Sunday, April 30, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

The Final Theory: two stars



A short comment: a reader has pointed out that right now, the crackpot book by

  • Mark McCutcheon

has the average rating of 2 stars because of 200 one-star reviews that suddenly appeared on the amazon.com website. The new reviews are a lot of fun: many reviews come from Brian Powell, Jack Sarfatti, Greg Jones, Quantoken, David Tong, me, and many others. Many of the readers have written several reviews - and you can see how they struggled to make their reviews acceptable. ;-)

When we first informed about the strange system, McCutcheon's book had the average of 5 stars and no bad reviews at all. The previous blog article about this story is here.

Saturday, April 29, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

How to spend 6 billion dollars?

Related: What can you buy for 300 billion dollars?
What is the best way to spend 6 billion dollars?
Two weeks of Kyoto
ILC: the linear collider
One month of war in Iraq
Millions of free PCs for kids
Ten space shuttle flights
Free polls from Pollhost.com
Additional comments: the world pays about 6 billion dollars for two weeks of the Kyoto protocol which cools down the Earth by 0.00006 degrees or so. The International Linear Collider would have the capacity to measure physics at several TeV more accurately than the LHC, but it is also more expensive - about 6 billion dollars. The U.S. pays 6 billion dollars for one month of the military presence in Iraq. One could buy 60 million computers for kids if the price were $100 as MIT promises. Whenever you launch space shuttle, you pay about 600 million USD.

Klaus meets Schwarzenegger



Figure 1: Californian leader Schwarzenegger with his Czech counterpart during a friendly encounter in Sacramento. Arnold has accepted Klaus' invitation to the Czech Republic.

When Czech president Václav Klaus visited Harvard, he complained that the capitalism of the European Union is not the genuine capitalism the he always believed - the capitalism as taught by the Chicago school - but rather a kind of distorted, socialized capitalism, something that could be taught here at Harvard. ;-)

Finally, he could have spoken to the peers - at the Graduate School of Business at University of Chicago. The other speakers over there agree with Klaus' opinions. In his speech, he explained that the Velvet Revolution was done by the people inside the country: it was not imported. Equally importantly, Americans have a naive understanding of the European unification because they don't see the centralized, anti-liberal dimension of this process.

Twenty years after Chernobyl

On Wednesday morning, it's been 20 years since the Chernobyl disaster; see news.google.com. The communist regimes could not pretend that nothing had happened (although in the era before Gorbachev, they could have tried to do so) but they had attempted to downplay the impact of the meltdown. At least this is what we used to say for twenty years. You may want to look how BBC news about the Chernobyl tragedy looked like 20 years ago.

Ukraine remembered the event (see the pictures) and Yushchenko wants to attract tourists to Chernobyl. You may see a photo gallery here. Despite the legacy, Ukraine has plans to expand nuclear energy.

Today I think that the communist authorities did more or less exactly what they should have done - for example try to avoid irrational panic. It seems that only 56 people were killed directly and 4,000 people indirectly. See here. On the other hand, about 300,000 people were evacuated which was a reasonable decision, too. And animals are perhaps the best witnesses for my statements: the exclusion zone - now an official national park - has become a haven for wildlife - as National Geographic also explains:

  • Reappeared: Lynx, eagle owl, great white egret, nesting swans, and possibly a bear
  • Introduced: European bison, Przewalski's horse
  • Booming mammals: Badger, beaver, boar, deer, elk, fox, hare, otter, raccoon dog, wolf
  • Booming birds: Aquatic warbler, azure tit, black grouse, black stork, crane, white-tailed eagle (the birds especially like the interior of the sarcophagus)

Ecoterrorists in general and Greenpeace in particular are very wrong whenever they say that the impact of technology on wildlife must always have a negative sign.





In other words, the impact of that event has been exaggerated for many years. Moreover, it is much less likely that a similar tragedy would occur today. Nuclear power has so many advantages that I would argue that even if the probability of a Chernobyl-like disaster in the next 20 years were around 10%, it would still be worth to use nuclear energy.

Friday, April 28, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Yuval Ne'eman died

Because this is a right-wing physics blog, it is necessary to inform you about the saddening news - news I heard from Ari Pakman yesterday - that Yuval Ne'eman (*1925), an eminent Israeli physicist and right-wing politician, died yesterday.



If you're interested, you can read the article about him on Wikipedia and Peter Woit's blog, much like the text of Yisrael Medad, Ne'eman's political advisor. News summarized by Google are here. In 1961, Ne'eman published a paper with a visionary title

  • Derivation of strong interactions from a gauge invariance
As far as I understand, the symmetry he was talking about was the flavor symmetry which is not really a gauge symmetry. Ne'eman co-authored the book "The Eightfold Way" with Murray Gell-Mann, contributed tremendously to the development of nuclear and subnuclear physics in Israel (which includes the nuclear weapons), and was the president of Tel Aviv University, among many other organizations.

Science and fundamental science

Chad Orzel did not like the proposals to build the ILC because they are derived from the assumption that high-energy physics is more fundamental a part of physics than other parts of physics - and he disagrees with this assumption. Instead, he argues that technology is what matters and it does not depend on particle physics. Also, Chad explains that one can have a long career without knowing anything about high-energy physics - which seems to be a rather lousy method to determine the fundamental value of different things.

There are three main motivations why people stretch their brains and think about difficult things and science. We may describe the corresponding branches of science as follows:

  • recreational mathematics
  • applied science
  • pure science
Recreational mathematics is studied by the people to entertain themselves and show others (and themselves) that they are bright. Chess in flash or without it may be viewed as a part of this category. People do this sort of activity because it is fun. Comedians are doing similar things although their work requires rather different skills. In this category, entertainment value is probably the main factor that determines the importance. People do whatever makes them happy and excited. If someone else does things on their behalf, they prefer those with a higher entertainment value. The invisible hand of freedom and the free market pretty much takes care of this activity.

The rules of chess depend on many historical coincidences. Other civilizations could have millions of other games with different rules and the details really don't matter: what matters is that you have a game that requires you to turn your brain on.

Applied science is studied because scientific insights can lead to economical benefits. They can improve people's lives, their health, give them new gadgets, and so forth. The practical applications are the driving factor behind applied science. People, corporations, and scientists pay for applied science because it brings them practical benefits. It is often (but not always) the case that the benefits occur at shorter time scales, and it is possible for many corporations and individuals to provide applied scientists with funding. And if you look around, you will see that many fields of applied science are led by laboratories of large corporations - such as IBM, drug companies, and others.

Pure science is studied because the human beings have an inherent desire to learn the truth. In our Universe, the truth turns out to be hierarchical in nature. It is composed of a large number of particular statements and insights that can typically be derived from others. For equivalent insights, the derivations can work in both directions. In many other cases, one can only derive A from B but not B from A. The primary axioms, equations, and principles that can be used to derive many others are, by definition, more fundamental. The word "fundamental" means "elementary, related to the foundation or base, forming an essential component or a core of a system, entailing major change".

If you respect the dictionaries, the physics of polymers may be interesting, useful, and important - but it is not too fundamental. If Chad Orzel or anyone else offers a contradictory statement, he or she abuses the language. Among the disciplines of physics, high-energy physics is more fundamental than low-energy physics. Moreover, I think that as long as we talk about pure science, being "fundamental" in this sense is a key component of being important. If we want to learn the scientific truth about the world, we want the most fundamental and accurate truth we can get.

I am not saying that other fields should be less supported. Nor am I proposing a hierarchical structure between the people who chose different specializations. What I am saying is that other fields that avoid fundamental questions about Nature are being chosen as interesting not only because of their pure scientific value but also because of their practical or entertainment value.

You may be trying to figure out what happens with a particular superconductor composed of 150-atom molecules under particular conditions. The number of similar problems may exceed the number of F-theory flux compactifications. How can you decide whether a problem like that - or any other problem in science - is important? As argued above, there are many different factors that decide about the answer: entertainment value, practical applications, and the ability to reveal major parts of the general truth. I guess that the practical applications will remain the most likely justification of a particular specialized research of a very particular type of superconductors.

