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First "Observation" of Hawking Radiation

kdawson posted more than 6 years ago | from the simulation-or-experiment dept.

Math 86

KentuckyFC writes "Italian physicists are claiming the first observation of Hawking radiation, but not from a black hole. Instead they've spotted it streaming from a sonic horizon in a Bose Einstein Condensate (abstract on the arXiv). That's consistent with previous predictions but they're claiming the 'first' even though the experiment was only a numerical simulation. Does that really count?"

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Maybe they read /. (5, Funny)

JeepFanatic (993244) | more than 6 years ago | (#22662810)

... and they wanted to get First Post?

Re:Maybe they read /. (1)

Digitus1337 (671442) | more than 6 years ago | (#22662912)

Look who is talking!

Story is distorted (what a surprise) (2, Informative)

Doug Merritt (3550) | more than 6 years ago | (#22665362)

The story is grossly distorted -- what a surprise. I was going to say that at least it was distorted by author of the linked-to news item, rather than by the /. submitter, but now I see they seem to be the same person ("KFC" and "KentuckyFC").

The abstract that is linked to merely claims "numerical evidence", not "first observation", and to get from that unobjectionable claim to the more sensational false accusation, one must distort the paper itself ( http://arxiv.org/pdf/0803.0507v1 [arxiv.org] ), which says:

...a recent work [11] has anticipated that the presence of Hawking radiation in this setting can be unambiguosly revealed from a very peculiar feature of the correlation function of density fluctuations.

Here we report numerical experiments that nicely confirm this prediction. Differently from most previous works on analog models [6], our calculations are based on the application of microscopic many-body techniques to an experimentally realistic system and never involve concepts of gravitational physics.

In this way, our observations can be considered as a first independent proof of the existence of Hawking radiation and rule out the frequent concerns on the role of short wavelength, "trans-Planckian" physics on the Hawking emission.

So for one thing, they never claimed "first observation", they said "first independent proof", which is sharply different.

For another thing, they softened even that claim; they said "our observations [of the simulation] can be considered" proof, not that it is proof.

At any rate, it's interesting in general; they're talking about predictions that Hawking-Unruh radiation might be found in many settings unrelated to domains involving gravity or acceleration, and that their simulation might be an independent confirmation of those predictions.

Re:Maybe they read /. (0)

Anonymous Coward | more than 6 years ago | (#22675606)

In Soviet Russia, Hawking Radiation observes YOU!

reverse engineer it (2, Funny)

OrochimaruVoldemort (1248060) | more than 6 years ago | (#22662828)

and you get a black hole. but, don't feed it.

Re:reverse engineer it (2, Funny)

TheMadcapZ (868196) | more than 6 years ago | (#22662864)

Especially after midnight. Keep it our of the rain too.

no... (0)

Anonymous Coward | more than 6 years ago | (#22662840)

no...

Doesn't Count (5, Insightful)

ObsessiveMathsFreak (773371) | more than 6 years ago | (#22662852)

Does that really count?
No, no it does not.

A numerical model is little more than a highly specific and round off error prone implementation of existing analytical results. All these guys have done, at most, is shown the correctness of Hawking's analysis. If that.

Re:Doesn't Count (2)

MozeeToby (1163751) | more than 6 years ago | (#22662918)

Well, it does prove that either our models of BEC are very accurate or there has been one hell of a coincidence. I don't think that they can say they were the first to discover this, but you may argue that they have produced evidence that supports the theory.

If they had found no radiation, that would not have been proof of anything since a flawed simulation would produce a flawed result. However, the odds of this particular flawed result (producing hawking radiation under very specific circumstances)must be pretty low, lending support to the theory.

Re:Doesn't Count (0)

Anonymous Coward | more than 6 years ago | (#22663600)

Real data from nature is proof of correctness (or not), not a numerical model. All they've done is analyze a hypothesis.

