One of the biggest weaknesses with string theory, as an explanation for the way the universe is the way it is, and a possible way to bring together relativity and quantum physics, is the paucity of testable aspects. And if it ain't testable, it ain't science. So say the critics. But maybe string theory is testable after all.
The most recent proposed test pops up in today's Science. Tom Siegfried's story reports that "Superstrings that were supertiny shortly after the big bang could have been stretched by the expansion of the universe to cosmic size today, says Robert Myers of (where else?) the Perimeter Institute for Theoretical Physics in Waterloo." And we should be able to measure cosmic-sized strings, he says.
Earlier analyses indicated that strings from the time of the universe's birth would be diluted away by the subsequent expansion or would be too unstable to survive to the current epoch. But advances in recent years have shown that's not necessarily true, Myers said. "We have scenarios where you get, in fact, a rich network of different kinds of strings generated at exit from inflation," the brief burst of superfast expansion following the big bang, Myers said. "So we have the exciting possibility that in certain scenarios, the superstrings might appear in a network of cosmic strings."
Myers isn't the first to suggest a way to test string theory. Don Colladay and Patrick McDonald at the New College of Florida propose a similar scaling up effort, only using Bose-Einstein condensates, those weird, super-cold soups of atoms held in a single quantum state. (New Scientist, June 3). Just as the cosmic-stretched strings would allow astronomers to get a glimpse of the effects of superstring that are otherwise too small to measure, so would a BEC allow for measurement of aberrations in string-level particulate behavior.
I don't know much about the actual science. My degree is in biology. And there are still lots of strange elements of string theory that may yet doom the whole idea. But it's beginning to look like string theory just might be testable. So dismissing it all as "not even wrong" as some have done, is perhaps premature.
This is good news, in part because the presence of a non-testable "theory" in the scientific mainstream makes it quite hard to argue that so-called "intelligent design" theory is not scientific largely because it's not testable. Of course ID is non-testable by definition, while string theory so far has fallen short due only to experimental scale limitations. But still, it would be good to be able to get rid even a perception of a double standard.
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A good place to follow string theory in layman's terms is over at Lubos Motl's blog Reference Frame. He's a string theorist at Harvard and one of the world's leading in the under 30 age-group, who doesn't seem to mind spending an inordinant amount of his time explaining what is going on at the frontiers of string theory to the general public. And he's good at it too.
The article you quote by Siegfried is full of misleading hype and misunderstandings. Part of what is going on is that the "cosmic strings" that you reproduce a picture of and the Bose-Einstein condensates you mention have nothing at all to do with elementary superstrings, which is what the controversy over testability is about.
There's more about this at my blog
http://www.math.columbia.edu/~woit/wordpress/?p=466
and if you want to see what is wrong with string theory, Luke Lea's suggestion is excellent.
The testability problems of string theory are a matter of principle and very real. Scientists and science journalists should not be trafficking in misleading hype in order to defend string theory against legitimate complaints that some aspects of it are pseudo-science. Doing this is just ultimately going to hurt the credibility of science as a whole, and play into the hands of the IDers.
'... Lubos Motl's blog Reference Frame. He's a string theorist at Harvard and one of the world's leading in the under 30 age-group...' - Luke Lea
Lubos Motl is 33 so unless he has discovered a worm hole in string which has sent him back in time more than 3 years, he isn't in the under 30 age-group.
Also, he is sexist and friendly with some bigmouth called Witten who claimed misleadingly: String theory has the remarkable property of predicting gravity. - Edward Witten, M-theory originator, Physics Today, April 96.
For an exposure of some of Lubos Motl's errors and prejudices see
http://nige.wordpress.com/2006/09/22/gravity-equation-discredits-lubos-…
Even if experimental tests are now possible, I think the term string "theory" is still inconsistent with proper scientific usage. Scientific theories aren't just testable. A proper scientific theory has already passed multiple experimental tests, and proven its ability to predict and explain observations that can't otherwise be predicted or explained. AFAIK, string "theory" is still a long way from meeting that standard.
