Deconstructing Strings?

November 14, 2006

“Deconstruction” is a method of critical analysis of philosophical and literary language that emphasizes the internal workings of language and conceptual systems, the relational quality of meaning, and the assumptions implicit in forms of expression.

Todays most fascinating paper is without doubt the one by Bert Schroer entitled:

String theory deconstructed (a detailed critique of the content of ST from an advanced QFT viewpoint)

In this paper Bert (BS) supposedly gives “a detailed and comprehensive critique of claims and methods of string theory from an advanced quantum field theoretical viewpoint.” BS starts out by listing nine claims of string theory “which afterwards will be shown to be fundamentally flawed”. These nine claims are:

1 ) The Kaluza-Klein argument can be used in QFT (or ST) to encode compactified spatial coordinates into inner symmetries
2 ) In ST supersymmetry is spontaneously broken
3 ) Holography is a construct which needs quantum gravity as a prerequisite
4 ) The Maldacena conjecture is about a AdS—CFT holography
5 ) The counting zero mode degree of freedom estimate about the cosmological
constant is consistent with the principle of local covariance
6 ) String theory solves the “information paradox”
7 ) Strings are quantum objects with a localization in spacetime which is
string- instead of point-like
8 ) It has been shown that ST contains QFT in the limit of low energies.
9) The S-matrix of ST has the properties of a particle physics S-matrix

For one thing, BS does not like KK compactifications (claim #1), since “I recently red that already Pauli had shown that this is impossible, but there was no reference given.” And concerning claim 3), BS states that “I think that anybody who knows the framework of particle physics (say beyond the level of recent QFT texts which where written by string theorists) would agree that holography from d+1 to d dimension and its possible inversion cannot be anything else than a radical change of the spatial encoding of a specified algebraic substrate; using this word for anything else would be a misuse and lead to misunderstandings.” This seems to debunk the idea that holography should be related to quantum gravity.

But BS’s arguments against “the Maldacena conjecture” are even stronger. For example, he says that “I do not know any competent quantum field theorist who does not accept Rehren’s work as the correct formulation of AdS—CFT holography (Hollands, Wald, Brunetti, Fredenhagen, Verch, Buchholz, …)”. It is – at least to me – unclear what the …’s stand for here; but even more staggering are BS’s adventures into advanced psychoanalysis: “For psychologically understandable reasons it was this metaphoric QG connection which attracted the attention of string theorists (QG is the raison d’etre for string theory) and which led Maldacena to formulate a conjecture involving a vague idea of supersymmetric string under the KK curling (with its even more vague idea of its QG content) on the dual AdS side in case one starts from a (supersymmetric) conformal field theory”.

For some reason also, quantum mechanics seems to be enough to understand black hole physics: “Of course one can use Bekenstein’s classical formula and equate it with this microscopically computed entropy to determine epsilon (I have not done this, but there can be no doubt that at this point the Planck length enters and determines the size of the vacuum polarization cloud). The calculations are in two papers […]”.

With Maldacena (and … and ….) literally on his knees, an alternative resolution of the apparent clash between quantum mechanic and general relativity was put forward by Wald: “His proposed solution was the start of the modern theory of QFT in CST in which the Lagrangian formalism is abandoned in favor of the adoption of the dichotomy of AQFT between the algebraic structure of QFT and the admissible states on such algebras.”

Numerous other advanced arguments seem to kill the claims 5) and 6) above. And for 7) I learned, that: “The localized algebras are monades with very different properties from algebras one meets in QM. There can be no doubt that the understanding of their positioning in a common Hilbert space will be an important step on the long way towards QG.”

But of course the “monad” (or, in biological terms, flagella) point of view also call into question whether string theory contains quantum field theory in its low-energy limit (8): “The message from this last case is that metaphoric arguments (e.g. looking at functional representations without actually doing the functional integrals) may turn out to lead to wrong results. Take for example the case of 2+1 dimensional QFT which have braid-group statistics. If the spin is anyonic (i.e. not semi-integer) the statistics is plektonic and the upholding of the spin-statistics theorem in such a case prevents the nonrelativistic limit to be a (second quantized) QM; it remains a nonrelativistic QFT. Only if one relinquishes the plektonic commutation relations, but preserves the anyonic spin one finds Wilczek’s anyons in the form of quantum mechanical Aharonov-Bohm dyons […]”, and then “The message from this illustration is that a theory can only be asymptotically (e.g. for long distances) contained in a more fundamental one if their structures harmonize.”

