Hawking's black hole theory revised

[ralphwiggum 6]

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http://www.cnn.com/2004....ex.html

Quote[/b] ]DUBLIN, Ireland (AP) -- Famed astrophysicist Stephen Hawking says black holes, the mysterious massive vortexes formed from collapsed stars, do not destroy everything they consume but instead eventually fire out matter and energy "in a mangled form."

Hawking's radical new thinking was presented in a paper to the 17th International Conference on General Relativity and Gravitation in Dublin.

It capped his three-decade struggle to explain an elemental paradox in scientific thinking: How can black holes destroy all traces of consumed matter and energy, as Hawking long believed, when subatomic theory says such elements must survive in some form?

Hawking's answer is that the black holes hold their contents for eons but themselves eventually deteriorate and die. As the black hole disintegrates, they send their transformed contents back out into the infinite universal horizons from whence they came.

Previously, Hawking, 62, had held out the possibility that disappearing matter travels through the black hole to a new parallel universe -- the very stuff of most visionary science fiction.

"There is no baby universe branching off, as I once thought. The information remains firmly in our universe," Hawking said in a speech to the conference.

"I'm sorry to disappoint science fiction fans, but if information is preserved, there is no possibility of using black holes to travel to other universes," he said.

"If you jump into a black hole, your mass energy will be returned to our universe, but in a mangled form, which contains the information about what you were like, but in an unrecognizable state."

At that point, the audience of about 800 people, including many of his peers, laughed.

He added, "It is great to solve a problem that has been troubling me for nearly 30 years, even though the answer is less exciting than the alternative I suggested."

In a humorous aside, Hawking settled a 29-year-old bet made with Caltech astrophysicist John Preskill, who insisted in 1975 that matter consumed by black holes couldn't be destroyed.

He presented Preskill a favored reference work "Total Baseball, The Ultimate Baseball Encyclopedia" after having it specially flown over from the United States.

"I had great difficulty in finding one over here, so I offered him an encyclopedia of cricket as an alternative," Hawking said, "but John wouldn't be persuaded of the superiority of cricket."

Later, Preskill said he was very pleased to have won the bet, but added: "I'll be honest, I didn't understand the talk."

Like other scientists there, he said he looked forward to reading the detailed paper that Hawking is expected to publish next month.

[Homefry 0]

I thought black holes were extremely hot... so things would melt before they even got close... or am I way off here?

[bonko the sane 2]

the pressure involved in such a process will surely cause a slight "warmth" to anything that gets sucked into it. This is some weird s**t, its like blackholes are a recycling bin of the universe, processing matter for its next cicle.

[da12thMonkey 1943]

I don't think they could be warm as infra-red energy probably cannot escape a black hole (they absorb other electomagnetic waves such as light after all) and other heating processes such as convection currents wouln't work either because all particles move into the black hole so energised particles cannot convect heat away from the black hole.

The matter collecting around the black hole on the other hand would generate a lot of heat as it collides in the vortex around the black hole. This is how they're photographed I believe.

[kavoven 4]

I'm just reading a book by him, and there it's said, that you've got a singularity, subjects (?? online translaters are strange ^^) concentrated on a infinitely small point in each black hole, so how could you get into a parallel universe, when your selve is infinitely small  

I hope you can understand me...

[Noon416 (OFPEC) 0]

Quote[/b] ]This is how they're photographed I believe.

Black Holes aren't photographed and don't have "warm vortexes". Their presence is deduced only by their gravitational effect on surrounding stars and objects.

Hence current "known" black holes tend to be found in binary/trinary systems (or hearts of galaxies in the case of super-massive black holes), where they can be found due to effecting items around them.

As far as I am aware, the only other way they show their presence is via bursts of X-ray radiation, which are very very brief, so you could 'photograph' them in the X-ray spectrum if you have good timing but not in the traditional sense that makes sense to the layman. ;)

[da12thMonkey 1943]

Am I misunderstanding this then?

Quote[/b] ]Because light cannot escape the gravitational pull of a black hole, it is impossible to see these objects with the naked eye. There is a good ammount of evidence that suggests they do indeed exist. Perhaps the most convincing (outside of our cosmological models, which are evidence enough for some, myself inccluded) are pictures taken with different renderings, such as infra-red, that can see gasseous movements that our own naked eye cannot

From http://campus.lakeforest.edu/~bell/astro/forrest/BLACKHOLES.HTML

[Noon416 (OFPEC) 0]

http://www.space.com/php....t%20al.

This is a good example of how detailed you get when viewing black holes in infrared.

Not much to go off huh? ;)

So there are indeed external interactions that give off indicators in different strengths and different wavelengths.

But any thoughts of "swirling vortexes" surrounding and marking blackholes are only that ... thoughts placed on paper by artists in their "artist rendering of what they think it would look like" pictures.

That was what I was getting at (sorry, wasn't so clear on my first post).

[InqWiper 0]

Quote[/b] ]As far as I am aware, the only other way they show their presence is via bursts of X-ray radiation, which are very very brief, so you could 'photograph' them in the X-ray spectrum if you have good timing but not in the traditional sense that makes sense to the layman. ;)

I think black holes dont emitt anything. Maybe you confuse them with pulsars (neutron stars). As far as I know they emitt X-rays from 2 poles when they spin. One pole is pointed towards earth, then away and then towards earth again like a lighthouse. This happens very fast and if you use a pulsar as a clock it will even be more exact than an atomic clock.