People and societies may have different motivations to study different questions of science. If you extend this line of reasoning, you will realize that people can also do many things - and indeed, they do many things - that have no significant relation with science. And they can spend - and indeed, do spend - their money for many things that have nothing to do with science, especially pure science. And it's completely legitimate and many of these things are important or cool.

When you think about the support of science in general, what kind of activity do you really have in mind? I think that pure science is the primary category that we consider. Pure science is the most "scientific" part of science - one that is not motivated by practical applications. As we explained above, pure science has a rather hierarchical structure of insights.

If something belongs to pure science, it does not mean that it won't have any applications in the future. In the 1910s-1930s, radioactivity was abstract science. By various twists and turns, nuclear energy became pretty useful. There are surely many examples of this kind. The criterion that divides science into pure science and applied science is not the uncertain answer to the question whether the research will ever be practically useful: the criterion is whether the hypothetical practical applications are the main driving force behind the research.

Societies may be more interested in pure science or less interested in pure science. The more they are interested in pure science, the more money they are willing to pay for pure science. A part of this money is going to pure science that is only studied as pure science; another part will end up in fields that are partly pure and partly applied.

Chad Orzel thinks that if America saves half a billion dollars for the initial stages of the ILC collider, low-energy physics will get extra half a billion dollars. I think he is not right. The less a society cares about pure science - even about the most fundamental questions in pure science such as those in high-energy physics - the less it is willing to pay for other things without predictable practical applications or entertainment value. Eliminating high-energy experimental physics in the U.S. would be a step towards the suppression of experimental pure science in general.

Thursday, April 27, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Iran may nuke Czechia, Italy, Romania

According to Haaretz, Iran has just received a first batch of BM-25 missiles from its ally in the Axis of Evil, namely North Korea. They are able to carry nuclear warheads and attack countries such as the Czech Republic, Italy, and Romania.

Such a conflict is not hard to start. Imagine that sometime in the future, for example on August 22nd, 2006, Iranian troops suddenly attack Romanian oil rigs on their territory. Romania will respond nervously - and the mad president of Iran will have an opportunity to check out his nukes.

The Czech Republic is, together with England, one of two European countries on an Iranian black list of countries whose citizens are not allowed to get 15-day visa for Iran. Some Muslims in the Czech Republic preach that Islamic Shari'a law should be adopted by Czechia.

The diplomatic relations between Czechia and Iran cooled down 8 years ago when the Radio Liberty (more precisely in Iran: Radio Tomorrow) started to broadcast anti-government programs in Persian from Prague. See here.

US told to invest in particle physics

PhysicsWeb.org

National Academy of Sciences has also recommended the U.S. to invest into neutrino experiments and high-precision tests of the Standard Model to stop the motion of the center of mass of particle physics away from the U.S.

New York Times

Dennis Overbye from the New York Times describes the same story: the ILC must be on American soil. See also Physorg.com and Nature.

CERN new tax

Meanwhile, CERN has adopted the digital solidarity principle: 1% of ITC-related transactions must be paid to CERN.

Pomeron

Matt Strassler has just described their fascinating work on

with Richard Brower, Chung-I Tan, and Joe Polchinski. Return 40 years into the past. The research that eventually evolves into string theory is proposed as a theory of strong interactions: something that would be known as a failed theory of strong interactions for the following 30 years. Things only start to slowly change after the 1997 discovery by Juan Maldacena and a steady flow of new insights eventually leads to a nearly full revival of the description of strong interactions using a "dual" string theory, albeit this string theory is more complicated than what was envisioned in the late 1960s. QCD can be equivalently described as the old string theory with some modern updates: higher-dimensional and braney updates.

The basic concepts of the Regge physics included the Regge trajectory, a linear relation between the maximum spin "J" that a particle of squared mass "m^2" can have; the slope - the coefficient "alphaprime" of the linear term "alphaprime times m^2" - is comparable to the inverse squared QCD scale. The dependence of "J" could be given by a general Taylor expansion but both experimentally as well as theoretically, the linear relation was always preferred.

Note that "alphaprime" in "the" string theory that unifies all forces is much much smaller area than the inverse squared QCD scale (the cross section of the proton). We are talking about a different setup in AdS/QCD where the four-dimensional gravity may be forgotten. This picture is not necessarily inconsistent with the full picture of string theory with gravity as long as you appreciate the appropriately warped ten-dimensional geometry.

At this moment, you should refresh your memory about the chapter 1 of the Green-Schwarz-Witten textbook. There is an interesting limit of scattering in string theory (a limit of the Veneziano amplitude) called the Regge limit: the center-of-mass energy "sqrt(s)" is sent to infinity but the other Mandelstam variable "t" - that is negative in the physical scattering - is kept finite. The scattering angle "sqrt(-t/s)" therefore goes to zero.

In this limit, the Veneziano amplitude is dominated by the exchange of intermediate particles of spin "J". Because the indices from the spin must be contracted, the interaction contains "J" derivatives, and it therefore scales like "Energy^J". Because there are two cubic vertices like that in the simple Feynman diagram of the exchange type, the full amplitude goes like "Energy^{2J}=s^J" where the most important value of the spin "J" is the linear function of "t" given by the linear Regge relation above.

The amplitude behaves in the Regge limit like "s^J(t)" where "J(t)" is the appropriate linear Regge relation. You can also write it as "exp(J(t).ln(s))". Because "t=-s.angle^2", you see that the amplitude is Gaussian in the "angle". The width of the Gaussian goes like "1/sqrt(ln(s))" in string units. Correspondingly, the width of the amplitude Fourier-transformed into the transverse position space goes like "sqrt(ln(s))" in string units. That should not be surprising: "sqrt(ln(s))" is exactly the typical transverse size of the string that you obtain by regulating the "integral dsigma x^2" which equals, in terms of the oscillators, "sum (1/n)" whose logarithmic divergence must be regulated. The sum goes like "ln(n_max)" where "n_max" must be chosen proportional to "alphaprime.s" or so.

If you scatter two heavy quarkonia (or 7-7 "flavored" open strings in an AdS/CFT context, think about the Polchinski-Strassler N=1* theory) - which is the example you want to consider - the interaction contains a lot of contributions from various particles running in the channel. But the formula for the amplitude can be written as a continuous function of "s,t". So it seems that you are effectively exchanging an object whose angular momentum "J" is continuous.

Whatever this "object" is, you will call it a pomeron.

In perturbative gauge theory, such pomeron exchange is conveniently and traditionally visualized in terms of Feynman diagrams that are proportional to the minimum power of "alpha_{strong}" that is allowed for a given power of "ln(s)" that these diagrams also contain: you want to maximize the powers of "ln(s)" and minimize the power of the coupling constant and keep the leading terms. When you think for a little while, this pomeron exchange leads to the exchange of DNA-like diagrams: the diagrams look like ladder diagrams or DNA.

There are two vertical strands - gluons - stretched in between two horizontal external quarks in the quarkonia scattering states. And you may insert horizontal sticks in between these two gluons, to keep the diagrams planar. If you do so, every new step in the ladder adds a factor of "alpha_{strong}.ln(s)". You can imagine that "ln(s)" comes from the integrals over the loops.

What is the spin of the particles being exchanged for small values of "t", the so-called intercept (the absolute term in the linear relation)? It is a numerical constant between one and two. Matt essentially confirmed my interpretation that you can imagine QCD to be something in between an open string exchange (whose intercept is one) and a closed string exchange (whose intercept is two). The open string exchange with "J=1" is valid at the weak QCD coupling - it corresponds to a gluon exchange. At strong coupling, you are exchanging closed strings with "J=2".