But the flagella (monads) also kill the S-matrix arguments 9): “A much more detailed correspondence of Leibniz’s image of reality in terms of indivisible monades to the conceptual structure of particle physics is provided by the algebraic setting of QFT (AQFT). If one identifies Leibniz’s monades with copies of the unique hyperfinite type III_1 factor algebras then it can be shown that any QFT permits a faithful encoding into the relative positions of a finite number of monades”.

At this point I started thinking: is this all a joke? Was I being fooled? Staring a the screen I was wondering whether or not I had really been fooled. On the one hand, if I wasn’t fooled, then this paper was serious, hence I was fooled by my understanding of physics. But if I was fooled, then I did get what I expected from BS, so in what sense was I fooled?.

Then suddenly I realized, that I had seen this text before, but just in another (isomorphic) disguise. It was the famous “Sokal hoax”, a hoax paper published by physicist Alan D. Sokal in 1994, entitled “Transgressing the Boundaries: Towards a Transformative Hermeneutics of Quantum Gravity”. (Sokal’s hoax served a public purpose, that of attracting attention to what Sokal saw as a decline of standards of rigor in the academic community; for this reason, Sokal’s text was “liberally salted with nonsense”). For example, quoting from Sokal:

“In mathematical terms, Derrida’s observation relates to the invariance of the Einstein field equation […] under nonlinear space-time diffeomorphisms (self-mappings of the space-time manifold which are infinitely differentiable but not necessarily analytic). The key point is that this invariance group “acts transitively”: this means that any space-time point, if it exists at all, can be transformed into any other. In this way the infinite-dimensional invariance group erodes the distinction between observer and observed; the [pi] of Euclid and the G of Newton, formerly thought to be constant and universal, are now perceived in their ineluctable historicity; and the putative observer becomes fatally de-centered, disconnected from any epistemic link to a space-time point that can no longer be defined by geometry alone.

and

“It is still too soon to say whether string theory, the space-time weave or morphogenetic fields will be confirmed in the laboratory: the experiments are not easy to perform. But it is intriguing that all three theories have similar conceptual characteristics: strong nonlinearity, subjective space-time, inexorable flux, and a stress on the topology of interconnectedness.”

.

So, was I fooled or not?

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The End of Astrology?

August 24, 2006

It has just been decided by the International Astronomical Union (IAU), that Pluto has lost its status as a planet.

A “planet” is now defined as (IAU):

…a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

Pluto fails on the third criteria, (c).

Does this mean the end of astrology? What theories will be invented to revive it?

Well, I’m sure it’s not the end of days for astrologers (and other crackpots) yet – for example, you can still obtain a free computer-generated horoscope here.

Update: there is a critical discussion about the definition of a “planet”, and whether we should really care much about such a definition, at Bad Astronomy; and Alan Stern, leader of NASA’s New Horizon’s mission to Pluto, thinks that the definition stinks.


Bubbles of “Nothing”

July 30, 2006

Note: Technical details and discussion are written with small print and can be skipped in a first reading 😉

What is a bubble of “nothing”? The answer clearly depends on which area of reality you are thinking about. I’ll illustrate this with a few examples.

In physics, a “bubble of nothing” refers to an effect discovered by Witten twenty years ago. Witten showed that the standard so-called Kaluza-Klein vacuum, Minkowski spacetime cross a circle M x S^1, is unstable to nucleating a “bubble of nothing”. It is of course important to have some criteria for determining whether a ground state of the form M x S^1 is reasonable as a unification of gauge fields with general relativity.

First of all, one should impose that this vacuum should be stable at the classical and the semiclassical level. The Kaluza-Klein vacuum is classically stable but unstable against semiclassical decay. Now, even if a state is stable against small oscillations, it may be unstable at the semiclassical level. This can occur if the state is separated by only a finite barrier from a more stable state. It will then be unstable against decay by semiclassical barrier penetration. To look for a semiclassical instability of a vacuum state, one looks for a ”bounce” solution of the classical euclidean field equations.

