Famous Hawking Black Hole Bet Resolved?

Mick Ohrberg writes "In 1997 the three cosmologists Stephen Hawking, Kip Thorne and John Preskill made a famous bet as to whether information that enters a black hole ceases to exist -- that is, whether the interior of a black hole is changed at all by the characteristics of particles that enter it. It now looks like Stephen Hawking and Kip Thorne may owe John Preskill a set of encyclopedias of his choice, since physicists at Ohio State University 'have derived an extensive set of equations that strongly suggest that the information continues to exist -- bound up in a giant tangle of strings that fills a black hole from its core to its surface.'"

Comments

Hawking radiation

[Space cowboy]

Steven had posited in the 70's that the black holes leak (Hawking radiation), but the paradox is that they radiate a 'black-body' spectrum (entirely thermal radiation) in inverse proportion to their mass (so as they get smaller, the radiation increases). The problem here is that all the information went in, but it's very difficult to infer information from a black-body radiated spectrum (!). Steven therefore thinks that information is lost forever.

The article though is a bit hand-wavy over why the information is preserved in this new theory... (I guess Nth dimensional maths doesn't appeal to the reporter :-). I don't think the fact that the string-theory radius matches the black-hole radius is sufficient to prove the case, though it's an interesting pointer, a curious coincidence if indeed it is such ...

Effectively this is a conjecture - if the strings continue to exist, then they'd have the same size as the black hole appears to have. The throwaway statement " That means a black hole can be traced back to its original conditions, and information survives." seems a bit of a stretch though :-)

Simon

Re:Hawking radiation

[Gil-galad55]

In my physics experience, coincidence typically means you got the right answer... unless it's a test question, in which case you're probably wrong.

Re:Hawking radiation

[dandelion_wine]

No, NO, Space_Cowboy, you have got it ALL WRONG.

Now I want you to repeat after me:

- First
- Post
- !

Re:Hawking radiation

[kfg]

My experience is that that sort of coincidence is suggestive, in other words you've gotten something right, but determining just what that something is is often a)problematic, and b)not always what you thought it was at first.

KFG

Re:Hawking radiation

[Gil-galad55]

And then there are the times when you get lucky and get the right answer for the wrong reason... which is, I suppose, why we have peer review!

Re:Hawking radiation

[Anonymous Coward]

Oh, I can't wait to read the Slashdotters trying to debate black hole phenomena with no education save some physics courses in high school.

It will sound as stupid to anyone with experience as the archetypical "your mom" and "your dad" debating computers sounds to your ears.

Re:Hawking radiation

[SeanTobin]

The thing about black holes emiting radiation is that they don't actually emit any radiation. Anything that enters the event horizon is gone - for good. It doesn't come back ever, even as black body radiation.

The way theorists get around this is through virtual particles. Assume that virtual particle pairs are blinking in and out of existance all the time, but are never noticed because before they become 'real' particles they destroy each other (think particle/anti particle). The fun part comes when the particles appear on opposite sides of an event horizon. One gets sucked into the black hole, and the other becomes a full-fledged particle with a small chance of escapeing. Because the escapeing particle was never in the event horizon to begin with, it can contain no information from within the black hole.

Now, how the black hole doesn't gain mass from the anti-particle I'm not quite sure... I'll leave that up to all the ./ theoretical physisists.

Re:Hawking radiation

[dnoyeb]

In my mathematical experience, coincidence usually means you have used circular logic/calculations somewhere. In effect proving your foundation.

But its always nice to figure out how you fooled yourself :)

Re:Hawking radiation

[kfg]

Damn that peer review. The Nobel board laughed at me when my theory was submited, but I'll show them. Yes, I'll show them.

Mwuhhahahahahahha!

KFG

Re:Hawking radiation

[smittyoneeach]

Because you are right, your loose definition of tautology is true.

Re:Hawking radiation

[Anonymous Coward]

I suppose, why we have peer review!

Peer review might help, but normally people attempt to recreate the experiment. That's how science weeds out "luck".

Re:Hawking radiation

[CAlworth1]

IANATP (theoretical physicist), but I think I may be able to shed a bit of light on the last question.

As I understand it, the idea is that the particle and the anti-particle come into being at the same place, moving in different dirrectsion, and the anti-particle is more prone to being pulled in somehow due it its being the opposite of the other mass in the black hole. The particle escapes, generating the black-body radiation, and the anti-particle enters the black whole and collides with a corresponding particle, leaving existance as the original particles came into existance - messed up I know.

If anyone is curious, (stolen from The Universe in a Nutshell by Stephen Hawking, the temp of a black hole is

Temp = (h * c^3)/(8 * pi * k * G * M)

where h is planck's constant, c is the speed of light, G is Newton's gravitational constant, k is Boltzman's costant,T is temp, and M is the mass of the black hole.

Re:Hawking radiation

[imsabbel]

Well, you are mostly right.
BUT:
If an anti-particle enters the black hole, it LOSES mass. So its a process in which energy is emitted outside of the event horizon and the mass inside the event horizon is decreased. That no mass actually transfered out of the black hole is only a semantic problem (like tunneling, ect).

I cant really speak about the asymetry that enables this process, because its a few years about my quantum physics level, but it could be possible.

Btw: There are theories that the resulting radiation isnt REALLY blackbody radiation, but only "shaped" like BR, but with an "overlayed" information contend.

Re:Hawking radiation

[nihilogos]

The article though is a bit hand-wavy over why the information is preserved in this new theory...

The abstract from the NPB article is

• 
  It has been found that the states of the 2-charge extremal D1-D5 system are given by smooth geometries that have no singularity and no horizon individually, but a `horizon' does arise after `coarse-graining'. To see how this concept extends to the 3-charge extremal system, we construct a perturbation on the D1-D5 geometry that carries one unit of momentum charge P. The perturbation is found to be regular everywhere and normalizable, so we conclude that at least this state of the 3-charge system behaves like the 2-charge states. The solution is constructed by matching (to several orders) solutions in the inner and outer regions of the geometry. We conjecture the general form of `hair' expected for the 3-charge system, and the nature of the interior of black holes in general.
  

If your institution is a subscriber you can get the full text from here

Re:Hawking radiation

[Anonymous Coward]

Steven had posited... Steven therefore

If you're going to get all Hollywood and refer to him by his first name, you could at least take the trouble to spell it properly.

Re:Hawking radiation

[XaXXon]

If an anti-particle enters the black hole, it LOSES mass.

So we have these virtual particles blinking in and out of existence. One particle, one anti-particle. I understand that when an anti-particle falls into the black hole and the normal particle escapes, the black hole loses mass. Makes perfect sense.

I want to know, why don't an equal number of particles fall into the blackhole while the antiparticle escapes?

Seems you would get a 50/50 distribution leading to no mass change..

I'm sure I'm missing something. Can someone tell me what it is?

Re:Hawking radiation

[ralphclark]

Because the escapeing particle was never in the event horizon to begin with, it can contain no information from within the black hole.

Except that the pair of virtual particles are an entangled pair and if one catches the escaped one and measures its quantum state, one then knows the quantum state of the one that fell in. Catch enough of them and you know about an appreciable fraction of the black hole (in theory!)

Now, how the black hole doesn't gain mass from the anti-particle I'm not quite sure

The energy that was used to create the virtual pair came from the black hole's gravitational field, thus robbing the hole temporarily of mass. For each "virtual" particle that escapes as Hawking radiation, that mass is lost permanently so the mass of the hole goes down, over time. Now remember that this loss can only happen at the event horizon; if the black hole is very large, the tidal force (the gravity gradient) at the event horizon will be weak and thus the rate of particle loss will be very low. For very small black holes the tidal force at the event horizon will be enormous and almost all virtual pairs close to the boundary will separate in this way.

So large black holes will simmer coldly, shrinking only with glacial slowness if at all, and small ones will be hot and shrink very rapidly indeed - finally disappearing altogether in an brief, intense burst of radiation, according to Hawking's theory.

Re:Hawking radiation

[krlynch]

Now, how the black hole doesn't gain mass from the anti-particle I'm not quite sure...

The black hole doesn't gain mass, because the particle that fell in has negative energy. Remember, you can't create energy from nowhere, but you can "borrow" some from the vacuum temporarily ... that's where the virtual pairs come from. They borrow energy from the vacuum, which they have to give back after a time (roughly) Delta T < hbar/E, where E is the energy of the particle pair.

Now, if one half of the pair falls across the event horizon, it isn't coming back. The particle that escapes the hole becomes "real" because it has no one to annihilate with, so it carries off energy E/2. But since you can't yank energy out of the vacuum indefinitely, the particle that fell in had to be carrying energy -E/2 ... which isn't a problem, because it isn't a "real" particle, so it's energy need not be consistent with your expectations from freshman physics.

So, where does that energy E/2 that goes into the escaping particle come from? The only place it can: the black hole. Remember, a negative amount of energy fell in. So the hole has to lose some mass in the process. Which is why we say that the black hole "emits" particles.

The mathematical details are, of course, much nastier than that, but that's the gist of things...

Re:Hawking radiation

[MrGrendel]

From conservation of energy, we know that any energy radiated away from a black hole has to be matched by a decrease of energy inside the black hole. E==mc^2, so a decrease in energy is equivalent to a decrease in mass.

Re:Hawking radiation

[CheshireCatCO]

Careful there. A simple-minded Newtonian derivation gives the correct Schwartschild radius for a black hole, despite having two deep physical flaws and relying on completely inapplicable physics. For that matter, two words: "Bode's Law."

Re:Hawking radiation

[SeanTobin]

They aren't quotes ('), they are backtics (`). They are used to denote that a particular keyword is a field and not a command. For example, if you had a field called LIKE, some sql parsers may become confused. Now, not to many dba's would create a field called LIKE but often in programming you have no idea what the name of the field will be when you are generating a sql call. Placing the table name in backtics prevents problems both from odd table/field names and from users who abuse software.

Re:Hawking radiation

[rpresser]

You misunderstand.

A particle and an antiparticle both have a positive mass. The "virtual particle" mechanism means that for periods of times short enough, the measurement of the space right outside the hole is uncertain enough that there "might" be a pair of antiparticles there. So they are there. While they're there, one of them falls into the hole - it doesn't matter which one - while the other gains potential energy from its mate falling in, and escapes. Yaay.

But you can't get something from nothing. Some mass escaped from the vicinity of the hole, so some mass has to disappear from the vicinity of the hole. So the hole loses mass.

How's that for handwavy?

Re:Hawking radiation

[dandelion_wine]

10% troll...
20% off-topic...
70% funny???

you people spent 10 mod points on this snippet of humour?! Scheisse!

Re:Hawking radiation

[Too Much Noise]

point: The energy uncertainty principle is connected to the vacuum fluctuations of all fields that interact with the field whose energy you're trying to measure.

hence: near the event horizon, the strongest fluctuating field is the gravitational field of the black hole - and you need quite a lot of energy for one of the 2 particles to escape, so the most probable source will be the hole's field. Fluctuations come as proprotional to the gradient of the field (through the field equations) so the larger the gradient (the smaller the hole) the more 'energetic' the virtual particles, thus the more energy the hole loses when one escapes. How's that for handwaving?

second - keyword virtual. The pair does not exist 'by itself' on shell. On the other hand, if one of the particles interacts with a real particle(/field) during its brief existence, it can acquire enough energy for the pair to appear 'on shell'. This is the other perspective from which you can argue that the hole loses mass - it has to generate the 'on-shell' particle that escapes.

(this is nowhere near a rigorous explanation, but since /. won't eat mathml anyway and ascii-art feynman diagrams are not an option ...)

Re:Hawking radiation

[Anonymous Coward]

of course hawking radiation was not hawking's own theory.. it was in fact a theory posed by an american scientist and two russian scientist, they were berkowitz, zel-dovich, starbinksy or something like that.. in fact hawking said they where completely wrong and that it could never happen, then he took there ideas and got the credit for it

hawking is a theif in the scientific community.

Re:Hawking radiation

[Anonymous Coward]

I have to agree with you. Once something goes beyond the event horizon of a black hole (that is, the point at which an object accelerating directly away from the black hole at the speed of light, is standing still), there's no way that is can come back. To even stand still on a black hole's event horizon, the object has to have infinite energy (as it takes infinite energy to reach the speed of light), it has an infinite dimension, and its time dimension is reduced to zero.
So, once the object goes past the event horizon, it's being accellerated _faster_ than the speed of light toward the center of the black hole.
I don't have the math to prove any of this, of course, but basically the object ceases to exist for our universe on the event horizon as physics breaks down.

Re:Hawking radiation

[Anonymous Coward]

First, virtual pairs are created due to Heisenberg Uncertainty Principle (Et>=h/4pi variant) even in absence of any gravitational field.

Yeah, but they're virtual. You need a horizon to produce real particles from the vacuum.

Second, if a virtual pair can rob black hole temporarily, what mechanism prevents it doing so permanently creating a real p -p pair?

Energy conservation. It works with horizons, because horizons allow one real particle to acquire a positive energy relative to an external observer, and the other (the one that falls in) to acquire a counterbalancing negative energy relative to that same observer -- the fact that the horizon separates the infalling particle from the observer is what allows the particle to have negative energy. The net energy remains zero. If there's no horizon, that can't happen.

Re:Hawking radiation

[Machine9]

it's not even losing anti-mass? such a pity :(

Re:Hawking radiation

[Dukeofshadows]

I keep getting 2 + 2 = 5, I think my value of 2 is too large ;)

Not if you're dealing with teenagers. Hence why occasionally 1 + 1 = 3...

Re:Hawking radiation

[Anonymous Coward]

And as of this writing, it ain't over yet (+3). Throw in a few under and overrateds and you have a classic Slashdot Karma Black Hole (which, as I understand it is filled with wee little strings). Ah well, let the Mertamods sort it out next month.

Re:Hawking radiation

[jmlyle]

It's a special case of the general rule.

Re: Hawking radiation

[Black Parrot]

> Newton can actually say nothing about space around a black hole, at least not anything insightful. He just thinks that the gravity is pretty intense.

Does he ever comment on conditions in the hereafter?

Re:Hawking radiation

[Anonymous Coward]

You're neglecting the two lesser "ones", hiding in the closet watching the success of the greater "one". It's associative and communicable, IYKWIMAITTYD.

Re:Hawking radiation

[falsified]

60% Funny
20% Overrated
10% Offtopic

Explain that! (In a funnier way than saying "rounding".)

Re:Hawking radiation

[Anonymous Coward]

Like on Futurama?

Re:Hawking radiation

[Sivaram_Velauthapill]

I am not a physist but my limited understanding is that gravity does not repel ANYTHING. Gravity only attracts. I have never heard of any particle or matter/energy that is repelled somehow by gravity. (someone correct me if I'm wrong--thanks).

If you go with that view (i.e. gravity doesn't repel) then your final conclusion is wrong (since you are assuming some particles are repelled).

I think the best way to think of these things is as VIRTUAL particles.

BTW, if you are interested in black holes, an excellent book (for the layperson, like me :) ) is Black Holes and Time Warps by Kip Thorne. Check it out. It's a really good book... no, I don't get paid for advertising this book :( :)

Sivaram Velauthapillai

Re:Hawking radiation

[Mr Guy]

Obviously, 42 / 6 (which is 2 times PI, which is exactly 3)

Re:Hawking radiation

[Sivaram_Velauthapill]

DISCLAIMER: I am not an astrophysist

It is best to think of these things as VIRTUAL particles. A pair of virtual particles form anywhere in the universe (has nothing to do with black holes). After a short while, the pair merges with itself (i.e. the two particles (pair) collides and annihilates itself). That is what happens in general.

If there is a black hole, and hence an event horizon, there is a probability that one part of the virtual pair can form inside the black hole (i.e. within the event horizon) while the other part of the pair forms outside the horizon. Since nothing inside the event horizon can escape the black hole (gravity of black hole stronger than anything else), the pair inside gets sucked in while the pair outside can freely leave. The outside particle is what we call as radiation form the black hole.

So to answer your question ('If not, why don't the particles that don't fall in destroy each other, and why does the black holes net mass change?')... the pair that completely forms outside does destroy itself. The pair that is partly outside and partly inside does not get destroyed (because the gravity of the black hole won't let the inside particle get away and collide with the outside one).

Sivaram Velauthapillai

Re:Hawking radiation

[Sivaram_Velauthapill]

So, once the object goes past the event horizon, it's being accellerated _faster_ than the speed of light toward the center of the black hole.

I'm not an astrophysist but I think that's wrong. I don't think anything is accelerated beyond the speed of light--even within a black hole!!! Can someone else shed some light on this? I don't see why something would pass speed of light inside a black hole...

... on the event horizon as physics breaks down.

I think that is not correct either. Physics does NOT break down at the event horizon (from what I know). Rather, physics breaks down at the singularity deep within the black hole. I think the event horizon is well understood. (Actually you may mean something else--in which case you would be right. You are correct if you say that Newtonian Physics breaks down at the event horizon. However, Einstein's Relativity Theory can be used at the event horizon. However, inside the singularity, everything breaks down. We* need quantum gravity, which merges quatum physics and relativity. We haven't developed quatum gravity yet).

Having said that, we don't know what happens inside the black hole. Since nothing can escape, we have practically no observational evidence of anything inside. So all we have are theories.

BTW, someone correct me if I'm wrong in any of this. I am not 100% sure either--since I'm not in the field :(

(* When I say 'we', I'm talking about humanity. I'm not saying *I* am part of this whole thing. I never even took physics in university :| )

Sivaram Velauthapillai

Re:Hawking radiation

[Scott Carnahan]

The black hole doesn't gain mass, because the particle that fell in has negative energy. Remember, you can't create energy from nowhere, but you can "borrow" some from the vacuum temporarily ... that's where the virtual pairs come from.

The virtual particle approach to Hawking radiation seems to be more of a perturbative approximation that has caught on in the popular press than a reasonable description of reality. It may be more natural to describe the radiation in terms of the Unruh effect, which predicts a thermal spectrum around uniformly accelerating bodies - quasistationary objects near the event horizon are bathed in thermal radiation, and this is gravitationally redshifted as it propagates to the distant observer.

