Is Witten working on loop quantum gravity?

In this text, I would like to analyze the methods and logic of PW, a well-known critic of string theory, in one particular context.

Relevant sources for this article:

Frame: Monstrous symmetry of black holes
Frame: Witten's paper is out
Wrong: Assorted news
Musings: Report on Witten's talk
Witten: Preprint
Witten: PDF for his talk

This text will be exclusively dedicated to the analysis of the description of Witten's work by PW which I find rather incredible (see "Assorted news"):

• Witten’s talk is entitled “Three-Dimensional Gravity Revisited” ... So, at least one talk there will be about a non-string theory approach to quantum gravity more along the lines of the LQG program.

Wow. ;-) The picture below is a refined version of a photograph by Chehak and symbolizes how sane, natural, and correct the statement of PW approximately is:



Let us start with a simple question:

Why does PW write such a statement that will be shown to be a flagrant absurdity?

Well, the answer is obvious. If you read his blog or his book, you will learn that he believes that decisions in science do reflect and should reflect the emotional power of authorities. Edward Witten is such an authority, even according to PW, which is why PW thinks that if he manages to convince others about his interesting "story" that Edward Witten has largely switched from string theory to loop quantum gravity, it will have a dramatic impact on the scientific community.




Well, I happen to think that if Edward Witten started to work on loop quantum gravity, as defined by the existing contemporary methods and standards of the loop quantum gravity community, it wouldn't mean that physics is undergoing a phase transition. Instead, it would simply mean that Edward Witten would be getting senile. We all admire him and love him, if you want me to say strong words, but he is still a scientist, not God.

There have been many cases in which his opinion had much weaker impact on other scientists than what I would have found appropriate. And there have been cases in which quite many people started to do things because Witten did. On the other hand, it's clear that if Witten were saying things that don't make sense and can't be used by anyone to do logically coherent research, no one sensible would listen to him.

The motivation of PW is clear so let us ask another question:

Is PW's statement true?

No, it's absurd. Let's start with a simple, sociological description of the situation that should be comprehensible to non-experts.

If you open the preprint, you will see that most papers that are being cited were written by string theorists. You will see names like Maldacena, Strominger, Kachru, Dixon, Ginsparg, Harvey, Dijkgraaf, Moore, Seiberg, Verlinde, Friedan, Shenker, Gukov, Maloney, Vafa, and, indeed, Witten, among many others. They are related to physics of conformal field theory, AdS/CFT correspondence, partition sums, black hole physics. Their results and methods are used throughout Witten's paper.

On the other hand, one paper about loop quantum gravity by Ashtekar is cited in a footnote on page 3 of Witten's preprint as a curiosity and no results from that paper or any other loop quantum gravity paper is ever used by Witten. That would be really impossible because all of these results are wrong. They're simply results of faulty math.

Even without a deeper knowledge of physics, the reader should be able to verify that Witten is not doing anything that is "more along the lines of the LQG program", as we were told by PW. But let us analyze some details a bit more carefully.

Spacetime dimension and loop quantum gravity

Witten talks about physics of three-dimensional gravity in the anti de Sitter space. Is that the same dimension as loop quantum gravity? The answer is No. Loop quantum gravity is only loop quantum gravity if the spacetime dimension is four.

Neither Witten nor any other sane physicist I know of thinks that it is possible to define four-dimensional or higher-dimensional gravity - i.e. general relativity - as a pure gauge theory in the same number of dimensions. Witten, just like other big shots, thinks that the loop quantum gravity people have no standards. Physicists like Witten, Gross, and others would never discuss loop quantum gravity in a polite company. It's been a polite standard to allow the loop quantum gravity people do whatever they want, and simply ignore them.

What we're talking here, in the context of Witten's recent work, is another possible reinterpretation of a gravitational theory - namely three-dimensional gravity - in terms of gauge-theoretical degrees of freedom, namely using something that has also been called Chern-Simons-Witten theory. Fine, so let's ask:

Is Chern-Simons-Witten theory equivalent to three-dimensional gravity?

We must realize that the bulk of this question is vacuous.

Three-dimensional gravity is very different from gravity in higher dimensions because it has no local excitations. Why? Because Einstein's vacuum equations, namely Ricci flatness, imply complete flatness because in three dimensions, both the Riemann tensor R_{abcd} as well as the Ricci tensor R_{ab} have three independent components. These two tensors can therefore be calculated from one another. It follows that no gravitational waves are allowed. By quantizing this empty set, we obtain an empty Hilbert space of gravitons. There are no gravitons. There is no S-matrix to calculate. The situation is vastly less interesting than it is in four dimensions.

If there are no scattering amplitudes to calculate in this theory, what do we mean by the equivalence of two systems of equations both of which predict zero objects? Well, we mean that there must exist some other mathematical objects that can be mapped onto each other. Is it true?

Is Chern-Simons-Witten theory equivalent to three-dimensional gravity in some more general setup?

Sloppy physicists like to say Yes because at the classical level, one can make a field redefinition that changes the three-dimensional metric to a gauge field. Witten and more serious physicists have been explaining for quite some time that the answer at the quantum level is No. The Chern-Simons-Witten action and the gravitational action are not globally equivalent, they imply different ranges of path-integration, and absolute values from the gravitational action are not included in the Chern-Simons-Witten action.

Witten has also explained that the Kodama state, a popular formal solution of four-dimensional gauge theory occasionally employed for loop quantum gravity with a positive cosmological constant, is unphysical for a variety of reasons.

So is his new work finally confirming the LQG-like description?

The answer is "Just on the contrary." One of the main messages - or, using the words of Jacques Distler, the main message - of the work is that the gauge degrees of freedom simply don't give the right & full description of the quantum gravitational system.

The three-dimensional gravitational theory has no gravitons or other local excitations but it has black holes that macroscopically look like BTZ black holes. However, the precise quantum character of these black holes is not included in the Chern-Simons, gauge-theoretical description of the system. For example, the Chern-Simons gauge field gives us no hint that the black hole microstates transform as representations of the monster group, at least for some values of the curvature, even though this fact can be argued to be the case by other methods.

So Witten's point is really the opposite one than what PW wants his undemanding readers to believe: Witten argues that even in systems that can superficially be written in terms of bulk gauge fields and nothing seems obviously wrong - such as the case of three-dimensional gravity that predicts no light local excitations - the bulk gauge-theoretical description is always a bad language to talk about the theory at the quantum level.

The boundary conformal field theory whose existence is postulated via string-theoretical arguments always gives a more accurate description of the full quantum theory and the sloppy LQG-like formulae should never be viewed as the full story, not even in the cases where it's harder to show that they're inconsistent.

The three-dimensional anti de Sitter background is not connected with the ten-dimensional and eleven-dimensional vacua in any obvious way but such a fact never means that a given background is not a part of string theory: we already know a lot of islands where moduli are frozen which makes decompactification and other processes impossible. However, what's important is that the basic framework in which the physical laws are formulated and in which the observables are calculated and the consistency of the theory is deduced is the standard framework of string theory - including the AdS/CFT correspondence, one of the main topics of string theory in the last decade - and it has nothing whatsoever to do with loop quantum gravity as we know it.

Summary

You can see that one needs to write many kilobytes of text to carefully debunk vicious lies that PW can compress into one short sentence but I hope that it should now be clear to virtually everyone that these particular statements by PW are lies.

However, consider that PW has been intentionally generating tens of thousands of such lies on his blog for more than three years. Virtually everything he has ever written is junk and he's been probably preparing to do this dirty job for decades. And many people are so uneducated and uninformed that they are ready to buy some of these lies. If they don't buy all of them, 1% is enough because it is still hundreds of vicious lies.

You can't be surprised that using Bush's jargon from 9/11/2001, I think that we should make no distinction between the individual who generates these lies and those who harbor him. ;-)

And that's the memo.

Lee Smolin vs Thibault Damour

Le Monde informs about another battle in the neverending War on Crackpotism.

Thibault Damour faced no one else than Lee Smolin. Le Monde first summarizes how string theory solves the schizophrenia of the 20th century physics and talks about unification and dimensions.

