If you believe the headline of a press release issued today by Northeastern University, its researchers have found evidence of extra dimensions. The actual text of the press release tells a different story, that they haven’t found evidence of extra dimensions. One can’t blame the headline writer too much though, because the text itself is full of enough hype and nonsense about string theory and extra dimensions to confuse most people.
According to the press release text:
Researchers at Northeastern University and the University of California, Irvine say that scientists might soon have evidence for extra dimensions and other exotic predictions of string theory.
… IceCube, now under construction, could provide the first evidence for string theory and other theories that attempt to build upon our current understanding of the universe…
“To find clues to support string theory and other bold, new theories, we need to study how matter interacts at extreme energies,” said Anchordoqui…
In recent decades, new theories have developed – such as string theory, extra dimensions and supersymmetry – to bridge the gap between the two most successful theories of the 20th century, general relativity and quantum mechanics…
Anchordoqui and his colleagues say that extragalactic sources can serve as the ultimate cosmic accelerator, and that neutrinos from these sources smacking into protons can release energies in the realm where the first clues to string theory could be revealed….
“String theory and other possibilities can distort the relative numbers of ‘down’ and ‘up’ neutrinos,” said Jonathan Feng.
The half a dozen references to string theory in the short press release might lead the gullible to think that we’re about to be provided with evidence for the “exotic predictions of string theory”, but that has little relationship to the reality here, one aspect of which of course is that there are no “predictions of string theory” about any of this.
The occasion of the press release is the appearance in Physical Review Letters of a paper by Anchordoqui, Feng and Goldberg entitled Particle Physics on Ice: Constraints on Neutrino Interactions Far Above the Weak Scale. The authors discuss the possibility of using the difference between up and down observed rates for collisions of ultra-high energy cosmic ray neutrinos to get information about neutrino cross-sections at around 6 Tev center of mass energy, far above the energy scale for which we now have data about these cross-sections. They conclude that the data from the AMANDA array operating at the South Pole since 2000 already provide some constraints, and that IceCube, the next generation array now being installed there, could at 90% confidence level rule out a 40% enhancement of the neutrino cross-section over the Standard Model values.
What’s interesting here is not that extra dimensions have been found, but rather the opposite. AMANDA results show no evidence of the kind of enhanced cross-sections you might expect from some extra-dimensional scenarios, and it seems possible that IceCube will rule out such extra dimensions at energies accessible by the LHC even before the LHC comes on line. For a similar but earlier argument of this kind, see a discussion by Jacques Distler a year and a half ago concerning an earlier paper by these same authors that argues that the Pierre Auger Observatory, another cosmic ray observatory now taking data, may also be able to rule out extra dimensions observable at LHC energies before the LHC is turned on.
There’s also some mention of this over at Lubos Motl’s blog, with half the posting devoted to scatological attacks on this blog and its readers. I really think he’s losing it. Note that following current arXiv policy, a trackback linking to Lubos’s posting has appeared at the arXiv listing for the Anchordoqui et. al. paper, but no such trackback will be allowed to appear to the posting you are now reading.
Update: One of the problems with the endless number of absurdly overhyped press releases about string theory is that they get widely distributed.
Update: The Slashdot article does contain a useful extended comment from someone working for AMANDA/IceCube.
Update: The headline on the press release has been changed by the people at Northeastern. It now reads “NU researchers say South Pole detector could yield signs of extra dimensions “.
“There’s also some mention of this over at Lubos Motl’s blog, with half the posting devoted to scatological attacks on this blog and its readers. I really think he’s losing it.”
Look at his replies to Quantoken…
I did. Scary to see Quantoken making a lot more sense than Lubos.
I must say sometimes reading this blog is so amusing.
One the serious side, concerning these experiments and the search for extra-dimensions, see this interview dated April 2004 with Dr. Feng (sorry if that has been posted before).
Christine
Thanks Christine, that interview does provide some interesting context for this.
There’s something that I don’t like about when headlines which say “X has been found” are followed by stories which say “X has not been found”. It strikes me as dishonest, in a very precise and obvious sense. Perhaps it was always this way and it’s just being brought to my attention more nowadays, but I have the impression that this kind of thing occurs more frequently now than it ever has in the past.