Re:Doesn't Count (4, Informative)

Beetle B. (516615) | more than 6 years ago | (#22663626)

but you may argue that they have produced evidence that supports the theory.
No, you can't.

Without knowing the details of both theories, it's hard for me to judge. Basically, if their formalism is more or less isomorphic to Hawking's (without their realizing it) - then all they've done is do Hawking's work over again.

If they used independent formalism to get Hawking radiation, then it's a good sign, and shows that their theory is consistent with Hawking's (and perhaps later someone will link the two).

In either case, they did not produce any evidence. At best, they're saying, "If you look at this our way, it is consistent with what Hawking predicted."

Re:Doesn't Count (1)

MozeeToby (1163751) | more than 6 years ago | (#22664078)

I see what you are saying and I think it comes down to this. If the theory that hawking radiation is produced is derived from the same information that the simulation is derived from, very little is shown.

If, however, the simulation is derived from seperate data (experimental, different aspects of BEC theory) then the results could be meaningful as they would show that the two different sets of data are in agreement.

Could count... (1)

Per Abrahamsen (1397) | more than 6 years ago | (#22665050)

If they used independent formalism to get Hawking radiation, then it's a good sign, and shows that their theory is consistent with Hawking's (and perhaps later someone will link the two).

In either case, they did not produce any evidence.
If they have correctly use an independent formalism to verify Hawking radiation, they may not technically have "produced" any new evidence, but it means that all the existing evidence that backs the independent formalism, now also counts as evidence towards Hawking radiation.

[ I haven't read the fine article either. ]

Re:Could count... (1)

Bloater (12932) | more than 6 years ago | (#22667450)

> If they have correctly use an independent formalism to verify Hawking radiation

They have not verified Hawking radiation. They did not observe Hawking Radiation in a Bose-Einstein Condensate. They produced a computer program that draws an animation of what Hawking radiation might look like and then watched it - thus they "observed" the radiation just like you or I might observe the existence of Martians by looking at the right Bugs Bunny cartoon ("Look a Martian! And he's wondering where the ka-boom is!")

Verifications vs validations (1)

Per Abrahamsen (1397) | more than 6 years ago | (#22672826)

They have not verified Hawking radiation.
A verification consist of comparing the predictions made with one formalism with the predictions made with another (presumably more trusted) formalism, and see that they match.

A validation consist of comparing the predictions made with one formalism with actual measurements, and see that they match.

Verifications are not as strong as validations, but none the less quite useful. Typically it works the other way around though, we verify a numerical model against one or more analytical solutions. If they match, we gain trust in that the numerical model also can make correct predictions for the cases where no analytical solution can be found. Of course, we would like to eventually add actual validations. But that might be much more time consuming and/or expensive. I work in agricultural science, an experiment takes a year. We would like to sort out as many bad models as possible before starting that, hence we always use verification as the first step. [I shouldn't complain, the people in forestry are much worse of. ]

like you or I might observe the existence of Martians by looking at the right Bugs Bunny cartoon
Bugs Bunny cartoons are not a very strong formalism. If they predicted Hawking radiation by hawing a Bugs Bunny cartoonist draw what he would think it might look like, that would not lend much credibility to the theory.

It all depends on the formalisms used.

Re:Doesn't Count (2, Insightful)

CrimsonAvenger (580665) | more than 6 years ago | (#22665370)

but you may argue that they have produced evidence that supports the theory.

No, you can't.

I agree. Physics is an attempt to model the universe mathematically. The fact that two models agree says nothing whatsoever about whether either is an accurate map of the universe.

GIGO (1)

Stephen Ma (163056) | more than 6 years ago | (#22674660)

Right, "Garbage in, garbage out".

That's the problem with computer simulations that are unsupported by real observations: you never know if there's a problem with your input data, a bug in your simulation program, or a serious weakness in the theory you are simulating, or some combination of all of these. So it's hard to believe your outputs until you can check them against a real measurement.