Lee Smolin urges everyone to study any alternatives, whether they're garbage or just junk, and dares to talk about "tragic consequences" for "suicidal young physicists" who would like to work on these alternatives. (Similarity of his language with global warming is not a coincidence.)

All readers who understand anything about reality know that the situation is just the opposite than what Smolin says - namely bad consequences are more likely to meet those who publicly disagree with politically correct fashionable crackpots like himself. But "catastrophic" language and victimism is exactly the weapon used by those who already have about 500 times higher influence than they would deserve. (Similarity with crying feminists who already control the Ivy League is not a coincidence either.)

Damour has argued that not even Smolin can be so limited that he would actually believe the naive Popperian dogmas. Well, I am afraid that Smolin is much more stupid than Damour can even imagine. Accepting statements of philosophers as dogmas, blowing them out of proportion, applying them behind the range of their validity regardless of physical arguments, and using them to organize witch hunts is something that Lee Smolin is very good at.

Damour has also sketched the unprecedented conceptual richness of string theory as well as some experimental tests of string theory and its features by the LHC and other experiments. Damour also mentioned his work about the runaway dilaton that would generate a fifth force that would violate the equivalence principle. If the scenario in this paper were confirmed, it would prove their particular low-energy model that at some level naturally fits into string theory. I think that the runaway dilaton is unlikely but it could be experimentally proved if it is right and it would violate the usual consequences of the equivalence principle.




Predictably, the black crackpot has no idea about any of the actual papers so he thinks and even writes that Damour's statement contradicts my statement that all known semi-realistic F-theory and other major flux vacua exactly obey the equivalence principle. Everyone who has any clue about these things knows very well that there is no contradiction here simply because Damour talks about some very different scenarios.

I think that they're unlikely and as far as I know, he can't construct fully realistic backgrounds containing well-known particle physics (and if you ask me, it will never be possible in Damour's picture), but he is of course right that these models could be in principle experimentally proven, making the case for string theory and his particular structure of scalar fields strong. His models are 10 times more concrete a theory of future physics than anything in DSR or LQG and 50,000 times more than anything that Peter Woit has ever written down.

The usual models referred to as the landscape however don't have a runaway dilaton that would fit Damour's models. That's what I mean by the equivalence principle to be a general prediction of the whole landscape.

I just can't understand why some people read this breathtaking moron from Manhattan even after several years - when it must be so clear to absolutely everyone that he has no idea whatosoever about the topics he is writing about and everything he writes about anything that depends on physics, at least indirectly, is 100% junk. The people who read him must actually enjoy when a vitriolic simpleton constantly annoys and lies about other, much more sensible people. They must also enjoy when a wild dog attacks a human and eats her. They must suffer from some kind of deviation.

Concerning the other statement, I don't know whether Damour knows a construction to get some bizarre DSR-like dispersion relations from string theory. Maybe he knows something I know, maybe knows something I don't know, maybe he is wrong. But I can't judge what he says before I actually see a quantitative description of what he means and what's his evidence. Needless to say, crackpots can always judge anything, centuries before they understand the very basics. That's one of the millions of advantages of being a crackpot.

And that's the memo.

Why are there gravitons in string theory

Sean Carroll has written a text for Nude Socialist. It has an optimistic name

• String theory: not dead yet. ;-)

After I read the full text, it looks fair even though I am flabbergasted by the very observation that some people apparently think that physicists can suddenly change their opinions about theoretical physics because of a campaign organized mainly by two crackpots.

If an activist such as Al Gore organizes such a campaign in climate science, he can scare all sane people and everyone starts to twist the numbers and publish higher, catastrophic estimates of the future warming. It is hard to figure out that what the scientists produce is a biased pile of nonsense because every number a priori seems as good as every other number.




But in theoretical physics, this is simply not possible. If someone scares you into studying a theory of quantum gravity that differs from string theory, it simply won't work. Ingredients won't fit together. When you're ordered to work on such an inconsistent theory, you will feel like an idiot after you write down the second equation. Rightfully so. The whole machinery will collapse just like if you replace gasoline in your Chrysler by used toilet paper.

Gravity in string theory

But back to the main topic. Some people ask why string theory inevitably predicts spin 2 massless particles that moreover interact as gravitons.



Let me explain. Consider a closed string - a loop of energy - that oscillates in a spacetime. There exist functions

• X^m (sigma,tau)

that describe the embedding of the two-dimensional worldsheet, a history of propagating string, in this spacetime. The laws controlling the oscillations may be described by a two-dimensional field theory defined on this worldsheet - a two-dimensional manifold with a spatial coordinate "sigma" along the string (X^m have periodic conditions in sigma, to make the string closed) and a temporal coordinate "tau".

Its equations of motion are essentially wave equations for the scalars X^m.

For every background geometry (and possibly other fields such as dilaton and gauge fields), there exists a two-dimensional action on the worldsheet. But only some geometries lead to a consistent string theory. In fact, the worldsheet theory must be invariant under conformal transformations - transformations of the worldsheet coordinates that preserve angles - because the internal geometry on the worldsheet and the choice of coordinates on the worldsheet must be unphysical: if they were not, we would introduce new, unwanted degrees of freedom (essentially new spacetime coordinates). Scaling is the most important conformal transformation.

How does the theory on the worldsheet change under scalings? A quantum field theory - and the theory on the worldsheet is an example - has various coupling constants. The change of a "running" coupling constant under scaling transformations is generally encoded in the so-called beta-function. For each coupling constant, you have one beta-function.



At the beginning, we mentioned that for every background geometry, we have one theory on the worldsheet. All numbers describing such a geometry, namely all components of the metric tensor

• g_{mn} (X^k)

as functions of spacetime coordinates, are thus coupling constants of the theory on the worldsheet. How much do they run? What are the beta-functions? It is not hard to see that for every value of a component of the metric tensor, there will be one beta-function. Consequently, the beta-functions will depend on X^k and they will carry two vector indices. Moreover, they can be seen to include second spacetime derivatives of the metric tensor. When you think about the "manifest" spacetime diffeomorphism symmetry, it is not hard to see that the full answer for the beta-functions must actually be proportional to

• R_{mn} (X^k).

If the worldsheet theory is consistent as a string theory, it must be scale-invariant, and the spacetime geometry must thus be Ricci-flat! We have just derived Einstein's equations from scale invariance of a two-dimensional theory. Or at least we have sketched the derivation. If we considered backgrounds with other fields (matter fields), they would also contribute to the beta-function. We would obtain Einstein's equations with the correct right-hand side.

State-operator correspondence

Strings can only propagate consistently on backgrounds that respect the laws of general relativity or its generalizations. Does it mean that there are gravitons? Yes, it does.

Take the worldsheet action for a particular spacetime geometry, and make an infinitesimal (epsilon) change of the spacetime geometry so that the geometry remains Ricci-flat (for example, add a gravitational wave). Look at the difference of these two actions (and divide by epsilon). In other words, differentiate the worldsheet action with respect to the spacetime metric. You will inevitably get another integral over the worldsheet coordinates:

• integral d sigma d tau V(sigma,tau)
  

Any infinitesimal variation of the spacetime metric is thus associated with an operator V(sigma,tau) on the worldsheet. We can make something even more interesting. Cut a very small disk from the worldsheet. The new, short boundary of the worldsheet will look like a closed string. The actual length of this boundary is actually unphysical, because of the scaling symmetry of the worldsheet theory. For every wave functional on this closed string - a possible state in the Hilbert space of states of a single closed string - there will exist a local operator, and vice versa.

This one-to-one map is known as the state-operator correspondence.



Inserting the operator V(sigma,tau) at the point (sigma,tau) of the worldsheet is therefore equivalent to cutting a small disk around (sigma,tau) and integrating over all possible initial conditions on this circle weighted by an appropriate wave functional. For every local operator V(sigma,tau), there exists a state.

But previously, we have found an operator V(sigma,tau) for every possible infinitesimal variation of the background, e.g. for every gravitational wave. When we combine this old result with the most recent one, we see that for every gravitational wave, we discover one state of the closed string. In other words, closed strings will always have a state in their Hilbert space that is canonically associated with a change of the spacetime geometry.