Dear Peter,
Quantoken makes much more sense to you than I do because your understanding of physics is much closer to Quantoken than to mine.
Best
Lubos
It’s like they hired Ari Fleischer to start writing physics press releases.
Lubos:
Clearly you can’t make sense of your “prediction” except by deleting my last comment on your blog. In that comment I pointed that your so called string prediction:
Predictions from TeV-scale excited strings:
http://arxiv.org/abs/hep-ph/0204112
are merely groundless wild guesses. You first have to fix the string scale at certain arbitrary value, exactly 1TeV, before you can calculate something. But then no one from your camp is willing to tell us un-ambiguously exactly how much is the string scale, 1 TeV, or more, or less? As such you could always wait until you get the data and then tweak your parameters to make it fit, and thus always claim victory regardless of the outcome.
As a matter of fact, you are already hyping a victory of super string theory with champaignes, before the experiment even begins 🙂
That is NOT a prediction. A scientific has got to be falsifiable. You tell me some specific numbers and put them on the table, with no strings attached, and then if the experiment does not come up with the number you predicted, you admit you were wrong. And you claim victory if your number is proven correct. You are unable to make even one such definite prediction, so you are not science.
Of course, it will be impossible for super string theorists to make a none-ambiguous prediction with no string attached.
Quantoken
It’s true – Lubos didn’t have a good answer for Quantoken, so he deleted the comment. Surely even Lubos must be ashamed of this kind of sore-loser behavior. Is the shame of losing even a single point in an argument just too much to bear? Must he resort to censorship to prevent it?
Just an opinion – discussion of someone’s personality on a blog that is mostly about ideas is not good. Surely we can discuss – if it is interesting – Motl’s ideas on climate, physics, string theory etc., without discussiong Motl? Or for that matter, anyone else? I think it best that personal opinions about people remain just that – personal and private. Physicists – even when they blog – are not public figures in the nature of politicians and glitterati. The latter depend on getting people talking about them, but not so with physicists. I find comments like “Motl is such-and-such” or for that matter, our host “Peter Woit is such-and-such” rather distressing; I hope I’m not alone in this.
Peter:
You commented that IceCube could produce some results before LHC is turned on. That’s incorrect. The experiment hasn’t even been built yet by the time LHC is expected to be turned on. So far they have only installed 8 detection strings, out of a total of 80. The completion will be at least a few years away. Even when it’s all set up, they expect to run the thing for 15 years to collect just a few events.
See how the string theorists are already celebrating that extra dimentions have been verified, when in fact the experimental instrument has not even been built! Let’s wait until it’s all up and running, and an unfortunate matching penguin dropped his egg and tripped on the wires, triggering a false event record, I bet they will not hesitate to open up quite some champaigne bottles. Just look at how they hyped on the so called CSL-1 anormalcy.
Now as I point out on Lubos’s blog, the author’s estimation of event count, (4 down event and 20 up event), based on 15 years of instrument running, is way too optimistic and completely off the mark. In calculating the event count the author assumed 6×10^38 target nucleons, for example. Even a 3 year child can calculate that one cubic kilometer of ice contains only 9×10^37 nucleons, not 6×10^38.
Why researchers lack such basic skills to even estimate how many atoms are in one cubic kilometer of ice?
Also, when some one do an experiment like that and you know he has a full agenda to obtain a certain outcome that he prefer to see. How would you think about the credibility of such experiment result, before it even started? He is already going every where and give interviews claiming how extra dimention is confirmed! He probably have the experiment report written already, munus filling in the date and time, before the machine is turned on. How could you trust that he will not manipulate the actual data some how to fit his expected outcome, like Eddington did?
Quantoken
I’m only an undergraduate student (in Europe), so I’ll accept the fact that most people on this blog know far more physics than I do.
That said, I stumbled on to this blog some months back, because I wanted the other side of opinions on String Theory.
One thing I wish to say is about Lubos Motl. I am literally shocked after reading his posts that this man is a professor in a major university.
