanism by which information is preserved during the collapse of a black hole.... There is no obvious way to test the theory through astronomical observations – the gravitational fluctuations would be too tiny to be measurable.... 'It’s going to take some time for people to fully accept this. The paradox has been around for a long time and you’ve got very famous people all over the world who’ve been working on this for years.'"

From "'Quantum hair' could resolve Hawking’s black hole paradox, say scientists/New mathematical formulation means huge paradigm shift in physics would not be necessary" (The Guardian).

२७ टिप्पण्या:

Original Mike म्हणाले...

Quantum hair on black holes is old stuff. My guess is Calmet has brought something new to the party, but what that is isn't described in the Guardian article.

TaeJohnDo म्हणाले...

"There is no obvious way to test the theory through astronomical observations – the gravitational fluctuations would be too tiny to be measurable...."

Well since we don't need to test anything, I'm going to declare a new theory that I'll call the "bald spot theorem." This is different from the "receding-hair paradox" that weaves string theory into the whole mess.

Temujin म्हणाले...

Hmm. My wife's pet name for me. "My little bald, featureless black hole."

jaydub म्हणाले...

Where's Laslo when you need him?

rhhardin म्हणाले...

You can't comb the hair on a billiard ball. Old theorem.

rhhardin म्हणाले...

Hawking radiation was supposed to preserve entropy, the last I'd heard. Spontaneous particle pair production near the horizon, one particle escapes and the other falls back in. If you keep that up, eventually your black hole has evaporated.

Tom T. म्हणाले...

A flaw in our conception of something we've never actually observed can be corrected by positing something else that we can't measure.

Quayle म्हणाले...

From the former post on the impact of religion on educational achievement. "When [the] elites criticize religion, they often do so on the grounds that faith (in their eyes) is irrational and not evidence-based."

Two points:

1. It is a fallacy that religious people don't operate on evidence. Christ said "Anyone who resolves to do the will of God will know whether the teaching is from God or whether I am speaking on my own." Once some one resolves to do what Christ taught, the evidence of its impact is palpable. The Book of Mormon puts it differently. It compares God's word to a seed, which if you plant and tend, it will grow. (See here). And when it grows, your faith is replace with knowledge. When the seed is in your hand, you have only faith that it will grow into a tree. When you plant the seed (do what the word says) and the tree grows (you see the palpable benefits in your life) it is no longer faith, but is knowledge.

2. All science is forever based on faith, but that faith is rarely rewarded with knowledge. For example, all scientists must hold to the faith that what your body can observe is real, what what you observe is all that exists, etc. Science is also based on the faith that you have enough information that your present conclusions are meaningful. But the history of science shows that such faith is usually wrong. The history of science is littered with conclusions and explanations that no scientists today believes to be true or logical or meaningful. Rather than faith turned to knowledge, it is faith turned to new faith. Ever learning, but never able to come to a knowledge of the truth. Only able to come to "new and better explanations."

What could be more evidence based than my own experiment that when I read the scriptures daily over an extended period of time, I am happier, less prone to any anxiety, more emotionally resilient, and things clearly seem to go better in general (whether by outlook or actuality.) And in contrast that when I don't read from the scriptures daily for a period of time, things start to go the other way. And I'm not the only religious scientists who has proven that is the case - i.e. proven Christ's challenge and truth claim by experiment. There are millions of others. That is as evidence based is it gets.

Jupiter म्हणाले...

Zeroeth World problems.

Michael K म्हणाले...

It is far more important to drive "whiteness" out of Physics and get rid of "white boards" in classrooms.

Wince म्हणाले...

"The prediction of bald, featureless black holes has been nicknamed the 'no-hair theorem' since the 1970s."

Huh, I always thought it was called a "Brazilian"?

Narr म्हणाले...

Hair makes the hole easier to find.

Jersey Fled म्हणाले...

i have quantum hair every morning when i wake up.

Jaq म्हणाले...