Because closed strings in the Minkowski space - the simplest example (that approximates very well any background whose radius of curvature is much longer than the string scale, a typical distance scale associated with string theory) - are really described by a pile of ordinary harmonic oscillators, it is not hard to see that the states associated with the operators V(sigma,tau) corresponding to an infinitesimal perturbation of the spacetime geometry are spin 2 particles.

The operator V(sigma,tau) for a gravitational wave looks like

• exp(i k.X(sigma,tau)) partial_+ X^m(sigma,tau) partial_- X^n(sigma,tau)
  

It depends on a spacetime momentum vector "k". The complex exponential is multiplied by a holomorphic derivative of one "X" and the anti-holomorphic derivative of another "X". The two free indices "m,n" give it a spin equal to two.

Do the corresponding particles - closed strings with a particular vibration on them - interact as gravitons? You bet. When you deduce the interaction rates among these spin 2 particles composed of a vibrating closed string, the state-operator correspondence guarantees that they will respect the overall equations of motion given by Ricci-flatness - a condition that we have derived from the conformal symmetry.

There are other ways to see that the interactions of the string-theoretical gravitons must exactly respect the rules of general relativity. Every consistent gauge-invariant theory of spin 2 massless particles must inevitably have the diffeomorphism symmetry built in it which essentially guarantees that the theory is a version of general relativity.

You can indeed check that the spin 2 particles obtained from the vibrating closed strings are massless, gauge-invariant, and their interactions are consistent. That assures that the scattering amplitudes will coincide with those obtained from general relativity (in the long distance limit). You may also verify this conclusion by explicit calculations.

AdS/CFT

There are other approaches to string theory that have been shown to describe the same laws of physics. Holography in anti de Sitter spaces is a popular example. In this picture, there is a non-gravitational theory defined on the boundary of the anti de Sitter space at infinity and the key statement is that this theory is equivalent to a theory in the bulk.

The bulk theory is inevitably a gravitational theory. In other words, it is a consistent theory of quantum gravity, also known as string/M-theory. How can you see that there must always be gravity in the AdS bulk?

Well, the reasons are somewhat similar to the worldsheet arguments above. A particle that can go to the boundary of the AdS space corresponds to a local operator on the boundary. In this case, we are interested in the stress-energy tensor on the boundary, a rather special kind of a local operator. For every component of the stress-energy tensor of the boundary theory, there must exist a physical particle in the bulk. Once again, one can prove that the interactions of these particles must be consistent with the diffeomorphism symmetry: they must be gravitons.

There are other reasons why the bulk theory is always a gravitational theory. In non-gravitational theories, the entropy stored in a volume V is proportional to the volume. In gravitational theories, however, the maximum entropy you can squeeze into this volume is carried by a black hole and the black hole entropy is only proportional to the surface area. Gravitational theories secretly carry a small number of degrees of freedom than what you would naively think. This is a key fact that makes holography possible.

Matrix theory

In the BFSS Matrix theory, only highly supersymmetric backgrounds are well-understood. The origin of gravitons in any Matrix theory is always analogous to the case of the maximally supersymmetric, 11-dimensional background of M-theory.

If you have 32 supercharges, you can prove that there are states that preserve one half of the supercharges, namely 16. The broken generators can be combined into 8 complex pairs - 8 creation plus 8 annihilation operators in a fermionic harmonic oscillator. Each such an operator raises or lowers the spin by 1/2. They're exactly enough to climb from

• j_z = -2 ... to ... j_z = +2

because there are (+2 - (-2)) / (1/2) = 8 steps in between. 32 supercharges thus guarantee, once again, that the spin j=2 is the highest spin included in the simplest supermultiplet. Supersymmetry - one of the symmetries that can also be proven in Matrix theory - also implies that general relativity must be included in the effective action, by spacetime arguments.

There are other approaches to string/M-theory that can be proven to describe the same local physics in spacetime. In all cases, one can also explicitly show that the graviton is a part of the story. The methods to find the gravitons that we sketched above look very diverse but in overlapping situations, they are related.

Polchinski & science vs Smolin & sociology

A temporary linker-not-thinker recommends you to read Polchinski's answer to Smolin's answer to Polchinski's review of Smolin's book at

Cosmic Variance

Thanks to Charles Tye!

.....

Well, I actually don't like too much when evil, dishonest, and hypocritical people are treated with pink gloves but Polchinski's text is a very good one despite the gloves because Polchinski clearly demonstrates that he has no problems with his shoes. ;-)

Polchinski tries to re-focus the discussion on physics. He first explains that there is no sense in which Smolin's mysterious "catastrophic predictions of a non-positive cosmological constant by string theory" could have been fully logical.




Supersymmetry breaking & vacua

Polchinski continues with evidence that well-known string theorists have always correctly judged our actual knowledge about the vacuum selection problem, both in the literature as well as in their talks. The moduli stabilization is an example where Smolin interprets a major success as a failure.

Existence of gauge theories & burden of proof

Joe explains that when someone like Smolin is making one of his bizarre statements that gauge theories don't exist, in sharp contradiction with explicit constructions (especially by Wilson), he should have an argument that goes beyond the proclamations that "they are an evil mafia", ideally a rational argument. Well, that's about 123 orders of magnitude above what Lee Smolin can offer at this moment. ;-)

In this context, Polchinski analyzes one of Smolin's hundreds of untrue theses, namely that Horowitz and Polchinski have ignored Smolin's conjectured "non-existence of gauge theory." Polchinski politely explains that Horowitz and himself have thought about it much more profoundly than Lee Smolin and all of his fans and allies combined.

Validity of AdS/CFT, rigor, and background independence

Joe repeats that it seems impossible to define Smolin's "weak form of Maldacena's duality", a nonsensical rhetorical sleight of hand that Smolin has borrowed from the creationists who divide evolution to good microevolution and bad macroevolution. ;-)

Polchinski tries to explain Smolin some basic facts about science, e.g. that scientific results are only as valid as their weakest links. Joe reviews some arguments about the temptation of rigor, especially in the context of the so-called Rehren's holography.

To show a bug in Smolin's "paradox" about causality in AdS/CFT, Polchinski mentions his paper with Nick Toumbas and Lenny Susskind. Joe emphasizes that the translation of imprecise words to precise equations is a crucial step in theoretical physics; being unable to make this step is correlated with the tendency to replace scientific arguments by sociological ones.

AdS/CFT is a major example showing that we know how to describe physics that locally looks like very diverse backgrounds - including black hole mergers, evaporation, graviton scattering, and wormholes - which invalidates Smolin's opinions that we can only describe tiny perturbations of certain fixed backgrounds and that string theory is incompatible with background independence.

Constraints vs physical Hilbert spaces

Polchinski explains that only the physical Hilbert space is physical. A larger space including non-physical states (and constraints) may be useful but it is in no way necessary. The Reference Frame has discussed this topic recently in the context of myths about quantum gravity. Smolin apparently tries to sell his confusion about the "necessary" unphysical space to be a "conventional wisdom".

Assorted technical topics: ion physics, cosmology, and unification of concepts

Joe talks about the successes with cosmology, RHIC and heavy ion physics, and warns that analogies are rarely perfect. He also explains why Smolin dislikes the AdS/CFT correspondence so much: it's because according Smolin's point of view, gauge theory is pursued by mere craftspeople while quantum gravity is studied by the real seers - and the AdS/CFT correspondence seems to be a heretical statement that the seers are equivalent to the craftspeople! ;-)

More precisely and less entertainingly, the distinction between certain concepts has really been erased, much like quantum mechanics has erased the gap between particles and waves. Those seers who don't appreciate this progress may be backward-seers but surely not forward-seers. :-)

Polchinski explains what must be done to replace the S-matrix in time-dependent backgrounds and what problems it inevitably brings.

Ultraviolet finiteness

Concerning the discussions about the UV finiteness, Polchinski settles it with another one-line proof. UV divergences always admit an IR interpretation. Zwiebach's decomposition of the moduli spaces is, according to Joe, the simplest framework to see why it is so.

Final comments about ethics

Polchinski shows why Smolin's claims about his ethical high ground are "ironic", given the poor standards of Smolin's intellectual integrity. He praises the diversity of experiences and perspectives that string theorists have and appreciates the "interdisciplinary" topics as a method to avoid excessive specialization.

