Sheldon Glashow, Werner Heisenberg: birthdays

Also celebrating: Arnold Sommerfeld, Cecil Frank Powell, Giuseppe Occhialini, Franco Rasetti (RIP 2001)

For some mysterious reason, maybe because I am too shy (and I will remain shy, as you will see below) ;-), I have never written about physicists' anniversaries celebrated on December 5th. While Czech children are served a trio of an angel, St Nicholas, and a devil tonight (only 20% of the Czech households ordered one this year, however),



people are being born and they're dying, too. Believe me, I know something about it – thankfully about the former only so far. The physicists born on December 5th could have felt discriminated against. Let's try to correct this injustice.

December 5th is a pretty black day for music: in 1791, Wolfgang Amadeus Mozart died. In fact, many other composers made the same serious mistake – I would even call it a fatal mistake – on the same date. The day was dark for literature and painting as well: Alexander Dumas and Claude Monet died on December 5th. However, the day isn't so bad for physics.




Arnold Sommerfeld was born on December 5th, 1868, in Königsberg, East Prussia – now Kaliningrad in the tiny island of Russia between Poland and the Baltic states. He worked on maths for quite some time: David Hilbert, Göttingen (the global capital of maths at that time)...

Among the physicists, he was nominated for the Nobel prize record 81 times (a certain social connectedness explained below is the likely reason) but he has never gotten it. Sommerfeld could boast a scar from fencing, too.

He introduced the concept and calculated the value of the fine-structure constant in 1916. It's \(\alpha=1/137.036\) or so according to modern accurate measurements although it was believed to be around \(1/136\) many decades ago. Sommerfeld realized that this combination is needed to get a characteristic value of the strength of the electromagnetic interactions that is dimensionless i.e. independent of the units. We would agree with extraterrestrial aliens about the value as long as these aliens would be fair and balanced.

More nontrivially, he figured out the Sommerfeld identity relating two forms of Bessel functions. The 1919 Sommerfeld-Kossel displacement law related the ionization spectra of adjacent elements in the periodic table. He proposed an elliptic refinement of the old Bohr model of the atom, the Bohr-Sommerfeld model. The elliptic trajectories allowed him to interpret some new quantum numbers and he wrote the quantization conditions in a way that was closer to the not-yet-born modern quantum mechanics. He co-authored the Drude-Sommerfeld model, the free electron model for valence electrons in crystals and metals.

One could spend a lot of time by explanations of these advances that were very important. Instead, let me mention that Sommerfeld was a key physics educator. Wikipedia lists 26 of his students, 22 of which were grad students, including Wolfgang Pauli, Peter Debye, Hans Bethe, Rudolf Peierls, Linus Pauling, and many slightly less famous ones. The total body of work that has been done by his students is stunning.

And I haven't even mentioned another earthshaking student of Sommerfeld. His name was Werner Heisenberg.

Werner Heisenberg

Werner Heisenberg was also born on December 5th, like his adviser (birthday is the first thing that a good grad student should learn from his adviser), but in 1901. He was born in Würzburg, exactly in between the Easternmost corner of France and the Westernmost corner of Czechia on the map of Germany.

His father was an immensely achieved professor of classical languages, especially Greek. Werner studied in Munich under Sommerfeld as well as Wilhelm Wien. It was in the early 1920 and Heisenberg was already getting ready to revolutionize the world of physics. His adviser Sommerfeld did the best things he could for his students. He noticed that Werner was intrigued by the (old) quantum stuff so he managed to get a spot for Werner at a Bohr festival in June 1922 (Göttingen). Heisenberg and Bohr met for the first time over there. The friendship was destined to last.

Heisenberg is such a great figure in physics that I won't attempt to describe everything he did here. Some of it is covered in 105 other articles on this blog. Aside from the uncertainty principle and much of matrix mechanics (the original, Heisenberg picture of quantum mechanics), he discovered or constructed Heisenberg's microscope (a wrong thought experiment about the resolution of microscopes), isospin (a quantum number mathematically analogous to the spatial spin, making the doublet out of the proton and the neutron), the Euler-Heisenberg Lagrangian (a non-linear modification of QED proposed to regulate the UV divergences in electron's mass – an approach made obsolete by renormalization), the Kramers-Heisenberg dispersion formula (for cross section of scattering of photons against atomic electrons), and the Heisenberg group (of some upper triangular matrices).

But less typically, Heisenberg has also done work on turbulent flows, the atomic nucleus, ferromagnetism, and cosmic rays. His failed leadership in the development of the German nuclear bomb shows that a great physicist's failure may sometimes be a good thing. During the war, he was just incapable of making the estimate of the critical mass of uranium right. I think that he wanted to do the job carefully but he didn't.



Eine kleine Nachtmusik. Mozart died on December 5th, 1791. Mozart had never forgotten that Prague appreciated his work even when Vienna scorned him. "My Praguers understand me," he famously said.

As a kid, he was a German Scout, got into the German Youth movement, too. You shouldn't imagine that all of it was about politics: it was mostly apolitical. At any rate, he has always been a conservative and a German patriot to the extent that he vaguely endorsed the Nazi establishment and did some work for it, too.

In 1942, he published a paper on the S-matrix. After the war, he became a proponent of the S-matrix program that gradually evolved into the bootstrap paradigm. The idea is based on a wishful thinking (closely related to the partly obsolete dreams about the uniqueness of the stringy vacua etc.) that the general consistency criteria in a QFT-like theory dictate all the spectrum and interactions. He believed that we shouldn't prescribe the elementary fields and we shouldn't qualitatively distinguish elementary and composite particles. The theories should imply all the particles, remain silent about each particle's compositeness (each of them is partly elementary, partly composite – a comment that pretty much applies to strong coupling, if I use some modern jargon), and determine the interactions, too. It should be maximally non-constructive, so to say.

This philosophy got more or less defeated because the successful theories (later parts of the Standard Model) were very constructive, starting from well-defined fields. But the Heisenberg-inspired bootstrap paradigm was the soil in which string theory was born. However, even string theory got "very constructive" rather soon, so the bootstrap vision hasn't been realized by real-world string theory, either.

Heisenberg's life and work is just too much for a single blog entry. Because of Heisenberg's proximity to the official German institutions of the 1930s and 1940s, you could feel some kind of a bad flavor, perhaps even an anti-Jewish flavor. In that case, I have a great fix.