Makes sense, seems almost obvious in retrospect.

cubanbob म्हणाले...

I confess. I have no clue regarding the article. I'm waiting for the comments to see if any commenter does.

n.n म्हणाले...

A model... a pattern, consistent with a model, a pattern, an inference from signals of unknown and unknowable fidelity.

That said, a black hole... whore h/t NAACP. The Guardian is not worried that they will be accused of rabid diversity?

madAsHell म्हणाले...

What's next??......A string theory revival?

walter म्हणाले...

I'm getting tired of hearing about Whoopi.
She did ask us to stay out of her vagina.

Jaq म्हणाले...

The theory is that there can be no loss of information in the lifetime of the universe. It unwinds in a certain way and everything that happens leaves a trace through all of time, (like when Homer stepped on the butterfly back in time, and when he returned, it was raining donuts.) Therefore everything is recorded, even if there is no practical way to read it back. One of Hawkins students joked that if he threw his empty coffee cup into a black hole, this rule would be violated, information would be lost, and the cup's effects on the universe would come to an end. But if you threw the cup in, it would effect the gravity of the black hole by increasing its mass, and the crushing of the cup would produce minute gravity waves that can escape the black hole, information is getting out. Your coffee mug has gravitational attraction but immeasurably small.

Of course the loss of information assumes that at the quantum level, it's not just random to make the math work, but classical causality really is suspended, not just impossible to measure. Usually when we say "random" we mean the causes are too complex and varied to understand. If you get rid of that assumption, then no information is ever lost because it's all rattling around in the black hole until it comes out in the form of Hawking radiation. But that last paragraph is what physicists call "philosophy" and the joke is that the difference between the office of a theoretical physicist and a philosopher is that the physicist has a waste basket.

I didn't actually read the article, just the excerpt, so the above is just my guess from my memory. Maybe somebody who has cracked a physics book more recently than 1977 can correct me if I got it wrong.

JAORE म्हणाले...

Careful. I just read Biden says criticizing black hair is racist.

Jamie म्हणाले...

I am put in mind of the Heinlein book Job, in which God is revealed to be exactly the literal Old Testament God, the world is 6000 years old, and evolution is not a thing... but God has created fossils, has built in spurious genetic relationships between species that point to evolution, has started atomic clocks in the middle so rocks seem to be much much older than they are. All because He's capricious and bent on testing the "faith" of humanity. Human beings, to "win," have to see all the countervailing evidence, and still believe in a 6000yo Earth.

Wouldn't that be something?

(This is of course in response to the comment above about science's initial and utterly necessary faith that natural law always obtains. Heinlein also wrote the novellas "Waldo" and "Magic, Inc.," which deal with the presence, parallel to the universe we know, of a - place? - where we can tap into limitless energy and use that energy in ways that appear, in our universe, to be magic. Natural law no longer applies if someone has put this energy source to use in some way that interferes with it - but if no one were to use this energy to bend matter, time, or our local version of energy to her will, then natural law still would appear exactly as infallible as it does to us.)

walter म्हणाले...

Michael K said...It is far more important to drive "whiteness" out of Physics and get rid of "white boards" in classrooms.
--
I fear NASA's mission to help Muslims feel better about their math contributions has taken a back seat.

chuck म्हणाले...

Not new.

Jaq म्हणाले...

"Not new."

I don't follow physics, but It does ring a bell.

Robert Cook म्हणाले...

"What could be more evidence based than my own experiment that when I read the scriptures daily over an extended period of time, I am happier, less prone to any anxiety, more emotionally resilient, and things clearly seem to go better in general (whether by outlook or actuality.) And in contrast that when I don't read from the scriptures daily for a period of time, things start to go the other way. And I'm not the only religious scientists who has proven that is the case - i.e. proven Christ's challenge and truth claim by experiment. There are millions of others. That is as evidence based is it gets."

As circular evidence goes, I guess.

daskol म्हणाले...

Bald, featureless _______

chuck म्हणाले...

More informed take here.