Solving the planar limit of N=4 gauge theory: press releases

Since the visionary discoveries of 't Hooft in the 1970s, it's been known that gauge theories with a large number of colors should simplify and lead to a new kind of classical limit. Whenever the number of some objects is large, physics should simplify. Statistical physics simplifies into thermodynamics if you deal with many atoms. If you investigate theories with many colors, you should expect a simplification, too.

Indeed, shortly after the relevance of QCD for strong interactions was appreciated, 't Hooft has figured out that the most important Feynman diagrams start to look like a discretization of a two-dimensional surface - something we would call the worldsheet these days - that describes a history of propagating one-dimensional loops of energy, strings. ;-)

Gerard 't Hooft found out that whenever the number of colors is large, the Feynman diagrams can be split into groups according to the topology of the corresponding worldsheet that they discretize. The simplest topology, namely the "planar" topology, dominates while the more complicated topologies with "handles" are suppressed by powers of 1/N^2. The strict large-N limit is equivalent to strictly continuous worldsheets replacing Feynman diagrams.

This discovery was important for conceptual reasons - gauge theories are theoretically important even if the number of colors doesn't match the real world. But it was also important for observable physics because for QCD, 1/N^2 is 1/9 which is a small number and the new kind of stringy expansion could thus be useful.

Some key details about the behavior of the gauge theory at a large number of colors remained unknown for more than 20 years - until 1997 when Juan Maldacena famously merged 't Hooft's ideas with holography and new insights about black hole thermodynamics: the string theory describing the large-N limit of gauge theories has one additional large dimension besides those seen in the gauge theory and it includes strings and all other objects in an anti-de-Sitter space. Conformal symmetry, including the Lorentz symmetry, translations, scalings, and special conformal transformations, is interpreted as an ordinary isometry of the anti de Sitter space.

Integrability and media

That's great but can we actually calculate how these strings interact in the large N limit? Can we solve the planar limit i.e. to find all possible excitations on the corresponding string and the interactions of these excitations? In recent years, this question has been answer Yes.

• A recent press release

of Princeton University has promoted the paper by Klebanov et al. that has numerically verified hypotheses of Bern et al. and especially integral equations by Beisert et al. about the behavior of the N=4 gauge theory in the planar limit, based on the concept of transcendentality.

See Juan Maldacena and integrability and links in that article...

Now, I think that the press release is an example of news that the journalists should propagate much more intensely than they do - and they should think how to make them more attractive than they sound in the present form. The press release talks about serious work that is actually viewed to be exciting by the actual big shots who are respected by some of the brightest people, not just by journalists and their least demanding readers, and it uses honest language to analyze its numerous aspects of the relation between gauge theories and string theory.

These relations between gauge theory - an experimentally well-established pillar of modern physics - and string theory, together with the unity of string theory itself, are the main reason why string theory can never go away in the future, and only people unfamiliar with the structure of theoretical physics could think otherwise.

Controversial terminology

The only bizarre feature of the press release is the formulation at the beginning that "string theory is both one of the most promising and controversial ideas in modern physics." A nice politically correct formulation to make many crackpots happy. Is any theory whose critic is able to impress dozens of journalists automatically controversial? If it is, isn't the adjective "controversial" somewhat vacuous?

Well, I don't think that any of these calculations that tightly connect physics of gauge theory with numerous concepts and equations of string theory are controversial. Most people who like to create controversies would probably find these papers rather boring. What is really controversial is the stupid caricature of modern physics that has been invented by a few evil people and promoted by their friendly journalistic jerks.

But once again, that's very different from the actual scientific results that are somewhat intimidating and, as far as I can say, almost certainly right.

And that's the memo.

String theory in 2 minutes or less: poll

Brian Greene has chosen the main winner but everyone can decide about her own Oscar among these

• eight strong candidates.

Thanks to Amos Kenigsberg.

Gore's guru, Dr. Roger Revelle, disagreed with alarmism

The Financial Post, a Canadian newspaper, shows much more evidence that Al Gore's mentor, Dr. Roger Revelle, thought that the significance of the greenhouse effect was unproven and existing knowledge didn't justify any "action".



The evidence includes not only his widely discussed paper with Singer and Starr but also earlier letter to lawmakers and others.

Unfortunately, his student was a pretty lousy student. Even more unfortunately, lousy students are those who have much influence in this sometimes lousy world.

Meanwhile, another student who is a staunch AGW believer and became an official member of "Al Gore's cavalry", which is the official name of the greenshirts, is surprised that her classmates think that she's nuts. Most of her generation doesn't find global warming that terrifying, she says. Thanks God.

Similar nutcases as Claire who have made it into the European Parliament want to outlaw burping, so far only for cows. Poor cows. For 50 million years, they thought that they were free to burp. Suddenly, everything can change. ;-) According to the U.N., farm animals create 18% of the greenhouse effect, more than 14% created by transportation. And because the greenhouse effect became politically incorrect, poor cows must change their diet and recycle their manure.




There is only one thing we can say about this lunacy: "Boo!"

The New York Times asks:

• Carbon-neutral is hip but is it green?

and explains that the environmentalist gestures have no positive effect on the environment. They quote the president of an environment grant-making group that the whole indulgence game needs a new Martin Luther.

Well, I am afraid that it probably needs a new Winston Churchill instead - but even Luther would be progress. It is somewhat but not quite unexpected to find relief in the New York Times at the same time when we can't rely on sanity of the White House and many companies in these issues anymore.

In the Financial Times, Lawrence Summers correctly argues that the carbon policies won't lead to any good results if they don't include the developing world where most of the growth will occur. However, the hard-to-swallow conclusion is that the developing world should really be choked, and most of the article is dedicated to technicalities how to choke it. As I see it, the text is written with the assumption that the global warming believers own the world and the only question for them is how to figure out the details of the policies to control everyone on this world and everyone's carbon cycles.

I just can't believe that some of the analogous attitudes were still insufficiently left-wing for many people at Harvard. I consider these particular comments extremely left-wing. The Western politicians or professors don't own the world or the developing countries and don't have any right to dictate someone how much carbon dioxide he should be emitting. They wouldn't have this right even if their theories looked convincing - and they don't.

Well, I happen to think that if someone really plans to do these nasty things to the third world - things based on the assumption that the absurd "fight against climate change" is as important as their future -, they will eventually understand what is the goal and they may try to protect themselves, and guess whether I would be too sad if they assassinated a couple of promoters of the carbon regulation who want to prevent them from developing.

And if I am gonna make any medium-term prediction, I don't believe that China and India will accept any significant mandatory cuts of CO2 emissions. China is already becoming the leading country to oppose this lunacy.

Update, May 1st:

My prediction about China turned out to be precious. The position of the country that will become the #1 CO2 emitter this year has intensified.

Reuters reported that according to the Global Times - daily that, because of idiosyncratic Chinese societal arrangements, represents the opinion of 1.2 billion people - Western politicians are using climate terrorism to put the Chinese growth at risk, and China will oppose it.

Of course that any ban or restriction will just move the corresponding industry to China that will benefit. I wonder whether algores want to do something about it. Do they want to threaten China with nukes, to accept their megalomanic Kyoto-like plans? China has nukes, too. Moreover, China has a fifth column in the West. I dislike communists but if this clash became serious, I would, for example, instantly promote the pro-market Chinese communists to the status of fellow fighters for freedom! ;-)

Algores' insane plans to control the carbon cycle in the whole world will surely lead to some escalation of tension and emotions and these algores may soon find themselves in the same situation as the German chancellor in the late 1930s. Let's hope that fewer human lives will be wasted before they're stopped than what happened 65 years ago.

NPR on LHC

Figure 1: A decay of the God particle in the CMS detector. Simulated, so far.

See:

• National Public Radio on the LHC
• LHC on Wikipedia
• LHC home page
• Clifford Johnson's report
  

Via Asymptotia.




Click the category "lhc" below to see dozens of articles about the LHC, its experimental prospects, why the doomsayers are wrong, how it works, many other videos, and so forth.

Richard Lindzen in Newsweek: Why so gloomy?