For large positive values of "t", you are in the deeply unphysical region because the physical scattering requires negative values of "t" (spacelike momentum exchange). But you can still talk about the analytical structure of the scattering amplitude - Mellin-transformed from "(s,t)" to "(s,J)". For large positive "t", you will discover the Regge behavior which agrees with string theory well. Unfortunately, this is the limit of scattering that can't be realized experimentally. Nevertheless, for every value of "t", you find a certain number of effective "particles" that can be exchanged - with spins up to "J" which is linear in "t".

The negative values of "t" can be probed experimentally, and this is where string theory failed drastically in the 1970s: string theory gave much too soft (exponentially decreasing) behavior of the amplitude at high energies even though the experimental data only indicated a much harder (power law) behavior. So now you isolate two different classes of phenomena:
  • the naive string theory is OK for large positive "t"
  • the old string theory description of strong interactions fails for negative "t"; the linear Regge relation must break down here
But the old string theory only fails for negative "t" if you don't take all the important properties of that string theory into account. The most important property that was forgotten 35 years ago was the new, fifth dimension. The spectrum of particles - eigenvalues of "J" - is related to the Laplacian but it is not just a four-dimensional Laplacian; it also includes a term in the additional six dimensions, especially the fifth holographic dimension of the anti de Sitter space. And this term can become - and indeed, does become - important.

What is the spectrum of allowed values of "J" of intermediate states that you can exchange at a given value of "t"? Recall that each allowed value of "J" of the intermediate objects generates a pole in the complex "J" plane - or a cut whenever the spectrum of allowed "J" becomes continuous. For large positive "t", the spectrum contains a few (roughly "alphaprime.t") eigenvectors with positive "J"s, and a continuum with "J" being anything below "J=1". For negative values of "t", you only see the continuum spectrum (a cut) for "J" smaller than one.

Don't forget that the value of "J" appears as the exponent of "s" in the amplitude for the Regge scattering. We are talking about something like "s^{1.08}" or "s^{1.3}" - both of these exponents appear in different kinds of experiments and can't be calculated theoretically at this moment.

Matt argues convincingly that the Regge behavior for large positive "t", with many poles plus the cut below "J=1", is universal. The "empty" behavior at large negative "t" where you only see the continuum below "J=1" is also universal. It is only the crossover region around "t=0" that is model-dependent and where the details of the string-theoretical background enter. And they can calculate the spectrum of "J" as a function of "t" in toy models from string theory. They assume that the string-theoretical scattering in the AdS space takes place locally in ten dimensions, and just multiply the corresponding amplitudes by various kinematical and warp factors - the usual Polchinski-Strassler business.

The spectrum of poles and cuts in the "J" plane reduces to the problem to find the eigenvalues of a Laplacian - essentially to a Schrödinger equation for a particle propagating on a line. You just flip the sign of the energy eigenvalues "E" from the usual quantum mechanical textbooks to obtain the spectrum of possible values of "J". And they can determine a lot of things just from the gravity subsector of string theory - where you exchange particles of spin two (graviton) plus a small epsilon that arises as a string-theoretical correction.

For large positive "t", you obtain a quantum mechanical problem with a locally negative (binding) potential that leads to the discrete states - those that are seen at the Regge trajectory.

When all these things are put together, they can explain a lot about physics observed at HERA. The calculation is not really a calculation from the first principles because they are permanently looking at the HERA experiments to see what they should obtain. But they are not the first physicists who use these dirty tricks: in the past, most physicists were constantly cheating and looking at the experiments most of their time. ;-)

Wednesday, April 26, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Rae Ann: Alien recycling

By Rae Ann, one of the four winners who have seen the #400,000 figure.

My first grader brought home some interesting EPA publications for school children. While I totally support teaching children to recycle and be mindful of wise use of resources I think it's a little off to tell them that 'garbage leads to climate change'.

And what's with the little flying saucers and aliens (graphics in the publications)? What do they have to do with climate change and garbage?? One publication does open with the statement, "Space creatures might think the idea of reusing containers is an alien concept but here on Earth it's easy to keep an old jar out of the trash and give it new life." (That is a direct quote and the missing comma is their punctuation error.) Well, how does the government know that aliens don't recycle? Is it because they have left a bunch of their stuff here? Hmm? Sounds like a very prejudiced and discriminatory attitude to me. What is that teaching our kids about aliens??

The Czech Fabric of the Cosmos

My friend Olda Klimánek has translated Brian Greene's book "The Fabric of the Cosmos" into Czech - well, I was checking him a bit, reading his translation twice - and the book was just released by Paseka, a Czech publisher, under the boring name "Struktura vesmíru" (The Structure of the Universe). The other candidate titles were just far too poetic.

I think he is a talented writer and translator and there will surely be many aspects in which his translation is gonna be better than my "Elegantní vesmír" (The Elegant Universe).

What I find very entertaining is the different number of pages of this book (in its standard hardcover editions) in various languages:

  • Czech: Struktura vesmíru, 488 pages
  • Polish: Struktura kosmosu, 552 pages
  • English: The Fabric of the Cosmos, 576 pages
  • Portuguese: O tecido do cosmo, 581 pages
  • Italian: La trama del cosmo, 612 pages
  • French: La magie du Cosmos, 666 pages
  • Korean: 우주의 구조, 747 pages
  • German: Der Stoff, aus dem der Kosmos ist, 800 pages

I am not kidding and as far as I know, Olda's translation is complete. If you need to know, 800/488 = 1.64. ;-) The Czech Elegant Universe was also much shorter than the German one but the ratio was less dramatic.

I like the rigid rules of German but this inflation of the volume is simply off the base. The Czech language has similar grammar rules but it avoids the articles and it has much more free word order. A slightly more complex system of declination removes many prepositions. And Olda may simply be a more concise translator. :-)

Tuesday, April 25, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Uncle Al: on the equivalence principle

By Uncle Al who has submitted a #400,000 screenshot.

Does the Equivalence Principle have a parity violation? Weak interactions (e.g., the Weak Interaction) routinely violate parity conservation. Gravitation is the weakest interaction.

Either way, half of contemporary gravitation theory is dead wrong.


Gravitation theory can be written parity-even or parity-odd; spacetime curvature or spacetime torsion. Classical gravitation has Green~Rs function Newton and metric Einstein or affine Weitzenböck and teleparallel Cartan. String theory has otherwise and heterotic subsets. Though their maths are wildly different, testable empirical predictions within a class are exactly identical...


...with one macroscopic disjoint exception: Do identical chemical composition local left and right hands vacuum free fall identically? Parity-even spacetime is blind to geometric parity (chirality simultaneously in all directions). Parity-odd spacetime would manifest as a background pseudoscalar field. The left foot of spacetime would be energetically differently fit by a sock or left shoe compared to a right shoe.


String theory could be marvelously pruned. Does a single crystal solid sphere of space group P3(1)21 quartz (right-handed screw axes) vacuum freefall identically to an otherwise macroscopically identical single crystal solid sphere of space group P3(2)21 quartz (left-handed screw axes)? Both will fall along minimum action paths. In parity-odd spacetime those local paths will be diastereotopic and measurably non-parallel -- a background left foot fit with left and right shoes.

Frank Wilczek: Fantastic Realities

Technical note: Everyone who will be a visitor number 400,000 and who will submit an URL for the screenshot proving the number today will be allowed to post any article on this blog, up to 6 kilobytes. The reader #400,000 was Rae Ann who just returned from a trip - what a timing. :-) UncleAl has still opened the page (reload) when it was showing #400,000, much like Doug McNeil. I have no way to tell who was the first one. The others just reloaded the page and obtained the same number because it was not their first visit today, and it thus generated no increase of the counter. Congratulation to all three.

fantastic realities

Yes, I just saw this irresistable book cover at Betsy Devine's blog. The book is called

and Frank Wilczek is apparently using a QCD laser. The journeys include many of Wilczek's award-winning Reference Frame columns. Have you heard of Wilczek's Reference Frame columns in Physics Today? Let me admit that I have not. ;-)

Because of the highly positive reviews, your humble correspondent has just decided to double the number of copies that Frank Wilczek is going to sell. Right now, the yesterday's amazon.com rank is 100,000 and today's rank is 130,000. Look at the promotional web pages of the book, buy the book, and see tomorrow what it does with the rank. Remember that the rank is approximately inversely proportional to the rates of selling the books.

