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String Theory Tested, Fails Black Hole Predictions
eldavojohn writes "Back in 2006 there was a lot of talk of testing String Theory. Well, today CERN has released a statement for the Compact Muon Solenoid Experiment. The short of it is simply that as far as they could tell, 'No experimental evidence for microscopic black holes has been found.' The long statement indicates that since the highly precise CMS detector found no spray of sub-atomic particles of normal matter while LHC smashed particles together, the hypothesis by String Theory that micro black holes would be formed and quickly evaporated in this experiment was incorrect. These tests have given the team confidence to say that they can exclude a 'variety of theoretical models' for the cases of black holes with a mass of 3.5-4.5 TeV (1012 electron volts). Not Even Wrong points us to the arxiv prepublication for those of you well versed in Greek. While you may not be able to run around claiming that String Theory is dead and disproved, evidently there are some adjustments that need to be made."
Simple. The Creator obviously didn't NULL-terminate. Hence his strings have no black hole at the end.
One day, Bob the Scientist was puffing on some buddha. He smoked and smoked, and smoked some more. Suddenly, Bob the scientist looked down: the lines between the tiles on the floor started to wiggle this way and that, giving the tiles the impression that they were vibrating. Bob the Scientist blinked his eyes twice, only to see the lines still wiggling, enticing them with their random, chaotic dance.
"That's it!" Bob shouted. "That's the answer, man!"
Bob the Scientist went and grabbed Bill the Scientist. He pointed at the floor, saying over and over again "The lines, man! Look at the lines! Wooooooaaaaaahhhhh."
Bill the Scientist sniffed, and said to Bob "Bob...have you been smoking that crazy ganja again?"
"Yes, but so what? Duuuuude...the liinnnes...their taaaalking to meeeee..."
"Give me some of that shit." Bill the Scientist took a big drag, looked down at the floor, and they both stared. "Woooooaaaaaaah...we better write this down, so we don't forget!"
And thus, string theory was born.
Living With a Nerd
Does it matter if something inobservable exists? If you posit the existence of something that can't be observed, how do you verify that hypothesis? What are the applications for a theory that doesn't suggest effects we can detect and verify?
While you may not be able to run around claiming that String Theory is dead and disproved, evidently there are some adjustments that need to be made."
...again
String theory is one of those theories that get changed around every time they run into trouble. I can't imagine what it would take to have it go away, aside from a paradigm change.
Assorted stuff I do sometimes: Lemuria.org
It shows string theory is testable after all.
Even failing still sheds light on what is wrong with our theory (or reality if you're an economist :-).
How can we be sure that the black holes were not created? String theory posits that there exist physical dimensions outside of our 4 dimensional universe
But the theory is that they are so small that "moving through them" is not something that would cause things to "disappear" into them, but rather, that the position and momentum within them merely manifests itself as physical properties (charge, mass, spin, ...)
"His name was James Damore."
Then how DO you explain these infinite number of parallel universes? There must be some experimental rationale for the overwhelming evidence of these!
Signed, Arthur XXII, King of Britain and Jupiter.
"Flyin' in just a sweet place,
Never been known to fail..."
How can we be sure that the black holes were not created?
As one might suspect, the very opening to the paper in the arxiv explains this. After lengthy explanation of several peer reviewed papers that have been widely accepted on detection of black holes, they state:
The microscopic black holes produced at the LHC would be distinguished by high multiplicity, democratic, and highly isotropic decays with the final-state particles carrying hundreds of GeV of energy. Most of these particles would be reconstructed as jets of hadrons. Observation of such spectacular signatures would provide direct information on the nature of black holes as well as the structure and dimensionality of space-time [1]. Microscopic black hole properties are reviewed in more detail in [15, 16].
Now, as you can see by the [1], [15] and [16] references, each of these claims will lead you to a further longer paper on the concept of black holes themselves. Is it possible this method is flawed? I'm not a particle physicist so I'm not authorized to answer that. But I will say that this experiment has been a long time coming and I'm certain the authors of this paper were very careful in all their statements about String Theory.
String theory posits that there exist physical dimensions outside of our 4 dimensional universe, in fact that these are part and parcel of our universe. However, given our tools are all limited to 4 dimensions, it makes sense that there could be phenomena that is unobservable in our universe yet occurring in those other unexperienceable dimensions.
I know what you're saying but String Theory turns a lot of people off when its nature seems to be "unobservable" as you so put it. You'd have just as easy a time proving God exists as you would proving String Theory. The joke about String Theory is that it is conceived to make it untestable so it can never be wrong. This is dangerous ground and whenever a prediction is made by the theory that can be tested, it must be taken seriously. "Unexperienceable dimension?" Ahhh, I wouldn't go around talking to scientists about 'unexperienceable' things. I do not believe the scientific process looks kindly on such things.