Sheldon Glashow

Sheldon Lee Glashow was born in New York City to a Jewish family (originally from Russia) on December 5th, 1932, so he celebrates his 80th birthday today. Wonderful! I sent him this advent calendar (hover your mouse about each of the 100 persons and non-persons) and he replied it was "great". ;-)

A recent Gallup poll found out that 60% of the visitors of Wikipedia notice that Glashow's photograph above has some fingers on his right shoulder while 0% of the visitors know whose fingers they are. Well, I can tell you because I took this picture – in the Harvard's Science Center during the 2005 Sidneyfest. It's the fingers of Kenneth Lane of BU, a technicolor guy who was trying to provoke Harvard string theorists at the same time, in a friendly way, of course.

Glashow attended the Bronx High School of Science and one of his classmates was named Steven Weinberg. He got his BA at Cornell and PhD at Harvard. Julian Schwinger, Glashow's adviser, chose a rather lucky problem for Glashow: improve the lame attempts by Schwinger and construct some kind of a unified electroweak theory, with a gauge group like \(SU(2)\times U(1)\), and bring order to these two-out-of-four fundamental physical interactions. How did Glashow react? He took the lame attempts, discarded most of their details, and constructed some kind of a unified electroweak theory, with the gauge group \(SU(2)_W\times U(1)_Y\), and brought order to the two-out-of-four fundamental interactions in Nature. It sounds easy but it wasn't that easy.

Glashow shared the well-deserved 1979 Nobel prize in physics with Weinberg and Abdus Salam. The latter two mostly added the Higgs field in the late 1960s. I won't try to describe all the history correctly because it could have many bugs.

Glashow predicted the charm-quark together with James Bjorken in 1964, just by some (ultimately correct) "sentiments". He made the evidence for the existence of the fourth quark much more convincing in his 1970 paper "Weak Interactions with Lepton–Hadron Symmetry" with Luciano Maiani and John Iliopoulos; their construction is known as the GIM mechanism. The paper showed that the fourth quark is the most natural player that achieves the suppression of \(\Delta S =\pm 2\) flavor-changing processes while it allows those with \(\Delta S=\pm 1\), in agreement with observations. Note that \(S\) is the strangeness.

In 1973, Glashow with Howard Georgi at Harvard proposed the first minimal \(SU(5)\) grand unified theory. The theory predicts rather speedy proton decay which was soon ruled out. The authors lacked courage – of course, they describe it differently (it's science to abandon your baby instead of trying to nurture it and shape it, they think!) – and immediately abandoned the whole program. Of course, the grand unification approach to non-gravitational interactions is alive and well and it may be motivated in many ways. I think it's more likely than not that some sort of grand unification is a valid approximation at some high energy scale. String theory allows both grand unified vacua and those without grand unification, too, so even a belief in string theory isn't enough to settle the question whether grand unification exists in Nature. Both answers are possible.

In May 1986, right after the greatest salvos of the first superstring revolution, string theorist Paul Ginsparg – ready to invent the arXiv in a few years – and Sheldon Glashow wrote an early (and therefore relatively friendly) criticism of string theory called Desperately Seeking Superstrings for Physics Today. They didn't like that string theory's (or quantum gravity's) characteristic phenomena were inaccessible to doable experiments. That's nice but that doesn't mean that one can't study them.

All the later critics of string theory were just trying to repeat these 2.5 superficial pages of criticism thousands of times, much more idiotically and in a much more hostile way. They didn't add anything new at all, not even to the trash-talk; even the terms "String Wars" and the quote "Not Even Wrong" may be found in that two-page 1986 article.

In the mid 1990s when the second superstring revolution exploded and one could see that the amazing progress a decade earlier wasn't an isolated fluke, it became clear that every good physics department at every good university has to have a strong string theory group. Harvard had to create its own powerful string theory group, too. And it did. Sheldon Glashow didn't like it and emigrated to Boston University.

In some sense, string theorists also threw him out of their natural community as an artifact from the history textbooks of physics and I think it's wrong. People like Glashow obviously don't understand stringy seminars etc. and it wasn't just his fault; it's also their communication skills' fault. Teaching string theory – and the reasons behind its demonstrable inevitability – to Glashow was something I wanted to do at some point because I think that important and utterly sensible (and not yet senile) physicists such as Glashow simply shouldn't remain ignorant about the most important developments done by the "generation younger by one" just because of some bizarre stubbornness but it has never happened (so far).

The Boston University's physics group has done some fair, normal, somewhat interesting and occasionally exciting work in physics but I kind of believe that Sheldon Glashow realizes that what has been done in high-energy theoretical physics at the Harvard group between the mid 1990s and now is more important than what has been done at the BU. I am not saying that the results at BU weren't legitimate and impressive pieces of physics work. But there's the extra X-factor linked to true conceptual advances such as microscopic calculations of black hole entropy or the AdS/CFT correspondence in whose light the work at the BU may look mediocre.

Glashow is remaining immensely active, however. To mention the most cited papers since 1995, he co-authored a 1998 paper with Sidney Coleman in which they found all the 46 CPT-even perturbations of the Standard Model that break the Lorentz symmetry but preserve the consistency conditions. Note that he is affiliated with Harvard on that paper. In 1997, he wrote another paper with Coleman about cosmic ray and neutrino tests of special relativity.

In 2002, Glashow wrote a paper with Paul Denise Milani Frampton that just surpassed 250 citations now – about cosmological signatures of neutrino CP-violation. He actually wrote several more papers above 100 citations with Paul Frampton. Another typical co-author of well-known papers was Andrew Cohen (whom I wrote a paper with, too: so the author distance between me and Glashow is 2 steps). Most recently, in September 2011, Cohen and Glashow presented a simple yet very explicit argument why the neutrinos couldn't be superluminal because even if they were, assuming some Lorentz-breaking but still quantum field theory, they would quickly lose the energy by emitting electron-positron pairs (a sort of Bremsstrahlung).

I've met Glashow at various physicists' dinners, and so on, a fun guy. Glashow is mentioned in 79 TRF articles.

Sorry, I will skip Cecil Frank Powell (a Nobel prize winner) and the two Italian guys... Also, James Stirling who died on this day in 1770 will be ignored because at the end, I didn't use his approximation to win $300 in a recent challenge.

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Climate delegates in Qatar agree to wear gas masks

CFACT – via ClimateDepot.com and Planet Gore – went to Doha, Qatar, and asked the delegates of the annual anti-climate-change conference to test a gas mask that "sequesters" carbon dioxide (which it didn't, of course):



You may watch the people from numerous countries of the world to agree that the horrible mask is comfortable, they're ready to wear it for hours a day and while they're sleeping, recommend it to children, pets, and so on.

What makes it even more amazing is that the pranksters say that they're from CFACT, Committee for a Constructive Tomorrow. I think that everyone who follows the climate issue must kind of know that it's one of the rather visible skeptical groups. Those people don't have a clue.