How is this applied to the Kaluza-Klein vacuum? First you analytically continue the Kaluza-Klein vacuum to euclidean space, i.e. to

ds^2 = dx^2 + dy^2 + dz^2 + dt^2 + dphi^2,

where phi is a periodic variable running from 0 to 2pi R, so that dphi is the line element of the circle S^1. Equivalently,

ds^2 = dr^2 + r^2 dTheta^2 + dphi^2.

A solution to the Einstein equations with the same asymptotic behavior is

ds^2 = dr^2/(1-k/r^2) + r^2 dTheta^2 + (1-k/r^2) dphi^2.

This is actually the five-dimensional Schwarzschild solution (but should not be interpreted as a black hole). Regularity at the point where r^2 = k, requires that we set k = R^2, where R is the radius of the circle. The metric of the resulting space – continued to Minkowski space – is

ds^2 = dr^2/(1-R^2/r^2) + (1-R^2/r^2) dphi^2 – r^2dpsi^2 + cosh psi^2dOmega^2.

This space is nonsingular and geodesically complete (which roughly means that there are no possible light-rays that suddenly “end”, like there are in spacetimes with black holes); it is the space that the Kaluza-Klein vacuum decays into.

What happens in the decay of the Kaluza-Klein vacuum is that a hole spontaneously forms in space. As a function of time, t, the boundary of the hole is at x^2 = R^2 + t^2. After a very brief time, this hole – or bubble of “nothing” – is expanding to infinity at the speed of light. So, why is it called a “bubble of nothing”? This is because the Kaluza-Klein vacuum decays into nothing, or more precisely into a space which is bounded by a bubble of nothing – space does not exist “inside” this bubble – which is expanding to infinity and pushing to infinity anything it may meet!

In pseudoscience the examples of “bubbles of nothing” are abundant. I’ll just mention two examples. One is the crackpot book The Final Theory by Mark McCutcheon; another one seem to be the research carried out at The Quality of Life Research Center in Copenhagen, directed by holistic physician Søren Ventegodt.

In politics, there are plenty of examples of “bubbles of nothing”. Recently, there are the examples of various reactions to Israel’s extreme aggression against the palestinians and the people of Lebanon (the massacre in Qana being just one very recent example)- such as those by president Bush, Rice and many others (however strange, my friends over at Cosmic Variance have had nothing to say about this conflict). Another one is Bush’ veto against research in stem cells. (In an upcoming post I’ll explain why research in stem cells is so important).

In sports, a recent example of a “bubble of nothing” was apparently Floyd Landis’ “victory” in the 2006 Tour de France. But to be fair this doping “scandal” might in itself be a “bubble of nothing”. This is, however, not very likely (as recent findings showed that some of the testosterone in his body had come from an external source) and Floyd might end up being considered by historians as the most naive and stupid “winner” of the Tour de France.

The list of “bubbles of nothing” is endless. Other examples, anyone?

Update: Floyd Landis’ B sample was positive; welcome in the historybooks and adieu to the title as the winner of the 2006 Tour de France…;-)


Amazon.com and “The Final Junk”

June 1, 2006

June 7th
Review of “The Final Theory” rejected with the reason that: “… the comments you submitted did not review the title itself. Instead, your comments focused on another reviewer and were more suited to a chat room discussion.”

June 6th
Review of “The Final Theory” submitted to Amazon.com yesterday, the 5th of June around 1 PM.

As described earlier, I’ve been trying to post a review of the crackpot book “The Final Theory” by Mark McCutcheon. My review appeared on the website of Amazon.com on May 7th, only to disappear a few hours later. I’m sure this was because my review was a one-star review. As this review was deleted, I’ll try posting a new one and include it here, so that the author of this book, at least, – or whoever else – cannot make it disappear into oblivion 😉

“The Final Theory” (by Mark McCutcheon)

This book is “not even wrong” (to use a famous quote of physicist Pauli). I’ll explain what that is supposed to mean.