Only numerical simulation (4, Funny)

jayhawk88 (160512) | more than 6 years ago | (#22662866)

That accurately describes about 90% of theoretical physics doesn't it?

Re:Only numerical simulation (5, Funny)

Thanshin (1188877) | more than 6 years ago | (#22662998)

That accurately describes about 90% of theoretical physics doesn't it?
Yes, the other 10% actually test empirically all their theories. They just keep the TP name because chicks dig it.

Re:Only numerical simulation (2, Funny)

TeknoHog (164938) | more than 6 years ago | (#22665112)

They just keep the TP name because chicks dig it.

I am Cornhawkio! I need TP for my blackhole!

theoreticaly (0)

Anonymous Coward | more than 6 years ago | (#22663070)

theoreticaly

Re:Only numerical simulation (0)

Anonymous Coward | more than 6 years ago | (#22664570)

So, theoretically, yes; they found it first. Now, since you can make a Bose-Einstein condensate experimentally, can you observe it there? The experiment always wins an argument.

Re:Only numerical simulation (1)

rmerry72 (934528) | more than 6 years ago | (#22672642)

That accurately describes about 90% of theoretical physics doesn't it?

And 100% of String Theory. If you have a theory you can't ever test is it a real theory at all?

First Observation of The Meaning Of Life (2, Funny)

Thanshin (1188877) | more than 6 years ago | (#22662974)

6 * 7

It's just a numerical simulation, but everybody knows it counts anyway.

Re:First Observation of The Meaning Of Life (3, Funny)

Selfbain (624722) | more than 6 years ago | (#22662992)

I think you mean 6 by 9.

Re:First Observation of The Meaning Of Life (1)

Thanshin (1188877) | more than 6 years ago | (#22663064)

I think you mean 6 by 9.
There's nothing fundamentally wrong with my universe, thank you very much.

Re:First Observation of The Meaning Of Life (2, Funny)

bugnuts (94678) | more than 6 years ago | (#22664600)

I think you mean 6 by 9.
There's nothing fundamentally wrong with my universe, thank you very much.
Same thing, it's just base 13.

Re:First Observation of The Meaning Of Life (1)

Thanshin (1188877) | more than 6 years ago | (#22664744)

I think you mean 6 by 9.
There's nothing fundamentally wrong with my universe, thank you very much.
Same thing, it's just base 13.
 
Your universe is base 13?

You must have one extra finger in each hand and... Ok, let's stop right there.

Re:First Observation of The Meaning Of Life (0)

Mr2cents (323101) | more than 6 years ago | (#22664828)

Your universe is base 13?
My universe says "All your base are belong to us!".

Re:First Observation of The Meaning Of Life (1)

An ominous Cow art (320322) | more than 6 years ago | (#22664936)

Same thing, it's just base 13.

 
Your universe is base 13?
It's a very unlucky universe.

Re:First Observation of The Meaning Of Life (1)

Mr. Beatdown (1221940) | more than 6 years ago | (#22664866)

Nobody makes jokes in base 13.

Re:First Observation of The Meaning Of Life (1)

cnettel (836611) | more than 6 years ago | (#22672870)

There's something fundamentally wrong with using a prime base...

Re:First Observation of The Meaning Of Life (1)

ComaVN (325750) | more than 6 years ago | (#22673194)

You mean like 2?

Re:First Observation of The Meaning Of Life (0)

Anonymous Coward | more than 6 years ago | (#22666782)

Perhaps not, but I'd see a doctor about those three extra fingers of yours.

Re:First Observation of The Meaning Of Life (0)

Anonymous Coward | more than 6 years ago | (#22663558)

Don't you mean 7 of 9?

Re:First Observation of The Meaning Of Life (0)

Thanshin (1188877) | more than 6 years ago | (#22664624)

Don't you mean 7 of 9?
Don't you mean Jessica Devlin?