Lubos, you act like a five year old. Your obviously a very intelligent man, but you do yourself a disservice with your highly reactionary writings across the net.
If there is one thing you’ve shown me it’s that adults who revel in “playground politics” make their way into the highest levels of acedemia.
Finally, if you respond to this, at least come up with an insult that supersedes the “U r gay” classification.
Great blog Peter and thanks for directing me to modest theoretical physics and away from exotica.
Given that string theory gives something like 10^500 predictions for any given experiement, Lubos figures the odds are pretty good that one of those predictions will be verified. Predicting which of the 10^500 predictions will be verified is an uninteresting task left for lesser minds.
Undergrad: It takes a lot less to be a professor in an American university than in a European university. In Europe, you have to hold a specific chair, and that often means waiting for another professor to retire. In America, “professor” is little more than a lob title, more or less equivalent to “researcher” or “lecturer”. That said, a job as a professor at Harvard was considered quite prestigious before they gave one to Lubos.
Quantoken,
You’re quite right that it will take longer than I thought for IceCube to be completed, not till 2009-10. However, between now and then I believe AMANDA will still be running, and taking data together with increasingly large parts of IceCube as it is completed in stages. I haven’t really looked into whether and when these South Pole experiments will be able to put the kinds of bounds on neutrino cross-sections needed to rule out various extra dimension scenarios at various scales. Maybe someone reading this blog knows the answer to this.
On the other hand, your constant belief that the people designing these experiments don’t know what they are doing is kind of out of control. The idea that they’re making elementary mistakes and intent on fabricating data or not carefully analyzing it is just ridiculous.
Haven’t there been a few rare recorded cosmic rays that were so wildly energetic they were dubbed “Oh My God” particles? Did anyone notice those creating micro-black holes? I imagine if they did, we would have heard about it…though maybe no one was looking for that properly at the time, so it passed undetected. If not, wouldn’t they put a pretty high-level constraint on micro-BH production? Like millions of times more energetic than what we can produce in the LHC kind of constraint?
Oh, that was kind of in response to Christine’s link…
Peter:
I believe you should be able to calculate the number of atoms in one cubic kilometer of ice. Any one can do that calculation. But they got the number wrong by 7 times. Would you not call that an elementary mistake if one can’t even count atoms?
It’s unbelieveable, but many researchers are incredibly stupid. Example like this. A researcher tried to figure out how much cloud is covering the earth, but looking at the dim reflection on the dark side of the moon. Some one with average intelligence would know it’s much easier just to look at the earth directly from satellites.
And these few days some researchers claimed on the Nature magazine that they discovered an earth like planet 25, 000 light years away, but detecting brief brightening of certain stars due to gravity lensing. And Mark Troden et al appraised it. Some one know a little bit of GR should at least be able to estimate the focal length of the allerged gravity lense, and find out that it could not possibly focus the light on the earth 25,000 light years away, but the focal point where you can see the brightening effect should be much closer. See my comment here, which was by the way censored by certain cosmologists. Some people really just don’t know the stuff they are supposed to know in their profession.
To a researcher nowadays, I guess publishing paper and being able to survive in academy, is way much more important than maintaining some decent scientific honesty. Outright fabrication of data may be rare and exceptional, but dirty tricks in data manipulation are widespready. When you have collected a rare data sample which you are not sure whether it is just background noise or legitimate, and you have not collected much data in 15 years, and the data seems to be a “good” one adhering to your expected result, I bet most people will be VERY inclined to simply count it in, instead of discarding it, especially when is no one watching over your shoulder.
The bottom line is scientists are as human as every one and they do pee on the streets, when no one is watching. The important thing is one should always maintain a healthy skepticism against everything and cross-exam things in order to find the scientific truth.
Good question, Dumb Biologist.
Don’t know if this is what you were referring to, but since 1972, there have been some very high energy cosmic ray events reported with anomalous characteristics, called “Centauro events”. There was some speculation these were black holes, I haven’t heard anything about these recently, and am also curious what is now known about them.
