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How the Black Hole Firewall Paradox Was Resolved

Soulskill posted about 8 months ago | from the black-holes-are-made-of-cantaloupes dept.

Space 118

Stephen Hawking's recent comments about the nature of black holes have bred uncertainty about physics concepts that were relatively well understood. This article from astrophysicist Ethan Siegel explains that yes, black holes still exist, and how a group of three academic papers answered the black hole 'firewall' paradox. Quoting: "... And so what these three papers, in tandem, have done, is demonstrate that there is no firewall and that the resolution to the firewall paradox is that the first assumption, that Hawking radiation is in a pure state, is the one that's flawed. You won't read about this in the popular write-ups because it doesn't have a catchy headline, it's complex, and it's not work by someone that's already very famous for other work. But it's right. Hawking radiation is not in a pure state, and without that pure state, there's no firewall, and no paradox. There is still an incredible amount to learn and understand about black holes, event horizons, and the behavior of quantum systems in strongly curved spacetime, to be sure, and there's lots of very interesting research ahead. These findings arguably raise more questions than they answer, although at least we know that black holes won't fry you when you fall in; it will still be death by spaghettification, not by incineration!"

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THERE IS NO BLACK HOLE !! (-1, Offtopic)

Anonymous Coward | about 8 months ago | (#46128949)

It is all black !!

Slashdot explained (-1)

Anonymous Coward | about 8 months ago | (#46128957)

Let us play a thought game, for a moment.

Imagine a giant penis flying towards your mouth, and there's nothing you can do about it. And you're like "Oh man, I'm gonna have to suck this thing", and you brace yourself to suck this giant penis. But then, at the last moment, it changes trajectory and hits you in the eye. You think to yourself "Well, at least I got that out of the way", but then the giant penis rears back and stabs your eye again, and again, and again. Eventually, this giant penis is penetrating your gray matter, and you begin to lose control of your motor skills. That's when the giant penis slaps you across the cheek, causing you to fall out of your chair. Unable to move and at your most vulnerable, the giant penis finally lodges itself in your anus, where it rests uncomfortably for 4, maybe 5 hours.

That's what using Slashdot is like.

Re:Slashdot explained (-1, Offtopic)

fleabay (876971) | about 8 months ago | (#46129013)

You can't rape the willing.

Re:Slashdot explained (-1)

Anonymous Coward | about 8 months ago | (#46129225)

so we're hoping you leave, you giant penis. then slashdot will be better

Re:Slashdot explained (0)

Anonymous Coward | about 8 months ago | (#46130981)

You must be using the beta.

Begs the question (5, Insightful)

alaskana98 (1509139) | about 8 months ago | (#46128961)

"death by spaghettification" Perhaps this is the ultimate end for a 'Flying Sphaghetti Monster' fearing Pastafarian? Ramen!

Re:Begs the question (2)

Livius (318358) | about 8 months ago | (#46129091)

Why do you think His Noodiliness is the Flying Spaghetti Monster and not the Stationary Spaghetti Monster?

Re:Begs the question (3, Funny)

Anonymous Coward | about 8 months ago | (#46129279)

I sense a schism forming. Flying Orthodox vs. Liberal Stationary. Go!

Re:Begs the question (5, Funny)

Anonymous Coward | about 8 months ago | (#46129169)

Black holes are some of the most dramatic events the cosmos: As round and powerful as his meaty balls, and within spaghettified as his noodly appendages.

Ramen, indeed. The proof of His divine influence is writ in all scales throughout the heavenly quantum sauce.

Re:Begs the question (1)

Zubinix (572981) | about 8 months ago | (#46129393)

"it will still be death by spaghettification, not by incineration!"

Thats a relief.

Re:Begs the question (0)

Anonymous Coward | about 8 months ago | (#46130701)

Just like the lake of fire, that is the fire wall of the event horizon, is for a condemned during the Christian end times, death by spaghettification is the fate of Pasta-denier during the Pastafarian end times. May the Science bless you!

Re:Begs the question (2)

corbettw (214229) | about 8 months ago | (#46132573)

No it doesn't beg the question, it raises it.

Re:Begs the question (1)

ultranova (717540) | about 8 months ago | (#46133171)

No it doesn't beg the question, it raises it.

"Raising the question" and "assuming the conclusion" are both valid interpretations of the phrase "begging the question". English is context-sensitive, so the same expression can mean multiple different things. And nothing you do will change that.

Re: Begs the question (0)

Anonymous Coward | about 8 months ago | (#46133277)

"Means multiple different things" contains a redundancy and would be clearer without the word different. In other words multiple meanings are understood to be different. If you had multiple meanings that all meant the same thing it would be a singular meaning

Re:Begs the question (0)

Anonymous Coward | about 8 months ago | (#46133747)

No it doesn't beg the question, it raises it.

If you want to ignore all changes in English since 1950, then it doesn't raise the question either.
Raise meant to lift or move something up or to a higher position, or to be standing.

Raise did not mean to "increase the value of" until after the point in time you are ignoring changes to the language.

Obligatory: You are a bad person and have the grammar of a sloth, we can't understand you, and you need to go back to school to learn English.

At least we don't roast. (4, Insightful)

fleabay (876971) | about 8 months ago | (#46128983)

"it will still be death by spaghettification, not by incineration!" +1 for Pastafarians

I always thought... (1)

Anonymous Coward | about 8 months ago | (#46129001)

I always thought Black Holes were just one-way wormholes into another dimension of space-time. What gets sucked in from our universe is spat out in some other dimension, and these other dimensions contained the "missing" matter and energy supposed by "Dark Matter"/"Dark Energy". Basically, our universe lives on one side of a sheet of paper, a black hole is just pulling the stuff through to the other side of the sheet that we can't see.