Thinking in circles anyone? (2, Insightful)

bikin (1113139) | more than 6 years ago | (#22662990)

I am sorry, but I don't buy it... You have a theory how the world behaves. You do a numerical simulation based on that theory, and amazingly, it proves true. And you consider that a proof of your theory?
I guess I will make a theory stating that fairies exist... simulate that in a computer, and when fairies appear in my simulation I write an article that I have observed fairies. Mmmmhh, this certainly sounds like proving ID.

Re:Thinking in circles anyone? (1)

gardyloo (512791) | more than 6 years ago | (#22663118)

I guess I will make a theory stating that fairies exist... simulate that in a computer, and when fairies appear in my simulation I write an article that I have observed fairies. Mmmmhh, this certainly sounds like proving ID.
Sssssssshhhh! Do not give the IDers any ammunition with which to bullshit the public.

Re:Thinking in circles anyone? (1)

rucs_hack (784150) | more than 6 years ago | (#22663310)

Sssssssshhhh! Do not give the IDers any ammunition with which to bullshit the public.

Since they live in the information equivilent of a closed and shackled ecosystem, this could hardly do any damage.

Re:Thinking in circles anyone? (0)

Anonymous Coward | more than 6 years ago | (#22663296)

Mmmmhh, this certainly sounds like proving ID.
How would this be better suited for ID yet not equally so of Evolution? There's no proof of either - it's all conjecture, guesses work, theory and faith.

I can't go back in time and prove 'God did it!' and you cant show proof of macro-evolution 'it just happened, stupid!'.

Thus far there is NO definitive proof of either. So how is ID worse off than Evolution? I could plug numbers into my theory machine "proving" either one - That don't make real world examples of either actually exist or prove either exists.

Re:Thinking in circles anyone? (0)

Anonymous Coward | more than 6 years ago | (#22663824)

...and the kooks come out of the woodwork.

Re:Thinking in circles anyone? (0)

Anonymous Coward | more than 6 years ago | (#22663976)

You can only state that there is no proof of evolution if you are willfully ignoring it. Or trolling. So basically you're either malicious or a moron. Or both.

I vote both.

Re:Thinking in circles anyone? (0)

Anonymous Coward | more than 6 years ago | (#22670068)

Hi!

You scored [ucr.edu] 73, mostly due to having a theory with no testable predictions.

Re:Thinking in circles anyone? (4, Funny)

CmdrGravy (645153) | more than 6 years ago | (#22663484)

Not quite, if you imagine the theory as a car then the scientists suspected it might have been a Porsche Cayenne 4x4 and once they had built their simulation ( imagine that as a carwash ) it turned out that it was indeed a Porsche Cayenne 4x4. However the amazing thing was that even though they hadn't considered the driver specifically in their simulation it did indeed turn out the simulated driver was a enormous wanker thus proving beyond doubt the truth of their simulation.

Re:Thinking in circles anyone? (0)

Anonymous Coward | more than 6 years ago | (#22664480)

Yeah, it's boring, but that doesn't mean it useless. Many important things are done in simulation first. Sure it doesn't *prove* anything, but you can't ever *prove* anything in physics.

Re:Thinking in circles anyone? (1)

spongman (182339) | more than 6 years ago | (#22665212)

well, if your theory was consistent with known physical theories (modulo GUT), then couldn't you confidently say that modern physics predicts the existence of fairies.

so, either:
1) fairies exists
2) physics is fundamentally wrong

whichever it is, it's pretty profound.

Re:Thinking in circles anyone? (1)

DougWebb (178910) | more than 6 years ago | (#22666158)

I am sorry, but I don't buy it... You have a theory how the world behaves. You do a numerical simulation based on that theory, and amazingly, it proves true. And you consider that a proof of your theory?

To turn it into a proof, you need to get the UN to claim that "every non-kook scientist in the world agrees that this is true, and every scientist who does not agree is a kook, or is being paid to disagree by a global corporate conspiracy that is trying to suppress this proof". Then you get the Nobel committee to give Al Gore a prize for making a movie about how true your simulation is.