Quantoken,
Sometimes you write sensible things, other times, like this, you behave like a complete crackpot. I’m so baffled I can’t quite bring myself to delete your latest nonsense. But no more, please!
Well, being very unoriginal, I just googled it, and got this:
http://en.wikipedia.org/wiki/Oh-My-God_particle
According to a link from this wiki, the original OMG was a proton with the mass of a bacterium.
There might be more on this stuff of greater technical interest to you via the Hi-Res Fly’s Eye, that might answer your questions. They link some talks that I probably can’t understand:
http://www.cosmic-ray.org/
undergrad,
“Great blog Peter and thanks for directing me to modest theoretical physics and away from exotica.”
Sorry to hear that you are letting this blog affect the direction of your career. It is a sad reminder that this small nuisance that I believe most of us think little of (at least I do aside from the occasional comic relief that it provides) actually has sway over people who don’t see it for what it is: a gathering place for individuals who have discovered that it is far easier to obtain a sense of intelligence by attacking the accomplishments of others than to learn a subject thoroughly and make a serious contribution themselves.
The constant attacks on string theory that take place here are based on a very superficial knowledge of the subject and display an amazing level of ignorance. I do not mean to denigrate the intelligence of those who make such attacks, as there is a difference between ignorance and stupidity. Rather, it appears to me that the attackers simply have not taken the time to learn the subject. That is certainly not a crime as I, for instance, have not taken the time to adequately learn LQG despite the fact that it is a subject that one might argue is quite relevant to my career, more so perhaps than string theory is to many of the posters here. On the other hand, I don’t spend my time publically attacking LQG based on the superficial knowledge that I do have. I recognize that I lack credibility on the subject and leave the debate of LQG’s problems and merits to those whose interest is sufficient that they took the time to thoroughly understand it.
Finally, I should mention that you might take a look at the recent posts of Lubos and Hmm in order to put this blog into context. Both of these individuals are a bit abrasive to say the least (I see that you have noticed this about Lubos already 🙂 ) but the main points that they convey are actually quite accurate.
Peter, DB – this is just a rumor, and I’m not saying where it came from, but certain people believe that the impossibly high-energy cosmic ray events seen at AGASA weren’t actually as high-energy as it was originally thought, and the energies looked artifically high due to miscalibration of instruments. That leaves only one event at the Fly’s Eye detector, and one event alone isn’t enough to justify all the excitement. Certain people were asked not to say these things too loudly at a time when it might have jeopardized funding for the Pierre Auger observatory.
Time will tell. If certain people are right, then there will be no more cosmic rays observed with energies beyond 10^20 eV.
D.B.,
The kind of events seen by Hi-Res are the ones that Auger is designed to study, gathering a lot more events in order to understand what the flux of these things is at the highest energies. There’s a controversy here, since above a certain energy, such cosmic rays from extra-galactic sources should lose energy by collison with CMB photons. If they’re really there, something interesting in going on, one proposal is that Lorentz invariance gets modified, with a modified dispersion relation at these energies. Within the next few years, data from Auger is supposed to resolve this.
I still don’t know though what happened to the Centauros…
DB – yes there are cosmic rays that are so energetic that nothing known can account for them. They aren’t little black holes, just ordinary matter moving very, very fast.
Now if you look at galaxies, there is all kinds of evidence of extraordinarily energetic processes, fitting into characteristic patterns (rings, jets, ..). Most likely whatever is ripping these galaxies to shreds is also making these ultra-energetic cosmic rays. One doesn’t need to impute some new pathological state of matter – just explain why these galaxies are so disturbed, and with such a consistent morphology. Science used to be like this – look, measure, speculate, theorize, calculate, confirm.
(The standard answer is “supermassive black holes”. Basically, anything that can’t be immediately understood is thrown over into the catchall of black hole dynamics. It’s instant gratification for academics.)
-drl
Peter, you and Quantoken behave like an aging married couple. First, you publicly defend him. Then, in the privacy of your own blog you chastise him.
I think you two are made for each other, so be nice. Emphasize things you have in common rather than disagreements. For example, you could try and figure out if the off-diagonal SU(2) is compatible with the GUITAR. Good luck!
