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New Calculations May Lead To a Test For String Theory
dexmachina writes "A team of theoreticians, led by a group from Imperial College London, has released calculations that show string theory makes specific, testable predictions about the behaviour of quantum entangled particles. Professor Mike Duff, lead author of the study from the Department of Theoretical Physics at Imperial College London, commented, 'This will not be proof that string theory is the right "theory of everything" that is being sought by cosmologists and particle physicists. However, it will be very important to theoreticians because it will demonstrate whether or not string theory works, even if its application is in an unexpected and unrelated area of physics.' In other words, string theory may finally have shed its critics' most common complaint: unfalsifiability. However, given the second most common complaint, I can't help but wonder: which string theory?" Update: 09/03 23:34 GMT by S : Columbia University's Peter Woit, author of the Not Even Wrong blog, says these claims are overblown, and adds that a number of string theorists said as much to Wired.
That's a good news for Dr. Leonard Leakey Hofstadter...
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It seems I may have jumped the gun on this one. My bad for being such an easy mark of sensationalist pop science headlines.
However, given the second most common complaint, I can't help but wonder: which string theory?
Exactly, if this turns out to be false it won't disprove all string theory.
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I scanned through the article and from what I see, they have made an equivalence between the maths used in string theory and the maths used in entanglement. This is interesting in itself, because this allowed them to port a result from string theory to entanglement theory, a result which was not known before and could be falsified.
However, this is like saying that the mathematical theory used to count apples harvested from an orchard (addition of natural numbers) is the same as the mathematical theory behind the algorithm the slashcode uses to count the number of comments below threshold (addition of natural numbers). It allows one to port result from ancient mathematics to modern applications without having to rederive everything from first principles; it does not mean that sub-threshold comments are, deep down, really made of apples.
As a physicist, I do get a bit annoyed at the constant attacks on string theory in public media.
Let me just state a few points please:
* We have Quantum Mechanics for the realm of the very small
* We have General Relativity for the realm of the very heavy
* Both of these theories fit observational data and work very well
* The two theories contradict each other in the case of very heavy and very small object (e.g. tiny black holes)
So, we need a new theory that gives the same predictions at QM and GR in the realms that we can measure them. This is where string theory etc comes in. But we do not yet have experimental data for very heavy and very small objects. If you want to complain about string theory not being testable, then accept that your same complaint is going to apply to EVERY grand-unified-theory that we know of.
Conclusion
=========
If you complain at string theory, then PLEASE state what you are proposing. What is the use in complaining when you have no alternative? The main scientific proponents against String Theory also just happen to have their own pet theories (e.g Quantum Loop Gravity) which are in an even worse situation.
If you complain about string theory taking so long, then what do you expect? It has taken 16 years just to do a single experiment (The LHC).
The only way we can make String Theory etc testable is by further research. If you dislike, please propose a better solution rather than just complaining.
TL;DR - People complain at string without proposing anything better.
God is love. You believe in love, don't you? So there must be God, because there is love.
Obviously, it follows that love created the world in six days. Then love created a flood that destroyed just about fucking everyone, because you don't fuck with love, love is a sociopath.
I don't believe in time. It's a grand conspiracy designed to sell watches.
Just for the record: Gödel did not proof math to be not consistent. He showed two things:
1. That in every axiomatic system strong enough to capture aithmetic there necessarily are true sentences that can be expressed with the means of the system but cannot be deduced from the axioms (he presented a method to construct such sentences).
2. You cannot deduce a system's consistency from the axioms of such a system. (Which is something completely different from prooving that math is not consistent).
God has also failed every test thrown at it.
I don't believe in God, but if he (i'll use the 'he' pronoun for convenience) exists then he's the one making up the rules not us, so 'testing' for God is a bit dumb. We can prove that the universe could have happened without God but we can't prove he doesn't exist.
And if he does exist I bet string theory is giving him the best laugh he's had in centuries :)
which string theory?
