Wednesday, November 25, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

100 years of general relativity

LHC is colliding lead ions whose lab energy is \(82\times 6.369\TeV\), a new record!

On Thursday, November 25th, 1915, exactly 100 years ago, Einstein presented the final form of his equations (defining the general theory of relativity) to the Royal Prussian Academy of Sciences in the afternoon.

The building sits at the famous Unter den Linden 8 avenue (the big street that leads to the Brandenburg Gate from the East), see Google Maps, was designed according to the military tastes of Emperor William II, and it was inaugurated just a year earlier, in 1914. These days, the once only building of the Academy is used as one of the three homes of the (Berlin) State (formerly Imperial) Library or "Staatsbibliothek" ("Stabi" as Germans call it).

Einstein had prepared the final form of the equations for that talk and had to work hard, relatively to the standards of this "lazy dog":

One thing is for sure, that I’ve never been so plagued in my life,” wrote Einstein at the time. “Smoking like a chimney, working like a steed, eating without thought, sleeping irregularly.”
So much whining about some work that may be basically reduced to writing \(S=\int R\). ;-)

His wife Elsa remembered that he was absent-minded in the last two weeks or so and sometimes played the piano mindlessly or stared blankly to the space as if he were Witten. Einstein was exhausted and stinking of cigarettes during the talk (strangely, he only allowed to be photographed with tobacco pipes which "contributed to his calm and objective judgment", he stressed; Albert remembered that to beat his doctor, his grandfather smoke cigarette butts from the street) but he gave us his general relativity. The content of papers was more or less ready but they only appeared in 1916.

Institute for Advanced Study has organized an event, GR at 100, and this lecture by the IAS director and my once co-author (and an independent co-father of our matrix string theory) Robbert Dijkgraaf previously gave this October 2015 talk which was the only one whose video I could find two weeks ago.

But now, the IAS YouTube channel offers you 10 videos from the gathering. Search for "GR @ 100" on that page. A talk by Andy Strominger about his very recent findings is there, too.

Does dark matter clump to radial filaments?

Earth's dark matter hair?

Lots of media including The Washington Post, Popular Science, Space Daily, Christian Science Monitor, Russia Today, and Fox News bring us the happy news that Nude Socialist already hyped in August.

The Earth is sprouting hair – radial filaments of dark matter.

This claim is taken from the July 2015 paper by Gary Prézeau, an experimenter at JPL NASA in Pasadena and a member of Planck,

Dense Dark Matter Hairs Spreading Out from Earth, Jupiter and Other Compact Bodies (arXiv)
which has just appeared in the Astrophysical Journal (which produced the new wave of interest). He claims that the ordinary cold dark matter (CDM) is organizing itself in such a way that compact objects including the Earth or other planets develop radial thick enough filaments of dark matter, the hair.

Tuesday, November 24, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Turkey is a problematic ally of NATO, everyone else

For centuries, the Ottoman Empire was the key power attempting to Islamize Europe. It was the regime that our ancestors had to fight against to protect the "European" values on our continent.

The Austrians, Hungarians, and others had to sacrifice their lives. Meanwhile, the interaction has led to a partial convergence of the Ottoman Empire and the European countries. We (at least in Bosnia, Czechia, and Greece) have learned to drink the Turkish coffee that almost no one drinks in Turkey. At the same moment, Turkey has imported tons of European civilization advances.

It seems obvious to me that the know-how that Turkey has gotten was far more valuable than the know-how that we have obtained from them. So when Mustafa Kemal Atatürk, the father of Turks, became the prime minister of Turkey in 1920 and the president in 1923, Turkey could reinvent itself as a modern secular state. The Western drift has stopped at some point and since those times, Turkey has been a country "in between" Europe and the Muslim World.

Point-like QFTs in the bulk can't be a consistent theory of QG

Dixon's research is impressive applied science using deep insights by others, mainly string theorists

Lance Dixon is a prominent particle theorist at SLAC. A few days ago, he gave an interview about quantum gravity.