Until recentily, it should have been called the string model or something similar. Perhaps now its reasonable to call it the string hypothesis. Continuing to call it string theory comprimises the scientific meaning of theory, IMHO.
Sorry, Lubos Motl is only 33 years young if nigel says so and I bet he is right.
OTH, he is wrong when he writes: But women physicists are more careful and so more likely to be correct [than males]. Now that's what I would call sexist bias even if only delivered in jest.
Nigel is more seriously wrong when he accuses Motl of sexist bias in the opposite direction. Not only does the guy regularly use the indefinite pronoun she instead of he, when writing about science he is fulsome in his praise of female colleagues when he thinks they are on to something.
As for Motl's irrational "faith" in the truth of string theory -- or, rather, his faith that string theory is the only current intellectual frame-work that might conceivably unify the four forces of nature and explain the physical universe at a deeper level than The Standard Model -- he is quite out-front about this. And he is frankly optimistic that real predictions will eventually be made by advances in string theory, though, again, he is explicit that this is is based on nothing more than his personal faith in the possibilities of science together with his physical and mathematical intuitions. Given his demonstrated achievements and obvious command of the mathematical and theoretical issues involved -- something most it not all of critics cannot match -- I would say that his opinions are worthy of respect.
But there is a more serious issue involved. Laplace, when asked about the role of God in the operations of nature once famously remarked that God was not a hypothesis that he entertained. The whole point of science in other words is to see how far the empirical/logical/mathematical approach can go in explaining the structure and operations of nature without invoking the idea of an intelligent designer. So naturally there is a kind of blind faith among scientists that they can go, if not all the way, at least further than they have gone so far, which is already a lot further than anybody could have reasonably predicted a couple of centuries ago. That particular scientists have faith in particular hypotheses is not only unsurprising, but in fact necessary if they are going to make the sacrifices and pursue their researches with the requisite energy and time.
As for my own biases? Well, personally, I favor the strong Anthropic principle. I actually applaud the fact that string theory currently allows for the possible existence of more universes than there are grains of sand on the beach, and I would be quite satisfied if they never narrow it down. In other words I am secretly hoping that Motl and company, and all future generations, will be frustrated in their quest for an ultimate theory that explains in principle the whole of nature. I feel this way because it would bring the enterpise of science to an end of sorts, which would be discouraging in itself and unfair to future theoretical physicists, and because it would take away some of the mystery and magic of matter and the physical universe, which I find both fascinating and humbling.
These prejudices of mine do not prevent me from being fair to Lubos Motl, however, much less do they tempt me to defame his moral character. I feel that Nigel owes an apology not only to Motl but also to the readers of this blog.
I am not a physicist and cannot in any way judge the merits of Motl's assertions about string theory on his blog.
I have to say, though, that they do not resemble the tone or structure of what are familiar to me as scientific arguments. They sound more like the arguments of a member of one school of painting or musical composition against another. They are very blustery and "true-believerish".
But, again, maybe he's absolutely correct. I simply can't judge the content.
I tried reading a bit of Motl a year or so ago. But after seeing him make an ass of himself at other blogs, I decided I just couldn't take him seriously. (Search No Se Nada for 'Motl' to see some of his asshattery; he also generated some nonsense at Cosmic Variance a while back.)
Moreover, what I have read does jibe with PhysioProf's analysis. He doesn't come across as someone ready to accept the possibility that string theory may be a dead end.
As for the string theory stuff itself, it only really seems interesting mathematically, at the moment. But at least it's generated some interest in my field (algebraic geometry intersects string theory in all sorts of ways).
I think even a cursory review of Motl's views would suggest a lack of intellectual rigor. Certaintly not on the level of, say Lee Smolin.
"... I feel that Nigel owes an apology not only to Motl but also to the readers of this blog." - Luke Lea.
Luke, recently in comments on his blog Lubos has written the opposite of what you say. He states firmly that string theory is as scientific as evolution, and he says string critics are 'moronic crackpots'. I've put a full response to your comment on the blog page as it seems to be too long to be entered here. Notice that his nick name the "Motley fool" is now being used to sell humor, see the slogan at: http://www.fool.com However, I apologise: sorry Dr Motl for pointing out what a stringy clown you have become.