Re:I always thought... (-1)

Anonymous Coward | about 8 months ago | (#46129189)

You thought? No you didn't think at all. White holes are pretty entertaining from a fantasy fiction perspective, but if you keep making shit up as you go along, your going to end up exactly where we are with your current understanding of physics. - Which is not too physical these days. Complicated physics is indistinguishable from magic,Theoretical Physics is indistinguishable from bullshit.

Re:I always thought... (0)

Anonymous Coward | about 8 months ago | (#46129227)

The big bang model is comparable to a "time-reversed black hole". Try searching that term and see what you come up with.

Re:I always thought... (5, Informative)

Anonymous Coward | about 8 months ago | (#46129363)

No it isn't. A cosmological model is a foliation of maximally-symmetric spacelike hypersurfaces. A black hole is not maximally-symmetric. A black hole is a non-evolving system -- it possesses at least one timelike Killing vector -- and a cosmological system is the exact opposite, an evolving system that has no timelike Killing vector. The only real similarity is that a black hole (as you're doubtless meaning it; a Schwarzschild solution) is spherically symmetric, and the spacelike slices in a cosmological spacetime are also spherically symmetric. But so is flat Minkowski space, and so are Tolman-Bondi spaces.

Re:I always thought... (-1)

Anonymous Coward | about 8 months ago | (#46129409)

Look at all the Flying Spaghetti Monster jokes getting +5 Insightful, and this awesome science dump is idling at 0. I bet I could tie this story to a denial of global warming or a complaint about Obamacare and immediately get myself +5 Insightful. Slashdot is a joke.

Re:I always thought... (1)

Oligonicella (659917) | about 8 months ago | (#46129513)

Lighten up, it's not like that's what's **really** happening at a black hole, just a refined math guess.

Re:I always thought... (-1)

Anonymous Coward | about 8 months ago | (#46129623)

OK, I'll lighten up. But the post I was replying to was a really interesting reply to the claim that the Big Bang is a time-reversed black hole, not about anything related to the what happens at black holes. A very interesting and accurate (from the point of view of its description of current theory) reply, but still sitting at Score: 0. And you gotta admit, Slashdot really has gone down the toilet, even compared to a year ago.

Re:I always thought... (-1)

Anonymous Coward | about 8 months ago | (#46130283)

Funny, someone posts random, baseless musing on what they think is going on, not using any math despite the idea they are trying to ramble about having origins in a deeply mathematical theory, and they get modded up. Someone replies to them trying to refer to actual details of the theory, and gets chided for just using refined mathematical guesses. I'll take refined math guess over armchair musings any day.

Re:I always thought... (1)

TapeCutter (624760) | about 8 months ago | (#46130205)

There's no space at Bondi, it's tourist season!

Re: I always thought... (2)

MorphOSX (2511156) | about 8 months ago | (#46129499)

So instead of educating you choose to belittle and trash others. You want more erudite folks? Teach.

Re:I always thought... (5, Informative)

wisnoskij (1206448) | about 8 months ago | (#46129259)

The problem with that is that black holes need the mass they suck in to exist.

The mass cannot both be in the black hole and shot out the other side into a new universe.

So unless you can come up with a theory that has black holes creating mass out of nothing, that is simply impossible.

Re: I always thought... (1)

MorphOSX (2511156) | about 8 months ago | (#46129403)

Fair enough, so then what's the big deal with this firewall thing?

Re: I always thought... (-1)

Anonymous Coward | about 8 months ago | (#46129447)

Fair enough, so then what's the big deal with this firewall thing?

RTFA.

Re: I always thought... (1)

MorphOSX (2511156) | about 8 months ago | (#46129489)

I did, but I was hoping for the "for dummies" version

Re: I always thought... (3, Informative)

wisnoskij (1206448) | about 8 months ago | (#46129573)

There is some debate exactly what happens when you get enough mass together to tie space-time into knots. The most important part of a black hole is really the event horizon, which is the point X distance from the center of mass of a black hole where the gravitational pull is so strong that nothing can escape. The original idea was that is was a very static place, a perfect circle.

There is a bunch of different problems with this. Because in this universe we have the idea that mass, energy, and information cannot be lost. Something cannot just go into a black box and all knowledge of it is lost, because then information would then of been lost.

Stephen hawking's has just come forward with the idea that it is a far more stormy area with fluctuating gravity. Which would allow this information to escape. Previously the idea was Hawking radiation, which would allow things to escape from the black whole even without fluctuation gravity.

One of the problems of with the horizon, that someone just proposed, was that it would be so tumultuous at the edge that everything would be burned beyond recognition,. This article is about how stuff entering a BH would NOT in fact be burned beyond recognition.

Re: I always thought... (1)

John Da' Baddest (1686670) | about 8 months ago | (#46132391)

where the gravitational pull is so strong that nothing can escape.

I always wondered about this. Isn't it just a basic calculation showing the point where escape velocity exceeds the speed of light? Meaning that ballistically nothing can escape on it's own, but if you had a "space elevator" (with super-strong cables not defined here) you could raise and lower things into a black hole (or planet Earth) at whatever speed you wanted. So why not lower in a camera and take a look? And if the super-strong cable also does Ethernet, you wouldn't even have to raise it back, unless gravitational escape velocity also applies to electricity.