Q&A: SLAC Theorist Lance Dixon Explains Quantum Gravity
He's been most tightly associated with multiloop calculations in quantum field theory (including some calculations at four loops, for example) and various tricks to climb over the seemingly "insurmountably difficult" technical obstacles that proliferate as you are adding loops to the Feynman diagrams. However, as a Princeton graduate student in the 1980s, he's done important research in string theory as well. Most famously, he is one of the co-fathers of the technique of the "orbifolds".

Also, most of his claims in the interview are just fine. But some of his understanding of the big picture is so totally wrong that you could easily post it at one of the crackpots' forums on the Internet.

Monday, November 23, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Could have a Nigerian teacher proved the Riemann hypothesis?

Not really, LOL, thanks for asking

The Clay Institute has announced its "seven millennium problems", a group of deep mathematical conjectures that had been neither proven nor disproven. To solve any of them means to win $1 million. Famously enough, Grigory Perelman has made the crucial steps in proving the Poincaré conjecture – a statement of the kind that "if something quacks and smells like a three-sphere, it is a three-sphere" – and rejected the bounty.

All six other problems remain unsolved so no money has been paid at all. I am among those who consider the Riemann Hypothesis to be the most profound conjecture among the seven. To say the least, I have spent much more time with efforts to prove it (and yes, I mostly believe it is true) than with the other six combined.

A week ago, all leading British media have brought us wonderful news: a Nigerian teacher named Opeyemi Enoch has solved the problem and will be paid $1 million.

Trump is obviously right on 9/11 Jersey City Muslim celebrations

During the weekend, Donald Trump said something that is considered common sense in my country. However, the hysterical reactions by the U.S. journalists and politicians proves that the discussions about similar fundamental issues have been turned into a big taboo in the "land of the free". Some people would obviously shut Trump's mouth if they could!

Donald Trump said that he remembers that thousands of Muslims in Jersey City, New Jersey were celebrating the 9/11/2001 attacks on that day. Is that true?

On 9/11/2001, your humble correspondent was defending his PhD at 9:30 am. The defense took place in the Busch Campus of Rutgers University, near Piscataway, New Jersey. After that, we went to the top of the Hill Center, the mathematics department at Rutgers, and saw the smoke above the World Trade Center which is 26 miles away (through the air). Those were terrible days for America.

Sunday, November 22, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Pi found in the hydrogen atom

...and in every other hole and round corner of the Universe...

Less than two weeks ago, dozens of media outlets brought us wonderful news. The number \(\pi\approx 3.14159265358979\) has been found in the hydrogen atom. Enthusiastic, magic reports of this kind have appeared at Science Alert, Rochester News Service, Science20, Forbes, Christian Science Monitor, Science Magazine, Space Daily, Physics World, and other places.

Saturday, November 21, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Tracking Muslims: bad but maybe better than alternatives

Those whose privacy is reduced could be compensated

Donald Trump has proposed a database for the citizens who are Muslims, some kind of a tracking system, and perhaps suppression of the mosques. Other candidates have criticized the proposal and Hillary called it shocking.

The "atoms" in Brussels' "Atomium" fail to behave as atoms according to the laws of quantum mechanics. Is this well-known structure among the potential targets?

But you know, in the current situation, Trump's proposal is one of the common-sense ideas that are ready to be at least considered. The actual support for this kind of ideas may be very strong even if people pretend otherwise – in order to look politically correct. Topics like that may very well become the driver that will move Trump to the White House.

Mamma Mia, the musical

Last night, we went to Prague's Congress Center to see the Czech eddition of Mamma Mia! The huge building formerly named "The Culture Palace" was opened in 1981 and the 16th convention of the Czechoslovak Communist Party was the first big event it hosted. (President Husák said the joke about his fall from a skyscraper during the 1986 17th convention.)

I am not some kind of a regular spectator of musicals but I like the genre. Some two decades ago, I went to Jesus Christ Superstar (CZ) which was great as well. Now, Mamma Mia! has in some respects become the most successful musical in the history. But that's partly due to the fact that the more recent, optimized world makes a big success easier even if the substance isn't necessarily better than it was in the older and old pieces.