There's no such thing as a "perfect" temperature

In the new issue of Newsweek, Prof Richard Lindzen of MIT explains that climate has always been changing, there is nothing special about one temperature as opposed to other temperatures, models can't be trusted just because someone says that he doesn't know another, correct explanation, and the CO2 growth or a hypothetical warming will bring as many benefits as problems if not more.

• Why so gloomy?

Roger Revelle, a late climate scientist, is described as Prophet Al Gore's mentor. Do you remember who was the mentor of Moses? Revelle, referred to as a scientific giant - because of his 6-foot-4 height (just like Bill O'Reilly), because of his fathership of USCD, and because he was one of the first scientists who studied global warming - argued that the existing knowledge didn't justify any action except if a non-climatic explanation existed.

New Zealand, skeptical radio program

You can listen to this 30-minute-long audio, featuring Richard Lindzen and the NZ Climate Science Coalition, reliability of surface measurements, hockey stick graph, Wegman report, economic absurdity of the Kyoto protocol, bizarre alliance of New Zealand with Europe as opposed to Australia and the U.S., and many other topics. The show ends with a professional Shakespeare-like theater performance of Prof Philip Stott in the New York debate. Thanks to Maksimovich.

Brian Greene vs Lawrence Krauss

If you're in DC today (Wednesday), you may try to see a debate of Prof Brian Greene himself with Prof Lawrence Krauss:

• Wed 3/28 7 pm in National Museum of Natural History (map)
  

Congratulations to Lawrence Krauss that he will be able to meet Brian Greene! Well, if a reader wants to meet a famous physicist, just write a silly book against his field and all the gates will open. ;-) I am partially kidding but not quite.

The event will be moderated by Prof Michael Turner.

A few days earlier, the Pioneer anomaly was discussed at the same place.

Update

As the Science magazine reports (while crediting "Lumidek" for a photograph, guess who's that), Krauss behaved as a simple-minded and aggressive warrior against science, pumping a lot of technically unsubstantiated and untrue statements and personal attacks (including statements that he wouldn't want his daughter to marry his string theory students - nice for Hong Liu and Raman Sundrum, among others) to the audience, and some of them bought it. It went far enough that Turner couldn't declare Brian a winner - claiming a tie instead.

Both Brian Greene and Michael Turner were very decent and tried to maintain a high quality technically focused discussion while Lawrence Krauss was mainly targetting the intellectual bottom of the audience with his incredibly cheap attacks and jokes.

As a famous colleague of mine is saying, Krauss is a typical example of a grumpy physicist who has never done anything important in science and decided that it's the more successful physicists' - string theorists' - fault and that he should revenge.

Krauss reminds me of the leaders of neo-Nazi parties from Czechoslovakia after the Velvet revolution who had nothing positive to offer but they were very good in supporting negative people's hatred against freedom, democracy, other nations, and successful people, among others. It took several years until these parties were eliminated from the political spectrum.

Audio plus another report is available.

Intelligence squared climate debate: audio and video

YouTube: video (10 parts)
MP3 from NPR (50 minutes, shortened and with summaries by an NPR host)
Full debate (92 minutes, Windows Media, more meat)
NPR web page of the event

As we have reported earlier, skeptics won. By the way, in a similar debate, skeptic Joe Kernen defeated alarmists Sheryl Crow and Laurie David.

When you listen to the audio, you can't be surprised. The alarmists are just categories below the skeptics as far as their scientific as well as rhetorical abilities go. Gavin Schmidt may be aggressive and says things that the audience doesn't like but he's clearly the brightest member of the alarmist team.

Opening statements

Richard Lindzen first explains basic facts. There has been warming in the 20th century: no side questions that. CO2 greenhouse effect contributes to the dynamics to one extent or another - probably not much - but no party questions this either. Then he says an important general fact that much of the confusion about the climate can be attributed to people's ignorance what is normal and what is not normal about the climate: weather events have always existed. Neither group claims that the climate change is a crisis today but the skeptics argue that it won't be a crisis in a foreseeable future either. Lindzen explains that most of the greenhouse effect expected from a doubling of CO2 has already occurred and it only led to a 0.6 Celsius degrees increase or so (and much of this small change could be due to other reasons). Sea level is more affected by tectonics than warming. Warm weather is more comfortable than cold weather. Warming helped to improve agriculture in India. Aerosols are often claimed to explain all gaps in the data except that IPCC admits that the impact of aerosols is virtually unknown and probably insufficient to cancel the warming. Other wrong predictions are blamed in the capacity of oceans except that these explanations start to look contrived. He says that the models can be adjusted to agree with the past behavior once it's known but that's very different from having a model whose future predictions can be trusted. Instead of accelerating, warming has been absent for 10 years. Data don't confirm a crisis. There's no way how we can be close to a "threshold". Temperature in the middle of the troposphere - one that should be caused by the greenhouse effect - is increasingly even slower than the surface temperature.




Everything that Lindzen says is based on relevant facts, broad scientific picture, and rational and quantitative considerations. (Applause.)

The initial testimony of another Richard, Richard Somerville, couldn't be more different. He first quotes several verses from the holy scripture that say that the climate change is unequivocally serious. He spends literally several minutes by prayers how his God is great. God who wrote the IPCC report is so great that there are 30,000 reviewer comments by great people who agree that God is great. Well, I apologize but if these 30,000 people are as unable to focus on the physical content as Richard Somerville clearly is, the value of the IPCC report doesn't necessarily have to exceed a dirty piece of toilet paper.

At the beginning, if I can be acausal a bit, Somerville tries to define what a "crisis" is, using a lot of big words that have obviously no relation with reality. He outrageously argues that individual geniuses almost never make progress in science and uses the word "contrarians" for all kinds of people. He even uses the continental drift as a success story for scientific consensus - no kidding. He collects several dozens of observations that have clearly no direct relevance for the question whether the climate change is a crisis.

He says that warm years occurred in recent era. Well, if you have *any* signal, natural or otherwise, whose period is comparable to one century, it is rather likely that most of the recent years will either be the warmest ones or the coolest ones. He glues together random data from a heat wave, a melting glacier, and speculations about a *positive* feedback from water vapor, and so forth - literally proving Lindzen's assertion that many people are completely unable to understand what's natural about the climate and what is not. He says that climate scientists have predicted these things. That's very funny because when they should have predicted them, they were predicting a new ice age. Climate science has so far made no long-term predictions that would be more successful than random guessing.

Michael Crichton starts by correcting Somerville's anti-history of the continental drift. The guy who had the right idea was vigorously ridiculed by all kinds of "leading" geologists at Harvard and elsewhere. The punch line of many such stories is that it is perfectly plausible that one person is right and a majority is wrong. (Applause.)

Crichton explains how surprised he was when he first looked into the climate numbers. The temperature increase was negligible. What drives the interest in the climate change is the future and the future is predicted by climate models that are unreliable and have already made all kinds of wrong predictions. He talks about the green preachers in the private jets who only talk about these things but have no intention to change their lifestyles. If they don't want to do it, why should anybody else? (Applause.) He explains some real problems of the world - poverty, no water and electricity for billions of people, and the immoral nature of the rich world that views these facts as less important than the hypothetical climate change.

Gavin Schmidt starts with a lot of correct general words about different levels of certainty in science, the task of scientists to find the most likely explanation without a bias and preconceptions. He correctly says that it's bad if a debate whose real driving force is a political concept starts to use science. He mentions creationism and CFC that may contribute to the ozone hole as examples where something that sounds scientific is used for politics. Although I would have certain problems with some of his examples, I completely agree that there's a lot of cases in which scientifically sounding arguments are not directed to experts but are meant to influence the lay public opinion. Well, he also includes the perfectionist and rational presentation by the other side as an example of the public being misled. I strongly disagree with it but even if I agreed, it's clear that most of the audience probably didn't like the idea that they're so stupid.

Schmidt tells the audience how they should count negative points. Every time the defenders of motion say an argument - for example about the lag of CO2 concentration behind temperature - the audience should add several negative points, Schmidt argues. ;-) Someone asks why and Schmidt obviously doesn't answer simply because there exists no "answer" to this argument that would be anything else than ridiculous.