Physics being what it is, the rebuttal could something like proof that such a super-strong cable couldn't exist, even if the thought-experiment is valid. To keep it from getting infinitely crushed, maybe you have to build it out of some sort of antidote physical-contradiction like magnetic monopoles

Re: I always thought... (1)

corbettw (214229) | about 8 months ago | (#46132581)

And if the super-strong cable also does Ethernet, you wouldn't even have to raise it back, unless gravitational escape velocity also applies to electricity.

Since electrons have mass they're susceptible to gravity. So no, you couldn't get any kind of signal out of a black hole.

Re: I always thought... (1)

wisnoskij (1206448) | about 8 months ago | (#46133657)

Yes, but no. They would be susceptible to the gravity, and could not be launched out of a black hole. But electricity works on more of a pump like system. And like he said, you might be able to theoretically pull the electrons out of the black hole.

Yes you could not easily transmit back, and a battery inside of a black hole simply would not work. But if you have a huge electron pump outside of the black hole and a cable that goes in and one that comes back, you might be able to push the electrons through and back (powering the equipment).

Still, practically, I am thinking the atoms of anything you create and put inside of a black hole would simply fall apart.

Re: I always thought... (0)

Anonymous Coward | about 8 months ago | (#46133769)

No I can guarantee that this is impossible. It's not called an event horizon for nothing, you know. You will *not* get electricity out of it. Are you pretending that electricity somehow propagates faster than the speed of light? Why, yes, yes you are. Hint: it doesn't.

Look, all these clever ideas are ultimately meaningless. You can drop a space elevator into a black hole, yes. If it somehow doesn't get ripped apart by tidal forces (which it will be), you can then send a lift down (which will also be ripped apart by tidal forces). You will *not* be able to get it back out again, because there's an event horizon. An event horizon literally, fundamentally, by definition, means the boundary between causally-disconnected regions. Without being able to propagate faster than light, there is no way, whatsoever, at all, that you can get anything back once it's gone over the horizon. Period. This isn't an in principle thing, it's an absolute.

(The get-out is what has sparked this whole thing: the horizon will, eventually, shrink as the hole radiates. But anything you dropped in has long since been mangled to oblivion, and you'd have to wait a few tens or hundreds of billions of years -- and the more you put in, the longer you have to wait.)

Re: I always thought... (0)

Anonymous Coward | about 8 months ago | (#46134503)

Regardless of the speed of propagation of electricity, if you look at the stress for any object at rest relative to an outside observer (i.e. the force a rope, cable, magnet, etc., would need to hold itself together as being lowered slowly into a black hole, as opposed to in free fall), it goes to infinity at the event horizon. So you would essentially need something with infinite strength to stretch across the event horizon and stay there. This isn't true in free fall which is why it seems possible for an observer to survive falling into large enough black hole, but that guarantees it would be going into the black hole.

Re: I always thought... (1)

wisnoskij (1206448) | about 8 months ago | (#46133619)

I am no expert, but I think you are right theoretically. Practically, I think it would simply be impossible to construct anything that that would survive.

Re: I always thought... (0)

Anonymous Coward | about 8 months ago | (#46134599)

Not quite - once you are inside the event horizon, space is bent to the point where "forward time" is towards the singularity at the center.

https://en.wikipedia.org/wiki/Schwarzschild_metric#Singularities_and_black_holes

Re:I always thought... (0)

thomst (1640045) | about 8 months ago | (#46130295)

wisnoskij blathered:

The problem with that is that black holes need the mass they suck in to exist.

The mass cannot both be in the black hole and shot out the other side into a new universe.

So unless you can come up with a theory that has black holes creating mass out of nothing, that is simply impossible.

Sorry, but you can't prove that contention. Period.

In the Standard Model, black holes are singularities. BY DEFINITION, the laws of physics as we observe and understand them break down in singularities. The SM can't explain what is going on inside a black hole, AND NEITHER CAN YOU.

Unless you have a doctorate in cosmology or astrophysics, you doubtless are profoundly unqualified even to have an OPINION on the topic ... so, kindly STFU.

Thank you.

Re:I always thought... (3, Interesting)

Anonymous Coward | about 8 months ago | (#46130363)

(I do have a doctorate in cosmology and I've a contention with what you've said: a black hole is not a singularity, whether by definition or otherwise. A "black hole" is simply a region in vacuum shrouded by an event horizon, and this situation occurs when a body is compressed enough that it lies entirely within its event horizon. In classical GR there are a few ways to get to this situation, with perhaps the most common being the collapse of a supermassive star. In classical GR there is also a singularity at the centre of the black hole, but a quantum theory of gravity would be expected to smear this out. What this does not imply is that a quantum theory of gravity would destroy the concept of a black hole entirely -- instead it seems very likely that in a quantum theory of gravity we would retain an event horizon, merely a somewhat "smeared" and non-absolute form of one (a distinction that would seem heartlessly academic to any poor sod falling into a hole). Hawking's conjecture, which is eerily similar to an equally unproven conjecture he advanced a few years back to "prove" that the information paradox was solved, is that ultimately there are no "black holes" because they are not an infinite state -- eventually they will dissipate, which immediately implies that their "event horizons" are actually apparent horizons. So far as this goes, it strikes me as eminently non-controversial.

Anyway, the concept of a singularity and a black hole are therefore rather distinct.)