Friday, November 20, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Find global warming, win $100,000

Mmanu_F has pointed out that Douglas Keenan, a climate skeptic who has done statistical calculations as a trader in New York and London, earned lots of money, and wrote some articles, has declared his own Kaggle-like challenge

Douglas Keenan's Contest 1000
whose winner will receive $100,000 (zero point one million dollars). The winner needs to be the fastest one; and send his entry before November 2016. An entry fee of $10 has to be paid so that non-serious contestants are suppressed.

Thursday, November 19, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Federica Mogherini, a personification of many evils of the EU

Ms Federica Mogherini, a would-be EU minister of foreign affairs, was supposed to arrive to Czechia yesterday or today. The visit was cancelled. For a while, people were led to believe that the reason was a leg injury of Mr Lubomír Zaorálek, our minister of foreign affairs.

But today, all the fog has disappeared and we have learned a more realistic explanation:

Mogherini shuns Prague also for its tying migrants to terror – Czech Public Radio
Her spokesmen etc. were heard as saying that
the atmosphere in the Czech Republic is not favourable for conducting a debate on foreign policy.
Wow. The atmosphere in any country is tautologically equally favorable for conducting a debate on foreign policy. And in free countries such as Czechia, the public is actually participating in this debate and the debate is calm, balanced, and reasonably intense. A more accurate description of the problem is that Ms Mogherini is unable to participate in a meaningful debate on foreign policy issues which is why she would feel out-of-place in the Czech Republic.

Intercontinental Wilson line as a proof of state dependence

Today, the hep-th arXiv offers us several noteworthy papers.

First, six authors including Heckman, Morrison, and Vafa study the little string theories – non-gravitational but non-local theories describing decoupled dynamics on NS5-branes (not to mention other equivalent definitions) – using compactifications of (Vafa's) F-theory in various geometric phases. They conclude that little string theories (at least those with two or more tensor multiplets) may be rather easily obtained from a six-dimensional superconformal field theory. Also, all six-dimensional superconformal field theories may be embedded in a little string theory. Little string theory's existence was pointed out almost 20 years ago and this beast seemed mysterious – and it's remarkable that people are befriending it and demystifying it in this way.

The remaining two preprints I will mention are dedicated to the black hole interior in quantum gravity.

Wednesday, November 18, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

First-quantized formulation of string theory is healthy

...and enough to see strings' superiority...

As Kirill reminded us, two weeks ago, a notorious website attracting unpleasant and uintelligent people who just never want to learn string theory published an incoherent rant supplemented by misguided comments assaulting Witten's essay

What every physicist should know about string theory
in Physics Today. Witten presented the approach to string theory that is common in the contemporary textbooks on the subject, the first-quantized approach, and showed why strings eliminate the short-distance (ultraviolet) problems, automatically lead to the gravity in spacetime, and other virtues.

Witten's office as seen under the influence of drugs

This introduction is simple enough and I certainly agree that every physicist should know at least these basic things about string theory but at the end, I think that it isn't the case, anyway. Here I want to clarify certain misunderstandings about the basics of string theory as sketched by Witten; and their relationships, similarities, and differences from quantum mechanics of point-like particles and quantum field theory.

Tuesday, November 17, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

FQ Hall effect: has Vafa superseded Laughlin?

A stringy description of a flagship condensed matter effect could be superior

Harvard's top string theorist Cumrun Vafa has proposed a new treatment of the fractional quantum Hall effect that is – if correct – more stringy and therefore potentially more unifying and meaningful than the descriptions used by condensed matter physicists, including the famous Laughlin wave function:

Fractional Quantum Hall Effect and M-Theory (cond-mat.mes-hall, arXiv)
Laughlin's theoretical contributions to the understanding of this effect are admired by string theorists and physicists who like "simply clever" ideas. But the classification of the effects and possibilities seemed to be a bit contrived and people could have thought that a more conceptual description requiring fewer parameters could exist.