Their vigilance is equal to zero, despite the fact that similar pranks have succeeded in the past – and they will probably always succeed in the future because these green people just can't use their brains if they have one at all. They're never capable of learning anything from their blunders. Recall Penn and Teller's wonderful petition to ban water. Most of the green folks banned it, just because the true facts about water were accompanied by emotional formulations describing where the "dihydrogen monoxide" has penetrated. They instantly became water-haters because this ideology was formulated in the same way as their psychopathological movement formulates hateful remarks about another vital compound, CO₂.

Those people don't necessarily have to be evil but the atmosphere of mindless group think at similar gatherings is totally unbelievable. It's clear that these people couldn't even afford to say that they wouldn't wear the gas mask because they felt they would instantly become pariahs. It's viewed as a moral duty for the participants to support an arbitrarily insane intervention into the human freedom – even their own freedom – if it is said to reduce CO₂ emissions. Now, imagine that these totally insane, brainwashed, fanatical people are allowed to influence the actual world. I just find this idea utterly stunning. In a more sensible world, the participants of the Doha conference – who would be ready to impose mandatory gas masks on you and your family if they had just a little bit more power – should be monitored by the intelligence agencies of civilized countries in the same way as Al Qaeda and bombers would occasionally be sent to deal with these groups when certain red lines are crossed.

I am not saying that the CO₂ resulting from exhalation is negligible. It's actually not negligible at all. It represents something like 5-10 percent of the mankind's CO₂ emissions. The total amount of CO₂ we exhale is about between 1/4 and 1/2 of the total CO₂ that transportation produces during the same time. And transportation produces the same amount as manufacturing and the same amount as agriculture, roughly speaking.

It's not my goal to update the exact numbers here. The point is that our breathing is in no way negligible – it's one of the major parts of the equation if you divide the sources of CO₂ sufficiently finely – and suggesting that there's something wrong about CO₂ emissions is indeed a path towards the ban of the normal, free breathing. That's really why people proposing CO₂ regulation are insane radical terrorists and loons who must be treated on par with Al Qaeda. It's about our freedom to breathe; it's about our freedom to live, to perform and display basic processes defining life. If the temperature changes by a degree due to the human breathing at some point (so far the influence is surely less than 0.05 °C although we don't know the exact number), then it's how things should be.

And that's the memo.

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Morano vs Nye

Last night, Marc Morano of Climate Depot debated Bill Nye, the "science guy", on CNN, on Piers Morgan's show.



It was five years after Nye appeared on TV with Dick Lindzen and humiliated himself in the face of the textbook authority personified by Lindzen; Julian Morris – offering some economist's common sense on priorities – and the alarmist babe proposing the Nuremberg Trials for deniers whose name I forgot but I will recover the memory in 25 seconds ;-) was there, too. Yup, Heidi Cullen.

Morano did a superb job – although he looked a bit unprepared to Nye's emotions focusing on CO2's being bad by itself, regardless of the climate. It should have been debunked more clearly.

What Nye and Morano would say was kind of expected. But I hadn't known that guys like Piers Morgan – whom I really know as a jury member in the American Idol only – would be so thoroughly brainwashed by the AGW panic as well. He's kind of unbelievable, almost on the same level as Nye. It seemed he wanted to crucify Morano for even suggesting that the right way to solve this non-problem is to do nothing.

Morgan would just pick several random pieces of weather data from random places that he considered extreme – although they were not extreme relatively to the history, by any stretch of imagination – and instantly linked them to CO2 regulation. It's just utterly amazing for me to see that similar guys fail to use their brains so miserably.

Why is it so? What's wrong with you, Mr Morgan, and so many others?

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Hawking radiation: pure and thermal mixed states are a micron away

I think that the recent paper by Raju and Papadodimas (arXiv) is the most convincing and least confusing paper about the black hole information available to the infalling observer that has been written on this planet so far.



However, I also think that the initial sections with the precise formulae for the bulk fields written in terms of the CFT variables – while being a professional piece of work that shows that the authors have been heavily trained in the AdS/CFT technology – are too long and tedious and may discourage many readers from getting to the most conceptually important part of the paper that may appear in Sections 4 and especially 5 and 6.

Because their picture seems to be the final word on many general puzzles concerning the infalling observer and black hole information – and I think that the people who won't be familiar with the basic results in a month shouldn't be counted as world's top quantum gravity experts – it may be meaningful to write short and separate summaries of some clearest results that everyone may read in minutes.

The following discussion covers some results of Subsection 6.2.2. See the paper for their original discussion and/or references.




Stephen Hawking proved that in the semiclassical approximation, the radiation emitted by a black hole is exactly thermal – i.e. described by a fully mixed state, a thermal density matrix. The information about the initial state – which may be pure – is totally lost. In fact, it's pretty obvious that even though general relativity has problems with renormalizability at multiloop level, Hawking's conclusion must be true to all orders in perturbation theory. Even if you consider some loop processes on the black hole background, it's still true that the information from the black hole interior – to be destroyed by the singularity – can't get out of the black hole. The reason is called causality, stupid.

When we expand around the black hole spacetime, the information just can't get out, and the Hawking radiation is exactly thermal. But we know that at the very end, the whole black hole evaporates and the full Hawking radiation must be nothing else than the evolved initial state which was pure – so by unitarity, it must be pure, too. Is it possible that the exact answer is pure but Hawking's thermal, mixed answer is valid up to all orders in perturbation theory?

The answer is Yes.

Mixed plus tiny corrections is pure

Assume that the black hole emits Hawking radiation whose total entropy is \(S\). So we want to describe it in the Hilbert space whose dimension is \(\exp(S)\). This entropy \(S\) of the Hawking radiation is proportional to the black hole entropy which is \(S_{BH}=A/4G\hbar\) in units with \(c=1\) where I restored \(G,\hbar\), however. But the evaporation typically increases the entropy so they're not equal.

At any rate, the detailed microstate of the Hawking radiation is described by density matrices whose size is\[

\rho:\quad \exp(S)\times \exp(S).

\] If you have trouble to calculate with fractional dimensions, think about the nearest integer to \(\exp(S)\) or, which is even easier to imagine, the nearest number of the sort \(\exp(S)\sim 2^N\) i.e. the nearest power of two which means that you imagine that the black hole has emitted \(N\) qubits (roughly one qubit per particle). Now, the simple and far-reaching point is that the exact pure state may be approximated by a mixed state \[

\rho_{\rm pure} = \rho_{\rm mixed} + \exp(-S) \rho_{\rm correction}

\] where the correction matrix has all matrix entries of order one at most. You might think that the identity above is impossible because it suggests that the distance between a "totally pure" density matrix and a "totally mixed" thermal density matrix is exponentially small, due to the \(\exp(-S)\) suppression of their difference. It would seem surprising because mixed and pure matrices seem to be very far – one of them has comparable and small eigenvalues; the other one has one large eigenvalue and multiple vanishing eigenvalues which seem "qualitatively different".