Re:Thinking in circles anyone? (2, Interesting)

Chris Burke (6130) | more than 6 years ago | (#22666464)

You have a theory how the world behaves. You do a numerical simulation based on that theory, and amazingly, it proves true.

Well that's not exactly the case. We have a theory of how the world behaves, and Hawking Radiation is a predicted emergent property of that theory. It's not an axiom, it's a predicted consequence, so it isn't a given based on the theory. Here, we have a detailed simulation that shows that yes, if the underlying theory is correct, then we should expect to see Hawking Radiation.

It is true that this is in no way a real-world observation that shows that the theory accurately models reality. However it does have a non-trivial and non-circular implication for our theory.

What an interesting question (5, Funny)

idontgno (624372) | more than 6 years ago | (#22663078)

...though the experiment was only a numerical simulation. Does that really count?

If so, then many slashdotters are no longer virgins.

Re:What an interesting question (0)

Anonymous Coward | more than 6 years ago | (#22671738)

It's too bad the summary didn't call the experiment a "digital simulation."

Slightly OT: Unruh effect (5, Interesting)

TeknoHog (164938) | more than 6 years ago | (#22663126)

My first thought from the headline was Unruh effect [wikipedia.org] . It's a kind of Hawking radiation you can get in a particle accelerator. It just happens that with black holes, the acceleration is due to gravity, but other sources of acceleration also work. There are huge decelerations from c to nearly 0 at heavy ion collisions, for example.

I first heard of the effect when some fellow physicists were considering the idea of tiny black holes created in particle physics experiments. It turned out that the presence of Hawking-like radiation doesn't necessarily mean a black hole.

Well, it also turns out that this has nothing directly to do with the article, but might be +i, interesting nevertheless.

Re:Slightly OT: Unruh effect (1)

Doug Merritt (3550) | more than 6 years ago | (#22665558)

Well, it also turns out that this has nothing directly to do with the article, but might be +i, interesting nevertheless.

Your comments have everything to do with the paper in question.

How ironic. Usually people don't read the article, then make irrelevant comments that they think are relevant; here you managed to do the exact opposite.

Black holes should radiate anyway (2)

LiquidCoooled (634315) | more than 6 years ago | (#22663132)

If you consider the cusp of the gravity well of the earth to be a simplistic representation of the event horizon then:

an object travelling inside the well is doomed to never escape without additional energy.
it will spiral to its death after some time period.

If two objects at this same point collide and explode, then some of the matter will have gained additional energy and will escape the gravity well, the rest of the body will spiral to its doom.

Re:Black holes should radiate anyway (2)

gardyloo (512791) | more than 6 years ago | (#22663256)

I'm being pedantic here:

      1. Cusp? What cusp? That's not how the term is used, in either popular language, nor in physics.
      2. If I understand "cusp" to mean the location at which an object released from rest will *just* fall to earth, there's no such location. ALL objects will, from any location (given no other mass or energy in the universe, of course).
      3. If one allows an initial momentum to your object, then the "cusp" location can be anywhere.

Re:Black holes should radiate anyway (0)

Anonymous Coward | more than 6 years ago | (#22663480)

I would assume he means the boundary of the volume inside of which an object at rest being released falls to the Earth.

Re:Black holes should radiate anyway (1)

Phanatic1a (413374) | more than 6 years ago | (#22666370)

There's no "outside" the Earth's gravity field; the entire universe lies within it. So that volume's pretty damned large.

Re:Black holes should radiate anyway (1)

TheCrackRat (589015) | more than 6 years ago | (#22756278)

But a ball 10 miles above the sun won't fall to the Earth.