I think the only way to spot black holes is by observing planets and stuff moving in ways that tells you there is a black hole somewhere. If I am wrong I will go read about it to relearn it

[denoir 0]

Well, the story goes like this: Black holes are by classical theory nice little singular points from where nothing escapes. Then you have quantum mechanics which tells us that particles are also waves. With a certain probability particles can get to any point in space, completely disregarding energy levels such as gravity pits. It's called 'tunneling' and is a well known and well used phenomena. Very popular in semiconductors - your computer has a bunch of devices that uses this principle. Anyway, according to quantum mechanics shit can tunnel out from black holes. This is called "Hawking's radiation". IIRC it has even been measured.

So far nothing sensational. The problem is that according to quantum mechanics in the case of the black holes, the tunneling is random and hence the observable radiation. According to classical physics information cannot be destroyed - only distorted, transformed etc And there's the catch. Ordered information comes into the black hole and it spits out some random crap. Which would mean that information got destroyed in the process.

That's why Hawking's theory was a sensation when it first came. It showed that information could be destroyed, not just distorted. And now he has reversed his position saying that the particles that the black hole ejects isn't randomized, but just distorted.

I don't know the finer details of it, but apparently nobody so far understands his new calculations.

[USSoldier11B 0]

It's an interesting revision in the theory. It makes sense to me in the aspect that, to put it simply, nothing lasts forever, except perhaps matter itself and/or energy depending on what you choose to believe. Either way I don't see how it much matters since traveling into a black hole is simply absurd by any measure of what we understand as physics. Perhaps we will one day be able to observe a "dying" black hole.

[kavoven 4]

Perhaps we will one day be able to observe a "dying" black hole.

I think that would even take as long as looking for a proton to collapses into his three quarks... I think that was a 1 with 31   0

But it would be very interesting to, what happens with the singularity

The reason is, that we actually don't know many black holes, we just expect, that a black hole could be there. Even that one in our galaxy in the middly isn't prooved. If you take many many protons in a small area and keep an eye on each one, then the probability to see one collapsing is increasing rapidly, perhaps you you do that with black holes, too.

[DarkLight 0]

Quote[/b] ]This is how they're photographed I believe.

Black Holes aren't photographed and don't have "warm vortexes". Their presence is deduced only by their gravitational effect on surrounding stars and objects.

Hence current "known" black holes tend to be found in binary/trinary systems (or hearts of galaxies in the case of super-massive black holes), where they can be found due to effecting items around them.

As far as I am aware, the only other way they show their presence is via bursts of X-ray radiation, which are very very brief, so you could 'photograph' them in the X-ray spectrum if you have good timing but not in the traditional sense that makes sense to the layman. ;)

Actually i've seen pictures of black holes absorbing stars and stuff like that... It looks pretty cool and it's very easy to see that something is being 'absorbed'.

Scary stuff too...

I saw this on a documentary of the national geographic channel... Sad enough i can't find any similiar pics...

Oh well...

Oh and there are also different techniques to see a black hole...

Imagine standing like this in the universe.

You-->-->--> Black hole -->-->--> Star

The arrow shows what direction you're facing...

When you, a black hole and a star are on one line like in my example the black hole will prevent you from seeing the star...

Black holes can be found like this, they literally create a black hole in the universe (because you can't look through them).

'Course this isn't really a very scientifical way of searching them and i bet it isn't a good way at all but that doesn't matter. It's one of the possibilities....

Oh and btw, the center of the milky way is a black hole, now i'e never bothered asking thsi to anyone but isn't thazt kinda dangerous for us? One day it'll swallow our world, won't it?

[MSpencer 0]

1. There are no pictures of black holes. There have been no confirmed black holes, only projected ones that have effected the normal orbits of planets.

2. The middle of every galaxy is a projected super black hole. this is what allows it to spin, and this is what in 10 billion years will cause Earth and the entire solar system to be swallowed up in the Andromeda galaxy's center (2/3) or to be flung off into space without a star for the atmosphere to fall off.

3. Because we haven't seen black holes, we're gonna have to go with Hawking on this one. Time dialation is still a theory, as well as anything else with a black hole. It's ALL theoretical, so nobody can say they've seen pictures of a black hole or the effects of a black hole. We're taking baby steps through a 30 mile long hallway here, we're not even close to understanding the effects of a gravitational singularity.

But we're sure it rips stuff apart.

[denoir 0]

Time dialation is still a theory, as well as anything else with a black hole.

Eh? Time dilation is described by the theory of relativity and has been measured and proven over and over again. The most classic experiment was when they flew atomic clocks in jets around the world and then compared the difference in time elapsed to stationary atomic clocks. Another very direct way of measuring it is through the known half-time of particles.

[kavoven 4]

Time dialation is still a theory, as well as anything else with a black hole.

Eh? Time dilation is described by the theory of relativity and has been measured and proven over and over again. The most classic experiment was when they flew atomic clocks in jets around the world and then compared the difference in time elapsed to stationary atomic clocks. Another very direct way of measuring it is through the known half-time of particles.

Yes, you have even a difference, when you put these two clocks in a high tower. *idea*

I'll move to tibet, or nepal ^^

When you, a black hole and a star are on one line like in my example the black hole will prevent you from seeing the star...

That's wrong I think. The gravity of the black hole curves the space time so extremly, that parts of the star's light is going around the black hole. You got the same, with a sun - eclipse, you can see stars, which are, in general, behind the sun.

I hope my exprations are not too strange