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Evidence for String Theory?
Izeickl writes "PhysOrg.com is reporting that scientists working at a neutrino detector nicknamed AMANDA at the South Pole report that evidence for string theory may soon be coming. Extra dimensions predicted by string theory may affect observed numbers of certain neutrinos and this is what the scientists will be looking for. The article further states 'No more than a dozen high-energy neutrinos have been detected so far. However, the current detection rate and energy range indicate that AMANDA's larger successor, called 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.'"
I heard that there was only one other dimension... and the only difference was we are all wearing mexican hats... I thought this was general knowledge - perhaps the scientists here should have checked the facts before they started considering 24 dimensional super gravities and the like
*''I can't believe it's not a hyperlink.''
so will string theory finally be falsifiable and be more than a religion?
It has been statistically shown that helmets increase the risk of head injury.
...one of those sci-fi christmas episodes: "parallel chihuahua dimension"
Great, now we'll be able to see Cthulhu and he'll get all embarassed because he'll be like, in a shower or something when that thing's turned on, and he'll eat the goddamn earth. Can't we be happy with *our* dimension of existence? Wasn't invading Iraq enough?
Ex nihilo nihil fit.
For those who aren't aware:
http://en.wikipedia.org/wiki/Heim_theory
Predictions of faster tan light travel (amoung other things)
"The weirdest thing about a mind, is that every answer that you find, is the basis of a brand new cliche" -
Is this in any way related to the Fifth Dimension, and Let the Sun Shine?
This is not the only experiment which could probe large extra dimensions; the Large Hadron Collider at CERN is another notable experiment. However, this article is not implying that AMANDA (or any other experiment) has found evidence for string theory, or even that they are likely to.
Normally, string physics is thought to appear at the Planck scale (far beyond what we will ever be able to probe directly), because that is thought to be the size of the "curled up" extra dimensions. However, it's possible that the dimensions aren't actually that small, that they could be much larger — possibly not much smaller than a millimeter. (They could even be infinitely large, not curled up at all, and we could be living on a 4-dimensional "brane" close to another one.) In those cases, stringy behavior is brought down from the Planck scale to as low as 1 TeV (tera-electron volt), which is the energy that corresponds to a distance somewhat below a millimeter. (By the Uncertainty Principle, higher energies correspond to shorter distances that can be probed.)
The problem is, there isn't a lot of reason to believe that these scenarios ought to be true; they are highly speculative (even relative to string theory as a whole!). To a large extent, they are just hopeful thinking — that stringy physics might occur at in an energy regime we can probe. They could be helpful in understanding the hierarchy problem (the question of whether and why there is an absence of new particles between the electroweak and Planck scales), but when you get down to it, most high energy physicists are not betting on large extra dimensions. So these experiments might very well not show up any evidence of string theory (even if string theory is true).
"Strings" are just another way of describing devine, Noodly Appendages.
Actually, this is really cool. Looking forward to what the use of the new detector shows, or doesn't, as the case may be. String theory is such a mind bender for most people (including me), that anything making it more directly tangible will really help focus the conversation. Or end it. Either way is good.
Don't disappoint your bird dog. Go to the range.
Construction on AMANDA began in 1994, and South Pole was chosen because you need high transparency ice. That means you need an ice sheet substantially thicker than 1400 meters (the bubble conversion zone) in a region with few dust or volcanic impurities. South Pole satisfies both these properties very well.
I remember what happened the last time some scientists were doing experimental research in the South Pole. Let's just nip this one in the bud, shall we? Launch Eva!
Bill Clinton: Pimp we can believe in. - The Shirt!!!
AMANDA's larger successor, called IceCube,
Also seen in such blockbuster hits as Boyz n the Nucleus, Three Quarks, and xXx: State of the Quantum.
It's cool that there's a testable prediction coming out of string theory, but I would take this with a grain of salt for the next few decades. For one thing, I don't think neutrinos themselves are well enough understood yet that string theory would provide the only (or even the best) possible explanation for discrepencies in their 'up' and 'down' neutrino rates. A multitude of experiments are being done now just to try to pin down the parameters governing neutrnio behavior. So if AMANDA sees the discrepency predicted by string theory, it would take a lot more work and many more years to demonstrate that there isn't a better explanation for it.
Peon: We've counted 12 possible events out of 789,567,345,754,234,567,876 (est) neutrinos passing thru the detector.
TS: Hmm, that's as expected, totally useless number of events to draw any inferences from. Keep at it.
(Next day) South Pole Grant Administrator: Hey, TS, got any news I can tell Washington? Your grant approval comittee meeting for the Big Project is next week!
TS: Oh, yes, Er, Um, hte data we got from their previous infusion of cash indicates Big Things, the possible proff of String Theory, SuperGravity, The AntiMacassar Postulate, and much more. But better just mention String Theory to the commitee, it was on the cover of Popular Science last month.
SPGA: Will do!
Will this neutrino evidence support or detract from Heim Theory, which also predicts multiple dimensions?
I think you were joking, but astrophysicists extracted a surprising amount of information from the 19 neutrinos observed from Supernova 1987A.