Update: At 7:00 p.m., the rank was about 11,000, better than 136,000 in the morning. On Wednesday 8:30 a.m., the rank was 9,367, an improvement by a factor of fifteen from the rank 24 hours earlier.

The promotional web pages also reveal that Betsy is proud to be the 4th Betsy found by Google. Congratulations, and I wish her to capture the most important Frank Wilczek blog award, too. ;-)

Monday, April 24, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Bruce Rosen: brain imaging

Bruce Rosen started the colloquium by saying that it is useful to have two degrees - PhD and MD - because every time he gives a talk for the physicians, he may impress them by physics, and every time he speaks in front of the physicists, he may impress them by medicine. And he did.

Although there are many methods to study the anatomy and physiology of the brain - such as EEG and/or flattening the brain by a hammer which is what some of Rosen's students routinely do - Rosen considers NMR to be the epicenter of all these methods. (This is a conservative physics blog, so we still refer to these procedures as NMR and not MRI.) This bias should not be unexpected because Rosen's advisor was Ed Purcell.

Some of the results he shown were obtained by George Bush who is an extremely smart scientist as well as psychiatrist, besides being a good expert in B-physics.

Rosen has shown a lot of pictures and videosequences revealing how the activity of the brains depends on time in various situations, on the presence of various diseases, on the age, and on the precise way how the brains are being monitored. Many of these pictures were very detailed and methods already exist to extract useful data from the pictures and videos that can't be seen by a naked eye.

Human brains are being observed at 10 Tesla or so, and magnetic field of 15 Tesla is the state-of-the-art environment to scan the brains of smaller animals. The frequency used in these experiments is about half a gigahertz. Many tricks how to drastically reduce the required amount of drugs that the subject must take before the relevant structures are transparent have been found.

Most of the data comes from observations of water that is a dominant compound in the human body and not only the human body. It turns out that the blood that carries oxygen and the blood that carries carbon dioxide is diamagnetic and paramagnetic, respectively. That simplifies the NMR analysis considerably.

There's a lot of data in the field and fewer ways to draw the right conclusions and interpretations out of the data.

OVV in higher dimensions?

Brett McInnes proposes a generalization of the Hartle-Hawking approach to the vacuum selection problem pioneered by Ooguri, Vafa, and Verlinde (OVV) and described by this blog article to higher dimensions. McInnes identifies the existence of two possible Lorentz geometries associated with one Euclidean geometry as the key idea of the OVV paradigm. He argues that the higher-dimensional geometries must have flat compact sections which is certainly a non-trivial and possibly incorrect statement:

Everything you wanted to know about Langlands

... geometric duality but you were afraid to ask could be answered in this 225-page-long paper by Edward Witten and Anton Kapustin:

Previous blog articles about the Langlands program the following ones:

A semi-relevant discussion about related topics occurs at Not Even Wrong.

Translation and related news

Just a technical detail: I've added two utilities to the web pages of individual articles:

  • related news and searches, powered by Google (blue box under each article)
  • translations of the blog articles to German, French, and Spanish, powered by Google (three flags at the top of the articles)

I apologize to the readers from the remaining 142 countries that also visit this website - according to the Neocounter - besides the three countries indicated above that their language has yet to be included. :-)

Recent comments

Also, "recent comments" were added to the sidebar of the main page. The recent slow comments in the lower Manhattan (skyscraper) area are sorted according to the corresponding article. You may find out which article the comment belongs to if you hover over the timestamp. You can also click it.

There are also ten "recent fast comments" in a scrolling window at the upper portion of the sidebar.

Sunday, April 23, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Leonard Susskind Podcast

I am just listening a podcast with Leonard Susskind. You can find the link somewhere on this page. I will add it here later. Then you click "Podcasts" on the left side, and the second one is Susskind: the 5.57 MB is 23:55 long. Entertaining, recommended.

Manic Miner

Manic Miner...

Manic miner flash game removed from the page because it was making a lot of noise. Please click at the second "Manic miner".

How many people used to play such things 20 years ago? Links to previous flash games on this blog can be found here.

PageRank algorithm finds physics gems

Several colleagues from Boston University and from Brookhaven have proposed a method

to look for influential papers using the same algorithm that Google uses to rank web pages. This algorithm uses the list of web pages (or papers) and the links between them (or citations) as input. The web pages or papers are nodes of a graph and the citations are oriented links. It works as follows:

You have lots of "random walkers". Each of them sits at some paper XY. In each step, each random walker either jumps to a random paper in the full database, with probability "d", or it jumps to a random paper mentioned in the references of the previous paper XY, with probability "1-d". Once the number of random walkers associated with each paper reaches equilibrium (approximately), the algorithm terminates. The number of walkers at each paper gives you the rank.

Saturday, April 22, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Illinois: Particle Accelerator Day

Illinois' governor has declared this Saturday (or Friday?) to be the

and everyone must celebrate. Mr. Blagojevich is trying to attract the future linear ILC collider to his state. Congratulations, Argonne and Fermilab. PhysOrg.com illuminates some ILC attempts of these two facilities here. Meanwhile, on the same day, the celebrations of the Earth Day, invented by John McConnell, dominate in Massachusetts. Those who are already fed up with the Earth - and with Google Earth - may try Google Mars.

Via JoAnne.

Detlev Buchholz: algebraic quantum field theory

Prof. Detlev Buchholz who is a rather famous researcher in the algebraic quantum field theory community has given the duality seminar today and we had a tête-à-tête discussion yesterday.

He has attempted to convert the string theorists to the belief system of algebraic quantum field theory which is not a trivial task. Algebraic quantum field theory is a newer version of the older approach of axiomatic quantum field theory.



In this approach, the basic mathematical structure is the algebra of bounded operators acting on the Hilbert space. In fact, for every region R, you can find and define a subalgebra of the full algebra of operators, they argue. A goal is to construct - or at least prove the existence of - quantum field theories that do not depend on any classical starting point.

This is a nice goal. Because the string theorists know S-dualities and many other phenomena in field theory and string theory which imply that a quantum theory can have many classical descriptions - more precisely, it can have many classical limits - we are certainly open to the possibility that we will eventually be able to formulate our interesting theories without any direct reference to a classical starting point. Instead, we will be able to derive all possible classical limits of string/M-theory from a purely non-classical starting point.

On the other hand, the particle physics and string theory communities are deeply rooted in experimental physics and we simply do not want to talk about some abstract concepts without having any particular theory that can at least in principle predict the results of experiments and that respects these concepts. In fact, we want to focus on theories of the same kind that are relevant for observational physics.

Friday, April 21, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Evolving proton-electron mass ratio?

Update: In 2008, a new experiment with ammonia found no time-dependence in the last 6 billion years.
Klaus Lange has pointed out that

describes a Dutch experiment performed primarily in the European Southern Observatory - hold your breath, this observatory is located in Chile. They measured the spectrum of the molecular hydrogen that depends on the proton-electron mass ratio "mu".

Note that this ratio is about 1836.15. Twenty years ago I played with the calculator and it turned out that this number can be written as

  • 6.pi^5 = 1836.12.

This agreement has promoted me to the king of all crackpots: with only three characters, namely six, pi, five, I can match around 5 or 6 significant figures of the correct result.

Actually my calculator only had 8 significant figures (with no hidden figures) and I exactly matched 8 significant figures of 1836.1515 written in the mathematical tables of that time.

Later I learned that someone else has actually published this "discovery" fifty years ago, and the agreement got worse with better calculators and better measurements in particle physics.

More seriously, the Dutchmen now claim that the ratio was 1.00002 times higher twelve billion years ago. The New Scientist immediately speculates that this could prove extra dimensions or string theory. I, for one, have absolutely no idea where this statement comes from. I personally believe that these constants have been constant in the last 12 billion years - and moreover this opinion is completely and naturally compatible with string theory.