Re:I always thought... (1)

thomst (1640045) | about 8 months ago | (#46133205)

An Anonymous Coward commented:

(I do have a doctorate in cosmology and I've a contention with what you've said: a black hole is not a singularity, whether by definition or otherwise. A "black hole" is simply a region in vacuum shrouded by an event horizon, and this situation occurs when a body is compressed enough that it lies entirely within its event horizon. In classical GR there are a few ways to get to this situation, with perhaps the most common being the collapse of a supermassive star. In classical GR there is also a singularity at the centre of the black hole, but a quantum theory of gravity would be expected to smear this out. What this does not imply is that a quantum theory of gravity would destroy the concept of a black hole entirely -- instead it seems very likely that in a quantum theory of gravity we would retain an event horizon, merely a somewhat "smeared" and non-absolute form of one (a distinction that would seem heartlessly academic to any poor sod falling into a hole). Hawking's conjecture, which is eerily similar to an equally unproven conjecture he advanced a few years back to "prove" that the information paradox was solved, is that ultimately there are no "black holes" because they are not an infinite state -- eventually they will dissipate, which immediately implies that their "event horizons" are actually apparent horizons. So far as this goes, it strikes me as eminently non-controversial.

Anyway, the concept of a singularity and a black hole are therefore rather distinct.)

I sit corrected.

However, I'd like to point out that nothing in your analysis validates wisnoskij's contention that the mass of a black hole has to be considered as existing entirely within this universe, therefore preventing it from acting as a "wormhole" to another one. As I understand it, whether the event horizon is actually a hard boundary or a more diffuse one, we don't currently have a solid cosmological model of what's "on the other side" of that boundary. AFAIK, Hawking's position on the issue of whether information is, in fact, lost once it passes an event horizon has evolved over the years, and his most recent thoughts are more conceptual arguments than mathematical models. (That's apparently more a factor of his increasing communications disability than necessarily a weakness in his logic, but still ... I don't believe he's provided the math to back up his current mental model, yet.)

I'd be happy to have my grasp of the subject debunked by those who truly do understand the math involved. I make no claim whatsoever to that ability, myself - I just contend that wisnoskij was harumphing ex cathedra on the subject from the depths of his hat./p>

Re:I always thought... (2, Informative)

Anonymous Coward | about 8 months ago | (#46133637)

"However, I'd like to point out that nothing in your analysis validates wisnoskij's contention that the mass of a black hole has to be considered as existing entirely within this universe, therefore preventing it from acting as a "wormhole" to another one."

A fair comment - I put my entire reply in parantheses because it was meant to pick at one of your statements, rather than the entire post, something I should have made a lot clearer.

With the wormhole thing, the idea basically comes from a maximal extension of a black hole. You can split the spacetime of a black hole into four sections: section I is our universe, asymptotically flat. (So, evidently, not actually our unvierse but let's ignore that for now.) Section II is the future inside the black hole, section III is the past inside the black hole, and section IV is another asymptotically flat region on the "other side" of the black hole. (See here [prime-spot.de] .) This then obviously raises questions about what that other region is and how to get there -- perfectly valid questions, the answer to which is commonly called a wormhole.

Unfortunately it does have to be pointed out that this has arisen because we've maximally-extended the spacetime. In reality, we can already guarantee that section III does not exist, because the extension into the past cannot be made -- the black hole has not existed for all time. This basically screw us, and the realistic situation is more like this [ggpht.com] .

Of course, this isn't the only way we can envisage getting a wormhole out of GR, but it's one of the best studied.

And also, of course, the singularity does render any speculations -- even using GR -- nothing more than speculations. We simply can't say what goes on there. I know that in loop quantum gravity the singularity issue is rather lessened but I don't actually know what happens there, since it's very much not my field.

You're totally right that Hawking's more recent statements have been conceptual arguments rather than mathematical models. That was the case when he talked about the information paradox, and it's the case now talking about the firewall. That doesn't mean the arguments are not worth listening to, but it does mean there's no reason to think that the issues are finished just because Hawking's deigned to talk about them.

Re:I always thought... (0)

Anonymous Coward | about 8 months ago | (#46133855)

thomst eventually admits:

I'd be happy to have my grasp of the subject debunked by those who truly do understand the math involved. I make no claim whatsoever to that ability, myself

After thomst already said:

In the Standard Model, black holes are singularities. BY DEFINITION, the laws of physics as we observe and understand them break down in singularities. The SM can't explain what is going on inside a black hole, AND NEITHER CAN YOU.

Cheeky Anon Bastard observes:

You have a very funny definition of not claiming that ability by trying to state an untested theory as fact...

I wouldn't even mention it if you wern't being such an asshole initially.
Try not to blow up in a dickish way at people for doing something you dislike, only to follow up with doing that very thing you were bitching about disliking :P

Thank you.

Re:I always thought... (1)

wonkey_monkey (2592601) | about 8 months ago | (#46130639)

In the Standard Model, black holes are singularities.

Really? I always that the presence of the singularity is what causes the black hole to be, but they're not actually one and the same.

Comological Doctor AC agrees here [slashdot.org] .

Re:I always thought... (1)

maxwell demon (590494) | about 8 months ago | (#46130751)

Indeed, even without quantum gravity, both are not the same, because GR allows singularities which are not "protected" by horizons (so-called naked singularities). Since they have no horizon, they would not be black holes. AFAIK it is however conjectured that naked singularities cannot actually form (what is AFAIR definitely proved is that you cannot turn a black hole into a naked singularity).

I've once tried to calculate if an electron were a black hole, how large that black hole would be, and unless I've miscalculated, it would actually be a naked singularity (it violates the conditions for mass, charge and angular momentum for a black hole).

Re:I always thought... (2)

bitingduck (810730) | about 8 months ago | (#46131619)

AFAIK it is however conjectured that naked singularities cannot actually form (what is AFAIR definitely proved is that you cannot turn a black hole into a naked singularity).