However, the formula above is totally possible. Let's diagonalize the mixed density matrix calculated by Hawking and subtract it from the pure one. The difference will be:\[

\rho_{\rm correction} = \pmatrix{
\exp(S)-1& 0 & 0&\cdots & 0\\
0&-1&0&\cdots &0\\
0&0&-1&\cdots&0\\
\vdots&\vdots&\vdots&\ddots&\vdots\\
0&0&0&\cdots&-1
}

\] One obtains it by taking the difference between the thermal density matrix, whose eigenvalues are pretty much equal and of order \(\exp(-S)\) so that the trace equals one (we took all the eigenvalues being equal, a kind of a "microcanonical ensemble", but if you took a different ensemble, the main conclusions would be the same), and the pure matrix whose eigenvalues are zero except for one eigenvalue (in the left upper corner) that is equal to one.

You see that the matrix above has one entry, in the upper left corner, that is much greater than one. It equals \(\exp(S)-1\). Well, it may be a bit different, but still close to \(\exp(S)\), if \(\rho_{\rm mixed}\) and \(\rho_{\rm pure}\) are diagonalized in different bases, but the difference wouldn't matter for our conclusions. However, we must realize that the matrix has this form in some basis that is unnatural from the viewpoint of any low-energy observables you want to measure. What do the matrix entries look like in some more natural basis? Well, a more natural basis is related to the basis where the matrix is diagonal by the following conjugation:\[

\rho_\text{mixed, user-friendly basis} = U\cdot \rho_{\rm mixed} \cdot U^{\dagger}.

\] And similarly for the pure and correction matrices. The unitary matrix \(U\) has size \(\exp(S)\times \exp(S)\), too. We will assume it is rather "generic". If you approximate \(\rho_{\rm correction}\) (thanks, Karle) by its single large entry which you approximate by \(\exp(S)\), you may see that the matrix on the right hand side has matrix entries given simply by \(U_{i1}U^*_{j1}\exp(S)\): only one entry of \(U\) and one entry of \(U^\dagger\) "clicks" when you evaluate this product.

However, the matrix entries of \(U\) or \(U^{\dagger}\) are of order \[

U_{ij}\sim {\mathcal O}(\frac{1}{\sqrt{\exp(S)}})\sim{\mathcal O}(\exp(-S/2))

\] because the norm of each column (or row) of \(U\) has to be equal to one by unitarity and the (squared) norm is just the sum of \(\exp(S)\) terms (each of which is a square, from the complex Pythagorean theorem). That's why you may see that in \(U_{i1}U^*_{j1}\exp(S)\), the two factors of \(\exp(-S/2)\) cancel against \(\exp(S)\) and you get a number of order one. This correction to the density matrix is multiplied by \(\exp(-S)\) so each entry of this matrix-valued term is exponentially small!

Suvrat and Kyriakos offer you a different argument based the consistency checks for the trace of the "correction density matrix" and its square.

This general point – that a tiny modification of the large mixed density matrix is enough to "purify" it – has been known to me as a part of the lore but I have actually never seen this simple and unassailable calculation. Much of the rest of the paper is dedicated to calculating rather explicit forms of this correction matrix that "purifies" the maximally mixed state computed by Hawking. It really works.

Let me write down once again the relationship between the mixed, pure, and correction density matrices:\[

\rho_{\rm pure} = \rho_{\rm mixed} + \exp(-K\cdot A/4 G \hbar) \rho_{\rm correction}

\] Now I rewrote the entropy as a multiple of the black hole entropy. Note that this entropy scales like \(1/\hbar\). So if you use your quantum gravity theory to calculate anything for a black hole whose shape is fixed in some macroscopic SI units (imagine some occupation number for the Hawking radiation in a mode given by its wavelength), you may do so by a Taylor expansion in \(\hbar\) which adds increasingly quantum corrections to a classical result.

However, if you do this perturbative expansion, the result will be still mixed – all these terms will be a part of \(\rho_{\rm mixed}\). The correction term will be totally invisible – totally non-perturbative – because it goes like \(\exp(-K'/\hbar)\). Calculate the Taylor expansion of this exponential around \(\hbar=0\) and you will get zero plus zero plus zero, and so on. At the level of the perturbative accuracy, the correction needed to change the mixed density matrix to a pure one is so small that it is invisible. But the full theory of quantum gravity adds and has to add this contribution so that the exact state of the Hawking radiation is pure for a pure initial state.

Once again, note that the accuracy with which you would have to (statistically) measure the entries of the density matrix to determine that it's pure (and not mixed, so Hawking's qualitative conclusion has to be exponentially tiny) is exponentially high. It's so high that in the whole perturbative expansion, the whole unitary, information-preserving process of Hawking evaporation looks exactly thermal, mixed, and information-destroying. But the idea that the difference between the pure state of radiation and the mixed state of radiation is so great and "qualitative" that it must be seen through order-one corrections in observable quantities is an illusion.

I want and plan to write down a similar short text about the doubling of the degrees of freedom for pure states that resemble a mixed one.

Note that John Preskill wrote a blog entry on the black hole firewall saga on his/their blog. He clearly but somewhat uncritically summarizes the AMPS argument but also says that he probably doesn't believe the conclusions, without making the reasons for the disbelief clearly justified.

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Can physics blogs reach the general public?

The Higgs boson, apparently considered to be a musician or athlete of a sort, was nominated as the Time Magazine person of the year 2012, among 39 other candidates:

Who Should Be TIME's Person of the Year 2012? (Higgs boson)

It's fun that particle physics has some impact on the mass culture; everything else that will be said about the nomination is going to be mostly negative.



Jeffrey Kluger wrote five sentences. Amusingly enough, Matt Strassler wanted to correct all the flagrant mistakes in these five sentences so he wrote something like a book (a somewhat angry book):

TIME for a Little Soul-Searching

See also Particles Are People Too.

Of course, I agree with Matt Strassler, well, almost entirely, but this particular thing just doesn't drive me up the wall as intensely as it annoys himself because it's been many, many years when I abandoned the idea that ordinary people – and ordinary journalists who are really just average people – could understand the meaning of cutting-edge fundamental physics. Since that time, I have only been angry about the ignorance of people whom I still expected to know better – but of course, my expectations are gradually decreasing with the people's knowledge, too.