George Bush meets Prof. Albert Einstein

As soon as Lee Smolin asked the question

several gifted Korean engineers from a company called Hanson Robotics gave a possible answer by asking a better question:

Click the link above to see the final stages of the project. Anatomical pictures are here. The engineers decided that the body was not too important - what matters is Einstein's brain (plus face, to make a good package). They replaced the body by a robot.

Everything has worked fine so Prof. Albert Einstein, nicknamed Albert HUBO, could meet with the president of the United States of America. It is widely believed that Hon. George W. Bush has convinced Prof. Albert Einstein to oppose the attempts of Einstein's colleagues to force Bush to take the nuclear option off the table. HUBO said that the Iranians could be working on the same bomb.

Click the photograph above or here to see a directory with many other photographs. Einstein's robotic brother ASIMO supervised by Koizumi, the prime minister of Japan, has met the former Czech prime minister Špidla in 2003 and demonstrated that Špidla was a sourball. See here.

So far, Prof. Einstein, much like Honda's ASIMO, only knows how to walk, serve tea, and compute spin foam amplitudes, so it is not terribly useful. But they hope to teach Einstein quantum mechanics and bosonic string theory next week and how to climb stairs in a few years.

Meeting a robot in 1999

In 1999 or so, when I was at Rutgers, I met a robot in the Busch campus dining hall. He came to us, shaked my hand and we talked about everything - including Heisenberg's uncertainty principle. His voice was a typical computer voice equipped with a very authentic human intonation. He was so interesting and smart! The debate was much more meaningful than most debates with various loop quantum gravity people and many others. I was stunned: have they already succeeded to create artificial intelligence that exceeds not only 90% of people but also many senior professors?

The answer was mysterious for half a day. Later I could re-check that it was a "synthetic personality" that was remotely controlled by a human being from about 50 meters. The human being could see through the robot's eyes, and he could control the motion and submit his speech that was transformed into the computerized voice color.

Thursday, April 20, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Jefferson Physics Laboratory becomes a historic site

Jefferson Physical Laboratory where we have offices has been declared a historic site by the American Physical Society, mostly because it is the first building that was ever built in the U.S. for physics research.



Figure 1: The picture is mine

See the letter that President Lawrence Summers and the department chair John Huth received here. The picture above is from 2002 but you already see the new attick which is pretty these days. Recall that it is exactly this Jefferson tower where the first gravitational red shift experiment was done by Pound, Rebka, and Snyder in the early 1960s. Its 22.6 meters were enough to measure the 4.92 x 10^{-15} relative change of the frequency of 14.4 keV gamma rays from iron-57. The prediction of general relativity - of a red shift factor "(1+gh/c^2)" (verify the numbers!) - was confirmed with a 1% accuracy.

Integrability: giant magnons

Diego Hofman and Juan Maldacena - these two physicists should not be confused with Diego Maradona - study the

  • excitations of N=4 gauge theory in d=4 in the planar limit.

Recall that according to the gauge-gravity holographic correspondence, the strong coupling limit describes type IIB string theory on the product space "AdS5 x S5". A few years ago, Berenstein, Maldacena, and Nastase have shown that the gauge theory is not equivalent to pure supergravity but the full string theory; they identified the strings with the long traces. This research direction has been transformed into the studies of integrability and spin chains (these are the discretized strings) and we have talked about this topic at various places, for example here.

This spin chain itself carries excitations and the most important ones are called magnons: it's an excitation that reverts the direction of a single spin (or the "magnetic moment" if you wish) in the spin chain and propagates as a wave along the chain. In the planar limit, i.e. up to the leading terms in the "1/N" expansion, physics should simplify. Many people have believed for some time that a full exact solution of string theory in this limit should exist. This task is equivalent to a full understanding of the worldsheet of a string propagating in the "AdS5 x S5" background for the simplest choice of its topology.

In the variables mentioned above, the question is reduced to the spectrum, the dispersion relations, and the S-matrix of the magnons. Effectively, one needs to study the S-matrix for various polarizations and encounters a "256 x 256" matrix. Its form was recently fixed by Niklas Beisert, up to an overall normalization. Moreover, one month ago, Romuald Janik of Poland has shown how the crossing symmetry emerges from the formulae for the S-matrix.

Hofman and Maldacena confirm the results but add something extremely interesting: the adjective "giant". In analogy with giant gravitons, you may suspect that there will be a new picture that replaces the original point-like magnon excitations by something big.

Harvard Crimson: environmentalism is dead

The Harvard Crimson has looked at environmentalism with critical and bright Harvard eyes and concluded that

and that we have a chance to enter a new era in which the environment itself, not an ideology, is a winner. Piotr Brzezinski '07, a member of the Resource Efficiency Program, argues that all the dire predictions have so far been falsified, and if our care about the environment is supposed to impact reality in the future, those who care must abandon some methods such as the authoritative Soviet style manifested in the Kyoto protocol, open some taboos for debate, and start to publish realistic appraisals of reality even if they lead to less exciting headlines in the newspapers.

Wednesday, April 19, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Michele Papucci: neutrino optics

Michele Papucci from Berkeley gave a talk about neutrino optics. There will be a preprint about it with Gilad Perez, Hitoshi Murayama, and one more author whose name will be completed here if necessary.

When we test cosmological models, we rely on regular optics of photons. Are there other "eyes" we could use? They must be weakly interacting, so the only possibilities are

  • gravitational waves
  • neutrinos
Michele only focused on the last ones, the neutrinos. More precisely, it is the electron antineutrinos he is interested in. They are produced by supernovae (yes, there is some neutrino oscillation physics you must take into account); on the other hand, the Sun only creates neutrinos so the solar neutrino backgrounds does not affect their proposed experiments.

You can't really measure the direction from which they come (pretty fuzzy optics) because the particles created in the inverse beta decay have a momentum that is virtually uncorrelated with the antineutrinos' momenta. So the only thing you can measure is the distribution of energies.

BBC climate software confuses 200,000 computers

This story is a good example how the climate models work in the most optimistic case.

The idle time of most PCs is wasted. About 30,000 people like me run software such as MPRIME - the search for the greatest prime integers in the world. It is a well-defined activity and there are very good reasons to trust this software.

Actually, there exist other programs above the BOINC platform, and some of them can be found in this list:




However, some people don't like things like LHC at home too much. Instead, they want to save the world and help the humanity. So they download the third program in the list above, namely

You can also join the group of 200,000 enthusiasts, the saviors of the planet, if you click the link above and continue with "Taking part in CPDN". This community will calculate the date of the armageddon. ;-) But wait a minute. The Reference Frame has been saying that the existing climate models are not trustworthy and those who run them often fail to respect basic principles of science.

Ignore bloggers at your peril

Clifford Johnson has pointed out an article in the Guardian. The article discusses some kind of research about the influence of bloggers. It also mentions three companies that were affected by bloggers because the bloggers described physics of Kryptonite locks, McDonald's abracadabra, as well as Dell whose last CEO was possibly fired. Well, the visitor data indicates that very different segments of the society are being influenced. For example, many people were looking for Angela Merkel semi-naked today. And of course, people are still interested in Mary Winkler as well as a potential massive nuclear strike. More demanding readers look for physics blogs uncertainty as well as the sad story of John Brodie, the physicist.

Tuesday, April 18, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Cosmological breaking of SUSY and the seesaw

Tonight, Michael McGuigan has made a new step in his attempt to make the seesaw mechanism for the cosmological constant realistic:

The paper combines the previous work of Michael McGuigan - that we discussed here and that was mostly based on this blog article and/or comments of this article by Sean Carroll - with the brave proposal of my (former) adviser Tom Banks:
Recall that Tom has proposed to interpret the cosmological constant - the curvature of empty space - as the primary effect and the supersymmetry breaking in particle physics as its consequence. This changes the question from "why is the cosmological constant so small" to the question "why is the supersymmetry breaking in particle physics so strong".