String theory refuted:
When it moves in spacetime, the 1-dimensional stringy line gains an extra dimension (time) and becomes a 2-dimensional world sheet.
Then to get particle physics they have to add either 8 or 24 dimensions to give the required vibrational degrees of freedom for the known particles using the Ramanujan function to satisfy conformal symmetry.
This results in 10 or 26 dimensions in total. These 8 or 24 dimensions come from supersymmetry (1:1 symmetry of superpartner bosons for each fermion) which uses 8 dimensions, and the older bosonic string theory which uses 24 dimensions. Supersymmetry is included to make the Standard Model forces unify at about 10^16 eV or something, way too high to ever check even in a particle accelerator as big as the solar system. So it is a load of unobservables being invented in order to explain a completely untestable, uncheckable hypothesis.
Next, you get the problem of explaining why there are 10 dimensions when spacetime we see only has 4 spacetime dimensions!
Easy! The Calabi-Yau manifold can roll up the 6 dimensions we cant see, and it rolls them up at the Planck scale, very conveniently so we can never check them.
Plus, the Calabi-Yau manifold even constrained to 6-d has loads of unknown parameters to describe the size and shape of each of the 6-dimensions it has. The vibrational modes for it are extremely complex as a result, so the string has 10^500 possible ground states, the cosmic landscape.
This is explained in a brilliant manner in Peter Woits book Not Even Wrong.
... M-theory also unifies 10 dimensional string theories (there are many variants, all crackpot in the sense of making no checkable predictions) with 11-d supergravity which is the classical limit. Lubos has a long list of things string theory says about information theory, black holes, branes, the holographic conjecture, and such like. All uncheckable speculations.
Now consider the alternatives. One is Woits representation theory ideas which models the Standard Model with weak force chiral symmetries in ordinary low-dimensioan spacetime (see page 51 of Woits http://arxiv.org/PS_cache/hep-th/pdf/0206/0206135.pdf showing how the standard model can be produced with electroweak symmetry, without requiring extra dimensions).
Wikipedia shows the origin of representation theory:
There is a natural connection, first discovered by Eugene Wigner, between the properties of particles, the representation theory of Lie groups and Lie algebras, and the symmetries of the universe. This postulate states that each particle is an irreducible representation of the symmetry group of the universe.
As for gravity, Lee Smolins loop quantum gravity (an alternative to string) is also ignored by the string theory obsessed mainstream of theoretical high energy physics. Peter Woit describes what loop quantum gravity is about very clearly in Not Even Wrong.
When you look at Smolins lectures, Smolin sums the graphs of Penrose spin network interactions to yield a path integral quantum field theory which equals general relativity without a metric (ie, background independent).
Since Yang-Mills quantum field theories like the standard model involve the exchange of gauge bosons between charges to produce forces, and since gravitational charge will be mass, evidently the loops of Smolins theory are the loops created by gauge bosons being exchanged back and forward across spacetime between masses. There is a lot to be explored here, with many possibilities.
Instead of working on the standard model and gravity using these low-dimensional real modelling strategies, the stringers are wasting everybodys time and money on speculation which is now known to be hopeless due to the cosmic landscape problem. Mainstream string theory is both a fad and a fallacy.
I find the responses quite amusing. How much effort is used to proclaim a theory as testable just so that ID is kept as folly. Rather than struggling to prove string theory testable so that ID is on the other side of the fence, try looking for truth, wherever it may happen to exist.
Dr. Ranger McCoy Initial post FOR IMMEDIATE RELEASE
THE PHYSICS TIMES
Princeton, NJ
Ed Witten was seen reading Woit's THE NOT EVEN WRONG while simultaneuosly walking down Nassau Street in an inertial frame, followed by his 137 postdocs, who were chanting in unison, as measured by a stationy observer standing outside of PJ's Pancakes.
Some towards the front of the line started crying first (in the lab frame), as they realized it was the end of a free ride for blind obedience, and that for health benefits, trips to exotic conferences, and summers off, they were going to have to start thinking on their own.