The inkspiller in the magazine was confused about various issues, for example:

1. whether the Higgs mechanism is performed by the particle or the field
2. whether you would still have "mass" without the Higgs mechanism
3. whether the mass of the Universe could abruptly shift if the Higgs vev were set to zero
4. whether Peter Higgs is an English physicist or a Scottish one
5. whether Peter Higgs was the only man who contributed to these insights
6. what is the difference between energy, mass, and matter
7. whether the LHC experiments are made just by 3 political puppets, the so-called spokespersons
8. whether the Higgs mechanism is the culmination of general relativity
9. whether all particles are unstable
10. whether the decay products are "more fundamental particles" than the initial ones
11. whether physicists dream about the boson's getting awards designed for the people

You may predict what the Time Magazine writer wrote about these eleven questions if you have a bit creativity and if I tell you that he is about as ignorant as a Joe Sixpack on the street. Well, I exaggerate: I do believe that Joe Sixpack knows even less about the Higgs issues than the writer.

Unrelated but interesting: The DNA of the European Gypsies, especially the male Y chromosome, was found to match the lowest "untouchable" (Dalit) caste in Northwestern India by an Estonian-UK_Cambridge-Stanford team.

In some cases, I would argue that the mistake wasn't "too bad". Let me offer you some apologies – while you should understand that I could offer you many additional critiques but Matt Strassler has done it pretty well.

So, whether the Higgs mechanism is realized by the field or the particle depends on the formalism a bit. Everything that may be described by fields may also be reformulated in terms of particles. The Higgs condensate may be viewed as a coherent state with many zero-momentum Higgs bosons – actual excitations of the Higgs field – and the extra mass terms may be viewed as vertices with external legs connected to the Higgs bosons in this condensate. So while it's unusual, it's plausible you could turn the statement "the Higgs mechanism is caused by the Higgs boson" to a mathematically convincing picture.

Also, I have some understanding for the layman's way to distinguish "mass" and "energy". They're the same thing due to \(E=mc^2\). However, it makes sense to emphasize the word "mass" when the mass/energy is stored in particles with a significant/corresponding rest mass which can't be reduced further; and the mass/energy carried by massless particles ("radiation" in the cosmological jargon) may be called "energy". Of course, I don't have any excuse for those who confuse mass (a quantity, with a number) and matter (an object) – perhaps except that "hmota" is used in the Czech language for both (although the right modern word for "mass" is "hmotnost" and "hmota" for the mass is archaic and obsolete).

The contribution that protons and neutrons get from QCD – and what would happen in various worlds in which the Higgs mechanism and/or QCD is turned off – is a rather advanced stuff. I know very well that non-physicists, including some non-physicists who have been trying to understand physics for many and many years, just aren't capable of "getting" these basic things. Their resolution ends with "one physics" or perhaps "one particle physics".

But to distinguish the four forces and what they're responsible for, it's already too much to ask for. Almost all laymen I know confuse gravity which makes the mass important by allowing it to curve the space with the Higgs mechanism where the rest mass is produced by interactions with the Higgs field. What they "know" about both of these things is that they're fundamental new insights about the "mass". At this resolution, what they know about both is the same thing so the two physics mechanisms must be the same, they (totally incorrectly) conclude, too. But the conclusion is almost unavoidable if you just don't know enough.

All the filmmakers and movie people behind the Impact TV miniseries, for example (which I watched again a week ago or so), are routinely confusing electromagnetism with gravity. Everything they say about each of these two most well-known long-range forces is a confusing statement about some non-existent hybrid of electromagnetism and gravity. This comment actually applies to almost all catastrophic movies of this type. Distinguishing the weak nuclear force and the strong nuclear force is pretty much impossible for a non-physicist. I have some doubts whether one may actively distinguish all these things without realizing the mathematical meaning of the underlying formulae – which almost no layman can achieve.

There must be a moment at which one gives up certain pedagogical ambitions that are utterly unrealistic. While I think that the image of the world as painted by theoretical physics is a major part of the culture of our epoch (and knowing nothing about the W-boson or the genes is as bad as knowing nothing about Shakespeare), I find it obvious that an overwhelming majority of the mankind just can't understand its basics. The reason is an insufficient intelligence, insufficient motivation to follow these things, or both.

Journalists don't have any significant advantage. The average IQ of undergraduate students of communication/journalism is around 112 (compare with physics with 130 at the top). Among the college students, only education (109) and public administration (106) are closer to the average IQ (100). You simply can't expect too visible differences between journalists and average people on the street. They're not elite in any sense. In fact, this "mediocrity" of the writers is imposed upon us because if the journalists were too much smarter than the readers, the readers wouldn't be capable of reading the articles or they wouldn't be willing to do so.

In my family background, the discussions that start to reveal the limitations (or, politically correctly, the "differences") are discussions on whether the behavior of the human body (or other things of this kind) may be uncovered by biology (or other natural sciences) or by witches with tarot cards (or anyone else with self-described parapsychopathological "abilities"). If you were treated as a narrow-minded heretic for knowing (PC: thinking) that science is the right approach to learn reliable insights about all the observations, or even for daring to suggest that these scientific insights ultimately boil down to the laws of physics that you've mastered, you would surely forget about explaining subtleties of the chiral symmetry breaking to the general laymen. It's just utterly impossible.

In fact, even if I restrict my attention to people who have dedicated a significant part of decades of their lives to studying physics at home and following events in modern physical sciences, the results are pretty weak. I would say that if most of these people were forced to learn a 2-hour introductory physics lecture in the same way they had to learn at school (otherwise they would be spanked), they would know much more than they know after 20 years of "being interested" in physics. In spite of that, many people are very proud about their "unusual extra knowledge of physics" – something that may be worth $50 if converted to tuition in some sensible way. Of course, the extra pride often arises from the individual folks' "different knowledge" – they know something that others don't and they're proud about it even if it's unusually wrong (well, unusually when it comes to the precise type of the wrong knowledge; the very fact that the knowledge is wrong is usual).

A major reason behind this unreasonable ineffectiveness of the "home learning" of physics is that almost all these people pick sources that are full of garbage and myths spread by similarly confused and deluded average people. So this community of "not quite physicists" is keeping itself in the mud by cohesion. And of course that they teach each other to use the word "physics" and the best compliments for this mud. Authors of popular books usually contribute to this situation, too – even if they're good experts in their fields.