Philip Stott is a born poet. His passionate presentation reminds me of some heroes of classical theater or, indeed, some of the best priests in the Church. ;-) He explains that science makes progress by falsification and paradigm shifts, not by consensus. Stott reads from several newspapers in the 1970s that reported the consensus about the catastrophes of coming global cooling. Global cooling may sound different than global warming except that the evidence came from oceans, from polar bears - they always play a key role, - changing seasons, and it was always a disaster. Why do we believe them now? To make things even more funny, he reminds us of the orthodoxy behind the first Earth Day. They argued that the U.S. population would drop to 20 million by the year 2000, bringing the calories per day near the African levels. ;-)

Climate is always changing. If it were not changing, it would be an interesting scientific anomaly that occurred for the first time in 4.6 billion years. Climate is very complex and as chaotic as the streets of Glasgow. We should ask the politicians: "When the desired effects of the policies will emerge?" Poverty affecting billions of people is more important. He is thus a left-wing critic of these things. As a European, he thinks that the hypocricy in Europe about these issues is absolutely mind-blowing. (Applause.) The emissions in many countries grow like mad yet the people want to teach others. Stott decided not to say anything about Al Gore and his house. (Laughter.) Angela Merkel is specifically mentioned for her plans to control the climate within a degree: that's a political crisis. (Big applause.)

Brenda Ekwurzel offers her (and Al Gore's) silly analogy with the fever. We're a doctor that has determined that the fever is caused by the emitted greenhouse gases. She argues that "1.4 degrees F means everything to 'fragile' Earth although it doesn't mean much to us". Who could have thought. Everything is exactly the other way around than she says. Individual animals, objects, and people are much more fragile than Earth. Earth has survived much much more drastic variations of anything. If the temperature change doesn't influence a typical human person, you can be pretty sure that it won't kill "Earth" either.

Confrontation

Brian Lehrer asks Lindzen and Ekwurzel whether the world will become more stable or less stable. Lindzen explains that the predicted decrease of the temperatures between the poles and the equator would reduce all kinds of storminess and other extreme phenomena. He answers a question whether the world could get better: of course that it could. We're not guaranteed to be at any optimum now. Stott supports this assertion later by pointing out the holocene optimum that was warmer and apparently more optimal than the present. An alarmist claims that a basement could be flooded. Stott says that global warming can't be used as a justification for bad engineers. (Applause.)

Ekwurzel, on the other hand, says that everything will get worse. She offers no explanation or anything that would be related to the scientific question but immediately starts to talk about the governments that must spend everything she wants them to spend. Well, poultry brains have been getting their PhDs for quite some time and political correctness has certainly contributed to this misplacement of scientific degrees.

Crichton is asked why the audience should believe his team and not the "huge consensus". He explains that this way of thinking is a warning signal because if the statements were scientifically solid, no one would ever refer to a consensus - for example in the question whether the Moon is orbiting the Earth. He mentions an example with Einstein who was asked "How does it feel that all these 2000 scientists are against you?" Einstein answered: "It only takes one to prove me wrong."

Schmidt agrees with Crichton that consensus is not science - it's what's left after the science is done. That's of course true (whenever the consensus arises) except that this observation has nothing to do with the key comment about the consensus - that consensus simply can't be used as a scientific argument. Schmidt says that people should be at the cutting edge. Stott agrees and explains that being at the cutting edge means to study the role of the cosmic rays. Schmidt says that the cosmic rays couldn't have caused any recent changes because their flux hasn't changed. He has no other arguments against the general framework that the cosmic rays are an important factor influencing the climate - something that has been studied at longer timescales. So he says that he just knows it's bogus and his colleague knows it's bogus. Everyone is amused. ;-)

Lindzen mentions some examples of Somerville and Schmidt saying wrong things, for example that the current weather is warmer than in the last 1300 years. As the NAS panel confirmed, the hockey stick graphs reconstructions before 1600 are not credible because the Mann et al. methodology was flawed. Let me quote the paragraph of the politically correct NAS panel about the small confidence in the very long-term reconstructions:

• Based on the analyses presented in the original papers by Mann et al. and this newer supporting evidence, the committee finds it plausible that the Northern Hemisphere was warmer during the last few decades of the 20th century than during any comparable period over the preceding millennium. The substantial uncertainties currently present in the quantitative assessment of large-scale surface temperature changes prior to about A.D. 1600 lower our confidence in this conclusion compared to the high level of confidence we place in the Little Ice Age cooling and 20th century warming. Even less confidence can be placed in the original conclusions by Mann et al. (1999) that "the 1990s are likely the warmest decade, and 1998 the warmest year, in at least a millennium" because the uncertainties inherent in temperature reconstructions for individual years and decades are larger than those for longer time periods, and because not all of the available proxies record temperature information on such short timescales."

Schmidt suddenly screams that the defenders of the motion say things that the audience can't understand. The audience boos. ;-) When Schmidt is asked whether his foes are biased because of an agenda, he says that he doesn't care. Philip Stott adds that he is left-wing and has no money from oil companies. :-)

Andrew Revkin (New York Times) asks whether anyone besides Stott questions that CO2 will warm the atmosphere. Ekwurzel unexpectedly starts to talk about methane emissions in the context of a question that has nothing to do with it, as far as I can say. Stott criticizes the Stern report that he didn't include social discount: a generation is paying for a richer generation. Ekwurzel disagrees and thinks that the future generations will be poorer and economics arguments can't be used. Well, if similar Ekwurzels start to shape policies, it can't be ruled out that the future generations will indeed be poorer. Somerville tries to make this topic even more political, insisting that the electorate should exert pressure on the politicians and tell them that it is extremely important to fight against the climate change. Oops.

An articulate female non-scientist member of the audience says that the consensus of scientists doesn't need much, citing a few examples - and she asks Brenda why is it so that the Earth is more fragile than the human being - a bold hypothesis that I was also stunned by. ;-) She asks why the warmer periods were so bad, citing warm Greenland as good examples. Ekwurzel gives a long answer - a kind of hysterical screech that nothing can adapt anymore and everyone will suffer - whose meaning I haven't understood at all so I can't transform this incoherent confusion into meaningful sentences.

Stott of course agrees with the woman that the Earth is much more robust than we are. Another question leads Stott to explain how hard it is to model an important man-made factor - changes in reflectivity. Schmidt says that it's meaningless to say that we don't know 80% of the effects.

Somerville says that it is enough for climate scientists to be useful - much like a doctor who can be useful even if she hasn't solved all diseases. Well, that's very nice except that this whole debate is about the question whether the recommendations by climate scientists and activists are useful or on the contrary - which largely depends on the question whether they're mostly right or mostly wrong. That's a question he doesn't want to ask at all which is the main origin of his poor performance.

Stott replies to Schmidt that he, Stott, doesn't want to cross a Brooklyn bridge built by an engineer who only understands 80% of the forces on that bridge. (Laughter.)

The participants are asked how they prioritize. Somerville gives another confused answer, illogically attacking the pro-side while saying that the investment in this "horrible" climate change business doesn't have to reduce money for fighting poverty etc. He adds some crazy comments that the poor will suffer most from the global warming. Crichton says that we can indeed do several things at the same moment except that we don't do them. Instead, we're talking about some speculative scenarios that will happen in 2100 while 3500 poor people die during the debate. (Applause.)

Closing statements

According to Somerville, we will run out of oil and we're using the atmosphere as a dumping ground which will damage the planet. Science is only useful if we do things according to its predictions: he cites a Nobel winner. Decisions must be made: it's thus a crisis, and we will therefore face dire consequences if we don't act. Well, this logic is different from the logic that I am used to. Neither of his "implications" follows the laws of logic as I know them. He repeats that global warming is a crisis and not fighting is irresponsible about 5 times, without a glimpse of a rational argument. (Weak applause.)

Stott says that the last thing he wants to do demean any scientist. The point of science is a constant debate. The main problem is not demeaning of scientists but the attempts to close the debate. (Applause.) Using a music analogy - Stott is not only a blogger but also a musician - reconstructing climate is like playing Mozart's symphony without most of the instruments. He says that poverty and current energy problems are more important and that global warming is being used by everyone for their personal agendas. (Applause.)

