Hawking concedes - Black holes are not singularities after all

[astro]

Hawking changes his mind about black holes

[Askance]

The really odd thing about the article to me is that by extension Einstein was wrong too, but that does not get explicitly mentioned.

[Albert_Rose]

Quantum theory says any process can be run in reverse, so starting conditions can theoretically be inferred from the end products alone. This implies that a black hole must somehow store information about the items that fell into it.

Further implying that the collapse resulting in a black hole could reverse, and a black hole could expand (un-collapse?) right back into all that matter.

Forgive me for my simplistic understanding of these theories, but doesn’t that describe the Big Bang?

How could that information ever escape? The answer lies in one of Hawking’s greatest discoveries: that black holes slowly evaporate into space by losing particles from the very edge of the gravitational precipice at their rim, called Hawking radiation. The black hole eventually shrinks to a tiny kernel, at which point a growing torrent of radiation begins to leak out, potentially carrying the lost information with it.

Well, that’s not a Big Bang.

But Preskill says that Hawking’s new take on quantum gravity rests on shaky mathematical foundations, and is unlikely to be embraced by the physics community.

Back to the old drawing board, I guess.

[RTFirefly]

From the article:

The problem is that quantum theory, which describes space and matter on very tiny scales, contradicts this. Quantum theory says any process can be run in reverse, so starting conditions can theoretically be inferred from the end products alone. This implies that a black hole must somehow store information about the items that fell into it.

IANA physicist, but on the face of it, that makes no sense to me whatsoever - even leaving black holes out of it.

Under Newtonian physics - good old deterministic 18th-century physics - you repeat an experiment 100 times, under the exact same conditions, you get the same result each time. So there’s an argument that you could work backwards from the finish to determine conditions at the start.

The problem with quantum physics is the element of probability. You repeat a quantum experiment 100 times under the exact same conditions, and you won’t get the same result every time; each time, the dice are going to roll independently, and send the sub-atomic particles on different paths.

So if - by the laws of quantum physics - you can’t determine the finish from the start, how can you determine the start from the finish? If the laws are equally true running backwards as forwards through time, you can’t.

Hopefully a physicist will drop by this thread and explain why I don’t understand the principles of quantum physics nearly as well as Hawking does, which I’m sure is the case.

[AveDementia]

This is worrisome. I hope it doesn’t mean he’s mentally slipping. I’ve heard some disturbing things about his second wife possibly abusing him. Friends of his have said they’re concerned with how much control she appears to want over his life. He’s a mental giant, but physically and possibly emotionally as well, he’s as vunerable as a kitten. It would be sad if his home life started affecting his work, I hope this isn’t the case.

And I hope no one thinks I’m over-reacting here. I’m just concerned because I think what he is doing is important for the future. I love to hear the speculations about the beginnings of the universe and all that. Of course, I leave the math to others, but I still think it’s valuable.

Dammit.

[kanicbird]

Well BH’s can be run in reverse, it just requires time to go backwards.

Will this be a boost of the gravistar theory, which IIRC is supported my Einstein’s theorys but not Hawkins, and actually seems more realistic to me (though the name blows)

[ultrafilter]

@AndrewT

The really odd thing about the article to me is that by extension Einstein was wrong too, but that does not get explicitly mentioned.

I think it’s been a while since there was any serious doubt that Einstein was wrong. QM and GR have been known to be incompatible for a while, and GR is a classical theory (as it doesn’t take Heisenberg’s work into account), so everyone’s been thinking that it would have to go.

This is pretty cool–next year is the 100th anniversary of Einstein’s best year, which can generally be regarded as the beginnings of both QM and GR, and it looks like we’re getting even closer to reconciling them.

[GargoyleWB]

And the award for the best media headline on the subject goes to…

http://www.smh.com.au/articles/2004/07/16/1089694567008.html?oneclick=true

[Otto]

@GargoyleWB

And the award for the best media headline on the subject goes to…

“Soon you will need to register to read this article”?

I don’t get it.

[Ogre]

Hit the “Register Later and Continue to Your Article” link under it. The headline is pretty good.

[astro]

@Ogre

Hit the “Register Later and Continue to Your Article” link under it. The headline is pretty good.

And that’s a family newspaper?