It's because for a book to sell well, it must apparently contain a significant fraction either of some widely popular garbage or idiosyncratic garbage. There's pretty much just one way to answer physics questions – and the truth is just one possibility among millions of others, the book market tells you, so if you repeated all the time, it would be boring or otherwise wrong. So most of the stuff written in popular physics books has to be wrong. There's just almost no natural selection that would prefer "true" books to be sold to the general public. And maybe the selection is flipped upside down, too.

A decade ago, I considered Brian Greene's The Elegant Universe to be an unbelievable counterexample. It became a bestseller despite the fact that it was indeed presenting the proper science that the best experts would endorse. The book explained what was important and only a modest fraction was dedicated to Brian's personal contributions – although there had been many – and his idiosyncrasies. Brian's later books stayed close to this description although much of The Fabric of the Cosmos was more elementary and much of The Hidden Reality was dedicated to speculations, usually twisted in the misled way that's dominant in the popular literature (the anti-Copenhagen propaganda on quantum mechanics is the most irritating example of that).

Related: The Guardian says that Brian Greene will compete against Steve Pinker and others for some Royal Society popular science book award. Someone else won but they debated what good popularization meant. Via Chimp.

But most other popular books that (just several) millions of people in the world use as "sources to learn physics" are much worse when it comes to the validity of the statements. Most of these books try to make profit with the perfect knowledge that most potential readers aren't really interested in real physics – and its sometimes modest and unsurprising implications for our observations, implications that still require hard work, attention, and precision to be derived – at all. Most people are only interested in the applications when they're useful – and they don't even want to know how they work.

The minority that declares some interest in "physics" for the sake of its knowledge is interested in "physics" as some kind of a buzzword that makes them feel special in the same sense as religious people are feeling special. I would even say that the largest group of readers of self-described "popular physics books" (some of the worst ones even try to pretend that they're not just popular books) are people who think that they have been harassed because of their lower intelligence and science skills but they want to be proved they were always right. So what they're eagerly waiting for are some revolutions that show that all the smart folks were wrong and vice versa. This is my best explanation why self-evident toxic junk written by dishonest scumbags and crackpots such as Woit and Smolin (and many other authors I don't want to enumerate) has been bought by many people (and is still being sold as you are reading this paragraph). Needless to say, this bias and desire to destroy physics as it exists isn't a good starting point to doing physics research – and it's a bad starting point to learning physics, too. Famous (or, using a different rule, the most typical) scientists may be wrong and they are often wrong but constantly betting that they must be wrong about everything isn't a viable strategy to make progress – it's probably even worse than assuming that they're always right although the two strategies are "comparably bad". Even when scientific revolutions take place, the previous wisdom is given a convenient armchair to spend the retirement age in. If you didn't understand the science before the revolution, chances are that your position will be even weaker after the revolution. True "counter-revolution" can't really occur in science because the acquired knowledge about the invalidity of obsolete theories is irreversible. If something has been ruled out, there's just no way to return to that defunct theory; a newer, usually more abstract or sophisticated theory, has become a "must".

So physics is interesting as a source of potential miracles, magic, telepathy, superluminal warp drives, and so on. But what about a solid proof that some of these things can't exist? Those insights just don't sell well. People are not interested in genuine physics; they are not interested in the truth whatever it is. They are interested in statements that pander to their prejudices and their special role among their peers. Either this sad fact or the reduced intelligence – or some superposition; it's often hard to disentangle what is at the very beginning – is the primary reason why we don't see any positive progress in the public's understanding of science. The public just doesn't want to understand those things well.

I believe that Matt Strassler still holds totally unrealistic ambitions. It's great to struggle for a better understanding of physics in the general public but if you want too much, you will be fighting the windmills. Various more or less inclusive parts of the public only have a chance to understand physics up to various levels of depth and sensible explanations of physics are likely to be a waste of time if they completely deny this distribution. That's why various types of simplifications (and various degrees of tolerance for certain misconceptions) have to be designed for variously inclusive target groups.

After all, the number of people in the general public who read (close to fundamental/particle/cosmology) physics blogs at least once a week – and redistribute tweets etc. going to physics blogs – is just totally tiny. It's really at most tens of thousands of people in the world. Even if we talk just about "interested laymen", it is just a few parts per million! The genuinely interested laymen aren't too much more widespread than the actual scientists. A larger group follows (and retweets!) science in the "mainstream media" and the distortions of science inevitably follow from this fact because the journalists usually don't know much more than the readers (and can't really know much more, for the communication to work efficiently).

We should think whether the public's belief in the "authority of the mainstream media" is inevitable, whether it brings more advantages or disadvantages, and whether we should struggle to undermine it in some way or not. Of course that there are many events after which I am tempted to think that the answer is a resounding Yes. But when I see what kind of much worse junk may be written in – and read from – some totally non-mainstream sources, I often change my mind again. In most cases, one has to choose between the bad, worse, and worst. ;-)

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Hillary wants to build (nuclear) Temelín 3, 4

Hillary Clinton is visiting Prague today – and even the official Iranian newspapers took notice. Her visit has one goal: she will try to convince Karel Schwarzenberg, her Czech counterpart, that Westinghouse, Toshiba's U.S. branch, is the better candidate to complete the Temelín nuclear power plant.



Both Clinton and Schwarzenberg are ministers of foreign affairs; both of them are potential future presidents, too. However, Hillary's candidacy isn't yet official while Schwarzenberg whose candidacy already is official doesn't have too high chances to win the office in the January 2013 direct elections.

Temelín in South Bohemia (Google Maps) has been running two 1,000 MW reactors for a decade; two more 1,000 MW are likely to be built. There were three candidates – French, American, Russian. France's Areva was said by our semi-state-owned electric utility company ČEZ not to obey the conditions of the tender. It was eliminated but appealed so its case is being studied by the anti-monopoly office now.




The remaining two contestants are Westinghouse (U.S.) and Atomstroyexport (Russia). The existing Temelín reactors are based on a combined Russian-American technology and, despite this explosive mixture of Russian mechanics and American control equipment, it is free of safety shortcomings according to the IAEA's report published a week ago or so.

Czechia has one more nuclear power plant in Moravia, Dukovany. In total, nuclei contribute 1/3 to our production and the percentage would increase to 1/2 if Temelín is expanded as planned. Of course, various factors, especially possibly dropping electricity prices, may still doom the project.

It's understandable that the whole governments are trying to intervene: the Temelín expansion contract is worth $10-$15 billion. On the other hand, I don't quite understand whether such visits of politicians may influence the process – and if they may influence it, whether it's legal and whether it's ethical.