Schmidt says that the climate change is not new. He attacks what his three opponents are saying although it's not clear how the attack follows from the context. He quotes some "serious scientists" in the 1960s - no idea whom he means - who allegedly predicted all details of the current climate. There are no coherent theories that fit the data better, he says. Well, even if it were the case, and it's not, it is not a reason to trust one so randomly chosen theory. To deny that we have a crisis at a planetary scale is to fiddle while a home burns. ;-) (Applause.)

Lindzen thinks it's difficult to respond if others are telling you not to attack scientists - while they are attacking scientists; when they tell you how to regulate methane - without telling you that it has stopped rising; when they only tell you that there's warming on Earth - but don't tell you about the warming at Mars, Jupiter, Triton, Pluto; they tell you how oceans fit into the theory - while they don't tell you that oceans have recently cooled down and two papers from 2006 lead to the conclusion that the sensitivity is 1/10 of what Jim Hansen got by making incorrect assumptions about the ocean. If everything is so certain, why does the data keep on changing? And as they change, do we want to ignore the changes and stick to the point? (Applause.)

Ekwurzel claims that global warming is not only there but it is "accelerating". She is apparently used not to be expected to give any explanation, even for the craziest statements, which is why she immediately talks about business leaders who think it is a great idea to fight global warming. She enumerates several big corporations that are asking for action: in this case, of course, those who agree with the big corporations are not corrupt dishonest stooges and charlatans although she doesn't explain why. Several obnoxious sentences filled with a vacuous political propaganda follow. (Short applause.)

Crichton mentions a story when he was a physician: a woman came and said she was blind. They looked into it: she had hysterical blindness. He says that the reactions don't always have the same strength as their causes. Crichton says that most proposed actions are symbolic - and he adds his own: a private jet ban. Greenpeace and NRDC should ask their members to follow these restrictions. If they can't do that, why should we? (Applause.)

The defenders of the motion "Climate change is not a crisis" from 30 to 46 percent. The opponents of the motion went from 57 to 42 percent. Hard core ambivalents went from 13 to 12 percent and are still among us.

The skeptics were much better than the alarmists and Gavin Schmidt was, despite his aggressive approach, much brighter and more convincing than the other two members of his team.

Other regularly visited climate articles on The Reference Frame

• Viscount Monckton & alarmism about warming
• Dr Oreskes & fake consensus on global warming
• Temp drove CO2 ppm numbers, not the other way around
• IQ2 US duel: skeptics win over alarmists
• Correlations of the Sun spots and cosmic rays - and temps
• 2006: a not too good year for little chickens
• 2006: coolest average temp since 2001

Elegant physicist makes string theory sexy

MSNBC has an interview with Brian Greene on Hawking, optimism, LHC, WMAP, predictions of the future of physics, the landscape, understandability of string theory, length scales, sci-fi movies, and balancing time.

Mark Srednicki argues that Alan Boyle's questions were very good. Also, Brian Greene answers a question about the landscape by saying that if it's true, it completely changes the way we think about the Universe. Mark emphasizes that Brian - much like real scientists - are interested in the question whether it's true or not: if it is true, then our de facto ability to say things accurately is clearly lower than many of us would like to hope. Bigots like the blue one or the black one are not interested whether something is true but whether it is consistent with some preconceptions and arbitrary assumptions what science should say. I fully agree with Mark: their approach is not an approach of a scientist.

P.S.: Those who click learn that I didn't invent the title. ;-)

If you think that one newspaper interview with Brian Greene in 24 hours is not enough, open The Seattle Times. The interview is about the Fabric of the Cosmos, steak (not terribly positive!), experiments to prove string theory, loafs of bread, and Brian's apparent inability to put the ironing board out without making a horrendous screech. :-)

DiscoverMagazine.COM: string theory in two minutes

A science magazine has just upgraded its design to a new generation of user interface:

• Discover magazine

Let's hope that ugly pages with ugly interviews with ugly crackpots have been permanently moved to the history textbooks of science journalism. There is a new fancy video player on the main page. Also, the magazine is going to organize user-generated video contests. The first video contest asked the participants to do something that Joe Polchinski needs thousands of pages for, namely to

• explain string theory in two minutes or less.

The magazine has received over 50 submissions. The winner will be chosen by Brian Greene and will be featured in an upcoming issue of the magazine.

Map of E8

Richard Feynman once needed a map of the cat. If you have 60 GB of space on your hard disk and you need a map of E8, the largest exceptional Lie group, you may think about asking Jeffrey Adams (University of Maryland) to send you the result of their multi-year work plus 77 hours of supercomputer time: a 453,060 x 453,060 matrix. Not sure whether it will be helpful to the heterotic string phenomenologists but it could be fun for everyone. See The Times or a slightly more technical presentation at liegroups.org which I can't quite verify right now.

"Einstein may have started the rot"

According to Roger Highfield, another rather unintelligent person with a PhD, in The Telegraph, "Einstein may have started the rot". This is an exact quote from his rant against modern theoretical physics. Wow. It was apparently a sin for Einstein to develop a theory (GR) based on mathematical principles if he couldn't simultaneously do all experiments to prove it, the author argues.

That's getting pretty far although it can't be quite unexpected: what string theory is doing is nothing else than continuing in Einstein's program of theoretical physics, while avoiding all of his known imperfections.

It's very clear that if someone dislikes string theory, she or he must dislike most of modern theoretical physics, too (Lee Smolin certainly does!). It's because string theory is nothing else than the crown, unification, or culmination of modern theoretical physics and all of its crucial results, insights, methods, principles, and values.

I believe that the reason why the stupidity of these writings about physics has exceeded all reasonable bounds is that everyone who knows the right answers is afraid to inform people like Roger Highfield PhD that they are breathtakingly ignorant, degenerated, bigotic, and obnoxious pseudointellectuals and it's not a good idea for them to write about something that exceeds their abilities by so much.

No one tells him that his more or less average intelligence is about 30 points smaller than what is needed to meaningfully evaluate these questions, and his education is 10 years shorter than what is required for these cutting-edge questions. This expansion of stupidity can thus be blamed on political correctness, more precisely the idea that all people are equally qualified to evaluate ideas in quantum gravity.

Virtually all of Einstein's papers, at least those written by 1916, were later proven to be either correct or nearly necessary steps that led to the correct answers after several corrections. Good physicists care whether what they write is right or wrong. Compare with more than 98% of Lee Smolin's papers that are complete hogwash.

The main criterion that divides the work in physics and the rest of science to good and bad is whether the results are right or wrong. All other adjectives may be a part of your strategy but they can be never counted as ultimate values in science. Whether things are politically correct, diverse, not even wrong, background-independent, easily testable, progressive, discrete, environmental, denialist, or anything like that is at most of secondary importance in science, and everyone who spreads these alternative criteria is contaminating science by BS.

Whether or not there were experiments available during Einstein's time is completely irrelevant for the main question in science - namely the truth (validity of general relativity, in this case). If the experiments are unavailable and physicists can nevertheless find the right answers to some questions in advance by a more careful, sensitive, and ingenious evaluation of the known facts and laws, it just means that they're ahead of time and their insights are perhaps more impressive (and they may be solving a more difficult task). It certainly doesn't mean that they're being unscientific or anything else that various Highfields keep on writing in their tabloids.

He also writes:

• Science is a never-ending dialogue between theory and measurement. At the intersection of these points lies the experiment, ...

That's a very biased and unrealistic understanding of science. Theory is as important - and as close to the intersection whatever it means - as the experiments. One can't make progress in physics without theory. Experiments wouldn't know what to expect and where they should look to find something interesting if they had no theorists. There has never been any multi-year progress in physics without theorists.

On the other hand, there have been many examples of progress of theorists even in the absence of experiments. That's how it works. Mathematics makes progress without any experiments whatsoever, and physics has always been and always will be somewhere in between mathematics and sciences that don't care about mathematics much. That's why purely theoretical progress in physics is possible whether someone likes it or not, much like progress made by experimenters and theorists together.

• Since the start of the 1980s, after two centuries of extraordinary fecundity in physics, Smolin admits that "we have made no real headway". "We have failed," he says. "It has produced a crisis in physics."