I agree with the summary, this isn't the defeat of String Theory. It is a chance to refine and improve it.
I am the submitter, I don't think I said anything too far one way or the other. Usually Not Even Wrong points me in the correct direction but they gave this paper an unusually short nod with little correspondence or refutation. I think this is a good indication that everyone is waiting for the real scientists (not my lame armchair ass) to look this over and weigh in. You know, if you make predictions and they're wrong and you stretch your model to always avoid any sort of direct contradiction but you never get anything correct, then you look more like a fortune teller than a theoretical physicist. They should have the option to revise but my prediction is that this result will lose them a large amount of support in the community. It doesn't outright disqualify them but it sure is a vote of no confidence in a lot of the popular String Theory models.
My work here is dung.
I agree with the summary, this isn't the defeat of String Theory. It is a chance to refine and improve it.
Why would you? This was the only ever testable prediction from String Theory, and it failed. Finally String Theory has its coveted falsifiability, and now you want to take it away again? People have been refining and improving string theory for decades, so far with nothing to show for it. Maybe we need to look elsewhere. (Loop Quantum Mechanics looks promising, if I understand The Big Bang Theory correctly.)
I think String Theory is vital! You take the early works of Chuck Berry, Carl Perkins and move through Hendrix, Trower and later Stevie Ray and without people furthering string theory then American Idol becomes the end-all! Granted we're in a glut of String Theory progress right now but these things are cyclical. I'm confident there's another genius out there that will take strings to the next level of understanding and I for one can't wait. And as for "tiny black holes," frankly the big one behind the strumming point on the strings has always worked just fine.
God, for example?
I agree with the summary, this isn't the defeat of String Theory. It is a chance to refine and improve it.
Am I the only one who sees 'string theory' as the modern equivalent of the geocentric model of the universe? When it makes a prediction that doesn't match reality, we 'refine and improve' it by adding more spheres within spheres (or presumably strings within strings in this case).
Wrong. A layman would tell you that 1 + 1 = 2. Layman means someone who understands a subject and can even work with it to some extent, but is NOT an expert. Most if not all of us are medical laymen for example. We can apply a band aid, apply CPR, know how to take a pulse and if one is not evident that a person is dead. But we wouldn't be the one to go to, to perform a complex diagnosis or prescribe medicine or perform an operation... because we are laymen. Laymen can know enough on a subject to sound like they know what they are talking about, and drive experts crazy. Now I am waiting for real language experts to go ballistic on me. [grin]
-- I ignore anonymous replies to my comments and postings.
I happen to be an actual theoretical particle physicist. The headline and summary are completely misleading/sensationalist and this has essentially nothing to do with string theory. If I hadn't seen the string-theory connection here on slashdot, "string theory" would not even have crossed my mind reading this. If you happen to actual read the so-called "long statement" (which is only half a page really) you would have noticed that it doesn't say anything about string theory. What this measurement has ruled out are certain theories that have some small extra dimensions that would predict these tiny black holes. Those theories don't really have anything to do with string theory per se. The only conceived connection is that string theory also has more than 4 spacetime dimensions.
Calling this "string theory tested, fails prediction" is close to the following analogy: Someone comes up with a crazy theory according to which once a while (say 1 in 100) an apple that gets detached from a tree should rise into the sky (say by using complex numbers to cleverly generate a minus sign in Newton's laws). After having observed sufficiently many apples all fall down, we can now say with confidence that apples don't rise but in fact always fall. The slashdot headline would be: "Complex numbers tested, fail apple prediction."
So rest assured, no string theorist will have a sleepless night and none of them will make any adjustments whatsoever. The main reaction in the particle physics world to this will be a lunch conversation along the lines of: "Told you so, this whole idea about mini-blackholes was ridiculous in the first place, in any case, glad they rule it out, so hopefully this will quiet down this whole black-hole circus now."
"Fuck."
I suspect a carat or other symbol was dropped by the slashcode, and it used to read "TeV (10 *to the* 12 electron volts)".
No kidding!!! What do you say at this point?
This one is evil only because we are taught that it is a sphere when it is really a 4 sided cube. At least that's what I learned at timecube.com.
No, "layman" doesn't mean "someone who understands a subject and can even work with it to some extent but is NOT an expert." It means simply "someone who is not a member of a particular profession", full stop. (That's actually the second, but relevant, definition, which evolved from the earlier and still primary definition, which is specifically someone who is not a member of the clergy.)