This avoids the rather cumbersome notions of negative energy and virtual particles which people tend to find counterintuitive. I have a recent post here which gives some relevant information and links.

Re:Hawking radiation

[Sivaram_Velauthapill]

I'm not in the field so I'm not sure what happened exactly... but my IMPRESSION was that Hawking PROVED it, while the ones you mention CAME up with some ideas.

Sivaram Velauthapillai

Re: Hawking radiation

[richie2000]

Does he ever comment on conditions in the hereafter?

Yes: They have great, juicy apples. He's currently trying to figure out how the snake delivers them but has a theory that it slaps them out of the tree with its tail.

Re:Hawking radiation

[Scott Carnahan]

As I understand it, the idea is that the particle and the anti-particle come into being at the same place, moving in different dirrectsion, and the anti-particle is more prone to being pulled in somehow due it its being the opposite of the other mass in the black hole.

Unfortunately for your theory, particles and antiparticles behave essentially identically near a heavy object, so neither type is favored and (assuming the particle description of the mechanism is accurate - which it isn't) you can expect an equal number of particles and antiparticles to fall in. At least, Hawking's calculations didn't take your proposed mechanism into account.

The particle escapes, generating the black-body radiation, and the anti-particle enters the black whole and collides with a corresponding particle, leaving existance as the original particles came into existance - messed up I know.

If an antiparticle were to enter a black hole, it would add to the mass. If it were to collide with a corresponding particle whilst in transit, there would be some kind of radiation released into the hole, conserving total mass-energy. The perturbative explanation people like to give explains the mass theft in terms of the particle-antiparticle pair "borrowing" energy from the vacuum in order to exist, and the event horizon splitting them before they can recombine, causing the energy debt to be furnished by the black hole.

Re:Hawking radiation

[Jugalator]

Now that's the level I'd like this discussion to be on. :)

Re:Hawking radiation

[LittleBigLui]

10% of the mod points fell into a black hole.

Re:Hawking radiation

[orin]

Actually a lot of complex experiments (unless they come up with something totally unexpected like Cold Fusion) - are not reproduced.

The reason is that it is difficult enough to get funding for a complex experiment at the best of times. If you try to get funding to perform a complex experiment that someone else has already performed, you are a lot less likely to be successful.

So although the theory is that scientific experiments are always directly replicated, in most cases scientists don't have the will (why go where someone has gone before) or the funds to do so.

Re:Hawking radiation

[odenshaw]

no, no, no...

You have to use the 2 equals 1 approximation.

We use that one all the time over in our physics department.

Re:Hawking radiation

[Anonymous Coward]

While they're there, one of them falls into the hole - it doesn't matter which one - while the other gains potential energy from its mate falling in, and escapes.[...] Some mass escaped from the vicinity of the hole, so some mass has to disappear from the vicinity of the hole. So the hole loses mass.

How does this happen? What is the mechanism of energy transfer?

Re:Hawking radiation

[maxwell demon]

Because the escapeing particle was never in the event horizon to begin with, it can contain no information from within the black hole.

Except that the pair of virtual particles are an entangled pair and if one catches the escaped one and measures its quantum state, one then knows the quantum state of the one that fell in. Catch enough of them and you know about an appreciable fraction of the black hole (in theory!)

That's not true. By measuring one particle of an entangled pair, you cannot even tell if the other one has been measured altogether. All you can say is, if it indeed has been measured, you can say what the result of that measurement with a probability depending on the precise measurement. Especially, you cannot gain any information from measuring your part of the entangled pair about anything that might have interacted with the other part.

It's similar to the encryption of a message with a one-time pad: The "encrypted message" doesn't contain the information of the real message. It's completely encoded in the relation between the pad and the "encrypted message", so unless you also have the pad (the equivalent of which is "sealed" in the black hole for the scenario in question, and for quantum teleportation is explicitly sent via classical communication), you don't have the message.

Re:Hawking radiation

[zhenlin]

a = b.
aa = ab.
aa - bb = ab - bb.
(a + b)(a - b) = b(a - b).
a + b = b.
a + a = a.
2a = a.
2 = 1.

From there, you can prove that 2 + 2 = 5.

Re:Hawking radiation

[chandra]

You can get something from nothing. In fact, you can get the entire universe from nothingness. As outrageous it idea it sounds, it doesn't violate any known laws of physics and nature.

Re:Hawking radiation

[maxwell demon]

Other way:

a = b + c
a(a - b) = (b + c)(a - b)
aa - ab = ba - bb + ac - bc
aa - ab - ac = ba - bb - bc
a(a - b - c) = b(a - b - c)
a = b

Now:

5 = 4 + 1

This is undoubtedly true, and it's the first equation with a = 5, b = 4, c = 1.
Therefore also the last equation is true:

5 = 4

Finally, use that equation with

2 + 2 = 4

and you've got

2 + 2 = 5

quod erat demonstrandum.

Now, to proof that we have really truth, let's proof the central equation (i.e. 5 = 4) again in a completely different way:

-20 = -20 (obviously true)
25 - 45 = 16 - 36 (just rewrote the numbers as differences)
25 - 45 + 81/4 = 16 - 36 + 81/4 (added 81/4 on both sides)
(5 - 9/2)^2 = (4 - 9/2)^2 (used binomic formula)
5 - 9/2 = 4 - 9/2 (took the square root)
5 = 4 (added 9/2 on both sides)

So, agan we have 5 = 4, using a completely diffferent proof. Now, this clearly shows 5 = 4 is true, and therefore also 2 + 2 = 5.

Re:Hawking radiation

[Ckwop]

The problem here is that all the information went in, but it's very difficult to infer information from a black-body radiated spectrum (!). Steven therefore thinks that information is lost forever.

That's not entirely correct. According to Hawking et al, Blackholes conserve three quantities:

• Electric charge
• Angular momentum
• Mass (minus gravitational binding energy)

Information is lost because when if I chuck in something in that is weakly charged or colour charged, like a proton or a neutrino, the blackhole doesn't conserve these quantities. The information disappears forever!

The problem is made even worse by Hawking radiation. Hawking radiation is made of photons. So, when a blackhole does eventually dry up by this mechanism. One has to ask where did also this information go?

Simon.

Re:Hawking radiation

[spongman]

exception: divide by zero (a-b)

Re:Hawking radiation

[redhog]

Then your universe is quite wierd... Can you even do multiplication and addition within it? Does (a + b) * c = a * c + b * c in your univese? Normally, 2 can be made to equal 0 (mod 2), with the basic mathematical laws still holding (including divission, since 2 is a prime number,but OK, it becomes a bit stupid to talk about a multpilicative inverse to 1, since it is its own one, 1 * 1 = 1...).

Re:Hawking radiation

[sigxcpu]

Its called the big number theorem:
2=3 for big values of 2.

Re:Hawking radiation

[FireFury03]

When they talk about the volume of a "black hole", are they talking about everything inside the event horizon? Because I was under the impression that the singularity itself has no volume.

Re:Hawking radiation

[dillon_rinker]

"Proof" #1:
a=b+c (step 1) implies that a-b-c=0
Thus the division that occurs between step 5 and step 6 is division by zero.

"Proof" #2:
Step 4 - (I've an interest in mathematical vocabulary and notation, so this makes me curious. In the US we call this the "binomial" formula. What's your nationality?)
In going from step 4 to step 5, you are misapplying the following theorem:

If x>0 and y>0, and if x^2=y^2, then x=y.

Clearly in step 4, the expression on the right-hand side of the equality is negative. There is no other theorem that lets you "take the square root of both sides of an equation.

[/pedant]

Re:Hawking radiation

[wtrmute]

So large black holes will simmer coldly, shrinking only with glacial slowness if at all, and small ones will be hot and shrink very rapidly indeed - finally disappearing altogether in an brief, intense burst of radiation, according to Hawking's theory.

Gamma-ray bursts? :-)

(Yes, I know GRBs' actual nature isn't known for sure, and that the universe would have to have a heck of a lot of small blackholes to fit with the number of GRBs that are detected, but baseless speculation is fun for the masses. The real physicists distill what might actually be science from there).

Re:Hawking radiation

[soupman]

if a==b
then dividing by (a-b) yields division by 0

Re:Hawking radiation

[stuffduff]

Beware of zebra crossings.

Re:Hawking radiation

[Short Circuit]

erm, this is probably a joke, but here's your error:

(a + b)(a - b) = b(a - b)

If we change all the b's to a's (due to a = b), we get:

(a + a)(a - a) = ...

2a * 0 = ...

0 = ...

So unless a = b = 0, the left side of your statement (as far as it can be simplified) is false.

Re:Hawking radiation

[hesiod]

> trying to debate black hole phenomena with no education save some physics courses in high school.

You elitist twat! I know everything I need to know about black holes from Elementary Science classes, and anyone who says otherwise is itching for a fight!

Of course black holes are proven to be a point in space where everything blew up & opened a hole to the next dimension where there is less pressure, so everything gets sucked up and spewed into it. This next dimension is heaven, and black holes are how you get there, duh! They are God's portals.

Geez, if it weren't for my terrific home schooling, I'd think future generations are doomed. Psh, quantum theory... more like quantum... uh... your mom! hehe, I'm so funny. And original!

Re:Hawking radiation

[hesiod]

> An anti-proton is as heavy as a proton, but it has opposite charge.

It has an opposite charge? Hmm. This is probably a stupid question -- are there anti-atoms? With protons & electrons in the center & protons going 'round? Or even protons in the nucleus still, swapped charge.

Re:Hawking radiation

[jkantola]

I don't see the present theoretical discovery directly related with Hawking radiation. Hawking radiation occurs when a pair of virtual particles is created right on the edge of the event horizon such that one of the particles ends up inside the Schwarzschild radius while the other one remains outside. Consequently the virtual pair cannot annihilate, and the particle outside the event horizon seems to be radiation from the black hole. The particle that ends up inside the black hole has a negative energy which translates to a negative mass, and as a result the mass of the black hole actually decreases due to the process. Ergo, Hawking radiation really should have a black-body spectrum as it originates from the quantum field fluctuation and is in no way a representation of the inner structure of the black hole.

The information loss associated with black holes is therefore an unrelated phenomenon and stems from other strange characteristics of black hole theory (perhaps most notably the possibility of a singularity, and the fact that we cannot do measurements beyond the event horizon). Therefore I find this correlation between string theoretical black hole structure and the 'classical' (ha) event horizon quite fascinating. Like someone already said, it might be too good to be just a co-incidence :)

IAAP but black holes are still just a hobby of mine, not a profession. I might have made a mistake somewhere; please correct me if I'm wrong.

Re:Hawking radiation

[maxwell demon]

I've an interest in mathematical vocabulary and notation, so this makes me curious. In the US we call this the "binomial" formula. What's your nationality?

German. FWIW, in German it's called "Binomische Formel".

There is no other theorem that lets you "take the square root of both sides of an equation.

I disagree:
If x<0 and y<0, and if x^2=y^2, then x=y.

Of course that other theorem doesn't help in this case either (surprise, surprise :-)).

Re:Hawking radiation

[Anonymous Coward]

Hawking radiation is the reason why the information loss paradox exists. Its thermal blackbody radiation is a mixed quantum state, but quantum theory says that a pure state (what the object that falls in is in) can't evolve to produce a mixed state.

Re:Hawking radiation

[dillon_rinker]

Och! You've managed to out-pedant me!

=)

Re:Hawking radiation

[Anonymous Coward]

> The problem here is that all the information went in, but it's very difficult to infer information from a black-body radiated spectrum (!). Steven therefore thinks that information is lost forever.

I bet no one ever gets close enough to really find out, without becoming lost themselves.

This is a little like the tree in the forest philosophical question.

If the information gets sucked into a black hole, and is preserved, but no one will ever be able to see it or decode it, was it lost?

On philosophical grounds alone, I agree with Hawking. The information is lost, never to be recovered, therefore, no one can prove one way or the other...; the information is lost. It will take a really long time (and transdimensional travel?) to figure out for sure...

Caveat: I am neither scientist, nor philosopher. I am a quantum mechanics/astronomical news junkie. There seems to be a huge amount of fascinating news daily in this field.

l8,
AC

Re:Hawking radiation

[bareshiyth]

I think your concepts of energy and the "vacuum" are problematic, however.
(1) Negative energy does not have negative mass.
(2) To "yank energy out of the vacuum" is consistent with an Einsteinian (hence, relativistic) concept of spacetime, and his infamous (and now-resurrected, by some theorists) Lambda. But Mathur is working within a string-theory paradigm, where a "particle" is a particular arrangement or configuration of string(s)... that is not the same as "yanking energy out of a vacuum", but imposing some order to the spacetime (temporary - unless the virtual particle or anti-particle escapes, then permanent) which, in Mathur's paradigm, is made up of strings.
In that case, there is information "escaping", not mass. And because one "created" the other (as an exact "anti"), by virtue of being a pair (whether encrypted or not) that information is available to the "outside", to the rest of the universe. And in that case, I think Mathur's ideas (whether "true" or not - which bears on whether he has won the bet) hold water (or those strings configured as the information we read as "water" :)

Re:Hawking radiation

[Anonymous Coward]

I think an "anti-atom" would consist of anti-protons (with negative charge) and neutrons (no charge) in the nucleus, and positrons (positive charge) orbiting this nucleus.

Re:Hawking radiation

[qeveren]

They've been working on creating anti-hydrogen in the lab, with some success, it seems...

50,000 atoms of anti-hydrogen made

It's simply an anti-atom comprised of a single anti-proton nucleus orbited by a single positron (anti-electron). :)

Re:Hawking radiation

[dandelion_wine]

30% Funny
40% Offtopic
30% Insightful

for the comment on my comment???

you people are insane.

Re:Hawking radiation

[hesiod]

> They've been working on creating anti-hydrogen in the lab,

Thanks for the link, that's pretty interesting. Don't know how much you know about all this, but if anti-hydrogen were eventually able to be made cheaper, do you think it could make a good energy source? When mixed with hydrogen, I'm assuming they "annihilate" each other? If there's enough power stored to annihilate a pair of atoms, perhaps it could be harnessed in some way. Of course, as you can tell, I'm no physicist.

Re:Hawking radiation

[Anonymous Coward]

First Proof: a-b-c is zero. Therefore x(a-b-c)= y(a-b-c) is true for all values of x and y. You can't divide out (a-b-c) because division by zero is undefined.

second Proof: I don't remember the binomic formula off the top of my head but I have a hunch its use is illegal due to some condition. Could be because your taking the square route of a negative number and forgetting to include the sqare root of -1 in your answer.

Re:Hawking radiation

[maxwell demon]

No, the binomial formula was applied correctly. It's just that from a^2 = b^2 you cannot conclude that a = b, but only that |a| = |b| (where |...| denotes the absolute value). The equation before taking the square root just said (1/2)^2 = (-1/2)^2, which is correct (since both are 1/4), but the conclusion that 1/2 = -1/2 was obviously wrong.

Re:Hawking radiation

[Anonymous Coward]

They aren't quotes ('), they are backtics (`)....(etc.)

Thanks. Good explanation. Who says you can't learn anything on Slashdot anymore?

stephen lost

[squarefish]

and he looks really pissed about it too.

Re:stephen lost

[FrostedWheat]

Prior Art!

Oh wait, this isn't about patents ... n/m!

Re:stephen lost

[Bobdoer]

He may have to do another album just about his loss.

Re: encyclopaediae

[gnu-generation-one]

"Stephen Hawking and Kip Thorne may owe John Preskill a set of encyclopedias of his choice"

Do they take Wiki?

status of string theory

[microbox]

Is there any hard evidence that string theory is correct?

I'd be holding onto my bet a little longer I think=)

Re:status of string theory

[Anonymous Coward]

nope

Re:status of string theory

[illuvata]

string theory does not predict anything that could be tested, so there is nno evidence for/against it.
this is also why quite a few people feel its more philosphy than science

Re:status of string theory

[kundor]

My physics professor certainly thinks string theory is a load of bunk, and as he's the most authoritative figure on physics I know, I'm taking his word for it. ;) So I certainly wouldn't be ponying up the encyclopedia.

Re:status of string theory

[Stuwee]

String theory is just what it says on the tin - a theory. And this new theory is exactly that too - a theory. So a theory based upon a theory looks rather shaky to me... not even the Aardvark tome in sight yet.

Re:status of string theory

[silicon not in the v]

You can't prove a bet with theoretical equations! Geez, get back to us when they have:
a) proof
or
b) a real headline

Re:status of string theory

[Anonymous Coward]

string theory does not predict anything that could be tested

That depends on what you mean by "could be tested". It certainly makes a lot of predictions in principle about string-scale physics. Whether any of those predictions can be tested in practice anytime soon is another matter.

Re:status of string theory

[the_2nd_coming]

string theory has prodicted some stuff, and work is being done to predict other stuff from QT and GR.

Re:status of string theory

[Anonymous Coward]

Responding as I am taking a string theory course from Prof. Zwiebach here at MIT ...

String theory certainly does predict a number of things that are easily testable ... just not right now. For instance, compactified extra dimensions (as SR includes) introduce additional energy terms to simple quantum problems (i.e. "particle in a box" problems, and SHOs). The problem is that these effects are very large; ergo, the energies necessitated to test these theories are somewhat higher than we can accomplish.

Yes, it's a theory, yes it's kinda off-the-wall and feels a bit contrived, but, studying it, I gotta say that it's pretty if nothing else. It's elegant enough and compelling enough - in terms of what it promises to explain - that it's worth following until it's found to actually be wrong.

A quantum theory of gravity might not be so motivating to you, but if you're a physicist, it's worth trying something wonky to get to it. (Speaking of which, Quantum Loop Gravity - also very wonky - is awesome).

And, as for "quite a few people" finding it too philosophical ... well, quite a few people aren't physicists. *shrugs*

Re:status of string theory

[OneArmedMan]

String theory is fairly easy to follow really.

i mean once you explain that a peice of string can be said to be twice the length that it is from the middle to one end..