A meaningful statement can be said to be either correct, or wrong. “The Final Theory” is full of so many meaningless and wrongful statements, that I consider it to be not even wrong. And I cannot consider it as being anything else.

First of all, it does not contain any valid physical arguments. Plainly speaking, it misrepresents current theory again and again. For example, it argues that gravity violates the law of conservation of energy, because it causes kinetic energy. As an example, the author asks: “How does it [gravitation] cause falling objects and orbiting planets without drawing on any known power source?”. This is simply explained by the fact that it is the kinetic plus the potential energy which is conserved – a falling object decreases its potential energy as it increases its kinetic energy.

Secondly, the author confuses the basic concepts of work and energy (which you normally learn about in elementary school). For example, it is postulated that if you want to move an object, you must spend energy, and that this is the only way how energy may be invested. This is obviously wrong. When you try to push a wall, no work is done – since the displacement is zero – but surely it costs energy!

Thirdly, the book relies on what one could call “common sense appeals”. The author seem to think that science shouldn’t be mysterious or hard to understand. From common sense we have learned many “important” things: that women are less intelligent than men, that homosexuality is “unnatural”, that the earth is flat, that the earth is the center of the universe, that airplanes cannot fly etc. etc. Serious scientist never use common sense as a guiding principle.

Amazingly, the book argues that modern physics – including the pillars of the special and general theories of relativity, and quantum mechanics – is incorrect. The actual situation is that the validity of the special theory of relativity and quantum mechanics has been experimentally established beyond any reasonable doubt; and there are numerous positive tests of the general theory of relativity.

The most complicated thing you’ll find in this book is the “Geometric Orbit Equation”, or

v^2 x R = K,

where v is the velocity, R is the distance separating two bodies and K is a universal constant. I find it very hard to believe that the fundamental workings of the universe can be understood from such a simple equation.

There is basically only one correct, and in the slightest degree, important statement in this book: It is, that we – including the author – do not know everything, or understand everything yet. But we physicists definitely know enough to say that this book is not even wrong.

Finally, let me mention something quite suspisious about the other reviews of this book. As of today (the 31st of May, 2006), there is a total of 95 reviews. 71 of these are 5-star reviews. This is – of course – quite stunning. Out of the 71 reviews, 63, or 90%, have written only one review in total; furthermore, one person wants to give a 1-star review, but is being counted as a 5-star review, twice; another person is counted with a 1-star and a 5-star review, and yet another 5-star review is counted twice. One top-10 reviewer grants the book another 5 stars, but as far as I can tell, all of this persons reviews (which there are more than 2500 of) are 5-star reviews.

If you really want to learn about modern physics, I recommend books by Weinberg, Randall, Greene or Hawking.

In conclusion, I cannot give this book anything more than one star. And sadly enough, nothing less.


Amazon.com: more science than junk-science (finally)?

May 5, 2006

Note: Updated on May 7th, 2006

The story about the crackpot book “The Final Theory” (by Mark McCutcheon) has taken a new – and rather surprising – turn.

As described earlier in Lubos’ blog, Anthony Kirmis’ tried to post a 1-star review of “The Final Theory” back in August 2005, but it did not survive for much more than one week. Many other people experienced that their 1-star or 2-star reviews were deleted. However, as of today, there are 289 reviews of the book, with a staggering 2-star average, mainly because of around 200 1-star reviews which suddenly have appeared on amazon.com.

I commented on this book earlier here. The book claims to describe the “final” theory of everything, ignoring – for example – the existence of gravity and using only extremely simple elementary-school arithmetic. Instead, the sensation that we feel as gravity is really the Earth expanding up and accelerating against our feet!

As I’ve said before, I think it is most likely, that McCutcheon originally arranged for the 1-star reviews to be deleted (but of course, he had to ask amazon.com to do it). Still, there are many phony things about the reviewing system of Amazon.com. As others have observed, many of the 1-star reviews seem to have been posted by fictive persons. Also, I noticed a 5-star review by John Matlock “Gunny”. This person is a top-ten reviewer, and has posted around 2575 reviews, but all of those which I have skimmed through are 5-star reviews! About “The Final Theory” he makes the comment, that:

I find the book highly amusing. It’s worth reading, but don’t take it too seriously.