The news spread far and wide. Up in Cambridge Lubos Motl changed his snarky one star amazon review for NEW to a laudatory five star review, so as to secure future NSF funding. And Michio Kaku added Woit as a friend on his myspace page, after a call from his media team.
"I've seen darker days than this," Brian Greene smiled, recalling the bar scene with the hot chick in his PBS mini-series. "I already got my two string theory coffee table books out and am set. I know that I have secured the Nobel--in literature."
Witten said, "It is time to make peace. The most important thing that we ST, LQGers, and Not Even Wrongers must do is continue to oppose physical theories, which unify disparate physical phenomena in the same physical framework. Otherwise mathematical masturbation will fall out of favor, and we will have to join the proletariat in working for a living and taking what they're giving."
I wish Woit would have talked more about his views on the future of physics. For it is not enough to criticize, and I would hate to see the future of physics dominated by those untying the knots of String Theory.
ST hath failed. Utterly and completely. It could not have failed more with twice as much NSF fundining.
String Theory was the only game in town, and now there are two--ST & deconstructing ST.
But there is another that actually unifies QM & SR & GR with a physical model: MDT--it's physics!
Moving Dimensions Theory is in complete agreement with all experimental tests and phenomena associated with special and general relativity. MDT is in complete agreement with all physical phenomena as predicted by quantum mechanics and demonstrated in extensive experiments. The genius and novelty of MDT is that it presents a common physical model which shows that phenomena from both relativity and quantum mechanics derive from the same fundamental physical reality.
Nowhere does String Theory nor Loop Quantum Gravity account for quantum entanglement nor relativistic time dilation. MDT shows these derive from the same underlying physical reality. Nowhere does ST nor LQG account for wave-particle duality nor relativistic length contraction. MDT shows these derive from the same underlying physical reality. Nowhere does ST nor LQG account for the constant speed of light, nor the independence of the speed of light on the velocity of the source, nor entropy, nor time's arrow. MDT shows these derive from the same underlying physical reality. Nowhere does String Theory nor Loop Quantum Gravity resolve the paradox of Godel's Block Universe which troubled Eisntein. MDT resolves this paradox.
Simply put, MDT replaces the contemporary none-theories with a physical theory, complete with a simple postulate that unifies formerly disparate phenomena within a simple context.
THE GENERAL POSTULATE
OF DYNAMIC DIMENSIONS THEORY
The fourth dimension is expanding relative to the three spatial dimensions.
If at first the idea is not absurd, then there is no hope for it.
-Albert Einstein
But after thirty years of the absurdity of String Theory, millions of dollars from the NSF, and billions of complementary dollars from tax and tuition and endowments spent on killing physics and indie physicists, perhaps it's time for something that makes sense-for a physical theory that actually accounts for a deeper reality from which both Relativity and Quantum Mechanics, from which time, entanglement, gravity, entropy, interference, the constant speed of light, relativistic time dilation, length contraction, and the equivalence of mass and energy emerge. It's time for Moving Dimensions Theory-MDT.
-The Physicist with No Name
I know what you're thinking. Did he say there were thirty-six dimensions or only thirty-five? Well to tell you the truth in all this excitement I've kinda lost track myself. But being this is a .45 Revolver-the most powerful hand gun in the world and would blow your head clean off, you've got to ask yourself one question--Do I feel lucky? Well, do ya punk!? -Clint Eastwood
I'm interested in the fact that the less secure a man is, the more likely he is to have extreme prejudice. -Clint Eastwood
Go ahead. Make my day. -Clint Eastwood
MDT IN BRIEF
Without further adieu, allow me to present the beauty and elegance of MDT by showing both its simplicity and far-reaching ability to account for and answer fundamental questions. All of the below will be elaborated on throughout the book.
Questions Addressed by MDT:
Why does light have a maximum, constant speed independent of the source? The fourth dimension is expanding relative to the three spatial dimensions. A photon is momenergy that exists orthogonal to the three spatial dimensions. It is carried along by the expanding fourth dimension. So no matter how fast the source is moving when the photon is emitted, the photon travels at the rate with which the fourth dimension is expanding relative to the three spatial dimensions. Thus c is always independent of the movement of the source.