There are singularities all over physics, even in something as simple as the velocity field of a classical vortex (v ~ 1/r). The world doesn't go all goofy at them-- the universe tends to take care of them in relatively convenient and pedestrian ways, like by sending the density to zero where the velocity goes to infinity. It's all fun to be a theorist talking about naked singularities (probably as close to naked anything as many of them get...) but if someone figures out a way to actually observe what's going on there, it will probably be interesting but probably won't be anything particularly magical.

Re:I always thought... (1)

maxwell demon (590494) | about 8 months ago | (#46133261)

Except that in GR, the density goes to infinity at the singularity. However it is indeed expected that in nature those singularities don't actually form — however the reason is not as mundane as a certain quantity going to zero; rather the reason being that in that region quantum gravitation should kick in, and thus the classical equations of General Relativity are simply no longer applicable. Somewhat similar to how quantum electrodynamics solves the problem of the field singularity of classical point charges (but not too similar, because the exact same procedure does not work for gravitation, which is the main reason why we don't yet have a generally accepted theory of quantum gravitation).

Re:I always thought... (1)

thomst (1640045) | about 8 months ago | (#46133217)

wonkey_monkey pointed out:

I maintained:

In the Standard Model, black holes are singularities.

To which wonkey_monkey responded:

Really? I always that the presence of the singularity is what causes the black hole to be, but they're not actually one and the same.

Comological Doctor AC agrees here [slashdot.org] .

Thanks for calling my attention to his post.

Re:I always thought... (0)

Anonymous Coward | about 8 months ago | (#46130307)

The problem with that is that black holes need the mass they suck in to exist.

Just think of the new universe as being inside the black hole, so that the mass is simultaneously part of a the new universe and part of the black hole - problem solved. To be more detailed, the black hole is creating (in this fanciful theory) a new universe that is the size of the black hole from the outside but that is the size of a universe from the inside. Gravity decreases by the square of the distance, so the gravitational pull inside the new universe is not too great for things to happen in there. In the outer universe all the mass is still clumped up inside the event horizon of the black hole, so the gravitational pull from the black hole is still there from the outside. Not that I have any reason to believe this theory, but the particular problem you point out doesn't seem to be a real issue.

Re:I always thought... (1)

avgjoe62 (558860) | about 8 months ago | (#46131353)

To be more detailed, the black hole is creating (in this fanciful theory) a new universe that is the size of the black hole from the outside but that is the size of a universe from the inside.

So what you're saying is it's larger on the inside? [wikipedia.org]

Re:I always thought... (0)

Anonymous Coward | about 8 months ago | (#46132149)

So what you're saying is it's larger on the inside? [wikipedia.org]

There are some things that only a Whovian can understand! :P

Re:I always thought... (1)

Horshu (2754893) | about 8 months ago | (#46131071)

Or black holes suck in matter, hold onto part of it for more mass, and shoot the other part out along its poles as radiation.

Disney really fucked up another generation (1)

dbIII (701233) | about 8 months ago | (#46133971)

Sometimes the stuff in movies is not real despite it totally eclipsing general knowledge.

is it time yet? (-1, Troll)

Gravis Zero (934156) | about 8 months ago | (#46129009)

at some point we are going to have rework some protocols to deal with stupid shit like this.

If you get Hawkings to shut up (-1, Troll)

Anonymous Coward | about 8 months ago | (#46129083)

Most of his false premises, that he later disproves never come up.

Re:If you get Hawkings to shut up (2)

rubycodez (864176) | about 8 months ago | (#46129265)

nonsense, it's the nature of the work. every famous theorectical physicist you ever heard of has produced provably false and bad models, disproved models, models in need of more refining, models they discard themselves. From the time of the Greeks to Newton to Einstein and onward.

hawking is overly famous (1)

Anonymous Coward | about 8 months ago | (#46129495)

Yes he is responsible for hawking radiation but most of the things we know about black holes now are contrary to things he has previously said. His only useful contribution was in stating that black holes destroy information but it wasn't him that disproved this - it was t'hooft and susskind. And even then he was reluctant to accept defeat. Yes his contributions were great. But other physicists out there have provided much bigger contributions with significantly less recognition. I'm mildly annoyed that this article kind of alludes to the "oh; hawking has weighed in this must now mean something" when most of the statements he has come out with about many areas were average or even poor. Don't believe the article when it says the firewall debate is over - until the big names start coming out in consensus (which they haven't yet).
What we may be seeing is a change in the focus of the argument from firewall/no firewall to argument around radiation can/can't be in an pure/un-pure state. If this is the case then expect this to go on for at least another 3-6 Months or so.

Re:hawking is overly famous (0)

Anonymous Coward | about 8 months ago | (#46130335)

By now you should probably have figured out that the correlation between a scientist's contribution to science and their general public fame is kind of light. While some scientists due become famous for major contributions or because their name is forced upon school children, many become famous because they wrote pop-sci books or otherwise did a good job of communicating to the public. You can't really talk about Hawking being overly famous in that regard. Even within the science community, fame often comes down to ability to get things done and communicated over ability to make big, difficult jumps in understanding.

Re:If you get Hawkings to shut up (-1)

Anonymous Coward | about 8 months ago | (#46129813)

nonsense, it's the nature of the work. every famous theorectical physicist you ever heard of has produced provably false and bad models, disproved models, models in need of more refining, models they discard themselves. From the time of the Greeks to Newton to Einstein and onward.

That's why we can't trust these so called "scientists" and "Experts". They've fallible, unlike God and Michelle Bachmann, who have never admitted making mistakes! Bachmann Palin 2016!