Monday, November 16, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Juncker et al. apparently want to exterminate the European nations

Some people have actively or passively supported the European open-door policy towards the migrants from Syria and the rest of the Middle East because of their naivite. They were not necessarily evil or stupid people; they just thought that millions of people may be happier and it costs "almost nothing".

The Friday 13th attacks – which have killed at least 132 people plus 7 animals so far – have changed these people's understanding of the issue. Slovak PM Fico said:

We have been saying that there are enormous security risks linked to migration. Hopefully, some people will open their eyes now.
I totally agree with that – and I am already seeing this effect in my conversations. Many people who have been ambiguous about the immigration policies have realized that our warnings weren't just some demagogic fearmongering. There are enormous risks to the security and the economy associated with the mass immigration.

Friday, November 13, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

New Paris attacks: a huge warning

My condolences go to the families and friends of the victims of the new, coordinated terror attacks in Paris. Things are getting worse; what happened tonight is more bloody and more widespread than the Charlie Hebdo attacks in January.

Shalom (CZ), original version by Olympic (CZ): Bon Soir, Mademoiselle Paris. The frustrated mood and lyrics (Love is your fate, God bless you...) sound totally appropriate for this sad weekend.

After 9 pm, terror erupted at least at seven places (I will mention only the well-known four); the total number of terrorists is said to be at least 8 (which may or may not include at least 3 suicide bombers) and the number of casualties is probably over 120 at this point, mostly in a theater. Once the attackers were killed, three of them carried 2 Syrian and 1 Egyptian passports, respectively. At least two attackers were "refugees" registered in Greece (in February and October, respectively). At least several attackers were teenagers; at least one was female.

Shooting at the "Little Cambodia" restaurant; at least 11 casualties there. Death metal concert at the Bataclan theater attended by a thousand of music fans; 100+ hostages taken and at least 100 (originally 35) killed (they were being slaughtered one-by-one and some of them are posting pictures on social networks; the earlier number "35" didn't include possible victims of 5 explosions over there after the midnight). Explosions near "Stade de France" where Hollande (identified as a primary target of the attack) was just watching a friendly soccer match against Germany; 10 people either injured or killed. (France won 2-to-0; Czechia defeated Serbia 4-to-1 tonight.) There was a shooting and bombing at the "Les Halles" mall, too; casualties are unknown.

A BBC documentary on quantum mechanics

It starts OK but ends with almost all the pop-science delusions against quantum mechanics that you know

First, let me mention that I have embedded a YouTube video to the blog post about Coleman's lecture Quantum mechanics in your face.

Are you capable of watching the nominally 56-minute-long video at the speed 1.5 times normal as I did? ;-)

I have just watched the first of the two episodes of the 2014 BBC Four documentary The Secrets of Quantum Physics. This first episode is called "Einstein's Nightmare" (the YouTube video gives the wrong names and wrong dates, maybe to avoid the erasure). There is also a second episode, "Let There Be Life" which I haven't watched yet.

ATLAS dijet events: mass up to \(8.8\TeV\)

The 2015 proton run at the LHC is over.

(Some \(5\TeV\) playground proton collisions are gonna be made soon which will train the collider for the new lead-lead collisions in December.)

At the center-of-mass energy of \(13\TeV\), ATLAS has performed 4.32 inverse femtobarns of collisions out of which 4.00 inverse femtobarns were recorded. (Maybe the number is round by accident, maybe the two zeroes are a bump suggesting some intelligent design.) CMS has collided 4.11/fb of proton-proton pairs. My estimate is that 3.8/fb of that was recorded but it's plausible that up to 1/2 of these CMS collisions occurred without the CMS magnet which would make this 1/2 of the data much less valuable in most channels.

The outcome of 2015 could have been better for the LHC engineers but it could have been worse, too.

The 2012 \(8\TeV\) run has recorded and evaluated (not in all channels so far) 20/fb of data (at ATLAS plus the same for CMS). So the integrated luminosity in 2015 was 5 times lower than in 2012. However, at the higher collision energy, some of the interesting new phenomena become much more visible.