Most people will understand you.

Re:status of string theory

[Durandal64]

String theory makes plenty of testable predictions. The problem is that we don't have the technology to actually perform the experiments. String theory deals with massive amounts of energy that we just can't generate yet.

Re:status of string theory

[samhalliday]

so the most authoritive figure on physics you know, rejects a theory before it has even been tested experimentally? please don't let his closed mind infect yours.

Re:status of string theory

[Too Much Noise]

heah, like some tens of orders of magnitude for energy differences ... heck, aren't we renormalizing that stuff already? talk about computing constant corrections to constants that one can't measure in the first place. Not that it means it's all worthless. We get some pretty elegant tools for some pretty nontrivial stuff - math tools are physics-theory agnostic. But compelling? which one of them were you talking about? (point me please to the compelling theory of ... quantum gravity for instance)

Re:status of string theory

[efuseekay]

String theory certainly does predict a number of things that are easily testable ... just not right now.

Ah, words from a theorist!

There are really very few things that ST actually predicts that is even remotely close to reality. Even things like compactified dimensions...we can only make handwavy arguments about what they should actually "look" like in reality (jargon : WTH is the ground state).

ST, despite its apparent elegance in its formulation (2 words : conformal invariance), runs into the problem of which realization of it is the correct "ST". Without experimental input, I think it is very difficult to find out.

I like to compare this (unfairly) to how a QFTheorist would face if he has *no* experimental input. I.e. how would we know that the standard model is SU(3)xSU(2)xU(1) if we have no experimental data? We can write down perfectly selfconsistent QFT in other gauge groups. Similarly, how would a STheorist know how which vacuum in the Calabi-yau manifold is the correct ground state of the universe?

In QFT, we are within reach of experiments, so we can pin down the gauge groups. In ST, unless we have planck-scale experiments (which is NOT easy, if downright impossible to build on Earth), we have no such help...

Re:status of string theory

[DarkSarin]

You missed his point though--it isn't technically falsifiable. Although I know little about physics, I do know a LOT about research theory and how to construct proper theory.

Essentially, any theory which allows for the limits of falsifiability to be arbitrarily changed when shown to be false in its current state is NOT falsifiable.

It's like trying to disprove God--you can't do it. This is because no matter what you do, someone will come up with a counter argument. Although I am quite religious, I don't see religion as being a scientific endeavour for this very reason. That says nothing about its validity, but it does say a LOT about its usefulness in terms of scientific understanding.

It's also like trying to disprove ESP and the like. Uri Geller will say that it doesn't work for skeptics, so he can't do it his tricks in a lab. This is the ultimate lack of falsifiability--sorry, you can't measure this! If you *can't* measure something, you can't falsify it. (Note that this is different from something being difficult to measure, or not currently feasible to measure).

I think what you are saying, technically, is that we cannot currently measure the mass of photons (providing that they exist). Presumably we will eventually be able to measure the mass of an arbitrarilly small object (even if measuring it destroys/alters the object). This just means that we get the mass of the object at a particular moment, and would likely infer the mass at another moment (not being a physicist, I may be wrong...high school physics is very far distant, and very low key).

Okay, I'll shut up now, seeing as how I have likely made several stupid comments.

Re:status of string theory

[Anonymous Coward]

You missed his point though--it isn't technically falsifiable.

No, I didn't miss his point. You missed my point: who cares? You're falsifying a portion of the parameter space of the theory. Even if you can't rule out all of string theory definitively, that doesn't mean the string theory is unscientific -- using experiments, you can definitively rule out portions of it, and that tells us something.

(If you want another analogy: the Standard Model doesn't predict the masses of any particles. So we could consider each version of the Standard Model with different combinations of masses to be a separate theory. Your argument would then be that particle physics is unscientific, because we can't rule out all versions of the Standard Model. But we can rule out a lot of them, all the ones with masses drastically different from what we observe.)

And, incidentally, string theory is technically falsifiable, if we can find a way to probe the string scale. It's the low-energy effective dynamics that we can only constrain. We don't know how to probe the string scale (we don't even know where it is), but it can be probed at least in principle, and possibly in practice.

Presumably we will eventually be able to measure the mass of an arbitrarilly small object (even if measuring it destroys/alters the object).

No, I don't think we ever will. No matter how small we go, it's always possible that the photon's mass will be smaller yet. You can never experimentally rule out a massive photon theory, you can only place tighter and tighter bounds on its mass. However, massive photon theories are still worth testing, because hey, maybe the photon is massive after all.

Re: status of string theory

[Black Parrot]

> string theory does not predict anything that could be tested, so there is nno evidence for/against it. this is also why quite a few people feel its more philosphy than science

Doesn't predict anything we can test, or doesn't predict anything different from current theories that we can test?

In the latter case, ST would have just as much claim to legitimacy-as-a-theory that any of its rivals would. There's no a priori reason to expect the an earlier theory is more nearly correct than a later theory, when their differences have not yet been tested.

Re: status of string theory

[Anonymous Coward]

(again, same anon_coward with the String Theory and the Gravity.)
Pardon me, but I think it is elegant. ^_^ Also, what do you mean by reality? There /is/ no reality save a model. If, perchance, someone models a new subatomic particle as, say, a cat or a ballpoint pen, who's to say that's not its nature? If it feels like an electron and it smells like an electron and if it responds to E and B fields like an electron ... if a model works, that is all the reality we can know.

The only way to know what something is like is to do an experiment on it. To interpret the results of an experiment, you create a model to explain how thing A causes event B. If the model fits, you see if the model agrees with /all/ your tests. As the model asymptotically approaches representing the thing in question, doesn't it approach the truth? Aren't things the way they act?

Specifically, there is a lot of evidence that reality really does behave as probability waves. Neutrons interfere with each other. Matter acts as a ripple of probability. Tunneling, Josephson effects, the very workings of electron microscopes, neutron diffractometers, neon signs and the fluorescant lights that are probably above your head say that matter behaves probabalistically, that reality is made of wave functions that can be measured to have discrete (quantized) values (in math terms, in measuring a wavefunction you will only ever get back the eigenvalues of the Hermitian operator that represents that observable).

If you prick us, do we not bleed? A model IS reality, so far as it is correct.

Re:status of string theory

[the_2nd_coming]

I asked some questions on physicsforums.com about string theory and how it is doing. that is simmilar to the answer I got from the moderator of the forum.

Re: status of string theory

[Anonymous Coward]

A model, no matter how useful, is not necessarily reality! For example, General Relativity is a fantastically good model of gravitation, but has singularities. Anyone who thinks such singularities are 'real' is confusing maths with the real thing. As far as we know the Universe doesn't 'do math', its just a thing we fit our equations to. If our equations go infinite or singular, that is simply a problem with our equations. With string theory, we get useful answers by pretending that the fundamental units of matter are strings, but that is merely a calculating device. If you assume the strings were real, you would have to wonder what they are made of... phlogiston? Rubber? Then you have to figure out how they can experience tension. Tension is a force. Forces exist between some particles and are are carried by other particles. What are the carriers of the string tension force?

Re:status of string theory

[kundor]

He rejects a theory because it CAN'T be tested experimentally, and has no basis in physical evidence.
Scientific theories are models of the world: until there are results that don't fit with the current model, and there is a model that fits actual results better, you don't change it. This is basic Kuhnian scientific progress.
Until string theory can be tested experimentally, it isn't science.

Re: status of string theory

[Anonymous Coward]

A model, no matter how useful, is not necessarily reality!

A model, if correct, describes everything we can possibly know about reality, so we might as well say that it is reality. Of course, we can never know whether a particular model is correct, but as far as our evidence is concerned, we can say that our best model is reality, as far as we have been able to tell from our existing experiments.

If you assume the strings were real, you would have to wonder what they are made of... phlogiston? Rubber?

You're missing the point: the strings in string theory aren't made out of any simpler material: they are the simplest form of matter, just like in the Standard Model, electrons, etc. are the simplest form of matter, and aren't made out of anything more fundamental.

Tension is a force. Forces exist between some particles and are are carried by other particles.

That's true in quantum field theory, not string theory.

Re: status of string theory

[Decaff]

You're missing the point: the strings in string theory aren't made out of any simpler material: they are the simplest form of matter, just like in the Standard Model, electrons, etc. are the simplest form of matter, and aren't made out of anything more fundamental.

'tension' and 'vibration' are not abstractions, they are physical properties of which require an object to be composite.

You can either have something fundamental, or you can have something non-fundamental that can vibrate and experience tension (IF you are using those terms in any real sense). You can't have both.

Re: status of string theory

[Anonymous Coward]

'tension' and 'vibration' are not abstractions, they are physical properties of which require an object to be composite.

They do not. Forget superstring theory and the like; go back to 18th-century, non-relativistic, classical continuum mechanics. You can certainly constuct down physical theories -- including ones describing strings -- that describe tension and vibration, without any recourse to a continuous medium being composed of more fundamental entities.

You can either have something fundamental, or you can have something non-fundamental that can vibrate and experience tension (IF you are using those terms in any real sense). You can't have both.

This is nonsense. Look at the ordinary wave equation: it describes a surface with tension and vibration that is not composed of anything. Of course, we know that things like sheets of rubber aren't fundamental, and are composed of atoms -- but that is not logical necessity, it just means that the wave equation isn't really valid for a sheet of rubber after all (you need the Schroedinger equation for atoms). But there is no logical requirement that the wave equation cannot be fundamentally correct for other objects.
The wave equation is a perfectly legitimate, internally consistent physical theory -- it is up to experiment, not your opinion, to decide whether it applies in nature.

Re:status of string theory

[killmeplease]

I Quantum Loop Gravity how they got Sam to Quantum Leap in the show Quantum Leap? This is what I am dying to know from the worlds top scientists!

Re: status of string theory

[Decaff]

If you want to go back to 18th-century and before you will end up with the same philosophical paradoxes that those models of physics involved. Any thinker of those times would point out that a 1-dimensional object was nonsense. You can't have extent alone. If you have extent + diameter then you have to have a substance composing the volume.

I realise I am being pedantic here, but I'm simply after some honesty about string theory's implausibility as reality.

The wave equation is not a theory. Its an equation. You can't decide if the equation applies in nature - there is no way of knowing what Nature 'actually uses'. You can only decide whether the equation has predictive usefulness.

Re: status of string theory

[Anonymous Coward]

If you want to go back to 18th-century and before you will end up with the same philosophical paradoxes that those models of physics involved.

You are as ignorant of philosophy as you are of physics. There are no philosophical paradoxes involved in continuum mechanics, which reigned supreme in the 18th and even 19th centuries. In fact, it was very difficult to convince anyone of the atomistic theory of matter.

Any thinker of those times would point out that a 1-dimensional object was nonsense.

This is, of course, false. Thinkers of those times spoke all the time of continuum theories, such as 3D volumes of matter that were not composed of atoms or anything more fundamental. It was only when we got experimental evidence for atoms that that changed.

You can't have extent alone. If you have extent + diameter then you have to have a substance composing the volume.

That is merely your philosophical prejudice, not a physical or logical fact. You have not given any argument to support this claim, and there are theories of physics in which your claim is false. Whether those theories apply to reality is a matter of experiment, not your opinion.

The wave equation is not a theory.

Of course it is. It is a theory that describes the mechanics of a classical, non-relativistic extended body. (There are other equations you could apply, too, such as nonlinear wave equations; those give different theories, describing different dynamics.)

Its an equation.

Physical theories are equations. Maxwell's equations, Einstein's equations, Schroedinger's equation, etc. Write down the field equation and you've written down the theory.

You can't decide if the equation applies in nature - there is no way of knowing what Nature 'actually uses'. You can only decide whether the equation has predictive usefulness.

We can never prove a given theory is correct, but so what? Yes, we can't prove that the wave equation describes a string; we can merely produce evidence that supports this claim. But we can't prove that any other theories of physics are correct, either. You're changing the subject: whether we can prove strings are fundamental is a different question from whether it's logically possible for strings to be fundamental. If we can write down a self-consistent theory describing fundamental strings (and we can), then their existence is logically possible, and only experiment can determine whether they do or do not exist in nature.

Re:status of string theory

[bareshiyth]

Although I am quite religious, I don't see religion as being a scientific endeavour for this very reason. That says nothing about its validity, but it does say a LOT about its usefulness in terms of scientific understanding.
But... I do see science as a religious endeavor. For some folks, it is their religion. For others, it leads them to, or affirms their chosen religion, like atheism or Evolutionism (evolution as creator, etc) or whatever.
For me, I began an atheist and scientist, and am now a Christian. I find science more and more affirms my theology, and the biblical account of creation (though I am not talking about the story you are used to, but the account I found when I re-translated the Hebrew).
And I do find some very good leads re cosmology. Among them, an alternative to Big Bang (looks very similar, but is what I consider a better picture), and another concept of the nature of spacetime and the reason the for the cosmological constant (which is just an attempt to account for what we don't understand about the nature of the vacuum/fabric of spacetime and the apparent expansion of the universe). It is, btw, compatible with String Theory, and most of the evidence that supports the Big Bang, but it doesn't need all the "tweaks" the Big Bang model does, or have any problems with the latest data on the MWB, etc. It is also OK with relativity, and will be equally supported the same kinds of research now being designed to verify relativity, like gravitational frame dragging, etc.

Re:status of string theory

[Anonymous Coward]

you talk out of your arse

Re:status of string theory

[samhalliday]

dude... you (and your tutor) have totally missed the point. string theory IS tested in experiment EVERY DAY. it predicts almost all the already known theories about the universe (General Relativity and Quantum Field Theory can be taken as approximations to string theory). the experimentally testable problem most people have about string theory is that the true tests of the new stuff it gives us cannot be tested yet, as our experimental apparatus cannot go to the high energies needed.

you should not have your mind made up for you by someone who has not explained the full story to you. as for your idea of not fixing a model until the experiment shows new things... that is only valid for the days when experiments were breaking the models faster than they were being created. now that we have theory prgressing faster than experiment, it is healthy to have models which predict more than we can observe with our apparatus... so that we can PREDICT what will happen when we go to higher energies (and hopefully observe it now). your Kuhnian model (which i have never heard of) is more applicablel to the engineers than the scientists nowadays. theoretical physics would not exist if people with your opinions were in charge. then science would be royally fscked when the experimentalists tell us the standard model is incorrect (which has just happened, by the way)

Re:status of string theory

[kundor]

But only when the current paradigm is in doubt, because values aren't coming out right or an experiment is demonstrating that assumptions were wrong (as with the Michelson Morley experiment, along with countless other famous examples) are new theories even considered; because otherwise they're unnecessary, and the status quo smothers innovation. Then, in the period of doubt, a sudden proliferation of lots of crazy new theories comes out. They battle it out for a while, and the one that best matches the facts wins.

You seem to think that we should just remove the "status quo smothering innovation" period and make science a constant roiling battle between new theories. The problem is that the period of status quo is necessary in order to develop tools of sufficient precision, to compile data and catalogues thorough enough to find the inconsistencies, and thus support the new theory. Without that period of status quo, there would never be sufficient evidence to support any of the new theories, and science would be in a constant state of argument and bickering while not actually GETTING anywhere.

(Hmm...that couldn't sound anything like theoretical physics today, could it?)

So, until string theory explains data otherwise unexplained, and until it makes prediction that disagree with the status quo and those predictions are validated, and until it's actually been rigurously mathematically defined (which, to the best of my knowledge, it has never been!) there's no reason to accept it.

Re:status of string theory

[DarkSarin]

I was speaking in for the masses, not the religious. When speaking for the religious, there is a different perspective, because what is considered evidence changes.

AFAIAC, there is no need for scientific confirmation of religion, although it IS nice when some bit of research that confirms my religions view is published.

Like I say, I am NOT a physicist, so my ideas on creation are atrocious to physicists because they lack information.

To each their own.

Re:status of string theory

[samhalliday]

i don't think you understand... the standard model IS wrong and has been prived wrong by the appearance of the neutrino mass. we ARE in that "period of doubt".

Tangle of strings?

[ENOENT]

Yikes! Sounds like all information that enters a black hole turns into spaghetti code!!! The horror! The horror!

Re:Tangle of strings?

[DoctorScooby]

Yikes! Sounds like all information that enters a black hole turns into spaghetti code!!! The horror! The horror!

Now I know where Windows98 really came from.

Re:Tangle of strings?

[AndroidCat]

the information continues to exist -- bound up in a giant tangle of strings that fills a black hole from its core to its surface.

I was thinking that it sounded a lot like Slashdot. :^P

Re:Tangle of strings?

[Anonymous Coward]

So, that would be "garbage in, spaghetti out?" Gee, we could replace many &lt insert least favorite language&gt coders with one black hole.

Re:Tangle of strings?

[Anonymous Coward]

So with an infinite amount of radiation gathered from outside the event horizon of a black hole... there's a copy of Windows 98 in there somewhere, somehow?

Cool. Who wants to take a bet that the source code of Windows 98 is in there too?

Re:Tangle of strings?

[Anonymous Coward]

I will bet against it. On the condition that you are the one who finds it.

Re:Tangle of strings?

[shfted!]

Apparently Romulan spacecraft aren't the only thing powered by deep, dark singularities...

Re: encyclopaediae

[dasmegabyte]

No, they want the accurate kind of encyclopedia.

Of course

[FreeLinux]

This all works on the assumption that you accept string theory in the first place. While string theory may be the darling of astro physicists at the moment, it remains far from proven. If I were Haking, I'd defer payment for a while.

Re:Of course

[Bingo Foo]

String theory has not been proved, but neither has any physical theory. Perhaps you are complaining that unlike other physical theories, it is unlikely that an experimentally accessible test for disproving string theory can be found. This makes string theory not really "science," in the sense that we normally understand it.

Additionally, people's names are conventional rather than scientific, but their legal usage has necessitated their meticulous recording. While it can't be proven, it can be verified beyond a reasonable doubt that the Lucasian Chair of Mathematics at Cambridge is Stephen Hawking.