Hi anon/Hmm,
Funny how yesterday there was one anonymous coward Lubos supporter from the Boston area writing in, but promising not to come back, now there’s a new anonymous coward Lubos supporter from the Boston area appearing here with the same personal attacks, made in much the same style. What’s your excuse for remaining anonymous? Are you also a very busy man like “Hmm”, too busy to explain why you are attacking me?
Whoever you are, your behavior is even more pathetic than that of Lubos.
OK. Well, if the OMGs were really spurious readings, then that’s a bummer. Let’s just say they’re not (which no one is claiming on-the-record, it seems), and that cosmic rays (probably protons) can whip around at these absurd energies. Where they come from is certainly interesting, but what I wonder is why people talk about detecting the decay of micro-BH’s (and hence evidence of large extra dimensions) in the atmosphere rather frequently, or even in the LHC if we’re lucky, when it would appear the most energetic cosmic rays detected rule out such observations.
It would seem, based on the above, the only way they can exist is if relativity needs modification in a rather radical way at high energies, and perhaps they don’t believe it yet.
Not that it matters the least bit, given that anonymous is anonymous, but I’m not “Hmm”.
Well “Michael”, who knows if you’re “Hmm” or “anon”. But, like them I know you’re in the Boston area. Maybe Boston is just full of lots of cowardly Lubos supporters who are very busy.
Actually, looking at the IP addresses, it looks to me like “anon” is a Harvard undergraduate, possibly living in Lowell house. Having done my time there, this conjecture seems all too consistent with the pompous tone of the comment.
Well, Peter, *I* know who I am. 😉 What does my IP-address look like?
Michael,
You’re a lot cruder and stupider than the conjectural Lowell House undergrad. What’s your excuse for remaining anonymous? As far as I can tell, you’re at home somewhere in the Boston area using a DSL connection.
What’s going on up there around Boston? Is it something in the water?
There have only been about 20 or so putative events observed so far beyond the cutoff, which is about 5×10^19 eV. You might need to observe millions of incoming highly-energetic cosmic rays before you’d see a black hole being created. Of course, nobody knows how many events you’d need or what energy they’d need to be at; it depends on factors like the size of the extra dimensions. Larger extra dimensions should make black hole formation easier, and so on. You might need energies hundreds of times what has been seen so far, and, unless there’s a source of ultra-high energy cosmic rays right beside us, scattering by the CMB should leach energy from the rays so that by the time they reach us, they’re below 10^20 eV.
Incidentally, Peter, didn’t Lubos accuse you of sock-puppetry not so long ago? I wonder if people are more inclined to suspect others of crimes when they commit those same crimes them themselves.
A. nonymous,
Thanks for the information about ultra high energy cosmic ray events.
Certainly Michael=Lubos is not impossible. I never did figure out what was up with Lubos and his strange idea that I was “MathPhys”, quite possibly you’re right that he thought that because of what he is up to.
Thanks, Peter. Yes, I am at home in Boston using my DSL connection. 😆 I laughed out loud when I saw that you actually answered my question, as if I didn’t know… On a second thought, I think it makes you look like a nice guy. Kind of guileless, I guess.
What’s my excuse? I don’t need an excuse. This whole blog thing of yours isn’t really serious in my mind. I don’t want to give my good name for this little bit of pastime bickering.
Don’t be too bitter about it, please. It’s not even my intention to offend you too much — well, I sure enjoy bantering you a bit. You must have known that you can’t run this kind of blog without facing some headwind, right? So please save the “all Boston is tainted” comments, will you?
No sir, I’m not Lubos either. 😆
Good lord, had I known I’d cause such a severe case of paranoia, I might have surfed elsewhere…
Michael,
No, I didn’t think you were Lubos. His style is quite distinctive and anonymity isn’t his thing. And no, I’m not the bitter sort, not in general, and certainly not at the moment, when life is quite good for many reasons. I didn’t say anything about “all Boston is tainted”, you string theory partisans have this mania for putting quotes around words I’ve never written.