What's amazing is that some of these shoddiest journalists are unable to even ask the question whether the blue crackpot's proclamations are true or false. They just uncritically copy this garbage.

• String theory strikes a false note, according to Smolin's clear analysis of the calculations behind it.

Smolin's text is not a "clear analysis" but a technically meaningless rant that has nothing whatsoever to do with any calculations - which he can't do - and that is addressed to the least demanding readers that one can imagine who have no idea how physics actually works and who don't want to have any idea about it in the future either: they just want a semi-reliably looking source of political clichés that confirm their anti-mathematical and anti-scientific sentiments.

• But it still managed to intoxicate a generation of physicists with the power of its promise.

It has almost become dangerous to say that string theory is clearly on the right track and "opinions" contradicting some very basic well-established results are silly. Are we intoxicating someone if we are teaching string theory? If we are stating a fact that is obvious to everyone who knows what's going on - just because it apparently irritates many pompous ignorants?

Well, I guess that it's still legal. What I personally call intoxication is Highfield's way of spreading emotionally loaded lies and stupid propaganda by non-experts among other non-experts. It's the blackmailing of experts by generic uninformed people who like to promote certain myths for purely irrational reasons and who try to force scientists to agree with these myths.

String theory is an amazing product of Nature's wisdom on one side and human creativity and ability to listen to Nature on the other side.

• But the widely shared hunch that it would be the final theory to unite all the particles and forces of nature has been undermined.

There has been nothing undermined whatsoever and string theory remains our one and only way towards our complete understanding of Nature. The only thing that happened is that crackpots and crappy journalists have been writing lies and nonsense for a year or so (and the black blogging crackpot has been writing vicious lies for three years - congratulations to all organized science-haters), and the most intellectually challenged part of the population (20%?) has bought it. But this is a social phenomenon that has nothing to do with the actual events and developments in science.

Highfield then offers some of the usual irrational misinterpretations of the number of stationary points in the landscape, and mixes up dark matter with dark energy, making it clear that he has no idea whatsoever how different roles these two concepts play in the structure of the world.

• Smolin resorts to sociology to explain how so many brilliant minds, his own included, became tied up with strings.

Smolin is a mediocre, slow thinker with a bad memory, below-average imagination, bad ability to focus and investigate details, and with kindergarten ideas - it is always hard to tell whether he is just joking when he talks about his childish ideas or whether he is serious - who is unable to learn the state-of-the-art physics at the technical level and who has never written a paper that would remain both valid as well as important among physicists who know their field for more than 10 minutes - you can check it yourself - and Highfield's description is simply another misinformation.

You may imagine whether Lee Smolin's disciples are more or less original and capable than himself.

The whole hype around Smolin's work is artificially created by himself, by the media, and by other crackpots. Smolin's work is much less correct and much less important than the work of a typical - even young - particle physicist or string theorist and the positive words about it are mostly created by politically organized ignorants. Whoever buys that Smolin is a good physicist is being had.

Let me mention that it is a very bad idea for Clifford Johnson et al. to participate in the discussions that create a feeling of legitimacy of these crackpots, a feeling that these discussions are a part of science. They are certainly not a part of science and these crackpots have nothing to say about science. They're a part of the frequently problematic interactions between the physicists on one side and the public on the other side.

I think that science requires a societal protection, and if there is no protection of science - and of the essential right of scientists to end up with any kind of answers - against similar aggressive imbeciles and their witch hunts in the media and elsewhere, there can be no honest science.

And that's the memo.

Boston Globe & Lene Hau

The Boston Globe interviews Lene Hau.

Our famous colleague explains that 300,000 km/s is incomprehensibly high a number ;-) so she decided to lower it and became passionate about the slow light. She argues that these tricks have applications for computing. Finally, they can't avoid the usual questions about women in science: she essentially says that there's no discrimination but the tenured female numbers lag. Also, she says that the Academia doesn't have free thinkers despite the tenure system that would be expected to support it. Well, experimentally it is clear that it does not.

See also Physics as a Danish enterprise.

Interview with Martin Durkin

The creator of The Great Global Warming Swindle has agreed to give an

• interview (MP3 by NicholasV; WAV original).
• Durkin's update in the Telegraph

What he says makes perfect sense while the criticisms, including the comments by Prof Carl Wunsch, seem completely incoherent to me. If I had to guess, I would guess that Prof Carl Wunsch is being blackmailed by the environmentalist advocacy groups right now. There is a lot of vague talk by Wunsch et al. about the impression one gives etc.

Jesus Christ, the main question is not about impressions - at least outside the anti-greenhouse religion, it is not about impressions. The main question is whether the set of hypotheses referred to as "man-made global warming" are right or wrong, whether the underlying facts are right or wrong, and the documentary has presented arguments that the answer is almost certainly Wrong.

Incidentally, Durkin also talks about the hockey stick graph - a scandal that was not discussed in the documentary - and some extra hogwash in Gore's movie such as the phony correlation between warmth and malaria.

What one should question are the arguments and facts, not impressions. I think it is clear that the temperature has been the driver and the concentrations of other gases, including CO2, were its product. The main reason why temperature changes the gas concentrations in the atmosphere is connected with the oceans, and Carl Wunsch helped to explain it even though he was certainly not the most comprehensible scientist in the documentary. If the causation is how Durkin's documentary says - the same relation between CO2 and temperature that we described last summer exactly in the same way as Durkin did - the idea that the data supports the influence of CO2 on temperature is a falsified idea, and any attempt to create a different "impression" is simply fraud.

And that's the memo.




Via Bob Ferguson.

Videos

Dr Sallie Baliunas (Harvard-Smithsonian Center for Astrophysics) has quite a cool talk about the 16th century superstition about extreme weather, precautionary principle, and post-normal science. Imagine that back in the 16th century they thought that weather events were supernatural and caused by special humans - witches - that had to be eradicated.

We have made a lot of progress in the last 500 years. It's hard to believe now in the 21st century when we already know the strength of nature and its laws, which are much greater than the strength of humans and their wishes, and when we enjoy a full tolerance in which it is inconceivable that weather events could be blamed on people, especially not specific people. Could you imagine that someone would demonize selected groups of people today, blaming these groups e.g. for hurricanes? Well, we have made a huge progress in the last 500 years. Well, at least some of us have. ;-)

Incidentally, the 16th century version of the scientific method wasn't too different from the contemporary IPCC template. Click to see a modern analysis of that method.

Baliunas mentions that there were also skeptics in the 16th century who thought that the witch hunts were a problem. Some of the bravest ones argued that it was physically impossible for the Satan to operate through the witches and weather-cookers. But the consensus had a different opinion: the skepticism had to be wrenched out of the society. Any country that tolerates these skeptics will be struck by plagues, famine, and wars, they figured out.

She ends up by saying that the only method to deal with weather and othre things sensibly is science but it needs a special societal protection - otherwise it will be replaced by myths such as weather-cooking. Very well said!

It's a part of States of Fear with Michael Crichton etc.

Via Greenie Watch.

Sabine: rapping theoretical physicists

Sabine Hossenfelder has created an amusing

• MP3 file

that features several well-known theoretical physicists. David Gross himself introduces string theory as the Wild West of physics. Lenny Susskind (full MP3 3:00, blog) then describes, in simple terms, the fate of all 100+ papers by Lee Smolin. Susskind continues to explain why two people, including a computer programmer, wrote certain infamous books.

George Johnson argues that no one in the public cares about string theory in one way or the other. Susskind (see another podcast) adds a few words. Amanda Peet joins by some not terribly deep comments about money, too. Susskind entertainingly quotes some silly statements about string theorists as a priesthood of scientists who are taking over science. Michael Duff explains that the real trouble with physics is that there is not just one Lee Smolin but two of them. He also adds the joke about the philandering string theorist who says to his wife: "But darling, I can explain everything."

George Johnson then entertains the Kavli Institute of Theoretical Physics by his rather bold conjecture that no one would call Lee Smolin a crackpot. A few more papers by Lee Smolin described by Susskind follow. Lee Smolin himself offers some philosophical wisdom how to social-engineer worlds and thoughts to keep people in trouble.

Thanks to Paul Frampton!