Re:Of course

[techno-vampire]

I'm thinking that all you can tell from this is what particles went into the black hole, and nothing else. That is, you can't tell what atoms they came from or anything about larger structure. Of course, said structure would have been ripped apart by the time the particles were engulfed anyway so that makes sense. Still it's rather interesting that you may be able to find that much out, even though the "information" seems to be useless.

Re:Of course

[hauer]

This all works on the assumption that you accept string theory in the first place.

Not really. (Apart from the fact that that non-string theories very often become "stringy" at extreme conditions, thus it just might be that everything is stringy...)

The information paradox suggests that any black hole sucks up all the incoming the information (which then disappears). This is a purely theoretical question with absolutely no way of testing experimentally. The answer by Mathur is similarly theoretical: he constructs one black hole (happens to use string theory for it) for which this is apparently not true, i.e. the information is preserved. One counterexample is enough.

Re:Of course

[Anonymous Coward]

No: if string theory is incorrect, it's still possible for every black hole to lose information. Mathur's proof assumes that it applies to a black hole described by string theory. If no black hole is microscopically described by string theory, then his proof doesn't say anything at all about real black holes.

Re:Of course

[Anonymous Coward]

While string theory may be the darling of astro physicists at the moment

Actually, most astrophysicists (excepting some early-universe cosmologists) are pretty skeptical about string theory; they're pretty conservative when it comes to exotic theoretical physics. String theory is the darling of theoretical particle physicists at the moment.

Re:Of course

[hauer]

No: if string theory is incorrect, it's still possible for every black hole to lose information. Mathur's proof assumes that it applies to a black hole described by string theory. If no black hole is microscopically described by string theory, then his proof doesn't say anything at all about real black holes.

As I said, it does not even make sense to apply the information paradox to the real world (i.e. testing it experimentally). It is a well-defined mathematical statement formulated in a (generalized) quantum theory of gravity. There is no assumption in Mathur's proof concerning about what real black holes are described by.

But in fact, there is much more which can be said. Although the language he uses is string theory, some statements (like the crucial one) are more general than that. Once you assume that quantum gravity exists (without which there is no information paradox at all...), you find some "invariant" statements which are independent of the formalism. It is like the solution of the quadratic equation is independent of the actual formula used to express it.

Re:Of course

[Anonymous Coward]

go back to school. This is as bogus as saying "don't teach evolution in school, it has not been proven" well duhh, you can't prove things, you can only disprove things. Arguing that something had not been proven is meaningless.

Re:Of course

[hauer]

just because you invent a theory in which information is provably preserved, does not "solve" the information loss paradox, unless you can show that the real world is described by that theory

But does not this very statement contradicts its claim? Just to state what the information paradox is, you are postulating a certain theoretical background (all of which is experimentally untested lacking experiments from the realm of quantum gravity). Thus you can hardly do better than confining yourself to the theory which provides the framework to be asked.

A completely theoretical statement is not anything that any physicist would accept as "solving the information loss paradox"

True, not any, but at least one might as this answer implies :-)

His proof does not generalize to, for instance, loop quantum gravity, Euclidean quantum gravity, dynamically triangulated or Regge quantum gravity, etc.

At this point I admit my knowledge becomes blurry thus I must be somewhat guessy. Can the information paradox stated in these theories at all? Is not it inherently perturbative in nature? All these theories you cite (well, I would not call dynamically triangulated a theory...) lack any description in the perturbative regime. What are the degrees of freedom which is needed for the information paradox? Nobody knows, probably they are strings after all... :-)

Re:Of course

[Otto]

Serious question, then. Science is an epistemology reliant on testing, and the knowledge gained from that epistemology. If there is no scientific test for string theory, how can string theory be considered a true theory? It seems it could be, at most, an hypothesis.

You're more or less correct. "String Theory" is just a name. It's possible that it can be tested, it's just that nobody has come up with a way to actually do it yet. It's not really far enough along to be able to come up with a good method to do so, methinks.

But "String Hypothesis" doesn't have the same ring to it. :)

Re:Of course

[Anonymous Coward]

I don't think Hawking cares too much.

if a consistent-looking theory can reclaim the information without mucking other stuff up, he'd accept it I reckon.

it's not as if any of his work or the work of others he's interested in has any basis in experiment at all (it's scarcely physics IMHO), so it'd be a bit churlish of him to reject string theory.

Re:Of course

[Anonymous Coward]

But does not this very statement contradicts its claim? Just to state what the information paradox is, you are postulating a certain theoretical background (all of which is experimentally untested lacking experiments from the realm of quantum gravity).

A statement of the information loss paradox does not require much in the way of theoretical background, other than the definition of "pure" and "mixed" state. It doesn't even require that quantum theory in general (let alone a specific quantum theory, like string theory) be true, because one proposed resolution of the paradox is that quantum theory isn't true.

The point is, Mathur has proposed a resolution of the paradox within the framework of string theory, but it's equally possible that the opposite is true in some other theory (e.g., information is not preserved). One cannot claim that one has definitively resolved the paradox, unless one has evidence that a particular one of these theories applies to the real world.

Can the information paradox stated in these theories at all?

Certainly; it applies to any quantum theory of gravity. The paradox merely states: "Hawking radiation is a purely thermal, mixed quantum state. The matter that falls into the hole is a pure state. The unitary time evolution of quantum theory states that a pure state cannot evolve into a mixed state ("losing information"). Therefore, either quantum theory is wrong, or the state remains pure ("information is preserved"). There are many specific quantum theories of gravity, such as the ones I mentioned, as well as ones that try to modify quantum theory; the paradox may be formulated in all of them (though it has not been resolved in any of them). As such, you don't need to specify the particular degrees of freedom involved, nor is perturbation theory required (although a perturbative theory is helpful in connecting the theory to experiment and the classical limit). You just have to be able to define pure and mixed states, and for that, all you need is a Hilbert space.

(And, incidentally, dynamical triangulations are as much of a formulation of quantum gravity as Regge quantum gravity, although a 4D version is still lacking.)

Re:Of course

[bareshiyth]

Serious Question indeed!
String theory is more metaphysics, more science fiction than science theory. It is essentially a story written in mathematics (much like prose creates a novel), but about things totally beyond any possible observation. I think we do play rather loose with the rules when we call it a "theory" (But then, there are so many others even more "sci-fi", like brane theory, multi-universes, etc..., also being graced by the name of theory).
Does that mean it's not useful in science, or even "testable" in the sense we might hold various observations or data against it to see if it's similar (a "fit")? Not at all. But remember, a play by Shakespeare, or a story on TV, however much disclaimed by "this story and the characters portrayed are fictional...", is also expected to imitate life and model certain realities. If it doesn't, we hardly want to bother reading or watching, but the ones we do watch, and call "good", are those that are useful and at least vaguely "testable" representations or "paradigms" of our reality. Same goes for a lot of scientific "theories", nowadays. Including String Theory.

Re: encyclopaediae

[frazzydee]

"Stephen Hawking and Kip Thorne may owe John Preskill a set of encyclopedias of his choice"
I guess so, but only if wiki is what Preskill chose.

Re:Is it me

[microbox]

Maybe the real workings of the universe can't be explained with everyday experiences. After all, quantum stuff and relativity has little bering on hunting, communicating and making little ones, and that's what our brains were designed to do.

So the question is...

[NeoTheOne]

is this like an infinite number of monkeys with those typewriters? And since time passes so strangly there, why the heck haven't we detected x-rays sending Shakespear?

Re:So the question is...

[frazzydee]

is this like an infinite number of monkeys with those typewriters? And since time passes so strangly there, why the heck haven't we detected x-rays sending Shakespear?
No, i think that we haven't detected Shakespear because we've been looking for him rather than Shakespeare

Re:So the question is...

[Gil-galad55]

Actually, if you work out the math, even using super-super-monkeys, the probability of a bunch of them producing the proverbial Hamlet in the lifetime of the universe is absolutely nill. But that's beside the point anyway!

Re:So the question is...

[Narcissus]

Except that seeing as William himself spelt his name in different ways, including Shakespear (apparently), maybe the grand parent post is on to something!

Re:So the question is...

[Anonymous Coward]

Actually, no. Think about it in the sense of work = rate * time. Hamlet is a finite piece of work, let's call it H.

H = R * T

We're talking an infinite number of super-super monkeys. Hell, even an infinite number of retarded monkeys would have rate = infinity.

H = (infinity) * T or T = H / (infinity) or T = 0

So, given these infinite retarded monkeys, all works produced and ever to be produced instantly.

Re:So the question is...

[NeoTheOne]

ah yes, but RTFM and you will see that exist in MULTIPLE DIMENSIONS! (insert gasp of awe here) So that's like parallel processing with hyper-dimensional-threading!

....meanwhile Intel patents Multi-Dimensional Monkey Technology (MDM Technology! tm) and is promptly sued by SCO for copyright infrigement since all those monkey would have had to have writen system V code in all that hyper-dimensional time


and indeed, yea verily, I welcome our multi-dimensional monkey overlords but remember that in Soviet Blackhole, singularity observes YOU!

Re:So the question is...

[NeoTheOne]

uh...yea! yea that's it! ;-)

Re:So the question is...

[Gil-galad55]

Well, infinity is clearly a different story. Most physical occurrences--with the possible exception of the wait time for a restaurant in Anderson on Saturday night--are finite. The point being, the blisteringly fast typing of the super-super-monkeys will never produce Hamlet in anything like a reasonable amount of time; I don't recall the exact numbers and I'm way too lazy to go get my copy of Kittel, but it is something on the order of billions of universe lifetimes. Anyone from Berkeley, spawning ground of Kittel, care to chime in? Also, since the monkeys are hitting keystrokes at random, it's not really valid to define a "rate" at which they produce Hamlet. Since generating the sequence of characters of which Hamlet consists is entirely by chance, Hamlet might never be created; or, it might be created immediately. We can only define a probability. And the probability is extremely small. Like, really.

Tracing origins...

[Theaetetus]

From the article: Since Mathur's conjecture suggests that strings continue to exist inside the black hole, and the nature of the strings depends on the particles that made up the original source material, then each black hole is as unique as are the stars, planets, or galaxy that formed it. The strings from any subsequent material that enters the black hole would remain traceable as well.

That means a black hole can be traced back to its original conditions, and information survives.

But, if the information about the origins is contained in the strings inside the black hole, that information is inside the event horizon, and can not be observed by anything outside the event horizon. Maybe the information survives, but there's no way to get at it... Unless I'm missing something here? Cosmologists?

-T

Re:Tracing origins...

[Tumbleweed]

> Unless I'm missing something here? Cosmologists?

"Is there a cosmologist in the house? Anyone? My god, get this man a cosmologist!"

Re:Tracing origins...

[PhuCknuT]

Maybe there's a relationship between vibrations in the strings within the black hole and hawking radiation (or something similar) releasing energy from the black hole. Maybe hawking radiation could be caused by strings near the surface tunneling out? In which case, the information going in could be related to the info coming out. Just what came to mind while reading the article, IANAP.

Re:Tracing origins...

[Anonymous Coward]

hawking radiation doesn't come from the blackhole, so what you are saying makes no sense.

Re:Tracing origins...

[PhuCknuT]

That's why I said 'or something similar'. The point was not that hawking radiation specifically was caused by strings, but that if strings existed inside the event horizon right up to the edge, then strings could in theory tunnel past the event horizon occaisionally. From the outside, it would look the same as hawking radiation, and it would have the same effect of slowly evaporating the black hole.

Re:Tracing origins...

[Anonymous Coward]

It's worse than that- it's physics, Jim!

Re:Tracing origins...

[Tumbleweed]

...but not as we know it. It's physics, Jim, but not as we know it.
Not as we know it, Jim!

Starrrr-Trekkin', across the universe,
Always going forward,
Cuz we can't find reverse...

BOOT TO THE HEAD! *thwop!* (whoops, sorry, wrong Dr. Demento song there...)

Re:Tracing origins...

[Mick Ohrberg]

Cosmologist, not to be confused with cosmetologist, or proctologist.

Ok, ok, mod -1 Offtopic.

Re:Tracing origins...

[maraist]

More interesting to me is the idea of a string inside a "potential-well", which tunnels for non perfectly-infinite barriors.

From my undergrad days of Elec-eng. Infinite barriors do not allow quantum particles (like electrons) to pass. But anything less than an infinite barrior will allow even the most lowly energetic particle to pass with some miniscule probability.

It stands to reason that some of the energy in the hole is near the inside of the event horizon (due to density-distributions). So long as the hole is perfectly spherical, there will be no place from which highly concentrated energy can exceed the escape velocity.

But if we replace the point-mass of the hole with a ball of strings, then we have fluxuating/undulating HIGHLY energetic strings. By nature, this energy is not going to be uniform, and may very well be periodic. This may allow regular minute disturbances in the event horizon such that super-charged strings near that rupture points can escape like a black-hole solar-flair.

Such flairs would give information about the non-uniformity of the hole, and thus provide information about the structure of the inside of the hole.

It's no less difficult then trying to figure out the internal structure of an active star.

Further, my lay-mind considers that holes may be as useful to the cosmos as stars.. Providing some alternate structured energy-source. Gravity-waves? Worm-holes? intersteller weapons? :)

Re:Tracing origins...

[ralphclark]

I dunno, If it had all that interesting stuff popping out of it all over the event horizon it wouldn't much resemble the black holes of current theory in which (Hawking insisted) black holes "have no hair" which I took to mean that they cannot carry any distinguishing marks. An event horizon is an event horizon is an event horizon. The only fundamental property it has is its size, and all its other properties are derived from that.

You'd need a new theory altogether, pretty much throwing the book away.

Sweet

[Laconian]

I wonder when the day will come when our computers have built-in singularities for mass data storage.

Re:Sweet

[Revek]

yes but how would you carry them around.

Re:Sweet

[Lehk228]

FAT32 is a pretty good data singularity, goes in but won't come back out

Re:Sweet

[Ashtead]

Actually, the closest equivalent to a black hole is the /dev/null -- everything sent there can never reappear.

Re:Sweet

[Anonymous Coward]

Actually, the closest equivalent to a black hole is the /dev/null -- everything sent there can never reappear.

Given enough time /dev/random can retrieve all of the bits sent to /dev/null.

This follows from theory of the kernel relativity, a subset of general relativity which that states that information entering /dev/null never completely disappears. Instead, it folds the fabric of space-time, and it can actually appear on /dev/random at any instant past, present or future.

Let's get closer...

[Lattitude]

I say we send someone to find out for sure... Darl, you interested?

Re:Let's get closer...

[McBride, Darl]

Yes.

Re:Let's get closer...

[Biege]

Wouldn't the black hole evaporate after that?

Re:Let's get closer...

[Anonymous Coward]

I suggest Johnny Five. He's always wanting more input.

Re:Let's get closer...

[Vengeance_au]

It's not nice to post falsely as a real person.

So someone tell Darl to stop posting falsely about Linux source code!

... either that, or stop pretending to be a real person...... ;-)

Re:Let's get closer...

[kcim]

In the cygnus, Disney we need a rewight, I`ll start building max. Darl can fill in for one of the zombe crue|:-)

Re:Let's get closer...

[danila]

Since we already established that black holes contain code, we need to find out where copyrights for any of that code rightfully belong to SCO. It makes perfect sense to go and check, doesn't it?

SHit

[Anonymous Coward]

Out come all the 'expert physicists' to give their opinions.

Re:SHit

[Anonymous Coward]

Yes. To whoever is reading this: If you don't have a degree in physics, shut the hell up, before you make an ass of yourself. You know shit, you dildo.

Re:Is it me

[NotQuiteReal]

Yes, it is just you. I knew everything, once - it came to me in a flash of insite... then, incoming email chimed for my attention, I read some spam, had another beer and read Slashdot until something on TV caught my eye.

Now, I forgot what it was that I thought I knew.

As soon as we figure out how to retrieve ...

[burgburgburg]

the information in the black hole, we'll finally find Amelia Earhart. And Jimmy Hoffa. And hundreds of millions of socks. And Duke Nukem Forever.

Re:As soon as we figure out how to retrieve ...

[psoriac]

And Duke Nukem Forever.

Hey, this is theoretical physics, keep your pseudo science out of here!

Re:As soon as we figure out how to retrieve ...

[brain1]

OMG... Nasa is launching Geraldo to the nearest one. He's going to have a special on what they (didnt?) find inside!

Re:As soon as we figure out how to retrieve ...

[Bake]

Don't forget the pens!

Re:As soon as we figure out how to retrieve ...

[rabs]

... and the complete set of rules to Brockian Ultra-Cricket ...

- rabs

Re:As soon as we figure out how to retrieve ...

[Anonymous Coward]

I just want to know if my cat is still alive.

Of course

[stratjakt]

Information wants to be free!

Yuk Yuk

Shut up, I could have posted a goatse link and referring to black holes.

Spaghetti code

[Hannes Eriksson]

GOTO or COMEFROM?

Tangle of Strings

[Gleng]

bound up in a giant tangle of strings that fills a black hole from its core to its surface

Sounds like the back of my desk!

Re:Tangle of Strings

[Anonymous Coward]

Sounds like his back.

Re:Tangle of Strings

[Anonymous Coward]

Sounds like the back of my desk!

No, those are cum stains.

Simple question maybe

[198348726583297634]

The gears turn slowly in processing that article, and I'm left with a question someone smarter than me ought to know - what is a string? What would one look like or how could one be described?

Re:Simple question maybe

[Ruzty]

C?
char *stringVar[1024];

Or perhaps Java?
String stringVar = new String();

Maybe you prefer PERL?
my $stringVar = '';

That's how I describe some of my strings...
-Rusty

Re:Simple question maybe

[benna]

Why not consult Official String Theory Web site :)

Re:Simple question maybe

[Anonymous Coward]

An array of characters.
Computer Science 101, fool.

Re:Simple question maybe

[Anonymous Coward]

A very tiny dimension all curled up on itself as opposed to extending to infinity (like we're typically familiar with). If a foam in a bubble bath is the whole universe, a bubble in the foam might be analogous to a string. Space is soap, we're not allowed to see it directly, but we can see its effect.