The one that will come out of the renormalization that they'll need to do to make it fit the observed outcome of this experiment, obviously.
[...] or assuming the correctness of math before Godel (who proved math is not consistent, whoops)
You got to improve your trolling - you have to be irrational and coarse enough to be enraging, yet not so loony that you self-identify as a troll. I rate you a 6 out of 10 for aggravating, which is OK I guess. What puts you over the top is stating that Godel proved that math is inconsistent. At that point the trolling just becomes too obvious.
"What you call love was invented by guys like me to sell nylons. You're born alone and you die alone and this world just drops a bunch of rules on top of you to make you forget those facts." -Don Draper, Mad Men
Is that it isn't. What I mean by that is it doesn't seem to make any testable predictions. At this point, it is just a bunch of math wanking. Now there's nothing wrong with purse math. A lot of useful theories start out that way and I like the Bacon quote "If in other sciences we should arrive at certainty without doubt and truth without error, it behooves us to place the foundations of knowledge in mathematics."
However when all you've got is a bunch of neat math with no real testable predictions, it is not a theory and it is not the sort of thing to be crowing about to the general public. XKCD, as usual, did a humorous job summing it up: http://xkcd.com/171/.
If you are going to complain that people complain about the lack of testability then you need to do two things:
1) Read The Logic of Scientific Discovery again and brush up on what a theory is and isn't.
2) Don't go making press releases. I'm not saying you personally have done this but physicists are awful happy to talk to the press about something they can't prove.
Part of it is simply wanting accuracy in the use of the words because let's face it: In science accuracy matters. Being pedantic about terms is important in science. Another part of it is this is the kind of thing that confuses normal people. With evolution, scientists have gone to a lot of trouble to explain that a theory is NOT a guess, NOT a wild idea, etc. They show other theories and how they work, how many things we accept as true are theories.
Well something like this undermines that to an extent, because here is something being called a theory that is not only untested, but that they can't even figure out how to test. It is the kind of thing that can make people say "But wait, if this is a theory then theory doesn't mean what you said."
Actually, it seems to me like we don't call those grand-unified things a proper scientific theory either. As long as there are no testable predictions, and it fails Occam's Razor, it's not a theory, plain and simple. It's a hypothesis.
Yes, there is a name for a theory which hasn't yet been tested: hypothesis.
And really, as someone who's gotten tired of hearing Young Earth Creationists go "well, evolution is just a theory" and having to explain to them "yeah, but theory in science doesn't mean what you think. It means it already made testable predictions and is the best we have"... it's getting annoying to see that a whole bunch of physicists are actually using it exactly as the YECs and conspiracy theorists think: as just an untested and untestable supposition, which may or may not actually hold any water at all.
Yes, I realize that calling it a "theory" is more science-y sounding and good for your funding. But it devalues the whole idea of science for everyone. If we accept that some untested and untestable calculation is just as worthy of being called a "theory" with a straight face as GR or electromagnetism just because it's the pet supposition of some physicist, then basically why wouldn't Behe's pencils-up-the-nose ID idiocies be a "theory" too? I mean Behe _is_ a professor of biochemistry.
Call it the String Hypothesis, and you'd see a lot less complaints, basically.
A polar bear is a cartesian bear after a coordinate transform.
is here: http://arxiv.org/abs/1005.4915.
No, it's nylons... and they only go down from the thigh (otherwise we're talking about pantyhose, which are a creation of the devil.) From the thigh up, it's garters. If you find turtles, retreat immediately. It's likely to get worse, and you don't want to know about that... guys that want to know about that become gynecologists. And no one with any sense at all wants to encounter dark matter. Also, garters first, panties (optional, of course), second.
Experimenting in this realm is highly recommended. Repeat a lot - you want to be sure.
I've fallen off your lawn, and I can't get up.
This has been solved for quite a long time. Perl's built in regular expression tests have had the ability to check for strings for many years now.
if( $var =~ /\w/) {}
Alex, I'll take keybindings not used by Emacs for $400....