The American company has a political advantage – Czechia has surely considered itself to be closer to the U.S. than Russia for 23 years; America is viewed as a more credible partner. On the other hand, the Russian company has an industrial advantage because various Czech companies would be likely to participate in the construction if the Russian side wins. Dr Ms Dana Drábová, our nuclear watchdog in chief, says that the Russian project has the usual flaws of likely problems in enforcing construction quality and supervision; the problem of the U.S. project is that it hasn't been tested – two blocks in China and two blocks in the U.S. are under construction now.



Schlafenberg and Hillary

Aside from the nuclear power plant, they may talk about three more topics: collaboration in Syria where the Czech embassy represents the American diplomatic interests (Hillary recommended Assad a great idea to use chemical weapons by telling him not to do so); issues of the Czech-American treaty on investments; possibility of exploiting U.S. supersonic fighters in the Czech Air Forces.

Military aircraft are a controversial topic here – some previously popular politicians are facing investigation because the purchase of Spanish CASA aicraft for $200 million a few years ago has been claimed to be a very bad deal by some people. There is some kind of a hysteria about this deal – it's being used to strengthen the widespread meme and myth that all politicians are criminals – even though the best thing that someone presented was an evaluation indicating that the price should have been $40 million lower.

I am utterly unimpressed by this sort of criticism. You may always find a posteriori audits claiming that the price should have been lower or higher; you obviously can't treat officials like criminals whenever you can achieve such a thing (which is really almost always). One may only convict people if they break the law – and the laws must always balance the efficiency of catching the misbehaving people and the ability of the business to creatively operate despite these laws. And even if the money could have been easily saved, $40 million isn't a big deal as a fraction of the money that the government wastes every year. In my opinion, the officials such as Ms Vlasta Parkanová (a former defense minister and pro-missile-defense singer) are almost certainly innocent (even if they didn't prove to be the most competent ones in similar issues) unless millions are found under their floor or boxes with wine. It's bad that they're being harassed and it's bad that so many people got brainwashed by this anti-democratic demagogy.

By a complete coincidence (or not?), today the Swedes lowered the price of their gripens that the Czech army may offer to replace Russian MIGs by 10 percent. It was announced by defense minister and ex-dissident Vondra who announced his political retirements just a few days ago.

Adrenaline in Tel Aviv

Look at this November 17th, 2012 video from Tel Aviv.



The Iron Dome – the top part of the Israeli missile defense system – seems to be so efficient (85% interception rate in the recent conflict with Hamas, counted from the 400 missiles fired to populated places; 1100 other missiles were correctly identified as fired to harmless locations) that even Hillary Clinton and the far-left wing U.K. daily The Independent admitted it deserves to be called a breakthrough. On that day, two Fajr-5 rockets were refused entry into Tel Aviv.

More sensible, listen to engineer "Ari" at Fox News. One Iron Dome missile costs about $50,000 (missiles expected to land away from civilian targets are ignored; that's a good idea because a generic Qassam missile may be built just for $800). About 400 hostile missiles were recently intercepted. Lots of good was done for $20 million, lots of praise has been earned by Amir Peretz, a left-wing ex-defense minister who was able to see the future through covered binoculars.

A light bulb revolution?

A new type of a light bulb is as efficient as LED bulbs, has better, more white light, is flexible, the color is adjustable.



FIPEL light bulbs are based on field-induced polymer electroluminiscence and could be sold commercially as early as in 2013. If the price is OK enough, that would probably mean an early death for the fluorescent light bulbs in particular.

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Sea level rise is the most reliable way to see global temperature trends

Tonight, I skipped another (3-hour) catastrophic movie on TV, Flood (2007). Some skeptics are writing lots of e-mails about a silly study that says that the sea level rise proves man-made global warming – without a glimpse of evidence supporting the attribution. It apparently has some impact in the U.S.

I am already way too bored by this junk. People who keep on writing this stuff are inferior inkspillers and one of the goals of my writing about the climate in recent years has been to convince sensible people that they should pay no attention to these liars and idiots. So it would be hypocritical – and a sort of masochism at the same time – if I were reading much of the alarmist garbage that is being published.



Via NOAA. Battery, NY is named after artillery batteries that use to stand there to protect the settlers from David Cameron's predecessors. If you think the trend is only this straight in New York, try Boston, San Francisco, Seattle, and London.

But concerning sea level rise, I want to say one thing. It is a great benchmark to estimate the rate of something that could be called the global mean temperature – a better method than the manual averaging of weather stations or satellites. The main reason why I say such a thing is that unlike the graphs of the global mean temperature reconstructed from weather stations or satellites, the graphs of the sea level rise are unbelievably straight. And you don't need to measure the sea level at lots of places in the whole world. One place, e.g. Southwest of Manhattan – see the graph above – is enough.




Compare the sea level graph with some typical graph of global mean temperatures over a similar period:



I think you must agree that the sea-level graph may be classified as a straight line with some nearly white noise added while the global mean temperature graph is much further from such a description: the global mean temperature graphs resemble random walks whose "trends" are changing all the time. Well, I am sure that you may demonstrate the visually obvious point quantitatively, too.

The Battery, NY sea level graph is constructed so that the average seasonal cycle – a rather simply calculable function of time that only depends on astronomy – is subtracted. What is left is a remarkably straight line despite the fact that the difference between the (two) maxima and (two) minima of sea level on a given day in Battery, NY is almost 2 meters and we need to isolate millimeters every year. It's so straight that NOAA has calculated the rate of the sea level rise as\[

\ddfrac{h}{t} = (27.7\pm 0.9) \frac{\rm cm}{\rm century}.

\] The relative error is just 3%. Quite amazing: the error of the known temperature increase in the last 100 years exceeds 10%. When you see how straight the graph is and how the rate hasn't visibly changed in the last 100 years, you must also agree that it's very hard to imagine that the sea level rise in the next 100 years will be too far from these 27.7 centimeters. Every sensible person knows that 27.7 centimeters per century is negligible for practical purposes. It makes no sense to be afraid of a sea level that 27.7 centimeters higher in 2112 than it is today.

You should also be able to see – just visually – that the average acceleration of the sea level rise is almost exactly zero. It's so close to zero that the error of the acceleration coefficient would be comparable to the acceleration itself. So it makes no sense to try to extract the acceleration from the time series: there's none. That's why I found a long text by Stefan Rahmstorf redundant and useless. It's a futile task to try to extract the acceleration from this graph simply because there's no significant acceleration in the graph. Otherwise his main claim is totally illogical. He tells you that you shouldn't try to estimate acceleration by fitting a quadratic. However, the average acceleration over the period is pretty much by definition the quadratic coefficient in the best-fit quadratic (times two, to celebrate Mr Brook Taylor). So the precise procedure he wants to ban is surely valid. The actual correct claim is that you shouldn't try to calculate the acceleration at all because within the error margin, it's zero (equivalently, the error margin is as large as the acceleration itself) and because the additional non-linearities that seem non-quadratic imply that it's not a good approximation to talk about a constant acceleration at all! But as long as you want to talk about a universal, constant acceleration, it is nothing else than the quadratic coefficient from the best-fit quadratic (times two), despite Rahmstorf's silly discouragement.