"faster tan light travel"? I think that's called a solarium/sunbed. ;)
http://oc.metblogs.com/archives/fsm.jpg
If you could reason with religious people, there would be no religious people
Religion that hides so far from rationality and logic that it become non-falsifiable, unproven and unprovable, is hardly the robust Christianity I find in the Bible.
If you find internal consistency (within the dogma of a religion, including their trusted documents) and external consistency with the outer (earth/cosmos) and inner (conscience/mind) world, then you can start taking it seriously.
Ordinary Christianity has its share of mystery and hyper-rational statements (that is, statements that seem to be beyond 19th century rationalism to fully unpack/understand), it seems to be extremely falsifiable and, to different degrees depending on your presuppositions, provable.
But that's just me.
New Scientist sure has created a lot of Heim groupies.
The fact is, pretty much nobody knows what the hell Heim theory predicts. Most of his theory was never published or reviewed by his peers. We don't even know if his theory is self-consistent, whether the predictions hyped by New Scientist or the Internet "Heim appreciation society" that's pushing it are actually predictions of the theory, etc. For that matter, hardly anybody knows what the definition of the theory is.
Just because some people have made a bunch of wild claims about what Heim theory can predict, doesn't mean it's something to get excited about. Nor does Heim's reputation. Schroedinger himself thought he had come up with a unified field theory, called a big press conference, privately spoke of winning a second Nobel Prize. Some reporter asked Einstein what he thought, and he responded with a carefully worded response to the effect that one shouldn't get the impression that physics is like unstable Third World dictatorships, always experiencing revolutions. Schroedinger's theory didn't pan out and the two stopped corresponding for over a year.
The really cool thing about the very thick ice on the south pole is that beneath the few douzend meters of surface layer, its incredibly pure and transparent.
Now if a neutrino causes a shower of cherenkow radiations, it can be detected many many meters away.
So instead of building huge watertanks in deep mines, one can use the deeper ice layers as a large detector.
You just melt holes into it and put photodetectors in a grid pattern, and get billions of tons of detector mass (which you need because low chance of neutrino interaction with matter)
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
Will it stop the onward march of socialism?
;)
I'm confused by this one. There's an onward march of socialism? I thought it fascism
You may think we are only operating in 3+1 dimensions, perhaps our terms of understanding other dimensions are limited. These other dimensions are said to make matter what it is, for instance a certain multi-dimensional vibratory resonance pattern is what makes a hydrogen atom different from an atom of gold. (IAACST (I am a crackpot string theorist)). A dimension "is a parameter or measurement required to define the characteristics of an object" (wikipedia) so i tend to look at things like color, taste or emotion as other "dimensions", though perhaps this is sematics to some, or difficult comparing mathematics to the real world.
Music, Games, Media Art and Programming
There's no need for all this deep theoretical work and all these expensive detectors. I've got plenty of string at home in a jam jar. If they ask nicely, they can have some; it's in this dimension too (I think..).
On y va, qui mal y pense!
You essentially ask: what use is fundamental physics research?
You can't ever predict what applications fundamental research will have on technology. Sometimes, things are immediate: after Roengten discovered X-rays in 1895, the medical application was obvious. On the other hand, in 1905 Einstein predicted that objects moving fast experience time dilation relative to stationary objects. In 1915 he also predicted that the same would hold for objects higher up in a gravitational well. This was completely irrelevant to then-current technology: Nothing man-made moved faster than 500mph, or got high enough off the ground, and anyway time couldn't be measured accurately enough for these effects to matter. Swing around to the 1980s. The US government is now launching the GPS system, which depends on exteremly precise timing synchronization between a satellite in orbit and the unit on the ground. It turns out that the two relativistic time-dilation effects have to be taken into account for the system to work at all. Who'd have thunk this in 1915?
Moreover, progress is usually incremental. No single discovery will "cure HIV" or give us infinite energy. New physics beyond the standard model might have technological applications in 80 years. Does that mean we shouldn't discover it today?
-William Brendel
I completely agree, at the time most fundamental physics research seems completely pointless at the time but often in 60-80 years time its extremely important. Take the example of quantum mechanics, in the early 1900s, researching into being able to explain the precise movements and behaviour of subattomic particles, effects so small they had no practical application in everyday life may have seemed a bit pointless. 60 years later the understanding this lead to the invention of the transistor, which some people might argue is of some importance in todays world.
Anyway as an aside, evidence for extra dimensions != evidence for string theory. String theory isnt the only model which predicts extra dimensions. Evidence for no extra dimensions is evidence that string theory doesnt exist. However we'ld probably have to go to the planck scale to be sure which is probably impossible for the time being. Anyway we're far more likely to pick up string theory by the breaking of the E6 symetry group which produces extra massive neutral gauge bosons (Z').
Just your friendly neighbourhood extra dimensional researcher (CDF expt, Fermilab)
Because Santa is an ID-proponent, and refuses to allow such blasphemy to be conducted on his pristine icy shores.
http://www.math.columbia.edu/~woit/wordpress/?p=33 5
A snippet of which is:
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.