Re:Black holes should radiate anyway (4, Informative)

ExecutorElassus (1202245) | more than 6 years ago | (#22663378)

yes, but Hawking radiation is somewhat different, and requires no material in the vicinity. It works like this: there are always opposite particles (say, positron-electron pairs) that spontaneously appear at the subatomic level. But in the normal universe, they immediately re-collide, giving back to the local space whatever energy was used to create them. That's a bad explanation (because I'm not a physicist), but it gives a rough picture. At the edge of an event horizon, however, there is a small - though nonzero - chance that one or the other particle will get sucked down the gravity well before it can remerge with its opposite. Thus the one that survived ambles off into space, no doubt pondering its cosmic parthenogenesis. The energy of the particle is - for reasons unknown to me - taken from the black hole. Also, this process steadily accelerates as the black hole continues to lose mass through the process: it eventually pops out of existence in a burst of gamma radiation.

So, it's a little more complicated/interesting than you described; I'm sure it would be even better if someone here could describe it from an actual background in physics, instead of the armchair variety I can muster.

Re:Black holes should radiate anyway (2, Insightful)

UncleTogie (1004853) | more than 6 years ago | (#22664796)

It works like this: there are always opposite particles (say, positron-electron pairs) that spontaneously appear at the subatomic level.

...and you wonder why the ID crowd looks annoyed when they're not allowed to use the same "well, it just appeared!" argument...

Re:Black holes should radiate anyway (1)

HappyEngineer (888000) | more than 6 years ago | (#22667416)

You're probably just being funny, but just in case you're serious: Saying that a particle just appears is not the same as saying that a more complex entity just appears. These particles are just static (white noise) in the fabric of the universe.

Re:Black holes should radiate anyway (1, Insightful)

Anonymous Coward | more than 6 years ago | (#22670928)

Wait a second, I thought we came from "static".

Re:Black holes should radiate anyway (1)

HappyEngineer (888000) | more than 6 years ago | (#22721382)

The processes aren't at all related. The surface of the oceans has waves constantly created and destroyed. There's nothing surprising that a bunch of water has waves appearing and disappearing constantly. The fabric of the universe has a similar sort of thing going on.

Re:Black holes should radiate anyway (1)

ChronosWS (706209) | more than 6 years ago | (#22665090)

I may be off the mark here, but I believe the energy comes from the black hole because the virtual particles are derived from the energy locked up in the space-time substrate itself - they don't just come from "nowhere", and their existence is not free in the entropic sense. The black hole is just a manifestation of this substrate, so any particles which temporarily appear must take their energy from it.

Re:Black holes should radiate anyway (2, Informative)

Anguirel (58085) | more than 6 years ago | (#22665700)

The energy comes from the black hole because the mass comes from the black hole.

The easiest way to conceive of it, in very basic terms, is that the Electron/Positron pair spontaneously converts to mass from the energy surrounding the black hole. The positron falls into the hole, and annihilates with an electron's worth of mass already in the singularity. The electron from the initial pair escapes. The black hole has been reduced in mass/energy by the amount of one electron.

If the electron, instead, falls into the hole, the positron escaping will annihilate with an electron being pulled toward the hole (probably) and release a burst of energy, leaving a net gain of no mass for the black hole as a particle that would have added to it no longer reaches that point.

Re:Black holes should radiate anyway (2, Interesting)

harryjohnston (1118069) | more than 6 years ago | (#22668808)

Not quite my understanding. Positron-electron pairs don't get created spontaneously as this would violate the conservation of energy. However, a pair of what are called "virtual" particles can appear spontaneously if one of them has a negative mass.

Now, a negative mass particle can't normally exist for very long, so it has to recombine in short order with the original particle and they cancel each other out.

However if the negative mass particle is trapped by the event horizon, "not very long" gets stretched out indefinitely by the time dilation, and the positive mass particle can escape. The total mass of the black hole goes down because the particle entering it has a negative mass.

Of course, this is all just a way of visualizing what goes on so that it seems to make sense. It doesn't necessarily correspond in any meaningful way to reality.