The supersymmetry breaking induced by the tiny curvature of our Universe would normally be negligible, and Tom circumvents this problem by suggesting that an important exponent in his power law is corrected from a classical value of 1/4 to the value of 1/8 by huge effects of virtual black holes whose loops are localized near the de Sitter horizon. The relation with the seesaw mechanism is not quite clear to me - although both methods of course try to obtain the same kind of result for the vacuum energy (but via different effects, I think).

Right now I don't have enough time to tell you exactly what I think about the proposal but the paper is rather concrete and tries to apply the Wheeler-DeWitt equation on various string-theoretical backgrounds. He seems to show that the off-diagonal elements of the vacuum energy (transitions) exist in three spacetime dimensions or less. Can you obtain these off-diagonal elements from Coleman-DeLuccia-like instantons? I believe that the proposal is interesting enough to be looked at.

Incidentally, Apple finally offers Mac users a decent operating system. It is called Windows XP.

Monday, April 17, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Stanislav Petrov supersedes Easter Bunny and Jesus Christ

During the paganic era, people would celebrate Easter as the holidays of spring, fertility, and Easter bunny. The Christians cleverly overwrote this special season by the anniversary of resurrection of Jesus Christ, our savior. However, things changed again in 2006. The liberal blogosphere, including Cosmic Variance and In Search of 42, among hundreds of other blogs, has replaced the Easter bunny and Jesus Christ by a Soviet military officer: the Easter has become the Stanislav Petrov Day.



It is not exactly clear why the Easter season was chosen. Well, Stanislav Petrov (*1939) saved the world on September 26th, 1983. He realized that the Soviet computer system was crappy - because it was a technology developed in a left-wing political system - and discarded the warning of his computers that the American missiles were approaching the Soviet targets. By having failed to inform his superiors, he has arguably saved half a billion lives. ;-)

The details have been secret until 1998. However, the rough story was not. I remember that on Monday, September 26th 1983, when I was in the 4th grade, during Andropov's era, we were just playing volleyball in the gym or something like that when the school radio announced that the international situation deteriorated and the conflict was imminent. We have never learned anything else beyond this single message in the school radio and the worries faded away completely.

Today, Petrov lives in relative poverty as a Russian pensioner. A San Francisco peace organization named him the new savior of the world (only one of his two predecessors enjoys the same honor; don't confuse the honor with the true savior of modern music) and awarded him with a breathtaking amount of $1,000. Congratulations. If someone wants to send him more money, let me know.

Back to 2006

But we live in 2006 and the main target right now is not Moscow but Tehran. Professor James Miller who is a game theory expert and a candidate for the president of Harvard - one that vows to defeat feminism - has offered a smooth scenario how the U.S. attacks on Iran will be started and justified. The Israeli prime minister will inform Bush that Israel is threatened and it will have to nuke Iran unless the nuclear program of the crazy mullahs is stopped. Because Iran wants to wipe Israel off the map, Israel has a kind of moral right to make such an announcement. The U.S. weapons are much stronger and cleaner than the Israeli weapons. By using both types against Iran, Bush will save not only Israel but he will also save millions of Iranian lives that would otherwise be lost because of the dirty Israeli nukes.

Next year, Easter Bunny, Jesus Christ, and Stanislav Petrov will be replaced by George Bush (and James Miller), the new savior.

Mahmoud is probably a nail

Meanwhile, it's been announced that Mahmoud Ahmadinejad is probably a nail. What kind of nail? He is a nail of the Hidden Imam who is secretly the Sovereign of the World and who has been hiding since 941. :-) See here. Mahmoud received the presidency from the Hidden Imam for promising to provoke a clash of civilizations.

Mahmoud realizes that the U.S. is the last infidel country whose military is not impotent and Mahmoud, supported by God, will defeat the U.S. in a long asymmetric war. But he will wait until 2008 when Bush is out of office because Bush is clearly an aberration - everyone else since Truman would run away. A divine anthropic coincidence puts the triumph of the Iranian Manhattan project, secretly pursued by Imam Hossein Nuclear University, to the same year 2008, Mahmoud argues. Wow. These people are real nutcases which is not a good combination with the advanced P-2 centrifuges that, according to the New York Times, are suddenly again being developed in Iran.

Mahmoud has just given Hamas the same thing that Harvard has pledged for the feminist programs: 50 million dollars. Finally, Reuel Gerecht from AEI asks the question:

The U.S. and the U.K. have already been training an occupation of a fictitious Middle East country called "Korona" in 2015 whose territory happens to coincide with Iran and whose citizens are Iranians. Well, obviously, some dynamics is on both sides.

Saturday, April 15, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Carlo Rovelli and graviton propagator

Several readers have asked me what I think about a new

in loop quantum gravity, an attempt described as a groundbreaking paper by a fellow blogger and included in the unfinished revolution by another blogger. It would be far too dramatic to say that I am flabbergasted but one thing is clear. The work is so manifestly incorrect that I just can't fully comprehend how someone who has attended at least one quantum field theory course can fail to see it.

But of course, yes, I am happy that people are still trying different things and some of them don't get discouraged by decades of failure - and I always open such papers with an enthusiastic hope that a new breakthrough will appear in front of my eyes. ;-)

The paper linked above is supposed to be a more complete version of Rovelli's previous graviton propagator paper. Indeed, you can see that several pages in these two papers are identical. Most of these two papers' assumptions are misguided, nearly all the nontrivial steps are erroneous, and the results are incorrect, too.

Semiclassical GR


Let us start with semiclassical gravity. At this level, the graviton propagator is philosophically analogous to the propagators of all other quantum fields you can think of - for example the electromagnetic field. You must start with a background; the simplest background is the flat Minkowski space. This means that you write the full metric as
  • g_{mn} = eta_{mn} + sqrt(Gnewton) h_{mn}
Here, eta_{mn} is a background, i.e. a classical vacuum expectation value of the quantum field while h_{mn} is the fluctuation around this background that remains a quantum field and is treated as a set of small numbers. The full gravitational action can be expanded in "h_{mn}", to get

Happy Easter



Something analogous to annihilating letters, jumping frog, shooting frog, and stained glass. Click here for Easter eggs in full screen.

Cuba vs. Czechia 1:1

Meanwhile, Cuba has expelled the Czech diplomat, Mr. Stanislav Kázecký, for spying on behalf of the U.S. - which is most likely not true. The Czech Republic has followed all the decent traditions and refused to extend the visa for a Cuban diplomat, too. :-) While the Czechoslovak Socialist Republic was one of Cuba's closest friends, the Czech Republic is its #2 foe. A large portion of the U.N. resolutions that criticize the situation in Cuba as well as the trade restrictions for the European Union members have been proposed by the Czech Republic.



There have been many recent incidents between the two countries. For example, the countrymate of mine above is a psychologist called Helena Houdová. (In fact, she is my citymate, from Pilsen.) She was former Miss Czech Republic 1999 and the Dean's world hero of the week.

In January 2006, she decided to take pictures of the Cuban slums, something that Fidel Castro pretends not to exist. She was immediately arrested (together with her friend, Mariana Kroftová, who is also a model) - for taking the pictures - and the commies have confiscated her film. As you can imagine, those communist morons can't really compete with a modern capitalist young woman from the Czech Republic and her state-of-the-art technologies. She stored a memory card from her digital camera in her bra. Today, she is showing the alarming pictures of the "island of freedom" all around the world.

Cuba has canceled various celebrations of the Czech national holidays and expelled or temporarily arrested many Czech citizens - the aristocrat Schwarzenberg and the politician Ivan Pilip (with his friend Filip Bubeník) are two most well-known examples. You can try to liberate Pilip by shooting 50 Cuban agents here.