Well, propositional logic can be proven to be consistent (there are no contradictions) AND complete (all true propositions can be proven out of the axioms), so can first order predicate logic (in the PhD dissertation of Gödel, 1929).
To construct arithmetic out of logic, we however need second order predicate logic. Gödel (1930, published 1931) showed that axiomatic systems in second order logic are either incomplete (true non-provable sentences can be constructed) OR they are inconsistent (containing contradictions).
So really math is not consistent (if something cannot be proved, even if not actually disproved, you cannot reasonably say that it *is*, because it isn't).
You are confusing "consistency" with "completeness".
"With all due respect, Dr. Cooper... are you on crack?" -- Dr. George F. Smoot III
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It seems I may have jumped the gun on this one. My bad for being such an easy mark of sensationalist pop science headlines.
Don't feel bad, I submitted it a day before you did. What really blows my mind is that Not Even Wrong used my submission as evidence that Slashdot was running a story on it:
Update: No press campaign for a “finally string theory is testable” claim is complete without a Slashdot story
Big news for theoretical physicists who are fed up with the inability to test String Theory
(that's from my submission)
My work here is dung.
In other words, string theory may finally have shed its critics' most common complaint: unfalsifiability.
It's critics? It's CRITICS.
Holy crap man. After spending a significant chunk of your life working on string theory, wouldn't you want to test it? That's part of the whole "I'm a scientist"!
Democrats or Republicans. They are both taking us to the same place and they are not afraid of us anymore.
No, you can NOT say that it is inconsistent, and you can NOT say that it is consistent. The fact that you prove you can't say some A doesn't automaticaly makes NOT A true.
Having a bit of trouble with math, isn't you? What are you proposing to construct the real numbers of? Rational numbers? If so, that is just a tautology. You don't need to construct the real numbers, as you don't need to construct the natural numbers. You don't proff that math exists, that doesn't make sense (well, except if you define "exist" in some mathematical way, but then, you'll be just applying your definition).
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Chill out, Pinky.
Where did I say I was using the one from Contact or anything. Yes, I'm using largely the version you explain there: as long as two hypotheses explain the exact same sets of measured data, go with the less complex one, leave the more complex one for when you actually have some data that the other one can't explain.
In exactly that sense, as long as the String Hypothesis doesn't have at least one testable prediction [b]of its own[/b], that can't be explained by the simpler GR and QM, it freaking fails Occam's Razor.
It doesn't mean it's _false_ and nowhere did I say it's _false_. I said until such time as it makes testable predictions of its own, it's just a _hypothesis_. Different thing from "false".
So basically, what, you made all that fuss to answer to your own strawman?
A polar bear is a cartesian bear after a coordinate transform.
Hmm, where is the -1 "Woefully misinformed" moderation when you need it.
It's not just that the consistency of Peano arithmetic cannot be proved inside Peano arithmetic, it can't be proved, at all (in any meaningfull way : the only way to "prove" it is to accept it's correctness as axiom).
Well this is just wrong. You can indeed prove the consistency of Peano arithmetic if you're willing to go outside it. Specifically you can use Gentzen's consistency proof, which doesn't "accept the correctness of Peano as an axiom" (but has other limitations). To add further weight to this, you may note that the Incompleteness theorems state that the system will either be incomplete (have unprovable truths) or inconsistent; Peano arithmetic is incomplete, for instance Goodstein's theorem is unprovable.
rational numbers and, God help us, real numbers have much, much worse problems than mere doubts. It is known that rational numbers are inconsistent, and real numbers cannot be proven to even exist. There are no known ways to construct real numbers that are not simple extensions of rational numbers.
This is just false as well. Real numbers are on firmer ground than the natural numbers as far as proof theory goes, since there is a complete and consistent axiomitization of the real numbers (in fact several) that aren't "constructed as an extension of the rational numbers". Since the axiomitization is simple enough, it doesn't fall afoul of the incompleteness theorems, and thus can be proved both consistent and complete.
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