Re:Black holes should radiate anyway (1)

Cecil (37810) | more than 6 years ago | (#22663874)

If two objects at this same point collide and explode, then some of the matter will have gained additional energy and will escape the gravity well, the rest of the body will spiral to its doom.

Yeah, you'd think that, wouldn't you? Unfortunately, relativistic physics do not follow the same rules as newtonian physics, and the former are the rules you need to use for anything that may potentially have enough energy to escape a black hole.

Re:Black holes should radiate anyway (1)

maxume (22995) | more than 6 years ago | (#22665762)

That's not what the event horizon is. The event horizon is the point at which collisions will no longer matter and is derived from the black hole, not the momentum of a particle approaching it.

Just a simulation (2)

wolverine1999 (126497) | more than 6 years ago | (#22663152)

It's just a simulation... hawking radiation hasn't been observed in real life yet.

Streaming from a what!? (1, Funny)

Anonymous Coward | more than 6 years ago | (#22663194)

Instead they've spotted it streaming from a sonic horizon in a Bose Einstein Condensate
Eh? Is that some kind of new MP3 player?

What's next? (2, Funny)

AbsoluteXyro (1048620) | more than 6 years ago | (#22663214)

How long until they "observe" a Fry, er, Hawking Hole? I could have swore I "observed" one on TV.

Shenanigans! (5, Insightful)

multimediavt (965608) | more than 6 years ago | (#22663266)

I'm sorry, but I'm with the "no way this counts" camp. Theories have to be tested in the physical world to be proved. Theoretical physics included folks. That's why we have supercolliders and Z-machines, duh! Numerical analysis can help predict physical behavior but it is not law until it is proved in the real world. Sorry guys.

Re:Shenanigans! (1, Insightful)

Anonymous Coward | more than 6 years ago | (#22663576)

I agree. Being a chemist, I can draw up any number of organic chemical reactions that theoretically will work on paper...Hell! Everything works on paper! But when I try them in the lab, and every conceivable reaction fails in real life; that is the reality I'm stuck with!

Theoretically, almost anything thought up is possible.

In the real world however, this is not the case until proven by a physical experiment...

Re:Shenanigans! (1)

Anguirel (58085) | more than 6 years ago | (#22665736)

In theory, there's no difference between theory and reality.

Re:Shenanigans! (3, Insightful)

huckamania (533052) | more than 6 years ago | (#22664088)

This is the 'new' science. First you have a theory, then you promote your theory, then someone takes a poll and then it becomes fact.

Computer simulations are acceptable proof in the 'new' science. Even flawed computer simulations are acceptable proof as they prove that the simulations are getting better.

Re:Shenanigans! (1)

Fujisawa Sensei (207127) | more than 6 years ago | (#22666590)

I'm sorry, but I'm with the "no way this counts" camp. Theories have to be tested in the physical world to be proved. Theoretical physics included folks. That's why we have supercolliders and Z-machines, duh! Numerical analysis can help predict physical behavior but it is not law until it is proved in the real world. Sorry guys.

Sorry dude, experimental evidence doesn't prove squat either.

Newton's experimental evidence for adding of velocities was correct until Einstein. And is corpuscular theory of light was correct until Young's "double slit" experiment. So even when an experiment demonstrates a theory, it doesn't prove it, is only shows that its not incorrect.

Ugh. (2, Insightful)

stonecypher (118140) | more than 6 years ago | (#22663456)

but they're claiming the 'first' even though the experiment was only a numerical simulation. Does that really count?
No. Observed means "in the real world." These people should be ashamed of themselves. Physicists are supposed to have standards.

Re:Ugh. (1)

Brannoncyll (894648) | more than 6 years ago | (#22667676)

I think you're being a bit unjust to the physics community. I agree that the observation of Hawking radiation from a simulated BEC is not an `observation' as such, but the model, which the paper states involves no gravitational physics concepts and has shown to be a valid model based on current data, shows the presence of Hawking radiation. The fact that it is demonstrated in a system that is considerably better understood than quantum gravity is important for the following reason: Although i am not a cosmologist, i believe that the event horizon is a prediction of general relativity (not quantum gravity) which, as a model, has very strong experimental support. Therefore showing that a BEC event horizon (which has the same properties) shows Hawking radiation is sound evidence that a black hole should also produce Hawking radiation.