Friday, April 14, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

La Griffe du Lion: prison ratios

La Griffe du Lion has a new technical analysis of a sociological issue. He asks:

His answer is based on mathematics that is more or less equivalent to his previous analysis of women in science. The conservative states impose a lower threshold to be arrested - they only tolerate smaller crime. This makes the groups of people behind bars less selective. Because the black crime Gaussian is broader and higher than the white ones in the same way as the male math aptitude Gaussian is broader and higher than the female one, smaller selectivity is translated to a less dramatic ratio between the black and white percentages. It is therefore logical and inevitable that the racial disparity is more striking in the left-wing states.

The indentity of La Griffe du Lion remains a mystery to us.

Is George W. Bush a feminist?

David Goss has sent me an insightful

that starts with the announcement that the Bush administration is going to investigate universities with fewer women in math and science than the feminists such as Barbara Boxer would like. Schlafly notices that even though Bush has been the president for more than five years, Bill Clinton's feminist policies are apparently still in force.

She asks: Is Bush a feminist or just a gentleman who is intimidated by the feminists? At the physical level of policies, there is no real difference between the two answers. 171 wrestling teams have already been intentionally destroyed by these dumb policies and math and science may follow.

Schlafly explains how this mindless feminist mentality, based on a striking misunderstanding of the differences between men and women, can have a devastating effect on universities and beyond. There is of course not a shred of evidence of any discrimination, she writes: men are simply more interested in competitive sports, math, and science.

Moreover, when it comes to muscle growth, testosterone is the key to success.

After having explained how unreasonable the feminist approach is, she says that the Bush administration is ignoring one example of increasing gender disparity that can indeed have bad consequences: a decreasing percentage of male schoolteachers.

With all my respect for George W. Bush, let me offer an obvious answer to Schlafly's basic question. Yes, Bush is a feminist and he in fact does think that women are brighter in many respects including science and math - and most discussions he has with the First Lady have to reinforce this belief. ;-)

Bert Schroer vs. path integral

Prof. Bert Schroer has publicized his essay in which he argues that there is something wrong with the path integrals and they should be universally replaced by algebraic methods. Because half of the Internet is going to decide that he must be right, at least in some sense, let me also post the correct answers to his doubts - which includes a trivial assertion that his statements are nonsensical.

The first couple of pages are filled with a content-free bitterness about the path integrals and a unsubstantiated promotion of algebraic quantum field theory: the kind of silly unphysical whining that all of us know very well from "Not Even Wrong" and other places on the Internet. The author is upset about the "string theory caravan" that does not support "great" ideas - such as the "great" idea of Prof. Schroer himself that the path integrals are bad.



The first non-trivial statement appears on page 3. Prof. Schroer essentially claims that the path integrals give a wrong result if you use them to describe a spinning top. The critical sentence is the following:

  • The paradoxical situation consists in the fact that although the higher fluctuation terms (higher perturbations) are nonvanishing, one must ignore them in order to arrive at the rigorous result.
Wow. The path integral fails at higher orders, he says. Of course that this statement is a complete nonsense. Path integrals are better, not worse, to compute loop effects, especially if one has to deal with non-Abelian gauge symmetries. By introducing the Faddeev-Popov ghosts, the best formalism to calculate higher-order effects in this theory may be developed. Moreover, the path integral is also a superior approach in obtaining non-perturbative corrections such as instanton corrections. Path integrals also make the Lorentz symmetry of quantum field theories manifest and they have other advantages, too.

Thursday, April 13, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Google calendar

A new service by Google is

You need to have a Google account - for example a Gmail account. With Gmail, you may also incorporate the calendar - with the list of things you have to do - into the corner of your Gmail inbox. The interface is based on a traditionally fresh, Google-like, no-nonsense environment. See Calendar help for more details.

Incidentally, you will also be able to make Google searches using your voice and telephone:

Flux compactifications of M-theory and F-theory

Today we had an oral exam, some minor progress in the calculations of the black hole corrections, and I attended Cumrun Vafa's class which is always a good opportunity to refresh one's knowledge of various things.

He started with the Dijkgraaf-Vafa correspondence, and finished with flux compactifications. I will write comments about Dijkgraaf-Vafa later, but let me start with the following:

Flux compactifications

As the Becker sisters explained, the compactification of M-theory on Calabi-Yau four-folds (which are eight-real-dimensional which leaves three large spacetime dimensions) actually requires nonzero values of the four-form field strength G4. It is because the eleven-dimensional action contains the terms of the form

  • S = int C3 /\ ( G4 /\ G4 - I8(R) ) + ...

The first term is a tree-level Chern-Simons term needed for classical supersymmetry of eleven-dimensional supergravity while the second term depending on the Riemann tensor R may be viewed as a one-loop correction. Note that the one-loop terms are often determined independently of the UV details of physics and M-theory is no exception.

Wednesday, April 12, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Richard Lindzen: Climate of Fear

Prof. Richard Lindzen of MIT is one of the world's most respected climate scientists or, if you at least allow me to use the alarmists' words, he is considered by them to be the world's most respectable climate skeptic.

See also: Lindzen 2008: Climate Science: Is it currently designed to answer questions?
Today, in his Wall Street Journal article, he describes not only the reasons why the public should not believe the statements that the carbon dioxide emissions are bringing us closer to the armageddon but especially the intense intimidation campaign that the scientists who reach politically incorrect conclusions have to face.

One of the topics that Lindzen talks about are the double standards in the journals where non-alarmist articles about the climate are commonly refused without review as being without interest. I have already learned how it works which is why I recommended Steve McIntyre not to spend too much time trying to get his articles published in "mainstream" journals. But the main focus of Lindzen's discussions seems to be funding. Funding is something that is cut for all of those who indicate the obvious - namely that science offers no justification for bizarre policies such as the Kyoto protocol.

On the other hand, the funding of climate science as such has grown nearly by one order of magnitude since 1988. Have you ever seen $1.7 billion, the amount that the climate science swallows annually? Or one point seven billion dollars a year worth of mostly junk science? It's not just the overall macroscopic number we are familiar with. I also know some of the microscopic mechanisms that generate it.

Harvard energy initiative

On Monday, we had a faculty lunch meeting at the Faculty Club and one of the topics was the so-called "Harvard energy initiative". A short story is that a large amount of money was given to something described by these three words - and up to 10 new faculty positions are expected to be created - except that no one knows what "Harvard energy initiative" means and what people should be hired.

Tuesday, April 11, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Microsoft: competition for Google Scholar

Everyone knows

a search engine that is used for more than 50 percent of the searches in the world. Many of us find another service comparably priceless:
That's a place where you can search through the full text of scientific articles in all fields you can imagine, and get the results sorted according to the relevance which is a criterion that includes the number of citations.

In the 1980s, IBM would be a very important company in the computer industry but Microsoft took over. Is Google going to make Microsoft obsolete in a similar way? What will be the result of the Microsoft vs. Google competition? Well, the guys in Microsoft seem to be smarter than those in IBM 20 years ago and they don't want to give up. So the counterparts of www.google.com are
while the counterpart of scholar.google.com will be
It became available tonight before 9 p.m. Eastern time - but the website so far fails to give any scholarly results. Instead, I get the standard live.com search results. Also, arXiv seems to be absent from their list of journals - the only journal with "arxi" in it is "Rethinking in Marxism".

Monday, April 10, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Elizabeth Lada: stars born in clusters

Elizabeth Lada from University of Florida is an astronomer who is most famous for defending the statement that most stars are born in clusters. This statement has brought two communities that studied star formation - those who only wanted the overall rate and those who investigated individual cases microscopically - closer together.

It was interesting to see a nice colloquium from an adjacent field - a field whose conclusions are slightly less theoretical, quantitative, universal, and principled than ours but one that can offer nicer pictures. Some of the main messages of the talk are the following:

CDF excitement - press conference

This is how good P.R. looks like at Fermilab. ;-) Or is it more than good P.R.?