Why are light and energy quantized? The fourth dimension is expanding in a quantized manner relative to the three spatial dimensions. Light and energy are matter rotated completely into the fourth expanding dimension, and as it expands in a quantized manner, light and energy are thus quantized.
Why is the velocity of light constant in all frames? Time is an emergent phenomena that arises because the fourth dimension is expanding relative to the three spatial dimensions. The flow of time is inextricably wed to the emission and propagation of photons. In all biological, mechanical, and electronic clocks, the emission and propagation of photons is what determines time. The velocity of light is always measured with respect to time, which is inextricably linked to the velocity of light. This tautology ensures that the velocity of light, measured relative to the velocity of light, will always be the same.
How can photons display both wave and particle properties? The fundamental photon propagates as a spherical wave-front, surfing the fourth expanding dimension. This is because the fourth expanding dimension appears as a spherical wavefront as it expands through the three spatial dimensions. The act of measurement localizes the photon's momenergy, taking it out of the expanding fourth dimension and trapping it in the three stationary spatial dimensions, and it appears as a localized particle, trapped by electrons as it blackens a grain on a photographic plate.
How can matter display both wave and particle properties? The fundamental electron is abuzz with photons. Photons are continually being emitted into the fourth expanding dimension and reabsorbed by the electron. The continual dance with these photons gives the electron its wave properties. Nothing moves without photons which up the net probability that the combine momenergy will be in the expanding fourth dimension. The more photons one adds to an object, the greater the chance it has of existing in the expanding fourth dimension, and thus it moves.
Why are there non-local effects in quantum mechanics? The fourth dimension is expanding relative to the three spatial dimensions. That means that what begins as a point in the fourth dimension is a sphere with a 186,000 mile radius one second later. So it is that the entire spherical wavefront of the photon exists in the exact same place in time. Hence the non-locality observed in double slit experiments, the EPR effect, and quantum entanglement. Take two interacting spin ? photons and let them propagate at the speed of c in opposite directions. They are yet at the exact same place in time! And too, they are yet in the exact same place of the fourth expanding dimension.
Why does time stop at the speed of light?
Time depends on the emission and propagation of photons. If no photons are emitted, time does not occur. This holds true whether the clock is an unwinding copper spring, a biological system such as a heart, or an oscillating quartz crystal. No photom emission=no time! As an object approaches the speed of light, its ability to emit photons without reabsorbing them diminishes. An object traveling at the speed of light cannot emit a photon.
How come a photon does not age?
A photon represents momenergy rotated entirely into the fourth expanding dimension. A photon stays the exact same place in the fourth dimension, no matter how far it travels. A photon stays the exact same place in time, no matter how far it travels. Again, time is not the fourth dimension, but in inherits properties of the fourth dimension.
Why are inertial mass and gravitational mass the same thing?
Why do moving bodies exhibit length contraction?
Movement is always accompanied by a shortening in length. This is because the only way for a body to move is for it to undergo a rotation into the forth dimension, which is expanding relative to the three spatial dimensions. The more energy an electron has, the more photons it possesses, and the higher probability it exists in the expanding fourth dimension. Hence its length appears contracted as perceived from the three spatial dimensions.
Why are mass and energy equivalent?
The fourth dimension is expanding relative to the three spatial dimensions. That means that a baseball sitting on a lab table stationary in our three-dimensional inertial reference frame, is yet moving at a fantastic velocity relative to the fourth dimension. Hence every seemingly stationary mass has a vast energy, as given by E=mc2. In a nuclear reaction matter is rotated into the expanding fourth dimension, appearing as high-enegry photons (gamma rays) propagating at the same velocity of the fourth expanding dimension-c.