I think that the sea nicely averages the heat at many places of the globe. Well, let's admit that the sea level graph is smoother also because the oceans have a significant "inertia" – well, I mean heat capacity. But it doesn't matter. The inertia is just doing something like 5-year or 10-year running averages of an underlying trend that could be more bumpy. But it's still true that the sea level in Battery, NY shows nothing like the global cooling between the 1940s and the 1970s. The sea level was rising rather uniformly (linearly) throughout the last 120 years or so, independently of CO2 production, aerosol emissions, and other things. The linear shape of the graph is a strong piece of evidence that the sea level rise isn't (mostly) caused by the bumpy (and exponentially increasing: the CO2 emissions increase e times every 57 years) human activity.

Despite the widespread hype about melting, most of the trend above is actually caused by thermal expansion of the ocean. (Melting accounts for 20% or so.)



On the graph above, you see that the density of water is actually minimized at approximately 4 °C (Howard W. is telling me that the salty seawater has the minimum elsewhere, actually at –2 °C). Water expands if you cool it or warm it from this particular temperature. At reasonable "room temperatures" (or the ocean temperature in a large majority of the globe), the coefficient of thermal expansion is something like 0.025% per Celsius degree. So if the ocean temperature increased by 0.5 °C in a century (probably a bit less than that because the oceans were warming less quickly than the land), you may see that the "height of water" should have increased by something like 0.01% in the last century.

Because we know that the actual rise was about 30 centimeters, we may estimate the relevant part of the ocean that was heating up and expanding. 30 centimeters is 0.01% of how much? Well, we get 3 kilometers. It's surely a thicker layer of the ocean surface than what is usually considered as the "circulating part of the ocean" capable of storing heat. But there are different effective descriptions at different time scales. If you consider longer time scales, like 20 years instead of 5 years, deeper layers of the world ocean become relevant.



It's remotely conceivable that the melting of glaciers and ice sheets in the Greenland or Antarctica could become more important in the future and the trend may start to change quite suddenly. But the impressive constancy of the sea level trend in Battery, NY – and any place that measures it as well as the Newyorkers do (there aren't too many places like that) – is a strong indication that such a melting contribution (and, independently of that, the human contribution) hasn't started to be important yet. Could we please postpone all the climate worries to the moment when the sea level rise trend (measured at least from a decade of data) increases at least to 50 centimeters per century? The data available so far indicate that we haven't changed an iota about the natural trends yet and the continuing expansion of the New York City is a strong hint that 27.7 centimeters per century is just fine from all points of view.

Bonus fun: Prof Chimp

Do you believe that this video via Peter F. is legit?

ALL IS IN ORDER from Science News on Vimeo.

He's better than you and me, isn't he? The official caption says: After touching the white circle to start a round, Ayumu breezily reconstructs the order of briefly flashed numbers. Credit: T. Matsuzawa, Primate Research Institute

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Enrico Fermi started nuclear era 70 years ago

An unusually well written article appeared in the financial section of the Czech Press Agency's server. Here's the translation into Lumo English.



Chicago/Prague – Exactly seven decades ago, on December 2nd, 1942, the mankind found itself on the threshold of the nuclear era. A team led by Italian physicist Enrico Fermi managed to ignite a controlled nuclear reaction for the first time in the history. The experiment opened doors towards the usage of the mysterious energy from the cores of atoms which is able to both kill and help.




Although Fermi belonged among the key minds of the U.S. Manhattan Project whose goal was to develop a nuclear warhead during the war, the place where the test took place wasn't a nuclear facility. Instead, the experimental reactor was constructed in the basement beneath the unused terraces of Stagg Field, a sport stadium in Chicago.

The equipment built by the team of Fermi's collaborators for several months was aimed to practically verify the possibility of a controlled fission chain reaction which was suggested by Fermi's colleague Leó Szilárd. It was composed of numerous graphite blocks into which uranium capsules were inserted. Cadmium-coated bars were dragged through the spaces in between the blocks and their sliding in and out was supposed to control the reaction intensity according to the experimenters' will. The whole 450-ton "atomic charcoal miln" was covered by wooden boards. Together with the bars, these were the only two safety arrangements.

Although the risks linked to the experiments were significant, 49 brave people gathered in front of the reactor on December 2nd. Young scientist George Weil was assigned an important role in this exercise. According to Fermi's instructions, he slowly began to remove bars from the reactor while others were breathlessly standing on an elevated podium.

Just like the physicists expected, the neutron activity grew every time the bars were sliding out. Once the fission chain reaction was in reach and the tension in the room could have been cut like a loaf of bread, Fermi astonished everyone who was present. In a calm voice, he declared a lunch break.



Painting via Gary Sheehan, Atomic Energy Commission, and Technet.Idnes.CZ. The three men behind the reactors have readied jerricans with cadmium, as Bill Zajc correctly recalled.

When the physicists ate the lunch together, the experiment could continue. The clocks were showing 3:25 pm when the accelerating ticks of the detectors changed to an uninterrupted sound. The reactor entered the critical state for the first time.

About half an hour later, Fermi ordered Weil to insert the regulating bars and stop the reaction. The viewers felt a feeling composed of relief and happiness. Someone managed to find a wine bottle and paper cups. Those who remember say that the room was as silent as a cemetery because everyone was aware of the importance of the moment.

Army officials were informed about the successful experiment by phone. To protect the information against eavesdropping, both sides had to exploit a curious code in their speech. "An Italian voyager landed in the New World," the basement of the Chicago stadium reported. "How did the aborigines react?" chemist James Conant was worried on the other side of the line. The answer was reassuring: "They were very friendly."

Fermi's experiment opened the door to subsequent developments that took place on two very different paths. The first path led to the construction to a nuclear warhead that was ignited in a New Mexico desert in July 1945 for the first time. A month later, inhabitants of Japan's Hiroshima could testify that the weapon was rather efficient.

A more friendly among the two "Janusian faces" of the energy from the cores of atoms is displayed in nuclear power plants. The first nuclear reactor that was actually producing electricity was started shortly before Christmas 1961 in the U.S. state of Idaho. Its power was so small, however, that it only covered its own energy needs. The first "nuke" power plant was connected to the grid in Summer 1954 – in the USSR.

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