String theory has modest successes with some things, and monsterous problems with others. It's essentially built to explain why gravity is so weak. At distances smaller than strings gravity is as strong as all the other forces. But it doesn't overwhelm everything at large scales because gravity is the only force which can see the strings, and so it leaks off into these other dimensions untimately becoming very dilute.

The hope of theoreticall physicists is to unite gravity with the other forces, understanding everything about it's divergance, hopefully uniting quantum electro/chromodynamics with general relativity creating one theory to explain them all, and, in mathmatics, bind them.

Re:Simple question maybe

[Anonymous Coward]

Look here for a series of clips discussing the string theory, the 'M' theory, and a lot of stuff that led up to it.

Re:Simple question maybe

[Bingo Foo]

Why should we, when it's so much more fun to speculate based on something we think we remember from a Nova episode or reading Omni at the barbershop that one time?

Re:Simple question maybe

[che.kai-jei]

one theory to rule them all?

Yeah, right.

[Anonymous Coward]

... physicists at Ohio State University 'have derived an extensive set of equations that strongly suggest that the information continues to exist -- bound up in a giant tangle of strings that fills a black hole from its core to its surface.'

Sure they do. Physics is the new theology.

Re:Is it me

[Pingular]

Maybe the real workings of the universe can't be explained with everyday experiences. After all, quantum stuff and relativity has little bering on hunting, communicating and making little ones, and that's what our brains were designed to do.
To me, it makes more sense that the real workings of the universe would be incredibly simple rather than complex. Not sure why, it just seems to make sense :)

Re:Is it me

[sisukapalli1]

I am a layman when it comes to physics, but let me put in my layman's two cents in...

Science normally deals with things that we observe, and scientists try to find out the whys and the hows. Once in a while, though there are things that are sometimes theoretically identified before, and it may be a while before such things are actually observed.

S

Re:Is it me

[E-Rock]

I found that in physics, going with 'common' sense or your gut was a good way to look stupid while making it obvious that you didn't review the lecture material the night before.
On the flip side, the math always did a hell of a job predicting the outcome of experiments.

I'll tell you when [in relativistic terms]

[NotQuiteReal]

Three Months after you buy a storage solution that is almost as massive, but was twice the price. D'oh.

*sob* It must be so sad in there.

[Andy Smith]

the information continues to exist -- bound up in a giant tangle of strings

Aw! Information wants to be free.

You're more right than you think

[Raul654]

Jimbo Wales (founder / benevolent dictator of Wikipedia) was recently approached by a major publishing company about the possibility of a printed version of Wikipedia.

Re:You're more right than you think

[Anonymous Coward]

+3, Funny

Re:You're more right than you think

[BabyDave]

Jimbo Wales (founder / benevolent dictator of Wikipedia) was recently approached by a major publishing company about the possibility of a printed version of Wikipedia.

Will it come with a free bottle of correction fluid and a pen?

Re:You're more right than you think

[poot_rootbeer]

the possibility of a printed version of Wikipedia

Perhaps they could bundle it with "People Who Miss The Point, Volume 1"...

Re:You're more right than you think

[Sethus]

Thats completely mind boggling. Aside from making the web service not free, who the heck would want to buy the printed version when you could get the free one online O_o

Re:You're more right than you think

[maxwell demon]

No, but the GNU FDL (which Wikipedia is licensed under) demands that they provide a machine-readable version (f.ex. a CD-ROM) of it in editable form (like HTML, Postscript wouldn't suffice).

Re:You're more right than you think

[juhaz]

For the same reason kazillion of other books you can get for free online continue selling pretty well in paper form?

Not all people are on the 'net all the time, and reading from a monitor is damn inconvenient compared to a book.

On the other hand, you can search an electronic much easier, they both have big pros and cons.

Re:You're more right than you think

[Anonymous Coward]

"Jimbo Wales (founder / benevolent dictator of Wikipedia) was recently approached by a major publishing company about the possibility of a printed version of Wikipedia"

It's all under the GNU Free Documentation License, so with careful attributation and license-notices, anybody could make a printed copy of Wikipedia

I noticed that CafePress include book publishing as one of their items you can customise -- upload a PDF file with the book contents and a JPEG for the cover, and all you need is a few tools to select and organise chapters, convert Wiki markup (or its HTML) into LaTeX and then PDF output.

Of course, if the people in charge of Wikipedia took a backstep at the thought of trying to format it for print, it might not be as easy as it first looks.

obligatory mchawking post

[enrico_suave]

MC Hawkings... and my humble air supply tribut to mc hawkings S. Hawking Karaoke: "all out of love"

*shrug*

e.

Re: encyclopaediae

[Raul654]

Bzzzt. Wrong.

all those lost by that article, raise your hands..

[The Other White Boy]

*raises hand*

Re:Is it me

[pyros]

Now, I forgot what it was that I thought I knew.

So would you call it an unknown unknown, or a known unknown?

It was a Playboy subscription...

[rmdyer]

I thought this was a Playboy subscription. Did someone change the wording here?

+1

Re:It was a Playboy subscription...

[kfg]

Here is an actual reproduction of the bet document you are thinking of:

Hawking/Thorne bet

Ain' the web grand?

Yeah, Stephen lost that one. Word has it that Kip's wife was a bit miffed about the payoff.

KFG

Re:It was a Playboy subscription...

[varaani]

Playboy for Thorne and Private Eye for Hawking, says here.

Re:Is it me

[mugnyte]

I don't understand this at all. Our everyday experiences are simply products of the "real workings" of the universe. You may think Newtonian physics suffices for what you need, but your "little ones" wouldn't be able to dream of being an astronaut, science professor, astronomer, or a myriad of other things without these other new-fangled theories.

When we achieve enough proficiency in our understanding to make accurate predictions, and validate them with observations, then publish them, have them scrutinized publicly and repeated, we're making vast improvements to the knowledge humanity holds. The fact that we're in so esoteric topics for new things at the moment just goes to show how valid this system is; we've built a cohesive worldview in physics down to the quantum level. There, mysteries abound, but it doesn't mean we shouldn't be there.

Physicist-speak

[jasondlee]

I think these physicists think that they're so much smarter than the rest of us that they can string a bunch of big words together in a sentence that really makes no sense at all and pass it off on us as the greatest discovery ever, assuming that we're ignorant enough to take their word for it. After reading that article intro, I think they're making a safe bet... :)

It has to be said

[Guspaz]

1. Read up on advanced physics
2. Make bet against famous physicists
3. ???
4. Profit!

Re:It has to be said

[Anonymous Coward]

That's just plain ol' not funny anymore.

Information? Not Matter?

[ackthpt]

In 1997 the three cosmologists Stephen Hawking, Kip Thorne and John Preskill made a famous bet as to whether information that enters a black hole ceases to exist

Slashdot, where information goes to die.

Oh my God!

[Anonymous Coward]

'have derived an extensive set of equations that strongly suggest that the information continues to exist -- bound up in a giant tangle of strings that fills a black hole from its core to its surface.'

They have, of course, been to my companys headquarters, which explains their source. If he could only explain how to get information back, I might be able to do my job...

The Catch?

[Anonymous Coward]

It now looks like Stephen Hawking and Kip Thorne may owe John Preskill a set of encyclopedias... in bed!

Would this have any bearing on evaporation?

[myowntrueself]

IIRC, the guys at CERN are about to start pumping out black holes on the assumption that this is safe since the Emminent Mr Hawkings Predicts that they will 'evaporate' before they can eat anything and that Mr Hawkings couldn't *possibly* be wrong about something like that...

Does this 'discovery' change anything in this regard?

Re:Would this have any bearing on evaporation?

[Anonymous Coward]

Any black holes they could make at cern would pose no threat because they'd have little energy, and very little mass. If there isn't enough juice in it to light up a lightbulb, there isn't enough there to destroy Switzerland let alone the Earth. The unlikelyhood of such a cascade of events is laughably. It'd be like worry about the posability that you might spontaniously quantum-mechanically tunnel to just outside the event horizon of the nearest black hole only to wake up as you fell in. In short: It's not going to happen. Better worry about that rogue asteroid, that at least has a comparitively good chance of killing you.

Re:Would this have any bearing on evaporation?

[Durandal64]

Micro-black holes will have extremely small event horizons. You can stop worrying about CERN collapsing the solar system now.

Re:Would this have any bearing on evaporation?

[tc]

No. In fact, the idea that black holes can store information tends to correlate with the evaporation theory. If black holes couldn't store information, then they couldn't have entropy. On the other hand, if they have entropy, they must have a temperature, and if they have a tempertature they must radiate. Luckily, Hawking radiation supplies a mechanism for a black hole to radiate, and so a black hole has a temperature, and hence it's possible for it to have entropy.

I think Hawking made the bet as a hedge. He wanted to lose the bet, because that would mean he was right and that black holes contained information. If they didn't, then that could cause problems for his radiation theory, but at least he'd get some encyclopedias out of the deal.

Wow, what a gig

[digrieze]

I have to change careers. These physicists (sp?) have just created the biggest manefestation of a quantom physics illustration ever (namely scrondiggers (sp?) cat). The black hole is the box, the information entering the event horizon is the cat. Anything at the singularity is not observable and is therefore in a permanent state of flux between states (not really, but our ignorance of what's going on creates that condition). When we make observation our predispositions on the data influence the observation and change the reality. In other words YOU CAN'T BE WRONG NO MATTER WHAT YOU SAY!

Is there some way I can get this gig?

Re:Wow, what a gig

[BigFootApe]

Umm, no.

These physicists (sp?) have just created the biggest manefestation of a quantom physics illustration ever (namely scrondiggers (sp?) cat).

The Schrodinger's cat scenario requires that you are able to retrieve the item (cat, superstrings, etc.) and check to see if it is alive or dead, intact or destroyed, or whatever.

When we make observation our predispositions on the data influence the observation and change the reality.

How, precisely? Does it read our minds?

In other words YOU CAN'T BE WRONG NO MATTER WHAT YOU SAY!

Perhaps if you're psychotic?

Re:Wow, what a gig

[digrieze]

Absolutely, that's the point, you can never actually retrieve the item (in this case a string, not a cat) and therefore you can only infer its' state by observation of external fluxes (i.e. xray and gamma bursts at the event horizon, etc.) This puts the item (string) in a permanent state of flux. Our predispositions influence our interpretation of the data to support or deny the proposition (in this case, string theory).

It's very similar to the argument that arises in archealogy and paleontology every 5-10 years when they discover a new "missing link" or "earliest ancestor" of modern man, namely is it an early human or just another early ape? The news media hypes the "new discovery" for weeks and a few years later most are reclassified as early apes and disappear from mention. The fossils never changed, one side just looked at them differently than the other and had different predispositions about what made it a man or an ape. The important point was never the raw, pure, evidence, it was always about the interpretation.

Re:Wow, what a gig

[jswalter9]

1. invent ridiculous but unassailable theory (you can't prove me wrong - nyah, nyah, n-nyah nyah). 2. WRITE BOOK 3. Collect $$$ had to be said.

Too bad for Kip Thorne

[overbyj]

If I remember correctly, Kip Thorne would have received a subscription to Playboy if he had won. Too bad for him that he didn't when. He could have done theoretical astrophysics and found out what Ms. March's turn-offs are.

Re:Too bad for Kip Thorne

[benna]

Actually that was a different bet between Thorne and Hawking which Hawking conceded to Thorne years ago. It was a bet on whether Cygnus X1 was in fact a black whole. Hawking bet it wasn't and Thorne bet it was. Hawking said he really did think it was a black hole but he wanted to win something if he was wrong so as to be less depressed about it.

The least of his worries...

[Anonymous Coward]

"It now looks like Stephen Hawking and Kip Thorne may owe John Preskill a set of encyclopedias of his choice, since physicists at Ohio State University 'have derived an extensive set of equations that strongly suggest that the information continues to exist"

I'm sure that losing a bet is the least of his worries...

http://www.nytimes.com/2004/01/24/international/ eu rope/24HAWK.html?ex=1390280400&en=e88eb4bbbbd9a343 &ei=5007&partner=USERLAND

Re:all those lost by that article, raise your hand

[CowboyNick]

HA! I couldn't even understand the summary....

Almost - wrong bet though

[Raul654]

Hawking has made several bets. You are thinking of his naked singularities bet (A naked singularity is a black-hole without event horizons) Hawking bet Roger Penrose(?) a subscription to Penthouse (I think) that they could not exist. He lost.

Re:Almost - wrong bet though

[frozen_kangaroo]

I was pretty sure that it wasn't encyclopediae either ! (it was though.) For the truth about hawking's wagers see here (6th paragraph down):

In 1975, he bet Kip Thorne a subscription to Penthouse (the loser would get it mailed to his home) that a celestial mystery named Cygnus X-1 would turn out to be a black hole.

Re:Almost - wrong bet though

[Scarblac]

The Nobel Prize-winning (1938) physicist Enrico Fermi was willing to bet anyone that the test would wipe out all life on Earth,

I am willing to bet with anyone, for huge stakes, against the wiping out of all life on Earth within the next year or so. Let's say a million dollars.

If all life (including all human life) on Earth is wiped out in the next year, I owe you $1,000,000 (ONE MILLION DOLLARS) and if not, you owe me.

Re:Almost - wrong bet though

[arsheive]

Funny, Kip and Hawking seemed to think the bet was between them. I thought it was Penthouse for Hawking, Playboy for Kip, and Kip mentioned that he had lost. These are just personal recollections from a dinner I had with them though. They were discussing Hawking's talk on time travel the next day and whether or not Kip would be against him on his postition.

What we really want to know is...

[freeze128]

Which one went into the black hole to find out?

No need

[bad_fx]

...Darl's already got his head really far up a big black hole...

I'm sure the bet will be collected...

[BigBadBus]

when Professor Hawking is released from hospital following a recent health scare...and also when the police have finished their investigation into who has been abusing and torturing him for months now.

Paul

Black holes have hair

[B2K3]

I had a conversation about this very topic this afternoon. I even uttered the phrase, "Thank God black holes have no hair!" I'm glad I didn't bet on it.

On a side note, what would be a good bet for physics today? "I'll bet you the Google cache..."

And remember, not only am I president of the hair club for black holes, I'm also a client.

Oh really, come on, get a clue!

[Jerf]

It is often... though not often enough... pointed out that the singular of "data" is not "anecdote".

Similarly, "fact" is not merely an emphatic form of "theory".

I might as well theorize that black holes don't exist at all; who owes what now? Oh, right, nothing changes, because theories aren't facts .

Mick Ohrberg, why don't you grow out of Physics Fanboydom and take some time to learn some real stuff? For starters, why don't you being with Science 101 and learn the definition of "theory", and "equation", and other such basic terms?

Re:Oh really, come on, get a clue!

[cardshark2001]

Similarly, "fact" is not merely an emphatic form of "theory".

I might as well theorize that black holes don't exist at all; who owes what now? Oh, right, nothing changes, because theories aren't facts .

Yeah, which is why it's silly that they ever had that bet. How could anyone ever win it? They might as well have set the stakes to be "The Jupiter moon of your choice".

Theories aren't facts, you're right, but I hope you're not one of those who believes facts don't exist and that "everything's a theory". Most theories try to be, after all, the simplest explanation that fits the available facts. I always get annoyed when someone makes the leap from: "theories change", to: "there are no scientific facts and I can't prove that I exist".

One statement is science, the other is epistemology (see also: fancy word-play).

Re:Oh really, come on, get a clue!

[Chris_Jefferson]

Can I just say, you don't have to reject the Theory of Relativity but, when you try to solve the relativistic equations around a black hole, two thoughts come up:

1) The solutions imply some infinatly small volumes and some infinatly stretched times (this seems like a possible sign your equations may in fact just not explain this

2) Even if we assume that relativity hasn't simply broken down here, we can expect quantum effects to become very significant. Dispite a lot of work relativity and quantum still don't sit happily together.

My main worry about all this black-hole related research is that they are using a hacked-up version of the relativity and quantum equations which we know aren't consistant with each other. I'm not convinced this is any more useful that just studying black holes with Newtonian mechanics...

Jim Carrey feels Hawking's rage

[B2K3]

The pictures prove it.

I love you, Stephen Hawking.

Diderot

[Anonymous Coward]

Give the degree of clout these guys have, I'd be hitting up Hawking for a Diderot.

What it doesn't say.

[DynaSoar]

I can buy that the information survives and continues to exist inside the Schwarzchild radius.
But when they say:

"The strings from any subsequent material that enters the black hole would remain traceable as well. That means a black hole can be traced back to its original conditions, and information survives." ... they're going to have to explain a bit harder just how it is we're supposed to be able to extract that information back out through the event horizon. Whether it continues to vibrate on linked strings or vanishes in a puff of nonreality makes no never mind if you can't get it back out.

Re:What it doesn't say.

[Rob Riggs]

I'd rather have a nice, comforting theory that states time could not run backwards, thank you very much! -- neat theoretical frameworks be damned.

.denmad eb skrowema...

Re:What it doesn't say.

[DynaSoar]

tverbeek (457094) sez: "The way to extract that information back from within the event horizon is quite simple: run time backwards....That may be nonsense talk,"

Sure it is. It's not quite up to snuff with Hawking's "imaginary time" (that is, imaginary in the sense of imagnary numbers, running perpendicular to thermodynamic time), but it's pretty good. If it's nonsense, it's the failure of language to be able to express the concepts.

Seriously, reversability is a symmetry that needs tested. It may be broken in the thermodynamic sense, but preserved via imaginary time. On the other hand, the black body radiation may indeed carry the information back out, but in a form we can't decode. I have no doubt the signals I decode represent, at some level, the processes of neurons doing their jobs. But with billions of them crammed together and locked inside a scalp, skull and dura mater, and with who knows how many processes being operated on simultaneously, I can't even begin to calculate the number of variables I'm looking at, much less how to figure out what the signal is carrying.