Why does time's arrow point in the direction it points in? The fourth dimension is expanding relative to the three spatial dimensions. Hence every photon naturally expands in a spherically symmetric manner. Hence every electron, or piece of matter that interacts with photons, is naturally carried outward from a central point in a spherically symmetric manner. Hence the particles in a drop of dye in a swimming pool dissipate in a spherically symmetric manner, and are never reunited. Hence time's arrow and entropy.
Why do photons appear as spherically-symmetric wavefronts traveling at a velocity c? The fourth dimension is expanding relative to the three spatial dimensions at the velocity c. Hence photons, which are tiny packets of momenergy rotated entirely into the fourth dimension, appear as spherically-symmetric wavefronts propagating at the velocity c.
Why is there a minus sign in the following metric?
x^2+y^2+z^2-c^2t^2=s^2
The fourth dimension is expanding relative to the three spatial dimensions at the velocity c. Hence the only way to stay still in the space-time continuum, and to achieve a 0 interval, is to move with the velocity of light.
What deeper reality underlies Einstein's postulates of relativity?
The fourth dimension is expanding relative to the three spatial dimensions at the velocity c. This single postulate assures that the speed of light is constant for all observers and that the laws of physics are the same in all inertial frames.
What deeper reality underlies Newton's laws?
Newton's laws are an approximation of relativity and quantum mechanics, and as MDT underlies QM & relativity, it underlies Newton's laws.
Why is an increase in velocity always accompanied by a decrease in length as measured by an external observer? All increases in velocity are accompanied by rotations into the fourth dimension. All particles can be represented by momenergy 4-vectors. The greater the momenrgy component in the expanding fourth dimension, the greater the velocity and speed of the particle. Rest mass is the invariant here. It never changes. It prefers the three spatial dimensions. In order for it to move, one must gain energy in the form of photons. These photons prefer the fourth expanding dimension. The more photons one adds, the greater the component of the momenergy 4-vector that appears in the fourth expanding dimension, the more energy the particle has, the shorter it appears, and the faster it moves.
How MDT Is Aiding Fellow Physicists
"The conclusions from Bell's theorem are philosophically startling; either one must totally abandon the realistic philosophy of most working scientists or dramatically revise our concept of space-time." -Abner Shimony and John Clauser
Moving Dimensions Theory provides this new concept of space-time. The vast ambitions of most tenure-track physicists, including string theorists and LQG hypers, causes them to focus on irrelevant, minute questions, and thus, though funded by millions for over thirty years, have not yet been able to string the bow. Deeper, true physicists, such as Abner Shimony and John Clauser are alert to the fact that physics need news ideas.
The expanding fourth dimension gives rise to non-local phenomena and quantum entanglement, as the expanding fourth dimension means that two events separated in the three spatial dimensions can yet appear to be at the exact same place in the fourth dimension. MDT thus provides the new concept of space-time.
"For me, then, this is the real problem with quantum theory: the apparently essential conflict between any sharp formulation and fundamental relativity. It may be that a real synthesis of quantum and relativity theories requires not just technical developments but radical conceptual renewal." -John Bell
Moving Dimensions Theory provides this radical conceptual renewal. The expanding fourth dimension gives rise to non-local phenomena and quantum entanglement, as the expanding fourth dimension means that two events separated in the three spatial dimensions can yet appear to be at the exact same place in the fourth dimension. MDT thus provides the new concept of space-time.
"Entanglement is not one but rather the characteristic trait of quantum mechanics." -Erwin Schrodinger
The expanding fourth dimension gives rise to non-local phenomena and quantum entanglement, as the expanding fourth dimension means that two events separated in the three spatial dimensions can yet be at the exact same place in the fourth dimension. MDT thus provides the new concept of space-time.
"For me, then, this is the real problem with quantum theory: the apparently essential conflict between any sharp formulation and fundamental relativity. It may be that a real synthesis of quantum and relativity theories requires not just technical developments but radical conceptual renewal." -John Bell
Moving Dimensions Theory provides this radical conceptual renewal. The expanding fourth dimension gives rise to non-local phenomena and quantum entanglement, as the expanding fourth dimension means that two events separated in the three spatial dimensions can yet appear to be at the exact same place in the fourth dimension. MDT thus provides the new concept of space-time.