From: June Matthews

We've received advanced word on some exciting new results from the CDF experiment at Fermilab, where Christoph Paus heads up the MIT effort. This is the wording:

Fermilab will hold a press conference at 4:00 pm today (Central Time) with details on the precision measurement of extremely rapid transitions between matter and antimatter. It has been known for 50 years that very special species of subatomic particles can make spontaneous transitions between matter and antimatter. In this exciting new result, CDF physicists measured the rate of these matter-antimatter transitions for the B sub s meson, which consists of the heavy bottom quark bound by the strong nuclear interaction to a strange anti-quark, a staggering rate that challenges the imagination: 200 billion times per second. There will be a life feed of the press conference available on the web at:

Regards,
Marc Kastner

P.S. You can click the envelope icon two lines below this one to send the announcement about the press conference to all your friends who might be interested. The online press conference started at 5:00 p.m. Eastern Daylight Saving Time or 2:00 p.m. Californian time and ended one hour later.

Main content: They determined that at 99.5% confidence level, they have seen oscillations between matter and antimatter with frequency 17.33 plus minus something inverse picoseconds. The results are consistent with the Standard Model and place new upper bounds on flavor violation of new physics such as supersymmetry.

Harper under pressure: scrap Kyoto

While many other politicians experienced pressure from the activists, Stephen Harper, the prime minister of Canada, is under pressure from

who urge him to scrap the "pointless" Kyoto protocol. See the full letter and signatories here. They explain that "global climate change" is an emerging science and the Kyoto treaty would not have been negotiated in the 1990s if the parties knew what we know today. The cliche "climate change is real" is a meaningless phrase used by the activists to fool the public into believing that a climate catastrophe is looming. Climate is changing all the time because of natural reasons and the human impact still can't be disentangled from the natural noise.

Meanwhile, Rona Ambrose has reviewed the situation and concluded that the targets can't be met by Canada: it's impossible. The Canadian economy is recently doing very well which is of course very bad for similar anti-growth policies: the emissions are growing while they should be shrinking according to the protocol.

I think that Canada itself should also honestly admit that if we will hypothetically face warming, Canada will benefit from it. The goal should be to isolate the countries that are supposed to be the "losers" of the hypothetical warming and help them. And also help those countries that face problems that are unrelated to warming which is far more often the case. ;-)

But help them not with the crazy egalitarian policies according to which the whole planet must be heated up or cooled down simultaneously, but help them by rational, focused, meaningful projects. The U.N. should allow Canada to change what its contributions will be and the whole U.N. framework for climate change should be re-built on new principles.

See also: Kyoto hopes vanish.

Rona Ambrose now intends to challenge the international focus on setting emission targets. I am sure she has enough intelligence and charm to do important things. Incidentally, the last link explains some proposed biomass projects that could actually make at least some sense but even these things should be studied and planned rationally.

Prof. Bob Carter, a paleoclimate geologist, explains in the London Telegraph that the main problem with the global warming is that it stopped in 1998. Meanwhile, Al Gore has admitted that the global warming is no longer a scientific or political issue: it is a moral or a religious issue, if you will, and Al Gore is a prophet.



Figure 1: The picture from the Boston Globe shows what the alarmists consider a "balanced journalism" and fair reporting about the climate.

John Brodie - sad story

Today, Rutland Herald offers a very sad story about

whom many people, not only at Princeton University, Stanford University and the Perimeter Institute, know pretty well. John has suffered from bipolar mental illness - the same disorder that Mary Winkler has been treated for - and jumped into a cold river on January 28th, 2006.



Technically, his most well-known paper was his work with Amihay Hanany about brane boxes but the paper he co-authored and one can't forget is

with Bernevig, Susskind, and Toumbas about the construction of the quantum Hall effect from D-branes.

Via Not Even Wrong.

Sunday, April 09, 2006 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Readying a massive (nuclear) strike on Iran

Update: Iran claims to have shot down an unmanned airplane from Iraq on Sunday.

In the Czech Republic, it is the news #1 at major servers such as idnes.cz but no one seems to care in the U.S.

According to the April 17th issue of

and its investigative journalist Seymour Hersh, the White House is finalizing plans for a major air attack against selected targets in Iran.

The situation has developed quite a bit during the last year.

The theory behind these plans is that an attack is the only method how to stop Mahmoud Ahmadinejad, a modern potential counterpart of Adolf Hitler as the White House officials describe him in private discussions, from developing nuclear weapons and using them against Israel and, with the help of terrorists, against the whole civilized world. The attacks are meant to humiliate the Iranian religious government and to make the people overthrow it.

I personally don't believe that the bombing would encourage Iranians to follow America. I did not believe similar idealistic predictions in Iraq either. The support of Hussain was clearly significant.

Environmentalists who like sustainability should like the bombing campaign because the "coercion" attacks will be "sustained".

Another theory is that Ahmadinejad sees the West as "wimps who will cave in". Some sources argue that it is a public misconception that Bush has been mostly thinking about Iraq since 9/11 - the main and more ambitious ideas were always about Iran. Even Quantoken agrees that the real danger is Iran. The White House is secretly communicating with the members of the U.S. senate and no one really objects to the idea of a war. There is no international opposition either because no one really likes the regime of Iran, Hersh argues. Even ElBaradei agrees that the Iranian leaders are 100% certified nutcases. On the other hand, no other country - not even Great Britain - is going to actively support nuking.

Some plans are already underway. Some of the Iranian nuclear facilities are deep underground (25 meters) and Pentagon believes that they will require a bunker-buster tactical nuclear weapon such as B61-11, the "earth penetrating" thermonuclear daughter of the old B61-7 gravity bomb, developed in 1997 under Clinton. The energy from this key nuclear product is able to penetrate up to 100 meters of soil (not rock) and the bomb explodes 6 meters beneath the surface. One of the main targets is Natanz, 300 kilometers south of Tehran. This particular plan is not technologically new because the U.S. was thinking about bombing a similar facility near Moscow in the early 1980s.

Rather detailed plans already exist how big a part of the air force of Iran has to be eliminated for the fix and what to do with the mess that would probably emerge in Iran and Southern Iraq. Controversy exists how many places would have to be bombed and whether the nuclear option is useful.

I definitely recommend you to read the article.

What about the Reference Frame? I am always afraid of a war - and I am always repelled by its obvious negative consequences. On the other hand, there seems to be a rather clear danger in the air (athough I can't rigorously prove it), and if this operation became necessary and remained a job for the air forces and avoided ground battles, I would be moderately optimistic because all these operations in the past were rather successful. Incidentally, the U.S. troops in Iran will mark the facilities by lasers to increase the accuracy of the operation and reduce the civil casualties.

Nuclear weapons have been silent for 60 years but they're not really a hot new technology.

At the high school, during the first Gulf War, our classes were often cancelled and we were watching. Most of the boys in our class were truly impressed. Whenever the U.S. technology edge is being displayed, one can always see the natural authority of America, especially if a maximum effort is made to minimize civil casualties.

The Reference Frame recommends all readers in Iran - and everyone they know - to move at least 50 kilometers from the neighborhood of the potential targets, especially Natanz (plus other targets enumerated in Wikipedia in the link at the bottom). We also recommend all citizens of Iran to start a revolution and establish democracy and freedom in Iran. This blog can't guarantee that the story from New Yorker is accurate but there are very good reasons to think that it might be true.

Hersh, the author of the article, has won a Pulitzer prize in 1970 for uncovering a massacre in Vietnam by the U.S. troops and he was also the reporter who broke the Abu Ghraib prison scandal. That's a pretty good record, I think. He likes to expose things that look anti-Bush but whether his new article is really anti-Bush remains to be seen. The contingency planning is obviously what many people in Pentagon are paid for but I can tell you neither how many decisions have actually been made, nor whether such a thing could work out as smoothly as some successful operations in the past.

Other sources:

The hypothetical bombing poses many dilemmas - moral, strategic, tactical, psychological, economical - and question marks but the psychological pressure could not be that bad. The Reference Frame also recommends Mahmoud Ahmadinejad to establish democracy, give up nuclear ambitions, and resign. Such a reasonable decision could hypothetically save millions of lives.