If they ever start a field of experimental cosmology, I'll sign up.

Re:What it doesn't say.

[redfenix]

The way to extract that information back from within the event horizon is quite simple: run time backwards.

This proves nothing! It's not extracting anything, it's only undoing what was done! It doesn't tell if the information survived the event horizon because it never went into it! If you run time backwards, then it hasn't happened yet and you're back where you started! Literally!

It depends on what "ceases to exist" means....

[HarveyBirdman]

...if I may wax Clintonian.

Maybe it exists on the other side of the event horizon, but I thought string theory tells us that things like event horizons shield the universe from singularities and other discontinuities. The information cannot be retreived, therefore, from the point of view of the universe, it has ceased to exist.

What's the difference, really, between destroyed information and irretrievable information?

Re:It depends on what "ceases to exist" means....

[vranash]

One is impossible to recover while the other has a chance of being recovered?

Kinda like accidentally overwriting the File Allocation table compared to completely wiping the hard disk. The data's still there, you just need to figure out how to find/put it back together.

Re:It depends on what "ceases to exist" means....

[HarveyBirdman]

No, by irretrievable I *mean* irretrievable. It cannot, and never will, be retrieved. It might as well be destroyed.

C'mon... an erased FAT is hardly the equivalent of an event horizon.

Re:It depends on what "ceases to exist" means....

[cptgrudge]

The difference is probably something along these lines:

If we die, and something happens to our "soul", does it matter whether it is destroyed or irretrievable with respect to our reality?

Not really, but we'd sure like to know.

Re:It depends on what "ceases to exist" means....

[Anonymous Coward]

What's the difference, really, between destroyed information and irretrievable information?

Damn, there's a good MS joke in there somewhere, but I'm too tired to think of it...

Re:Ohio State University?

[lerhaupt]

GO BUCKEYES

(ann arbor is a black hole)

Re:stephen lost - on the rampage in Boulder?

[cruff]

When I looked at the picture, the building in the background reminded me immediately of those on the University of Colorado (Boulder) campus.

Sanitized bet?

[Ralph Wiggam]

Was it this bet or another bet Hawking made where the prize was a subscription to Hustler magazine?

I could imagine a reporter just changing the bet to an encyclopedia.

-B

Mathur's tests

[trip11]

I've actually had Mathur for classes as I'm an undergraduate at Ohio state in physics. His tests really are not all that brutal as he is both an amazingly smart man and a good teacher. He has this dry humor that you have to pay attention to to get. Amusing quips include:

"It will be a big piece of fun" (talking about deriving equations)

"thats a rather large force" (after mentioning that the force to pull two pieces of a capacitor apart could lift the city of columbus)

If you get a chance to meet him, don't pass it up. He's a great guy

Re:Mathur's tests

[LurkerXXX]

Columbus was used as an example in his lecture because it's the city that Ohio State University is in. (that's where the lecture was held...)

Re:Mathur's tests

[balloonpup]

Oh, that Henny Youngman...

Black Hole Interior

[whig]

Perhaps the information survives in the black hole interior. Physics infers a black hole by an event horizon, but that does not necessarily imply a singularity. On the other hand, if the interior is considered as a "universe" with its own set of physical laws and structure, this conjecture could be quite relevant.

For a somewhat handwaving explanation of what I'm talking about, take a look at this hypothesis.

Re:Black Hole Interior

[jkantola]

Yup, especially given that what we know of the mass and radius of the cosmos indicates that the cosmos itself is very close to being a black hole.

And still, the majority of physicists thinks that parallel universes are just a flight of fancy ...

Re:Is it me

[be-fan]

I think the point is that while you may be able to understand physics, at an abstract level, can you understand it at a concrete level? Our real world experience is mainly a matter of the concrete. Things we can see, and touch, and hear. I drop something, it falls down. I push something, it moves, etc. Physics, however, is completely abstract. You can't see an atom --- you can't even visualize what it would look like if you could see it. The only way to truely understand it is to understand the mathematical model of it. But even when you have that understanding, you don't have something equivilent to your real world experiences. You still can't see it.

Party hard.

[tom taylor]

It now looks like Stephen Hawking and Kip Thorne may owe John Preskill a set of encyclopedias of his choice

Those crazy guys.

Bag of Holding

[Anonymous Coward]

Well, if we can pull that information back out of a black hole, maybe I'll finally get my bag of holding?

Isn't this simple physics?

[dacarr]

I mean, one of the laws of energy states that it cannot be created nor destroyed, only converted, and the same *generally* goes for matter (lacking antimatter). Yes, black holes can theoretically alter reality, but if they are effectively hypercompressed neutron stars, the alteration is that you get one hell of a monstrous compression algorithim.

So for the quantum astronomy and astrophysics geeks, am I missing something?

Re:Isn't this simple physics?

[1s44c]

You are missing something.

Noone doubted the energy continued to exist.
The bet concerned the patten of information held by the matter/energy. The questions was if you encoded something in a patten of laser light and sent that into the black hole would the encoded information continue to exist? ( given that no record of the data sent exists except that encoded in the light. )

Google for holographic universe, it's interesting stuff.

Re:Isn't this simple physics?

[Lord Bitman]

or, would be, if it didnt base its entire claim on one questionable claim after another. Sure, it's an interesting read, but not really worth mentioning.

Re:Isn't this simple physics?

[ciphertext]

The currently followed physics works up until you cross over into the event-horizon. Once you begin your spiral into infinite compression, the equations no longer produce dependable results. That is essentially where the model "broke down".

Re:Isn't this simple physics?

[Lord Bitman]

you didnt quite get the parent of my message, did you? Or my message, for that matter.
Google is your friend.

What?

[Anonymous Coward]

I can see it now: it would be a spiral bound notebook, "printed" in pencil... and of course every copy would come with a set of pencils and erasers.

Blackt holes shown to compress losslessly.

[Canthros]

Decompression support expected in next WinZip release.

Re:Blackt holes shown to compress losslessly.

[Creepy Crawler]

That stupid winzip. PowerArchiver has ALWAYS had BlackHole (de)compression. Good ol' .bh files. ....except they didnt look like strings..

But not Longhorn

[Anonymous Coward]

That's in another universe entirely.

The conclusion may be wrong

[jd]

I can prove that if you pour information into Congress, you end up with a tange of red tape, which is similar to a superstring. (Red tape is used to hold things together that would otherwise fly apart; red tape requires at least 10 more dimensions to exist; and there is some evidence that particles of beaurocracy have negative gravity.)

However, there is no proof that any of the information survives, after being caught up in red tape. Indeed, all evidence so far suggests that it does not.

(Beurocracy particles are a subclass of Strange Quarks that have beeen influenced by a politic Ion)

Re:The conclusion may be wrong

[Anonymous Coward]

Learn to spell, retard. Maybe this will help...

So *that's* how M$ is coding Longhorn

[Anonymous Coward]

Just toss in garbage and it becomes a tangle of strings.

No programmers necessary.

But even M$ can't seem to get it delivered from the inside of a black hole...

Stringy fuzzball?

[whig]

How's this?

Double-Dog dare you...

[Mulletproof]

A set of encyclopedias? I guess winning free sex or a blowjob doesn't faze these guys anymore...

Re:Double-Dog dare you...

[smart.id]

Steven Hawking is a parapalegic... I don't know how it would work with him.

penthouse not hustler

[goon]

doesn't everyone have a copy of a Hawking on their desk? I checked out the current Hawking book I was thumbing through (Non math) ...

• Steven Hawkings, A life in Science, White. M, Gribben. J, Penguin '92, 0-14-015615-1

and on page 139 it outlines a the bet over Cygnus X-1 (the first black hole discovered ~95%) where Kip Thorne (Caltech) bets that it does not contain a black hole.

If it is true, Thorne owes Hawking a years subscription to Penthouse. Thorne wins it was a 4 year subscription to Private Eye (English statirical mag).

Re: encyclopaediae

[Anonymous Coward]

They want the kind of encyclopaedia whose authors don't derisively post "Bzzzt. Wrong." when confronted with works that are, with a few minor exceptions, much more credible and accurate.

Re:Ohio State University?

[Anonymous Coward]

Just 'cause we whopped yer ass 2003!

GO BLUE!

re: is it me, is it really me?

[kyw]

"Maybe the real workings of the universe can't be explained with everyday experiences. After all, quantum stuff and relativity has little bering on hunting, communicating and making little ones, and that's what our brains were designed to do."

Black-out here,
lost in black

All we do us, humans is to experience and to reproduce "the workings of the universe".
Relativity is a concept we live with, everything moves, changes, disappears.

I dont think it's our brains who were designed to do the hunting and making little or big ones, more likely our instincts.

We use our brains for...... black holes.
linking strings together ;)

Kwatch

[Anonymous Coward]

Es ist so viel kwatch - schiesse. Wie die Astrologen zeit funf hundert Jahre.

Kwatch kwatch kwatch.

Re: encyclopaediae

[Anonymous Coward]

Wikipedia has just eclipsed EB in total word count [57 to 55 million]. Not bad considering they've been around for centuries and WP has been around for just over 3 years. As far as accuracy - that will come with time.

Woooosh!

[Barlo_Mung_42]

That's the sound of this article flying over my head.
"bound up in a giant tangle of strings that fills a black hole from its core to its surface"?

So it's really just a tightly wound baseball?

Re:Is it me

[Gldm]

To me, it makes more sense that the real workings of the universe would be incredibly simple rather than complex.

Maybe they are.

Re:Is it me

[mindstrm]

Part of the problem is the language used to describe these things.. the general approximations they make only really make sense if you understand a lot more background..

On the surface this might all seem like philosophical banter... but that's just what the news prints. What is behind this is tons of chalkboards and computers full of equations that fit modern theory.

Remember, we don't HAVE a theory of everything yet... i'ts not like everything is perfect, and scientists are trying to make things up to look smart.. there is a point where our current equations don't add up, don't make sense.. and that's where these guys are working now.

superstrings, quantum gravity, etc.. these aren't whimsical sci-fi dreams.. they are where science is currently trying to figure things out.

Re:Is it me

[Anonymous Coward]

Newtonian physics is quite adequate for becoming an astronaut (it got people to the moon), a science professor or an astronomer. Seem syou don't understand newton to well...

event horizons in string theory

[geordieboy]

Maybe the string theorists themselves don't know whether or not the information can be retrieved. The "a black hole has no hair" theorem is a result in classical general relativity. In string theory, apparently one can find solutions that look like black holes in some classical limit, but in fact have all the hair that is missing in the classical theory. But is there an analogue of the event horizon in string theory? (I always thought string theory was only done in flat spacetime anyway. How do they do it in Schwarzschild spacetime?) Any string mavens here?

Next on "Ask Slashdot"

[the cobaltsixty]

"What's the most expensive encyclopedia you've ever seen?"

Re:Next on "Ask Slashdot"

[Daniel_Staal]

A complete, signed by the authors, hardback edition of Wikipedia.

(I'm sure you could do it...)

Re:Next on "Ask Slashdot"

[trentblase]

My choice would definitely be the Encyclopedia Galactica... unless of course you could consider the Hitchhiker's Guide to be an encyclopedia.

Re:Next on "Ask Slashdot"

[Cappy Red]

Well, the signing maybe... lot's of people named x, though. Then there are those that just sign gobbledegook. Some of those don't even use a real alphabet.

I could see the hardback edition though. Really long mantle starting with "A-Aardvark".

*honken*

Re:Next on "Ask Slashdot"

[zhenlin]

Chapter ZZZZZ9999: Credits.

We'd like to thank the following people for their contributions to Wikipedia, in ASCIIbetical order:

11.0.0.1
11.0.0.2
11.0.0.3
11.0.0.4 ....
222.254.254.254 ....

Re:Next on "Ask Slashdot"

[dustmote]

I hear it cost one guy his whole planet to get a copy of that Hitchhiker's Guide.....

not singularity

[nonameisgood]

The whole point is that a singularity no longer consistutes individual bits, therefore and more precisely, you are looking for blackhole-encapsulated strings for storage of the information you have tried to store...
Unless you meant to say, "I want to buy Windows and let it lose my data faster than the singularity at the center of a black hole". Which is it?

Proof.....

[vwjeff]

I don't know about you but I need physical proof of this. I say the winner must travel to a black hole and prove that matter exists within the hole.

Publishing a website in book form

[srleffler]

Jimbo Wales (founder / benevolent dictator of Wikipedia) was recently approached by a major publishing company about the possibility of a printed version of Wikipedia.

He should read up on what happened to Eric Weisstein's Mathworld website. In short Weisstein licensed a publisher to produce a printed "snapshot" of the website. After the book came out the publisher sued him and had his web site shut down for a year because it was infringing the book's copyright.

Does it matter?

[dilweed]

And who cares? Does the fact that the information continues to exist in a black hole make my life any better or worse? How does it affect me and my family?

Does it affect my paycheck at the end of the week? Does it cure my grandfather's cancer? Does it stop my next-door neighbor from beating his girlfriend up? Does it help me figure out what's wrong with my car? Will it solve our dependance on petroleum based fuels? Will it remove the chemical pollutants from the atmosphere and seal the hole in the ozone layer?

I can appreciate these very intelligent people are thinking about very heady subjects, but why not solve problems here on earth that effect us mere mortals every day.

Re:Does it matter?

[dilweed]

Thanks for the crap moderation, cowards.

I posed a very serious question for very serious discussion, and only Fantastic had the guts to reply in a serious manner.

We've only recently have begun to discuss human travel to Mars, the next planet in our solar system. I question our ability to harness this discovery to better humankind in the next 5 centuries, much less tomorrow. Can you give me one deep space discovery that affects our daily life? The only one I can think of would be x-rays, over 100 years ago.

Re:Does it matter?

[Anonymous Coward]

Why does it have to affect anybody's daily life to be worthwhile? Most art, literature, music, etc. doesn't affect people's daily lives -- it's something that you dip into from time to time, to appreciate it. For that matter, why doesn't understanding better how our universe works constitute "bettering humankind"? Does it have to produce a better toaster or a more fuel-efficient car to represent an achievement of the human race? Do intellectual achievements count for nothing?

Re:Does it matter?

[Thanatiel]

The X-Rays discovery had nothing to do with space.

http://ctct.essortment.com/wilhelmroentgen_rght. ht m

OK, now prove string theory

[Jormundgard]

Now if they could just show that string theory is a realistic, predictive theory, then maybe there's a story here.

Re:Is it me

[wass]

ike they're so determined to make something make sense, they blindly look for something that'll fit the problem, even if it's obvious that it's probably not right

I actually recently responded to a similar accusation against physicsists, and you can read my reply here . That response has more examples listed of 'kludges' in physics, but I'll talk about a few in more depth in this post.

What you've just described is known as phenomenology. In other words, trying to come up with some sort of basic theory to match the given data. Examples include Planck's original quantizing of radiation into discrete quanta, which turned out to be right. Another example is the Landau theory of 2nd-order phase transitions, where one builds a power-series expansion of the free energy in powers of something called the 'order parameter'. This is a total hack, but in many cases can adequately describe phase transitions (including superconductivity).

In fact, there are many kinds of physics theories, some termed 'macroscopic' in which case they're phenomonoligical, and describe what's going on, but don't adequately describe the 'physics' of the system. Then there's the microscopic theories that talk specifically about particle interactions, and follow directly from quantum mechanics, statistical mechanics, E&M, etc. The goal is to make these two approaches mesh.

For example, superconductivity could be described fairly well using the Ginzberg-Landau expansion, where the order parameter described above is complex, instead of real. Many things can be described this way, including Josephson Junctions and fluxoid quantization of superconducting loops. (Ginzberg just won the Nobel Prize in physics in 2003. Landau, if he were still alive, would have probably won it too, and it would have been his 2nd physics nobel prize). This approach worked fairly well, but physicists weren't sure why that was.

But then in 1957 Bardeen/Cooper/Schrieffer came up with the BCS theory of superconductivity, which explicitly describes how the electrons can pair up into Cooper pairs. Electrons want to repel, but in the right crystal lattice an electron-phonon-electron interaction (ie, a local distortion of the lattice) can produce an attractive interaction. BCS describe how this attraction comes about, how the energy gap forms, and how the electron pairs can carry a resistanceless supercurrent. BCS won the Nobel Prize in Physics in 1972.

This was microscopic vs macroscopic development of superconductivity. Two years later, physicist Gor'kov was able to show that the Ginzberg-Landau theory comes as a limiting case of the BCS theory. Hence, microscopic meets macroscopic, and everybody's happy.

So yes, physicists do look for something to fit the problem, but they don't just stop there. They also try to make those hacks or kludges match up directly from physical laws of the universe. That's what physics is about.

Two Questions

[DrMorpheus]

First, how can he be sure that the strings in question hold the same information as did the strings that existed before collapsing into a black hole?

Secondly, why is information being preserved considered a good thing?

I would think, from the perspective of human free will, that we would want information to be creatable and destroyable.

Otherwise we're stuck with determinism running the universe. And no, quantum randomness DOES NOT allow for free will.

Quite the contrary, it just substitutes statistical determinism for classical determinism. That isn't a solution.

Re:Two Questions

[Sivaram_Velauthapill]

And no, quantum randomness DOES NOT allow for free will.

Why not? I always thought of that as being free will...