But still he rewards it with five stars…!?

I, myself, thought about posting a review. But it should be very short. Something like: “This book is not even wrong, but at any rate I’ll give it a 1-star review for money-making!”

Update: As of today (May 6th) there are now only 7 one-star reviews and 6 two-star reviews. The average rating is now 4.5 stars! I think I’ll have to withdraw my statement, that Amazon.com appears to be “more science than junk-science”. The rating system is completely flawed and obviously highly dubious.

I’ve posted a review of the book here. (Well, until somebody made sure that it was deleted….).


Amazon.com: more junk-science than science?

December 27, 2005

(This article was originally posted on blogger.com on Aug 29, 2005)

As described earlier in Lubos’ blog, Anthony Kirmis’ 1-star review of the crackpot book The Final Theory (by Mark McCutcheon) did not survive for much more than one week. As of today, there are 34 reviews of the book, with an amazing 5-star average. I commented on this book earlier here. Basically, the book claims to describe the “final” theory of everything, ignoring – for example – the existence of gravity and using only simple elementary-school arithmetic. Did McCutcheon himself ask amazon.com to delete the bad reviews? Did amazon.com delete the bad reviews since they feared that the book would not sell good enough?

I think it is most likely, that McCutcheon arranged for the 1-star reviews to be deleted (but of course, he had to ask amazon.com to do it). As an example of the contrary, Steven Weinberg’s excellent book “Dreams of a Final Theory” has received 9 reviews with a 4-star average (and this guy really knows what he is talking about) and Brian Greene’s famous books “The Elegant Universe” and “The Fabric of the Cosmos” received 425 and 117 reviews respectively, both with a 4.5-star average – and some of the reviews of these books are only 1-star reviews and have survived for much more than one week.


US Judge Rules Against Intelligent Design in Schools

December 21, 2005

The revenge of the monkeys… 

Today a federal judge ruled that a Pennsylvania school district cannot teach “intelligent design” (ID); the idea behind ID is that life is so complex, that it must have been created or “designed” by some kind of intelligent being. That being is usually assumed to be God.

Here is some more information from Reuters,

PHILADELPHIA (Reuters) – A judge on Tuesday barred the teaching of intelligent design as an alternative to evolution at a Pennsylvania school, saying in a scathing rebuke to the school board that it violated a constitutional ban on teaching religion in public schools. […]

“Our conclusion today is that it is unconstitutional to teach intelligent design as an alternative to evolution in a public school classroom,” Jones wrote in a 139-page opinion in the case, brought against the Dover School District.

Jones condemned the “breathtaking inanity” of the policy of the board, all but one of whom have now been ousted by local voters. “Any asserted secular purposes by the Board are a sham and are merely secondary to a religious objective,” he said.

Jones said the students and teachers of Dover High School “deserved better than to be dragged into this legal maelstrom with its resulting utter waste of monetary and personal resources.”

The school district was sued by a group of 11 parents who claimed teaching intelligent design was unconstitutional and unscientific and had no place in high school biology class.

 

Most of the reactions to this ruling were not really unexpected. For example,

Christy Rehm, one of the plaintiffs, said she was “ecstatic” about the judge’s ruling. “This is a victory for education, a victory for science and a victory for science education,” she told Reuters.

One of the proponents of ID, Casy Lusin of the notorious Discovery Institute surely did not agree:

But Casey Luskin of the Discovery Institute, a Seattle-based think-tank that champions intelligent design theory, criticized the ruling.

“The judge thinks intelligent design is a supernatural explanation, but it clearly is not. So the entire decision is predicated on a false perception of intelligent design,” Luskin said in a telephone interview.

What about president Bush who earlier actually promoted teaching Intelligent Design in schools? Well,

Asked about the ruling, White House spokesman Scott McClellan said the president has said he believed such decisions should be made by local school districts.

“The president has also said that he believes students ought to be exposed to different theories and ideas so that they can fully understand what the debate is about,” he said.

 

The White House still seems to think, that there really is something to debate about. Like if the next decision about the future of the US troops in Iraq should be determined by either political discussions or astrology?

More related articles can be found at google news.