Re:If you get Hawkings to shut up (1)

wonkey_monkey (2592601) | about 8 months ago | (#46130645)

every famous theorectical physicist you ever heard of has produced provably false and bad models

Or so everyone used to believe. ;)

Jesus Christ. May as well state... (-1, Troll)

Anonymous Coward | about 8 months ago | (#46129085)

... that black holes are there because GOD put them there, and if he had meant for us to understand them, he would have made us capable of it.

Whew! (2)

fahrbot-bot (874524) | about 8 months ago | (#46129101)

... at least we know that black holes won't fry you when you fall in; it will still be death by spaghettification, not by incineration!

Well, that's a load off my mind. I'll be sleeping much better - thanks.

Although, now I have a hankering for some fried spaghetti.

"But it's right." (5, Insightful)

Gaygirlie (1657131) | about 8 months ago | (#46129117)

No, this is all still highly theoretical and you cannot state that this hypothesis is absolutely, definitely correct. It may be correct, it may well be the best theory we have and all that, but it's still a theory.

Re:"But it's right." (1)

Anonymous Coward | about 8 months ago | (#46129213)

No, this is all still highly theoretical ....

Tell that to the experimentalist who was just torn apart by spaghettification (he was planning to go out in a blaze of glory)....

Re:"But it's right." (1)

Anonymous Coward | about 8 months ago | (#46129361)

ALL science is "still a theory". Remember that the scientific method isn't EVER about stating absolutes.

Examples: the theory of gravity, the shape of the Earth, kinetics and dynamics (which we know are more complicated than the Newtonian models we still teach but we know when they become wrong so it isn't a problem).

This is the problem with pitching science to a mainstream audience: they think it is a religion when it actually resembles that in no way.

Re:"But it's right." (1)

maxwell demon (590494) | about 8 months ago | (#46130801)

However, this is an untested theory. That is, up to now we have no experiment confirming it. Indeed, there's not even experimental confirmation of Hawking radiation (the black holes we can observe are too large to emit any non-negligible Hawking radiation).

Re:"But it's right." (1)

wonkey_monkey (2592601) | about 8 months ago | (#46130647)

you cannot state that this hypothesis is absolutely, definitely correct.

That's your theory.

Piffle (1)

onyxruby (118189) | about 8 months ago | (#46129127)

You fall into a black hole and you will heated up from friction to the point that you become atomized. The idea that wouldn't be incinerated is absurd when the brightest and hottest objects in the universe are quasars caused by material being incinerated from friction. Now whether you are incinerated first or spaghettified first or killed by radiation is a different story. One way or another though you will be incinerated.

Re:Piffle (1)

rubycodez (864176) | about 8 months ago | (#46129251)

  most black holes are not quasars (supermassive black holes at center of galaxy with large amounts of matter in accretion disk), and there can be black holes not surrounded by infalling matter

Solution (4, Funny)

rossdee (243626) | about 8 months ago | (#46129317)

But what if you reconfigure the main deflector to emit a tachyon pulse

Re:Piffle (1)

Bengie (1121981) | about 8 months ago | (#46129353)

I think they're talking about a blackhole that is not rotating and has no accretion disc. If you fell strait towards the blackhole, what would happen?

Re:Piffle (2)

Maritz (1829006) | about 8 months ago | (#46129595)

You fall into a black hole and you will heated up from friction to the point that you become atomized.

The most generous interpretation of this is that you're talking about the accretion disk. Yes if your trajectory takes you into the accretion disk (assuming there is one, there doesn't have to be) you'll be atomised. No reason you can't come in from an angle that doesn't take you into the disk though. In those instances you certainly won't be atomised; black holes are very very cold. So cold in fact that the vacuum in the universe won't be colder than any stellar-mass black hole for the very distant future.

"Science" at work (-1)

Anonymous Coward | about 8 months ago | (#46129131)

Bunch of science fiction. Extreme extrapolations of limited observations presented as the truth

There is another possible black hole's firewall (1)

CmdrEdem (2229572) | about 8 months ago | (#46129137)

Im not a physicist, but hear this. Imagine for a second that most of the photons that gets trapped on a black hole will certainly head towards the singularity. Now, there is a certain distance where the orbital speed is the same as the light's speed, and that is not at the core, presuming that at the core the gravity must be strong enough to stop light from going out even at the perfect escape vector. Therefore it is possible, but very unlikely, that this orbiting light around the black hole is enough to melt or crisp any objects that care about being burned.

Please correct me if I'm in any way wrong.

Re:There is another possible black hole's firewall (1)

ColdWetDog (752185) | about 8 months ago | (#46129231)

Please correct me if I'm in any way wrong.

What happens if you are in any way, right?

Re:There is another possible black hole's firewall (2)

HybridST (894157) | about 8 months ago | (#46129275)

There is a simple proof to the contrary but the /. comment system is too small a space in which to contain it. There are many, many hours of Susskind videos on Youtube, primarily and most recently "ER=EPR|Leonard Susskind", which deal with exactly this.

Re: There is another possible black hole's firewal (0)

Anonymous Coward | about 8 months ago | (#46129325)

http://en.wikipedia.org/wiki/Photon_sphere

Re:There is another possible black hole's firewall (1)

dentin (2175) | about 8 months ago | (#46129345)

There is a place outside the event horizon when light can orbit; however, it is an unstable orbit, and no light accumulates there. So no, you won't be fried (and there's not really even a chance it could happen.)