Actually I’m quite fond of Boston. I greatly enjoyed the years I spent living in Cambridge, as a student and later in life. I have old friends there and my brother and his family live just outside Boston, so I visit regularly. Still the fact that a metropolitan area of only 2-3 million people contains more than one person as delusional as Lubos about string theory seems quite remarkable. There must be some sort of explanation….
Peter, it’s not a coincidence, of course. Boston has the largest per capita density of high class academics in the world. This is particularly true for string theory.
Good night now.
Peter,
These string theorists REALLY despise criticism, surprising for so-called scientists. You should have seen this “Michael” type anonymous behaviour coming a mile away. When you initially started the blog, I recall that the physicists that were critical were not anonymous (e.g., the fool Mark Srednicki of UCSB made of himself, Distler’s moronic rantings, http://www.math.columbia.edu/~woit/wordpress/?p=3#comments, Motl of course, and others)
Once, however, having tried arguing and then realizing that they can’t deal with the arguments, the coming of ad hominem and anonymous attacks were as obvious as the coming of men in white coats to escort Lubos to a mental clinic.
I think these type of attacks are a sign of success. You’re quite a gadfly!
This time the controversy between Quantoken and Motl is about physics, so it can be clarified without insults. They miss that IceCube can also see events orginated below the instrumented region, such that its (energy dependent) effective volume can be bigger than 1 km^3.
As a general comment, I think we should pay more attention to people planning, building and operating experiments, rather than to people writing papers and funny press releases.
Somehow “high class” isn’t really the term that comes to mind to describe Lubos and his anonymous fans….
Boston has the largest per capita density of high class academics in the world. This is particularly true for string theory.
Population of Princeton, NJ: 14,203
Population of Boston, MA: 589,141
Population of Cambridge, MA: 101,355
So there are more than 41 times as many prominent string theorists in Boston than in Princeton?
a:
Wrong. First, the instruments detect visible photons. However clean the polar icea may be, lights do not penetrate much more than a hundred of so distance. Second the goal of the instruments is to correlate several detectors to identify the direction the muon is going, therefore inference the direction of the original neutrino. It can determine the direction only when the event is happening within the ice of the IceCube.
Peter says:
“Somehow “high class” isn’t really the term that comes to mind to describe Lubos and his anonymous fans…. ”
I would say high is the perfect word describing the status of super string theorists like Lubos et al. They are too high in the thin air they can’t make their feet touching the solid ground of reality. Of course you know what the word “high” is often associated with when it comes to certain substance.
I prefer to stand on solid ground. Let some one else high.
Quantoken
Quantoken: muons (not photons) can travel for kilometers in ice. And by detecting a part of their path one can reconstruct its direction.
Quantoken’s CosmicVariance Blog spells out his problem with the number of nucleons estimated in the ICE-CUBE paper. It seems the blog asserts that the water molecule has 3 nucleons, instead of eighteen which is the correct number. (You have to count all the protons and neutrons, not just the nuclei.) This accounts (almost) for Quantoken’s problem that the estimate given in the paper is 7 times too big.
I had to check it for myself since I couldn’t believe someone could make such a mistake while boldly chastizing others as apparently being below the toddler level in thinking. But you’re right, Nick, it’s there. “The water molecule contains three nucleons….” Wow. Just incredible.
Please, no more discussion of Quantoken’s mistakes about physics, this is far too large a topic and could easily overwhelm this poor blog.
And now for something completely different (as they say on Monty Python) … trackbacks. It seems that indeed the arxiv does not post trackbacks to this blog. But never mind. It seems that this blog has attracted sufficient prominence to garner interviews for Peter etc. I am reminded (perhaps for no good reason) of the blurb for Monty Python and the Holy Grail = “makes Ben Hur look like an epic”. Why worry about trackbacks? Make it a subtitle “Not Even Wrong” ~ “Not even trackbacked by the ArXiv” (trackedback?). Trumpet it to the world with pride! It puts the ball in their court.
sunderpeeche,
I kind of agree with you. But what is really weird about this story is that I can’t even get anyone at the arXiv to admit to me that they have decided not to allow trackbacks here.