Re:Ugh. (1)

stonecypher (118140) | more than 6 years ago | (#22671298)

I think you're being a bit unjust to the physics community.
By suggesting they have standards, and that as such, this small group of Italians is disgusting by contrast?

but the model, which the paper states involves no gravitational physics concepts and has shown to be a valid model based on current data, shows the presence of Hawking radiation.
Yes, and the Vatican's model showed crystal spheres. Models can show wrong things. That's what makes it disgusting that these people are claiming to have observed something which is in fact only the result of a hypothetical.

That you built an argument for "sound evidence" on a sentence beginning "I believe" pretty much seals any chance I'll take you seriously. Let it go.

oops (1)

Trikenstein (571493) | more than 6 years ago | (#22663488)

and they altered the phenomena by observing it.

God Exists! (4, Funny)

serutan (259622) | more than 6 years ago | (#22663718)

We've got millions of highly vivid simulations!

If true, I'm not surprised (1)

pclminion (145572) | more than 6 years ago | (#22669002)

This is far from proof. But I would not really be surprised, just at an intuitive level, if Hawking radiation can be found at ANY type of horizon. Hawking radiation itself was predicted by a post-doc whose name I forget, promptly forgotten for several years, then it was picked up and championed by Hawking. Hawking himself wasn't the one who made the original connection between entropy and certain horizon equations, although he did start the process in motion with a proof that the area of the event horizon cannot decrease.

It sounded incredibly far-fetched at the time -- just because the equations look similar can't possibly mean there is radiation, can it? And yet it was true. I'm not surprised at all. Anywhere you have a horizon and also a law which prevents that horizon's area from decreasing with time, you are probably going to see black body radiation.

Simulation (1)

jgoemat (565882) | more than 6 years ago | (#22669730)

So they have 'observations' of a 'simulation' of a Bose-Einstein Condensate which 'theoretically' would behave with sound waves similarly to the way a black hole is 'theorized' to behave with regard to particles that pop into existence all the time and it's proof of Hawking radiation? There are just too many theoretical leaps here to give it any weight. If these sound waves were ACTUALLY observed in a real-world experiment and not a simulation then that would be a step closer. Can't they just make a simulation of the event horizon of a black hole?

Observation vs Prediction? (1)

Dracophile (140936) | more than 6 years ago | (#22670314)

That's consistent with previous predictions but they're claiming the 'first' even though the experiment was only a numerical simulation. Does that really count?

I'm prepared to be corrected, but doesn't that count as a prediction rather than an observation?

A BEC machine that could do this for real? (0)

Anonymous Coward | more than 6 years ago | (#22672654)

It is called the RHIC (Relativtics Heavy Ion Collider) and it is on Long Island, NY at the Brookhaven facility.

They made have all ready made sub-femtosecond black holes, they are either still investigating or have classified this.

Does that really count? (1)

syousef (465911) | more than 6 years ago | (#22672838)

I hope so, because that would make me a fighter pilot, a train driver, and a theme park owner this week alone. I have after all used MS flight sim, MS Train sim and Trains, and Rollercoaster Tycooon. Oh I almost forgot I own a motorboat and a jet ski (Ship Sim 2008. We didn't say it had to be a GOOD simulation did we?). I'm so good I can ram a boat at high speed in a jet ski, duck under it instead of dying, and come out the other side!!! Come to think of it I rock, but only if simulations count!

MC Hawking (1)

StikyPad (445176) | more than 6 years ago | (#22683760)

Pfft.. I've detected Hawking Radiation spewing from the sonic horizon of my Bose Wave Radio for years!
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