Re:There is another possible black hole's firewall (1)

Bengie (1121981) | about 8 months ago | (#46129941)

When talking about quantum stuff, stating that there is "no chance" of something happening is pure bunk. There is a chance of anything happening, just highly unlikely.

Re:There is another possible black hole's firewall (0)

Anonymous Coward | about 8 months ago | (#46130319)

Quantum mechanics makes it all the harder to maintain an unstable orbit, because now in addition to worrying about perturbations from other stuff, you have to worry about any tunneling too. You can see this in ionization models of atoms, where adding in tunneling makes it easier for electrons to get stripped from an atom than using just an electric field alone for example.

Re:There is another possible black hole's firewall (1)

maxwell demon (590494) | about 8 months ago | (#46130665)

Even without tunnelling, you've got the finite size of the wave packet, which means that part of your photon will be inside and part will be outside that sphere. The part inside will fall into the black hole, the part outside will escape. Which means that the probability to find the photon on the sphere will quickly vanish, with the photon going into a superposition of "fallen into the black hole" and "escaped to infinity".

Re:There is another possible black hole's firewall (1)

dentin (2175) | about 8 months ago | (#46131441)

I accept that the probability is non-zero, and nothing I said conflicts with that. However, there's not really any chance that it could happen.

http://lesswrong.com/lw/ml/but_theres_still_a_chance_right [lesswrong.com]

sort of (1)

Anonymous Coward | about 8 months ago | (#46129545)

You are not entirely right but - there is a distance from a given black hole at which the orbital velocity is C. But this is actually OUTSIDE the event horizon and is known as the photon sphere. It will not result in a region of intense heat because any photon in that orbit is in unstable equilibrium. This means that any minor disturbance in their velocity and they will either fall into the black hole or escape to infinity.

I highly recommend the following series of lectures if you want to learn more.

http://theoreticalminimum.com/courses/cosmology-and-black-holes/2011/winter

Stop trying to plug holes in dirty QM (0)

Anonymous Coward | about 8 months ago | (#46129429)

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

Plug the holes that assume acceleration and gravity are linear at all scales.

Re:Stop trying to plug holes in dirty QM (0)

Anonymous Coward | about 8 months ago | (#46129695)

.....

Err...

Black holes are a prediction of general relativity, which is notoriously non-linear. MOND is notoriously non-relativistic and acausal, and is explicitly acknowledged as such by its practitioners, few of whom are silly enough to entrench themselves in some bizarre shit-throwing match between tribes. Formulated as it is to work on galactic (kiloparsec) scales I'm not sure what its relevance is to black holes.

Complementarity (4, Interesting)

Maritz (1829006) | about 8 months ago | (#46129559)

It all depends where you're observing from.

If you're alice, falling through the black hole horizon, you see no horizon, and no firewall. It's a harmless point of no return. In a particularly large black hole say with a horizon the size of the solar system (this would have to be a super-galactic beastie) you could potentially live out your life in there before getting crushed by tidal forces.

If you're bob on the outside, it looks like alice slows down and gets increasingly red shifted. Alice moves asymptotically towards the horizon but never quite reaches it. Just getting slower and redder. Of course the reverse is also true, if alice looked back at bob she'd see him all sped up like keystone cops.

Because the light coming to you from the regime around alice is so red shifted, you conclude that it must be incredibly high energy/frequency down where alice is (the firewall)

The funny part is, if you send photons at alice hoping to reflect them back to yourself (to see if she's alright) - the photons have to be so energetic to make the return trip that you end up vapourising alice just as the firewall would have done.

This is the impression I get from reading Leonard Susskind's stuff, broadly taken to be black hole complementarity. Neither view is objectively more 'correct' than the other. We've accepted wave/particle duality so I don't really see how we can't have two pictures of what happens in a black hole.

Re:Complementarity (0)

laejoh (648921) | about 8 months ago | (#46129923)

OB XKCD [xkcd.com] !

Re:Complementarity (1)

Bengie (1121981) | about 8 months ago | (#46130015)

Her time may slow down to a near halt, but she will keep moving relative to you. It's her movement relative to you that causes her time to slow down. In order for her time to nearly stop, she has to be moving away from you near c. She won't just "stop falling in".

Re:Complementarity (2, Interesting)

Anonymous Coward | about 8 months ago | (#46130111)

"It's her movement relative to you that causes her time to slow down."

No, it's a lot more than that. There are more causes of time dilation than movement, and more causes of redshift than movement, too. What Maritz is referring to are gravitational time dilations and gravitational redshifts, which in this situation dominate those from motion.

If you bother looking at the equations, yes, as she nears the event horizon, to an external observer she'll be moving ever slower and getting ever dimmer. (Classically) you will *never* see something fall into a black hole. It will just get redder and redder until you can only detect it in microwave, then radio, and then not at all -- and at the point it seemed to vanish it will still not appear to be on the horizon.

From the point of view of the thing falling in, on a classical level nothing untoward happens at all, which is readily apparent if you swap from the rather misleading Schwarzschild coordinates to the Painleve-Gullstrand coordinates, where spacetime at the event horizon is locally flat. The argument Hawking has attempted to address in what the media laughably refer to as a "paper" -- a ridiculous statement Hawking has himself not made for what is nothing more than a two-page collection of unsubstantiated speculations and arguments -- is related to whether this picture is still true when one considers quantum effects.

Re:Complementarity (0)

Anonymous Coward | about 8 months ago | (#46130551)

Bob's point of view is the only scientific one because that's the only one that can be tested.