"Layman" is sometimes prefixed with an adjective like "experienced", and so modified may mean something like what you suggest, but that isn't what it means on its own.
The summary is completely incorrect. Whoever wrote the summary simply didn't understand the paper. String theory does not predict the production of microscopic black holes at LHC eneries. The paper's abstract says, "Limits on the minimum black hole mass are set, in the range 3.5 -- 4.5 TeV, for a variety of parameters in a model with large extra dimensions, along with model-independent limits on new physics in these final states." Note that phrase "large extra dimensions." Here is the WP article on large extra dimensions. String theory has *small* extra dimensions: extra dimensions that wrap around on themselves at the Planck scale. The LHC doesn't probe the Planck scale. Theories with large extra dimensions have, er, *large* extra dimensions. This experiment falsifies those theories, not string theory.
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This isn't really a disproof, as I read it. All I see in the scientific summary (with the caveat that I have not read the arxiv paper) is a lower bound on the mass of black holes created in proton collisions. This would tune the parameters of string theory, not disprove it. And in principle, more bounds on parameters in the theory should allow for more predictions to be made.
Probably, but the number of tests that string theory failed is by now quite a few. Lots of incidents. But every time they "made adjustments" to the hypothesis. One might think this is all very well but there's a bit of a problem :
theorists : string theory "predicts" A ... no A ... no B ... we modified it again to predict C ... no C
-> experimenters : we searched
theorists: string theory's still valid because we modified it to predict B
-> experimenters : we searched
theorists: string theory's still valid because
-> experimenters : we searched
The problem is what the modifications prove : that string theory can predict all kinds of stuff. String theory is a model that is "too general". It's like answering the question of "what are the laws of physics" by saying "math", or "english".
The issue is also not that the laws of physics can't be expressed as mathematical equations, or can't be explained in english. But it is not an answer to the question at all. It's a bit like a customer came to the university for a voip installation and they give him a C compiler. Sure it's a tool that can be used to build what he needs, but it's a bit of a stretch to say it answers any question for real.
In reality we're barely a step further than when the standard model was finalized. Sure lots of mathematics were researched to get to "string theory", but none of it proved valuable in analyzing the real world (like climate theory, we're certainly not lacking in theories, or even proof that theories hold perfectly for some small subset of the problem, but when a prediction is made, they just don't match up to reality).
We're back in 1910. Quantum theory is very wrong. Relativity theory is very wrong (we've found experiments that violate both theories, and in any case, there are many real-world things they don't touch (quantum theory can't explain anything "big" and relativity can't explain anything "small"). The only attempts at finding alternatives have ... well ... they've basically failed. That also means that many "accepted" facts, like the many-worlds hypothesis are ... well there just isn't any proof for them, so actually they should be treated like the average star trek episode, a firm "FICTION" label applied to them.
Like in 1910, the conclusion should simply be : we need some new ridiculously simple idea, because we're stuck in a dead end with the theories we have.
The problem is string theory is firmly entrenched in universities, produces papers like Obama produces debt, and ... well ... even without those arguments there's the saying "paradigms change one funeral at a time". Lots of funerals need to happen before an alternative to string theory can be given real academic resources.
What are the applications for a theory that doesn't suggest effects we can detect and verify?
Accumulation of wealth?
BM3
It's not a bad analogy. But it's also important to realize that the geocentric model is a GOOD model. Navigators used it long after Copernicus and Galileo, and if it's going by the wayside there, it's only because GPS really is geocentric.
The key to heliocentrism isn't changing the center, but changing the shape of the orbit. If you think of the sun as the center of the universe but are still trying to force things into circular motion, you end up with as many correction factors as geocentrism does. Galileo and Copernicus were well aware of the mathematical difficulties. It wasn't until Kepler that they finally had a solution.
The problem with the analogy is that it's not string theory that's equivalent to geocentrism, it's quantum mechanics, quantum field theory, and general relativity. These are excellent theories that still have problems in that they disagree with each other. String theory is the epicycle tacked on to try to account for the differences.
That's still not quite apt, since the failure modes are different. Geocentric theory failed because data contradicted it without awkward modifications. Quantum and relativistic theories agree with the data, but disagree with each other under circumstances that are difficult to produce experimentally. So string theory is useful theory with no data, and epicycles were a good way to deal with the data but with poor theoretical support.
Some scientists are aggrieved that a theory with no data, and none forthcoming, should receive so much attention. Disproving it would actually be a great advance, and would actually reflect well on the people studying it. Unfortunately, the import of the experiment in this article is exaggerated.
Science gets results. Prayer gets... whatever it is that god happens to desire at any given time, which looks suspiciously like what science predicts would happen if no one did anything.