Comment removed based on user account deletion
Socialism? I thought that stopped decades ago...
I find one potential use for those extra dimensions - a place where emotions, ghosts and the whole paranormal zoo can reside. There's quite a bit of stuff there which has no space whatsoever in Newton or Einstein style universes, but which people routinely relate to in a more or less systematic way. Would be nice to have a rational explanation for this stuff :)
I'm in a Unix state of mind.
Will Jerry O'Connell be involved in this one as well?
Reality is a big nasty dragon. Fortunately I don't believe in dragons.
You're confused. This neutrino experiment won't imply that everything is made out of neutrinos. If string theory is correct, then everything (including neutrinos) is made out of strings, but that doesn't make replicators feasible. To make a replicator we would "only" need to manipulate protons, neutrons, and electrons, even without string theory; there is no need for those particles to all be the same thing. (We can transmute elements using nuclear physics, too, again without string theory, but this is not practical, and turning quarks into electrons using string theory is not only less useful, but is basically impossible using any conceivable future technology).
Loop Quantum Gravity: http://www.angryflower.com/dating.gif
http://www.coderoshi.com/
I think Einstein did a good job of visualizing the 4th dimension (or space-time). I work in the time domain myself, for instance when I compose music. My point was that "perhaps our terms of understanding other dimensions are limited", at least by our framework of representation.
Music, Games, Media Art and Programming
You make a good point and I fully agree. In addition to possible applications there is something maybe even more important one could say in favour of fundamental research. It is part of human culture to ask fundamental questions and seek answers to them. Just as it is to create works of art or literature. There is more about human life than just doing business and building things useful for practical purposes.
Unfortunately, this point is not made very often recently. Probably because scientists fear that this argument is all too easily dismissed as weak or a lame excuse. I think it is not. Otherwise one could next argue that theatres and galleries are useless and that we should print nothing but text books and reference manuals.
617B3B7F7E7C7D7F00EOF
A correct prediction is not necessarily evidence for a theory; the prediction might be a tautology or it might be true of many other theories as well.
For example, my hypothesis might be that Donald Trump's social security number is 666-66-6666. Now, I conduct an experiment in which I test the prediction that his social security number is not 123-45-6789 and the experiment succeeds. I have gotten a tiny bit of evidence for my original hypothesis, but it's so small as to be negligible.
Well, with scientific theories, it's even worse because there are not just 1 billion of them but an infinite number--unless you do things exactly right, a successful prediction gives you no evidence for a scientific theory at all.
I work for AMANDA/IceCube. It's nice to see that our supercool experiment gets media attention, but there are a few statements in that article which need a comment or two. User davidoff404 already commented on the theoretical aspects of the article, so I will mostly limit myself to the experimental aspects.
Actually, we see about 900 neutrino events per year. Their directions are homogeneously distributed over the sky and the energy spectrum is (still) compatible with the assumption that all these neutrinos were produced in interactions of high energy cosmic rays (protons, nuclei) with the Earth atmosphere (all around the globe). It might be that there are neutrinos among them from extraterrestrial sources, but individual events cannot be identified as such. We continue taking data until neutrino events from single extraterrestrial sources (or with higher energy than expected from atmospheric neutrinos) pile up enough such that they stick out over the atmospheric neutrino background.
Note: we do not detect those neutrinos directly; they interact with the ice, and may convert into a "muon" (which is like an electron, only about 200 times heavier, and it decays after a little while). That muon still carries most of the neutrino's energy with it, so it flies practically with the speed of light through the ice, sending out Cherenkov light (the electromagnetic equivalent of a sonic boom) along the way. The tracks can be kilometers long. We only see the part of the track in or near our detector, so we can only estimate a lower limit of the energy of an individual muon. When the neutrino does not convert into a muon, then the energy is dissipated in a relatively small volume; which makes it much harder to estimate the direction, but easier to estimate the energy.
(And of course those atmospheric neutrinos are not only background. We are happy to see them, as they prove that our detector is not blind. And we can use them to test the models of cosmic ray spectra and to study properties of neutrinos themselves.)
Actually, neutrinos are so weakly interacting that the vast majority of them just flies right through the Earth. It is really tiny fraction of them which happens to bump into an terrestrial atom. And an even tinier fraction which bumps into an ice molecule near our machine. So they come from all directions, up and down, the Earth is not shielding them. However, like everywhere on Earth there is a lot of cosmic rays thundering down on the atmosphere above the South Pole, and some of it results in high energy muons which make it all the way down to our detector. Their rate is about a million times higher than that of the muons originating from the neutrinos. Only when we see a muon track going upwards, or when it has an energy much higher than expected from the cosmic ray spectrum, then we call it a neutrino event.
When we start talking about really very high energy neutrinos (PeV and more) then the picture gets a little bit different: at those energies the probability that a neutrino interacts with atoms gets so high that the Earth is indeed opaque for neutrinos. If there are such high energy neutrinos flying through the universe, then we expect to see them from above and horizontally. This is already expected with standard model physics, without assumptions about microscopic black holes; so I am curious as to what Goldberg and Feng are after.