Sivaram Velauthapillai

Re:Two Questions

[bareshiyth]

First, how can he be sure that the strings in question hold the same information as did the strings that existed before collapsing into a black hole?
First, remember "strings" are a theory, not reality. In fact, we will never know if they are "real", but only if the theory is helpful, and contribute to a useful paradigm.
Secondly, why is information being preserved considered a good thing?
"Good" is a value, and that's your choice... the issues of physics are not about whether something is "good" or not.
I would think, from the perspective of human free will, that we would want information to be creatable and destroyable.
What we want, regarding "free will", is not our choice, nor up to physics or a theory about the nature of existence. "Free will" is up to the Creator, not the created. However,
Otherwise we're stuck with determinism running the universe. And no, quantum randomness DOES NOT allow for free will.
is not true. In fact, the theory of relativity is all about "determinism", and quantum theory is all about indeterminism. One exists within the other.
But your "metaquestion" is not physics. It's theology. And I don't find a problem there either.
For instance: if God says he "knows the end from the beginning", and testifies to that with prophecies that come true, whether in human affairs (history), or the movement and fate of planets and galaxies, God is saying He is in control. He determines, He is "running the universe", right? That's pretty much what Relativity talks about.
But suppose God also tells you that you, yourself, have free will. You, yourself, can do what you want, line up with, or oppose what He intends (determines). Is that a contradiction? Only if quantum theory is a contradiction of relativity. But it's not, because they deal with two different levels of reality.
Individual atoms, according to quantum theory, are quite free, individually. But in the aggregate (the macro scale, where relativity applies) they will "statistically" (in the aggregate) go where, be where, do as relativity says. Same for you. Free as a bird, but within the whole flock, you will migrate to South America (or get swallowed up by the black hole of death, and no longer matter to the species (macro) plan?). As a human, you are free to be with or outside God's plan, but you simply can't overrule it at the macro (relativity) level, where reality is deterministic.

Hmm, what a dilemma

[belphegore]

So on the one hand, I would like other people in my friends network to see amusing posts by "Darl McBride", so it would make sense to tag this user as a "friend". But on the other hand, it's "Darl McBride", so it would make sense to tag this user as a "foe"...

Aiiiiyeee...

[Anonymous Coward]

Who let the strings out?...

Re:I've often wondered if...

[Anonymous Coward]

Consider an extreme case, two black holes merging. Assume before they "see" each other, that their event horizons are spherical. As they approach each other, they feel each other's gravitional pull. The opposing pull has the effect of lessening the gravity at each BH's surface because the signs are reversed. As a result, the event horizon on each BH shrinks a bit.

The event horizon of a black hole cannot shrink, except in the case of Hawking radiation, which is completely negligible for any stellar-sized black hole. In particular, if you put two black holes close to each other, their horizons will deform and grow in size. They will emit a bunch of gravitational (not Hawking) radiation in the process, because the final merged black hole is not as big as the sum of the two original holes (as measured in area).

Naked singularities

[Anonymous Coward]

...are not anywhere near as much fun to prove as naked pluralities. I'd take a bet on those, any day.

Re:'String theory' is misnamed

[Anonymous Coward]

Because of this, you can't say that string theory is 'correct', simply that its more useful. Its nonsense to suggest that particles are really small vibrating 'strings' experiencing an tension force, otherwise you get an infinite regress: To explain the behaviour of everyday things (such as real pieces of string which can vibrate), we would be requiring the existence of incredibly small 'strings' which would 'vibrate', which doesn't really get us anywhere!

That's wrong. String theory really does involve small vibrating strings. These strings are unlike the string you've got on your yo-yo, in that they only have the properties of shape and tension -- they are fundamental strings, not made up of anything smaller. You could apply your same "logic" to argue that nothing can be made up of particles, because you'd be explaining the behavior of everyday particles (such as billard balls) in terms of smaller particles -- but there is no infinite regress: you get down to the smallest particles (quarks, leptons, etc.), which aren't made out of anything smaller. There's nothing wrong, ontologically speaking, with positing a "most fundamental entity" (be it a point particle, a string, or whatever).

There is a worrying tendency in modern physics to forget that the map (the maths) is not the territory (the real universe).

The maths describes everything we can know about the real universe. Everything else is untestable philosophy. Science itself does not and cannot say what things "really are"; it merely describes how they behave, by means of theories and mathematics.

Ok, now that we know that...

[Junior J. Junior III]

What I want to know is, how much pr0n can you fit in a black hole?

Re:Is it me

[ivan1011001]

Yes, it is just you. I knew everything, once - it came to me in a flash of insite

... and left just as quick in a flash of bad spelling

Re:Some questions from a non-physicist

[Anonymous Coward]

Tunneling effect - a particle has a certain chance of overcoming a potential barrier even if it doesn't have enough energy to do so. Why can't a particle from within a black hole escape it similarly?

Real particles can't tunnel outside the light cone (faster than light), which is what would be necessary to get out of the horizon. If you're talking about the vacuum production picture of Hawking radiation, there is a sense in which it can be interpreted in terms of tunneling.

Accumulation of mass/energy. What exactly prevents a black hole from exploding, after accumulating enough mass - what makes them so stable?

Why should it explode? There is no limit to how much mass a black hole can contain. The more mass you dump in, the bigger it gets.

Is it possible that the Big-Bang was an explosion of a huge black hole ?

Not really.

If a half of a quantum-entagled (EPR) pair enters the event horizon, can it somehow be used as a "probe" ?

No. Quantum entanglement can't be used to transmit information, regardless of whether there is a black hole around.

See also sections 9, 10, and 11 of this FTL FAQ.

Full paper

[Anonymous Coward]

Link to the paper in Nuclear Science
http://www.sciencedirect.com/science?_ob= MImg&_ima gekey=B6TVC-4B94K94-2-J1&_cdi=5531&_orig=browse&_c overDate=03%2F01%2F2004&_sk=993199998&view=c&wchp= dGLbVtz-zSkzV&_acct=C000022719&_version=1&_userid= 492137&md5=1e52451eaa2c384e849fe4520c04237b&ie=f.p df

Re:I've often wondered if...

[jmichaelg]

Am I wrong about the gravitional sign reversal as the black holes approach each other?

Data

[Anonymous Coward]

So black holes can contain data?

Quick! Someone port linux!

Re: encyclopaediae

[DJStealth]

I was just going to ask if they could buy a CD/DVD-ROM Encyclopedia

Re: encyclopaediae

[Keith McClary]

Fortunately for Hawking and Thorne, encyclopedias have collapsed into tiny, relatively inexpensive disks while retaining all their information content.

note to self

[NotQuiteReal]

Don't drink before slashdotting. D'oh.

Re:I've often wondered if...

[Anonymous Coward]

I don't know what "the gravitational sign" is, let alone whether it "reverses". Are you talking about the sign of the gravitational constant? Or are you implying that gravity repels? Or what?

As for the strength of the gravitational field, in general relativity there isn't even such a thing as a number which represents "the strength of the gravitational field". The gravitational field is determined by a tensor which, unlike a vector, doesn't have a scalar magnitude. You can speak about the strength of various components of the field, if you like.

I would guess 2^3 [nt]

[Synonymous Yellowbel]

Cat got your tongue? (something important seems to be missing from your comment ... like the body or the subject!)

Tools already available?

[Snork Asaurus]

... information continues to exist -- bound up in a giant tangle of strings that fills a black hole from its core to its surface

Like the WWW? So, finding information trapped in a black hole sounds like a job for ... (ta-daa) ...: Black Hole Google! Boldly going where no search engine has gone before...

Newton's gravity could cause lensing and redshift.

[astroboscope]

Once the speed of light is known, Newtonian gravity can be used (and was, IIRC, for lensing) to predict both gravitational lensing and gravitational redshift. It's off by a factor of 2 for lensing, but qualitatively correct.

It's very rare that a good understanding of Newtonian physics doesn't give you some insight, and in less time than a string theory calculation would.

Re: encyclopaediae

[Black Parrot]

> As far as accuracy - that will come with time.

My faith in that is starting to slip. I recently ventured out into some pages I hadn't previously been watching, and found several pages whose history shows that they have a k00k "squatter" who watches the page and insists on sticking his idiocy back in no matter how many people come along and correct it, whingeing all the while that everyone else is pursuing some dishonest agenda.

Wait a second..?

[MacDork]

Ok, I know I'm no black body, string theory genius like Mr. Hawking, so please point out what I'm missing. Black holes are very massive. So massive in fact that once close enough to the hole, nothing can escape it's gravitational pull. The point where even light is unable to escape from the hole is the 'event horizon'. The very foundation of this shrinking black hole theory depends on this mind boggling mass. So how is it that when it is only as massive as, say, our Sun that it is going to continue to suck in anti-particles to destroy itself? If this were the case, any body with mass in the universe would simple fizzle away in a flash of intense radiation, no? It seems to me that once the black hole dwindles to the point that it is no longer massive enough to capture light leaving it, you'll get a really big rock, ball of fire, super massive dust particle, ham, or whatever is left in there, available for all to see.

Re:Wait a second..?

[maxwell demon]

The very foundation of this shrinking black hole theory depends on this mind boggling mass.

This is where your mistake lies. The very foundation of the black hole is in it's mind boggling mass density. The absolute mass is important only in formation, because with too little mass gravitational forces are not able to compress matter enough to create the black hole.

You could get a black hole (complete with event horizon and Hawking radiation) by compressing earth into a radius less than about 9mm. Indeed, the less mass a black hole has, the smaller it is, and the larger the space curvature is on it's event horizon. Therefore all effects coming from space curvature are stronger for them, which also includes Hawking radiation. This especially means that finally black holes "explode": the more it radiates, the faster it gets smaller, and therefore it radiates even more in even shorter time scales, until it radiated it's complete mass away.

Of course, as soon as the black hole gets down to a size near the planck length (a mindboggling small length where quantum gravity effects are huge), we already know that all semiclassical reasoning must fail, therefore we cannot really say anything about what will happen at the last moment of a black hole, until we have a successfull theory of quantum gravity (or have watched black holes exploding, of course).

My God... it's full of, um, stuff!

[CptNerd]

"...the information continues to exist -- bound up in a giant tangle of strings that fills a black hole from its core to its surface."

That means my brain is a black hole...

Futurama Quote

[mr100percent]

Fry: So, you guys want to see my Fry-hole?
Stephen Hawking: I call it a Hawking hole. Fry: No fair! I named it first!
Stephen Hawking: Who is the Journal of Applied Physics going to believe?.

Re:I've often wondered if...

[jmichaelg]

I don't know what "the gravitational sign" is, let alone whether it "reverses".

This is what I'm thinking of. Say you're in earth orbit and as a result, are constantly being accelerated towards the earth. What the actual magnitude is depends on where you are but think of any acceleration that points "down towards earth" as negative. You now move towards the moon until the moon's gravity on you is stronger than the earth's at which point you start to fall towards the moon. Your acceleration vector has changed direction and hence its sign has changed from pointing in a "negative" direction to a "positive" direction. Where the sign flips over depends on the position of the moon and earth.

Similarly, if you could somehow manage to hover just inside the event horizon and another black hole moves by as it orbits your black hole, you'll feel the second black hole pull you just as the moon did when you crossed into its gravity well. But if you feel the second black hole pull you, that means your black hole isn't pulling on you quite as hard as it was before the second black hole passed by. If that happens, the original event horizon has just dropped below where you are - it has momentarily shrunk in response to the passing black hole. If you happen to be a photon whose vector is in any direction away from the black hole, you're free to go. You've just escaped from a black hole.

I'm having trouble seeing what's wrong with that scenario.

Re:Gravity

[Anonymous Coward]

(Same anon_coward as right above with the String Theory thing.)

First, this theory /requires/ that mass block the effect of "proportional displacement", i.e. this pushing gravity. It is the only way to achieve certain effects (i.e. the 1/r^2 classical dependence of Newtonian gravity, and allowing the earth to stably orbit the sun). First, though, you'd have to have this new force have no dependence on distance, otherwise you would find a field close to the sun to be repulsive (and the dependance of gravity as a function of distance would vary as something slightly different than 1/r^2, depending on the REST OF THE UNIVERSE.)

However, it seems like it would fail in the test of General Relativity, which is, well, more true than Newtonian Gravity. If you are close to the sun - close to a massive object - time slows. Space curves around large objects such that other objects fall in, not out - as you approach the center of something, the inverse-square dependence increases without bound. Why would light bend around a massive object - specifically, why would

Anyways, it also comes down to this ever-so-simple point: even if you create a careful proportional displacement model that completely mimics the current gravitational theory, so what? If it doesn't predict anything new, it seems massively more complicated. Gravity as it is, excepting the quantum regime (which your theory does nothing to deal with, it seems), just fine. (Also, there's the problem of self-attraction and collapsing stars ... if the rest of the universe is pushing on a star sufficiently to make it collapse, why the hell am I not crushed?)

Re: encyclopaediae

[Sivaram_Velauthapill]

You raise a good point: can a community created system ever be more accurate than a professionaly created one? It's almost like open-source with respect to knowledge. Another similar example is independent, non-profit, media vs established professional media.

I don't what the right answer is... it remains to be seen. All I can say is... open-source software (which is largely created by hobbyists and for non-profit reasons) seems to match professional software... non-profit, community-based, media is NOt as good as professional media right now... wikipedia is also not as good as professional encyclopedias (like Encarta for instance)...

Sivaram Velauthapillai

Re:Not an answerable question

[Sivaram_Velauthapill]

The basic stuructre of the universe may be fairies scrunched up by angels and used to play cosmological billiards with, but don't expect a mathematical theory based on it soon.

I'm sure some theist is working on that theory ;)

Sivaram Velauthapillai

Re:'String theory' is misnamed

[Scott Carnahan]

String theory is misnamed. It is more appropriate to call it the 'string method of calculation'. String 'theory' is simply a mathematical metaphor which allows predictions of the behaviour and interactions of sub-atomic entities.

Do you know any useful physical theories which do not boil down to methods of calculation? Any model of reality which predicts behavior and interactions is called a theory. Your semantic hairsplitting is useless.

For example, if you assume that particles are 1-dimensional lines or loops you avoid many of the problems (specifically, singularities and infinities) you get if you assume particles are infinitesimal points.

This sentence is completely pointless. Do you have any evidence that fundamental particles are modeled better by point objects than strings? You never gave any damning evidence against the string metaphor.

Its nonsense to suggest that particles are really small vibrating 'strings' experiencing an tension force, otherwise you get an infinite regress: To explain the behaviour of everyday things (such as real pieces of string which can vibrate), we would be requiring the existence of incredibly small 'strings' which would 'vibrate', which doesn't really get us anywhere!

Where is the infinite regress? Nobody claims that the fundamental strings are actually made of intertwined plant or polymer fiber. The name "vibrating string" is simply evocative of familiar phenomena to make excitations more amenable to study and discussion.

Simple

[DrMorpheus]

Because free will means that human choice and judgement determines each individual's actions. Randomness means that pure chance determines it. See the difference?

Re:Simple

[Dr.Ruud]

There is no difference necessary. Your consciousness evens out anything, to keep you happy with what you believe. It's a jungle out there, you know!

Re:Simple

[Sivaram_Velauthapill]

I kind of get what you are saying... but still not 100% sure...

What do you think humans are? Do you think animals (other than humans) have free will?

Sivaram Velauthapillai

Re:Some questions from a non-physicist

[Kiryat Malachi]

1. Tunneling - because to escape a black hole requires exceeding the speed of light. The reason Hawking radiation can get away with it is because one particle in the pair is created just outside the event horizon and gets a kick outward from the annihilation of its partner.

2. Gravity. An explosion cannot push matter at or faster than lightspeed. I guess, in theory, the center of a blackhole could explode continuously, but we'd never know because nothing would ever exit the event horizon.

3. I have no idea. Hell of an interesting question, though, and one that I bet there's some debate about amongst physicists - basically, you're asking is it possible to transmit information faster than light (being that FTL is the necessary condition for energy/mass escape of a black hole). This one is way beyond my handwavy quantumness.

Ironic Science

[Ralph Spoilsport]

First: I think String theory is probably correct HOWEVER:
Second: I can't see how you can possibly test any of this.

If you can't test it, then it's just a likely story. It might be a more likely story than saying little green elves did it all, but in essence, it;s not that different.

Tangles of strings - Suuuure.

As I said, it probably is true, and string theory is a lot cleaner, but damn - what are you going to do? Crack open a black hole to find out?

We. don't. think. so.

It strikes me as what Horgan calls "Ironic Science".

RS

Re:Ironic Science

[Adramelech]

Second: I can't see how you can possibly test any of this.

Perhaps because you're not a string theorist? :)

There is some interesting information about what kind of experiements could give us evidence for string theory here.
In fact, some researchers at my school have been involved in tests of the force law of gravity at very small scales in an attempt to find evidence for the extra dimensions that string theory claims exist. Nothing has turned up yet of course, but the likelyhood was fairly small at the scales observed; IIRC, the number of dimensions that gravity propagates through would determine the scale at which changes in the force law would be observed, with higher numbers of dimensions (I think they need to be "compact" dimensions) requiring smaller scales. (Or something like that).

As described in the site linked to above (though I didn't study the material on the site that closely) supersymmetry also offers some good opportunities for gathering evidence for string theory as well using particle accelerators. I'm not sure whether the tests could actually falsify the theory, but then, I'm not a string theorist either, and some more research would no doubt prove enlightening.

Re:Gravity

[DigiShaman]

I'm not a physicist. I am however, a philosopher. But I did watch an interesting program on Nova called The Elegant Universe. In the program, it talked about the problems of getting general relativity to complement quantum mechanics. If this can be done, you would in effect have a "theory of everything".

So, I think proportional displacement might be a worthy fresh view. And if this model is incorrect, then so be it. Regardless if it's right or wrong, the act of investigation is progress in the name of science.

Just something to chew on. Do with it as you will.

If a tree falls in the forrest ...

[Anonymous Coward]

So if a string vibrates in a black hole, and no sympathetic string links to it ...

Re:'String theory' is misnamed

[Decaff]

Shape and tension. Tension is a force. What is it 'between'? What are the force carriers of the 'string tension'? There is a considerable problem with positing a most fundamental entity which is just as complicated as the things you are using the entity to explain.

Science itself does not and cannot say what things "really are"; it merely describes how they behave, by means of theories and mathematics. Although you seem to be agreeing with me here that strings aren't "real", this is defeatist. Take biology for example. After the math of inheritance was discovered, no-one said that the biology could not say what really caused inheritance. There was a real underlying structure - DNA. There is no reason to suppose that there isn't an underlying reality.