Alice is redshifted to oblivion but her gravitational and coulombian effects can still be sensed at the event-horizon-to-be for ever. IOW, nothing can ever (seem to) cross the event horizon, and hence, the event horizon cannot even form as far as this universe is concerned.

Re:Complementarity (1)

maxwell demon (590494) | about 8 months ago | (#46130557)

Of course the reverse is also true, if alice looked back at bob she'd see him all sped up like keystone cops.

Are you sure? Certainly an observer at rest in the same place outside the horizon (let's call him Rob) would see Bob the more blue-shifted the closer he's to the horizon. However the closer he's to the horizon, the higher Alice's speed relative to him would be when she passes him, and since that speed is away from Bob, her view of Bob would be increasingly red-shifted relative to Rob's view. My intuition (which of course may be wrong) is that this should just cancel the gravitational blue-shift experienced by Rob, so that Alice would see Bob basically at original speed.

Re:Complementarity (1)

dissy (172727) | about 8 months ago | (#46133783)

(let's call him Rob)

No no no, scientifically his name must be Carl! Did no one teach you your A B C's? ;}

Differential space-time (0)

Anonymous Coward | about 8 months ago | (#46129827)

So as something gets closer to the black hole space-time gets more warped. Is there a point where space-time is so warped it becomes zero? Or, is this only the theorized state of our universe a moment before the big bang, where space and time were born? Anyone here God-like, and knows?

Slashdot commentary reaches a new low? (0)

Anonymous Coward | about 8 months ago | (#46129915)

Has something changed with the commenting opportunities on Slashdot? The comments used to be the best part of a new post, but now I'm reading about penises and balls in response to an interesting article about black holes...

Hawking just said there are no black holes... (1)

mysidia (191772) | about 8 months ago | (#46130255)

Or rather; there are no objects that have exactly the properties, of what we have been calling black holes.

Remember the article in Nature? [nature.com] : according to Hawking's paper [arxiv.org] : Notion of an 'event horizon', from which nothing can escape, is incompatible with quantum theory, physicist claims.

“There is no escape from a black hole in classical theory,” Hawking told Nature. Quantum theory, however, “enables energy and information to escape from a black hole”. A full explanation of the process, the physicist admits, would require a theory that successfully merges gravity with the other fundamental forces of nature. But that is a goal that has eluded physicists for nearly a century. “The correct treatment,” Hawking says, “remains a mystery.” ...

Re:Hawking just said there are no black holes... (2)

DMUTPeregrine (612791) | about 8 months ago | (#46130339)

Hawking made a proposition. It's not a theory, it's a proposition. His note (two page paper) shouldn't be taken to imply that it is anything more than a proposition. Once it has been fleshed out with equations it will be a hypothesis, if the math works out it will be a theory, and if it agrees with observations better than any other theory it will be accepted.

Re:Hawking just said there are no black holes... (1)

maxwell demon (590494) | about 8 months ago | (#46130573)

Observation might prove problematic, given that the next black hole is not exactly close to us ... we can't simply send a space probe there to measure what it experiences when falling into it.

Re:Hawking just said there are no black holes... (1)

mysidia (191772) | about 8 months ago | (#46130879)

Hawking made a proposition. It's not a theory, it's a proposition.

His alternative explanation is a proposition.

His refutation of blackholes is not. The original concept of a blackhole is dead. Shown to be impossible/a contradiction.

The only question is, what alternative is most accurate. His suggested alternative is indeed just a proposition, but NOT the concept that there cannot be blackholes as originally described.

Re:Hawking just said there are no black holes... (1)

Anonymous Coward | about 8 months ago | (#46130955)

Not true. Hawking has made a sequence of statements of the form "I speculate that..." leading to "This therefore suggests that...", in a two-page paper, backed up by precisely zero equations. If he wants to "show [it] to be impossible/a contradiction" he has to demonstrate this, within the context of the theories he's working in. There are three major reasons he hasn't done so:

1) He doesn't know how to
2) No-one knows how to
3) This wasn't his intention in the start anyway, since the "paper" was a transcript of a talk given over Skype which consisted of a string of arguments, some of which make sense and others of which are reaching somewhat

For a given definition of "black hole" then I think Hawking is right -- they don't exist. But you have to be very careful with that definition (as Hawking was). A "black hole" is typically taken to be one of a Schwarzschild, a Reisser-Noerdstrom, a Kerr, or a Kerr-Newman solution, consisting of a perfectly uncharged spherical hole, a charged spherical hole, an uncharged rotating hole, or a charged rotating hole respectively. These are stationary solutions: they apply at all times. But a real black hole is *not* stationary. Hawking himself demonstrated that if there is any truth behind a semi-classical approximation (and if there isn't then we're totally fucked) then holes have to radiate... which means they will evaporate. (Hell, even a hole absorbing matter breaks the assumption of stationarity; all calculations of orbits around, say, a Kerr hole calculate the orbits of test particles which don't disrupt the spacetime. But *everything* disrupts spacetime, and since GR is brutally non-linear this may have a catastrophic effect on some finely-tuned regions.) An event horizon is a region beyond which anything traveling will never communicate with the outside universe again - but given the existence of Hawking radiation, all holes must some day evaporate... implying there *are* no event horizons. Therefore, there are no "black holes", merely metastable bound states of the gravitational field, shielded by apparent horizons.

However, to us, to our children, and to a civilisation in a few billion years' time, that thing will look and act precisely as we've always thought black holes act.

Matt Strassler has an interesting post on this topic here [profmattstrassler.com] .

Firewall (0)

Anonymous Coward | about 8 months ago | (#46133613)

But firewall indeed often blocks goatse.cx links!

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