"Entanglement is not one but rather the characteristic trait of quantum mechanics." -Erwin Schrodinger
The expanding fourth dimension gives rise to non-local phenomena and quantum entanglement, as the expanding fourth dimension means that two events separated in the three spatial dimensions can yet be at the exact same place in the fourth dimension. MDT thus provides the new concept of space-time.
http://physicsmathforums.com
If string theory is valid, we should be able to prove it by creating a sky hook.
A few final words about Lubos Motl. I came to him via Peter Woit's blog and must confess that I was prepared for the worst. The guy is obviously full of beans, is uncouth, tactless, and rude to those with whom he disagrees on scientific issues especially, and he has an almost enfantile level of political sophistication as to the true character of George Bush, for example.
On the other hand, he is very out front about all this, and his brashness is somehow refreshing; if read closely you realize that he is actually quite humbel about his own abilities (admits when he cannot follow a colleague's arguments, identifies issues about which he is unsure, and so on). True, he calls the critics of string theory in the popular press idiots and worse, but only because they so obviously don't know what they are talking about. In the case of other physicists like Woit I gather there are issues of professional pride (Motl certainly does not respect the other fellow's amor propre (sp?) which no doubt earns him a lot of ill will.
It all reminds me of a cartoon I once saw which pictured God as a Chef in a kitchen cooking up the world in a big pot on the stove. He was shaking a can of spice into the broth labeled "jerks" justifying Himself by saying: "And now, just to make it more interesting. . ." Personally I am glad that people like Lubos Motl exist. I do not find him threatening, and I wish our society had more people like him. As the English used to say, you can judge a civilization by the way it treats its eccentrics.
As for Motl's achievements as a pure scientist, check Wikipedia: the story of how he emerged on the scene is right out of a fairy tale -- better than any of his antagonists'. Look at his serious publications, not his blog, if you want to judge him as a scientist. People don't become Harvard Fellows for nothing.
As for those who think Motl is a fool and a clown, think Shakespeare and the king's court. Somebody has got to be willing to say those God awful things out loud even if they do sound like farts.
Geez, there's so much personality politics in this thread I can't even follow what's going on. Anyway:
I doubt I know any more than you do about the actual science. However while positive predictions coming from a string theory, as with this condensate thing or this cosmic string thing, are encouraging developments, I'm not sure they actually take us firmly into testability country. The problem is-- this is just my understanding, I could be wrong-- that as far as I can tell, both of these proposed predictions do not flow from string theory itself, but just from specific individual versions of string theory. If we tested these things and they turned out to be right, that would be a big deal, but if we tested these things and they turned out to be wrong, then that wouldn't tell us anything at all-- it wouldn't give us any clue as to whether string theory is right, it would only tell us the one specific variant of string theory that made that prediction is wrong. And there are so many variants of string theory that we could test and discount a whole host of them without being any particularly closer to knowing if string theory is the right path at all.
Still, I'd expect it's worth looking into. By the way, I don't have access to this Science article-- how exactly are these cosmic-scale strings supposed to be detectable?
From the Science article:
Dr. Ranger McCoy, please get real about moving dimensions theory! There are 3 orthagonal, expanding time dimensions, not one! See: comment on Lunsford SO(3,3) theory at http://discovermagazine.typepad.com/horganism/2006/10/the_end_of_stri.h…
That predicts strength of gravity, cosmological constant (the CORRECTED cosmological constant!!), etc.
Moving Dimensions Theory provides this new concept of space-time. The vast ambitions of most tenure-track physicists, including string theorists and LQG hypers, causes them to focus on irrelevant, minute questions, and thus, though funded by millions for over thirty years, have not yet been able to string the bow. Deeper, true physicists, such as Abner Shimony and John Clauser are alert to the fact that physics need news ideas.
http://www.mathiverse.com
The expanding fourth dimension gives rise to non-local phenomena and quantum entanglement, as the expanding fourth dimension means that two events separated in the three spatial dimensions can yet appear to be at the exact same place in the fourth dimension. MDT thus provides the new concept of space-time.