Re:'String theory' is misnamed

[Decaff]

Do you know any useful physical theories which do not boil down to methods of calculation? Any model of reality which predicts behavior and interactions is called a theory. Your semantic hairsplitting is useless.
There are plenty of scientific theories that describe real entities. Some theories of cosmology predicted black holes and neutron stars, for example. The trouble with string theory is that there is a philosophical confusion between the mathematical model itself (vibrating strings) and what (if anything) actually exists. For example, someone might come up with an equally effective way of calculating particle behaviour that uses a different representation. Suppose, hypothetically, this involved coloured cubes. This does not mean that particles are in reality coloured cubes - its just a model.

This sentence is completely pointless. Do you have any evidence that fundamental particles are modeled better by point objects than strings? You never gave any damning evidence against the string metaphor. If you read what I wrote I said the exact opposite - particles are modelled better by strings.

Where is the infinite regress? Nobody claims that the fundamental strings are actually made of intertwined plant or polymer fiber. The name "vibrating string" is simply evocative of familiar phenomena to make excitations more amenable to study and discussion.

No - most physicists seem to claim that such strings actually exist, and aren't just evocative.

I think you missed my point...

[DrMorpheus]

But then again, maybe you were just trying to be ironic?

Re:Is it me

[Anonymous Coward]

I know what you mean. From reading most news reports and even popular science magazines, it seems the whole science of cosmology is built on guessing.

ie. the galaxy looks this bright, but it could be far away, but what if its small, lets see. (redshift and standard candles help but i still think its dodgy)

Man.. I must dumb...

[foreverzero]

I feel retared now, I need to be smarter. Man... Black holes are cool and everything.. but that?! Like i said , I could never fathom that, I must be retarded, or not worthy of /.

Re:Have you noticed that the singularity has gone?

[Chris Coles]

They are all wrong. There are several mistakes made and there is no chance that the bet has been won as the structure of a black hole is totally different to that conjectured by present day physics. Why has the singularity disappeared? Why did Stephen Hawking abandon his theory of everything last week, (Sunday Times London Fed 22nd. Hawking's Big Bang). It is because a book has been published that completely destroys the present theory. The primary mistake was to assume that the event horizon would go on expanding as the mass increased. In fact the event horizon is just a simple mathematical point. Imagine a coffee cup half full as a star shining and a full cup has reached the point where the mass is sufficient to prevent the light from escaping from the total mass. OK, now add to the mass in the coffee cup? What happens is that the additional mass MUST now be outside of the cup. The same with the black hole. from that initial point of the creation of the event horizon, all the mass must be outside of the event horizon and thus all the energy must be sucked into the area inside of the event horizon. The mass outside is completely inert. Super compressed inert mass. This was all written up in a book called The Universe is a Cloud. But you have not heard about it because no one would admit to it existing. Yet, the singularity has disappeared, (try and find it in the four latest cosmology articles in Scientific American), and Hawking has abandoned his theory of everything.

Re:stephen lost - on the rampage in Boulder?

[pjt33]

I was wondering what the building was, because I don't recognise it as part of the "Cambridge University campus" (as if there were such a thing).

Musical explanation

[Sapphon]

I keep getting 2 + 2 = 5, I think my value of 2 is too large

You're a Radiohead fan, aren't you?

Mass storage ?

[Thanatiel]

Does this discovery put the "Black Holes" in the "Mass Storage" category ?

How many Libraries of Congress ?

Re:Some questions from a non-physicist

[NonSequor]

One correction. Quantum entanglement can be used to transmit information, but only if you already have a classical (slower-than-light) information channel already running between the two places. Basically, if Alice and Bob each took half of an EPR pair then later if Alice has a qubit she wants to send Bob, there is a method by which she can perform operations and measurements and then send the results of the measurements to Bob who then acts on his half of the EPR pair which becomes the qubit that Alice wanted to send. There is no way to do this without the classical information channel though.

Inverse proportion to their surface area, not mass

[Anonymous Coward]

meh!

Now I know

[Cackmobile]

what its like to be the village idiot. THis is way beyond me. My brain just can not comprehend it.

That is not most interesting string approach to BH

[S3D]

Tere are other, conceptually more interesting. Gary and Juan in black hole final state suggested that blackhole itself have boundary condition in infinty - final state, and carry only limited amount of information. Here is Lubos Motl's explanation of the article in popular terms: "... They propose that the final state that defines the final spacelike singularity (of a Schwarzschild-like black hole) can't carry any information - the evolution approaches a universal state whose identity is determined by the semiclassical data and nothing else. In popular terms, a person who falls into the black hole knows his or her future - he will die. In fact, he can know it even at the microscopic level - the final state is a unique quantum state, they say. Once he or she hits the singularity, one can imagine that he is reflected - by a complicated but concrete unitary transformation - and becomes Hawking radiation that travels backwards in time inside the black hole. (The arrow of time might seem reflected, but Juan and Gary argue that such effects won't be measurable because of the space and information limitations inside the black hole.) Once this Hawking radiation reaches the horizon, it is transformed - via the Unruh state - to the Hawking radiation that escapes to infinity. All steps in this description were unitary, and one can show that the information will be preserved. The possible modifications of causality, locality, information loss, black hole entropy and its microscopic origin, (in)dependence of the degrees of freedom inside and outside the black hole, quantum treatment of singularities, topology change, the arrow of time and similar issues is what I - as well as most "real" quantum gravity practitioners - call "interesting questions about quantum gravity".

Re:'String theory' is misnamed

[Otto]

For example, someone might come up with an equally effective way of calculating particle behaviour that uses a different representation. Suppose, hypothetically, this involved coloured cubes. This does not mean that particles are in reality coloured cubes - its just a model.

Okay, but here's the deal.. We believe the universe to pretty much act in an ordered fashion, and the order is that defined by mathematics. In a sense, mathematics itself comes from the order that we can see.

So if the model says that strings work better than particles, then why not assume it is actually is strings? If a better model that uses cubes comes along, why not assume it is indeed made of cubes? Until we can actually *see* what the hell it really is, what does it matter if one assumes that the low levels are vibrating strings or colored cubes or vaguely unicorn shaped 8 dimensional objects? The truth is that point particles make no more sense than anything else does. We don't know what's really there, but if we find a model that describes the behavior to the limit of our observational ability, and the model says it has to be strings, then hey, strings it is. It makes no difference. The fact that it really might be something else doesn't matter if we cannot observe any differences in the behavior of reality vs. behavior of the mathematical model.

What really exists that far down in scale is so unbelievably out of our reach that it really doesn't much matter if you think it actually exists or think it's a handy metaphor.

Re:Encyclopedia alternative

[A55M0NKEY]

Now that Wikipedia is superior in content and often better in quality to dead tree encyclopedias, Preskell no longer needs a set of them. Wouldn't it be nice if Preskell had Hawking, and Thorne author some physics articles for Wikipedia instead?

2+2 != 5

[Anonymous Coward]

2+2 = 11
At least, in radix-3.

Re:'String theory' is misnamed

[Anonymous Coward]

Tension is a force. What is it 'between'?

There is a uniform tension along the string. There are no "particles of string" that the force is between. This is true even in ordinary classical continuum mechanics: strings don't have to be made up of individual "atoms" or anything in order for them to have tension.

What are the force carriers of the 'string tension'?

There are no force carriers of string tension. You're mixing theories here: interactions are are mediated by force carriers in quantum field theory. In string theory, there are exchanges of strings like there are exchanges of particles in QFT, but "string force" itself isn't exchanged by anything, it's a fundamental property of the thing being exchanged, just like (say) mass is a property of a particle being exchanged.

There is a considerable problem with positing a most fundamental entity which is just as complicated as the things you are using the entity to explain.

Strings as fundamental entities are much simpler than elementary particles (like electrons, quarks, etc.) as fundamental entities. Strings have many fewer fundamental properties, and their interactions are much simpler (free theory, as opposed to interacting QFT).

Although you seem to be agreeing with me here that strings aren't "real", this is defeatist.

No, in string theory, strings are as "real" as anything. The point is science itself does not declare what is real. It describes what happens; there is no distinction between its mathematical models and "what is `really' happening".

And no, it's not defeatist. It's a property of all fundamental theories. It's a property of the existing Standard Model; it's a property of Newton's laws of mechanics, or Einstein's theories, etc. All fundamental theories posit entities that cannot be described in more fundamental terms: that's what makes them fundamental theories. (Biology has never been fundamental in that sense, because it has always rested on chemistry and physics.)

Now, that doesn't mean that a given fundamental theory might not turn out to be fundamental after all, and be replaced by an even more fundamental theory. It just means that there's nothing wrong with postulating fundamental, indivisible objects. Maybe they're not fundamental, but maybe they are: every theory ultimately must rest on concepts that aren't themselves described by anything simpler.

But...

[juhaz]

But then Darl McBride would be preserved for all of eternity!

Can you think any more heinous crimes for undoing of entire universe?

Re:Newton's gravity could cause lensing and redshi

[CheshireCatCO]

Only if you fudge it. Newtonian mechanics figures that since photons have zero rest mass, they aren't affected by gravity at all. (Without SR you don't get the mass-energy equivelence.)

Re:I've often wondered if...

[Anonymous Coward]

In general relativity, there is no generic way of defining "the gravitational acceleration vector at a point", let alone its magnitude. (In a static spacetime, you can define it as the acceleration of a freely falling observer relative to a static observer at infinity, but in the case of two merging black holes, the spacetime is very non-static, although it's close to static far away from the holes.)

A horizon can never shrink past an object within the horizon: if it could, then it wouldn't be a horizon in the first place. An event horizon is, by definition, a surface within which nothing can escape, ever. The presence of the other black hole deforms the event horizon, but the location of the event horizon takes that into account, along with everything that will ever happen to the hole in the future: an event horizon is a globally defined property; you have to know the entire past and future history of the universe to define, once and for all, whether something will ever, someday, be able to escape it. That's why it's so challenging to determine what the merger of two black holes is like. We have crude simulations, which don't simulate the entire history of the universe, but merely "a long time", to get an approximation of where the horizons ought to be.

Re:That is not most interesting string approach to

[Anonymous Coward]

Wow, name-dropping on a first-name basis. What a cool string insider you must be.

First Post

[Anonymous Coward]

Ha ha! I am 733t!

Sincerely,
Steven Hawking, Ph.D.

Re:'String theory' is misnamed

[Decaff]

So if the model says that strings work better than particles, then why not assume it is actually is strings?

Because this restricts our thinking. Misleading ideas become dogma. Think of the confusion that is still caused by terms like 'electron orbits' and 'particle spins'. These are simply metaphors for quantum mechanical properties. We have no idea what these 'orbits' or 'spins' actually mean physically, yet because we use such terms, many physicists (and the general public) assume that we actually know what is going on in atoms. String theory is similarly misleading.

Re:'String theory' is misnamed

[Decaff]

You're missing the point: the strings in string theory aren't made out of any simpler material: they are the simplest form of matter, just like in the Standard Model, electrons, etc. are the simplest form of matter, and aren't made out of anything more fundamental.

I know that is what string theory says. My point is that it is absurd. You can't assign 'vibration' and 'tension' to fundamental objects - its philosophical nonsense. It would be far better to declare honest ignorance about what might really be going on down at the particle level than to add complexity (replacing points with extended entities) simply to help with the math.

Re:'String theory' is misnamed

[Anonymous Coward]

My point is that it is absurd. You can't assign 'vibration' and 'tension' to fundamental objects - its philosophical nonsense.

I note the complete absence of an argument to back up your assertion. Saying it's nonsense doesn't make it nonsense. You can write down physical theories that assign vibration and tension to fundamental objects; why do you reject those theories and not other ones? There are only two reasons why you can reject a theory: experimental falsification, and logical inconsistency. But string theory suffers from neither (yet, at least).

It would be far better to declare honest ignorance about what might really be going on down at the particle level

String theorists know that we're ignorant about what happens down at the particle level. That's why they don't go around claiming that string theory has been proven correct.

than to add complexity (replacing points with extended entities) simply to help with the math.

Extended entities are a lot simpler to describe than point particles. A point particle theory requires an interacting field theory, and there are infinitely many kinds of interactions you can assign to it. There are also infinitely many gauge symmetries it could have, which determine the kinds of "charges" it may possess. String theory is described by free field theory: there is only one possible way in which strings can interact (as opposed to the infinitely many complicated ways that particles can interact). And there are only a small number of kinds of charges a string (or rather, a string's endpoints) can have.

Information survives

[fadethepolice]

So I really can fly through one to another universe!!! woo hoo!!!

microlaughs

[Doc Ruby]

Neither joke is funny in this Slashdot page, not least due to the lack of... timing. The second joke has humor in the play on "coulomb" and "Columbus", as coulombs are rather large compared with human scale experiences with capacitance. Mnemonics are often funny, not least due to starting an English word with "mn".

Of course

[arantius]

42.

Preskill better hurry up...

[Anonymous Coward]

Preskill better hurry up and collect cuz Hawking is about to kick the bucket on this plane of existence. All the gimps die young...

Yes,

[DrMorpheus]

To the degree that they are capable of anticipating the consequences of their actions or inaction. Coupled with their ability to control their impulses and by that I don't mean simply supressing them but also harnessing them. E.g., I know I get a lot of good ideas when I take a shower while thinking about problems. So if I need to boost my creativity I'll take a shower.

Re:Newton's gravity could cause lensing and redshi

[astroboscope]

Newtonian mechanics figures that since photons have zero rest mass

Newtonian physics doesn't talk about rest mass.

(Without SR you don't get the mass-energy equivelence.)

Oh? Let's use my wormhole to tell Newton the value of c, and nothing else:

Hmm, let's see. Light carries energy, and now we've found that it has a finite speed c. That suggests that the corpuscles have mass m = 2E/c^2. I should add a new chapter concerning gravity to my Treatise on Opticks.

Re:Newton's gravity could cause lensing and redshi

[CheshireCatCO]

Um, yes, Newton does talk about rest mass. That's what he MEANS by "mass", period. Newton figured that mass was invariant. Which is why the second half of your post is, I hope, a comedy and not serious. Newton would have no idea what you were talking about, especially since you used the relativistic E=mc^2.

Where you got that 2, by the way, I have no idea. But, then, given how blithely you applied only part of the correct equation (and "proved" that photons have non-zero rest mass, oddly enough), I'm not surprised.

Re:Please mod up parent

[Anonymous Coward]

Oh, and neglect not the pun of 'loose' and 'taut'-ology.

Re:Is it me

[microbox]

I agree with you completely, however, I also subscribe to the idea that we might not be 'smart-enough' to work it all out. Maybe we are, but it seems unnatural to us to admit the possibility that our intellect is too limited - a kindof species wide know-it-all syndrome.

For example, you can't teach algebra to zebra, and the reason seems obvious... they eat grass and run around in herds! Okay, a zebra is a complex creature with complex social systems, but you know what I mean

Consider the existence of our attention spans. Now most humans have an attention span that lasts a good long time, but we can't solve a problem that exceeds our natural limits in this regard without stopping, resting and starting again.

Many creature don't have much of an attention span, and I think that's really interesting.

Why do we have attention spans? What evolutionary pressure caused this? The answer to that question will give you what the (original) primary purpose for our attention span... and indicate it's threshold for usefulness.

Most all hunters have exceptionally good attention spans when compared to herbivores. Not having been any creature other than a human, I can only suggest that the act of stalking a prey requires it!

So lets take this further. My attention span is long enough to stalk an animal and hopefully kill it. If there's a gram of truth in that, you might agree that that same attention span is not sufficient to understand _all_ the workings of the universe! Oh the arrogance of mankind! Well, there's most likely an evolutionary reason for arrogance as well, and it's helped us understand a lot about the world =)

Please don't assume that I think this is gospel. I only want to draw your attention to what we are - you and me.

maybe nothing actually goes in?

[Anonymous Coward]

I saw a theory (speculation really) that there is nothin at all inside a black hole. Everything is crushed against the event horizon which becomes an impenetrable wall. On the inside, all the gravitational forces are toward the outside, again crushing all the contents against that inpenetrable wall.

Now if there is a lot more space inside than outside, and the inside has its own time, disconnected to the outside, there could be a universe inside that is forced to expand by the irresistable gravitational force of the outer wall. Maybe that explains dark energy. Maybe the universe creates black holes which spawn more universes inside them, and so on and so on ad infinitum.

Re:Newton's gravity could cause lensing and redshi

[astroboscope]

second half of your post is, I hope, a comedy and not serious.

Sheesh...

especially since you used the relativistic E=mc^2.

No. Ever heard of E = 1/2 m v^2? E = mc^2 wasn't published until Einstein came along, much LATER than Newton. Admittedly applying E = 1/2 m v^2 recklessly assumes that the energy of a photon is completely kinetic, but that's not the point. The point is that the possibility of gravity affecting light was not, as you claimed, inconceivable before Einstein, or even Michaelson and Morley. The proof of that point is that gravitational lensing was predicted using Newtonian mechanics. Look it up.

is it an encyclopaedia?

[MozillaFireBird]

In 'Brief History of Time', Hawking talks about a bet for one year subscription to 'Penthouse'. Any idea about that bet?

info, theories.

[Anonymous Coward]

Your readership responding to this post does not understand Hawking Radiation. A black hole will clearly never become a singularity. It "gets smaller" while its radiation spectrum increases because it decreases in size as mass is added, while simultenously attracting mass faster as mass is added. "hawking radiation" refers to a slowing of the black holes spin due to absorbing something while accelerating an unabsorbed portion of the object as a result. The more mass a black hole "eats" the faster it will spit off this radiation. Holes are in the process of absorbing stars and other objects constantly! Therfore they will emit this radiation faster over time and always grow smaller over time. The situation in which a hole could theoretically ( in my opinion) cease to be a critical mass density to sustain gravitational collapse would be where two different black holes are interacting. If they "collide" or pass near enough to each other to be streached appart by gravitational force. If the mass became "thin" enough the hole might no longer have enough gravity/area to be a black hole and then all that mass could be "deposited" in an event which would look A LOT like "the big bang" for that region of space in the aftermath.

Thanks for reading all that, Hope to hear from you.
Eric Arezzo