Friday, October 09, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

A thesis on bulk locality in AdS/CFT

RAF III is clearly following the papers on the arXiv in some detail so he was able to see the PhD thesis by Jennifer Lin,

Bulk Locality from Entanglement in Gauge/Gravity Duality,
who is getting her PhD under David Kutasov at the University of Chicago. She has written almost a dozen of papers and cooperated with folks like Klebanov etc. at Princeton and Ooguri etc. at Caltech, not to mention interactions with Jeff Harvey in Chicago and others.

Also, RAF III was able to notice that the thesis refers to a 2013 TRF blog post. I assure you, it's not usual to cite blog posts and the technical author needs some balls to do a thing like that in an otherwise formally flawless technical piece of work. Thanks for that, Jennifer!

Jennifer cites my blog post as the first source of the observation that the "existence or non-existence of a [non-traversable] wormhole in quantum gravity" is not observable by a well-defined apparatus or a procedure; and, correspondingly, it is not an observable in the theoretical sense (i.e. a linear Hermitian operator). This negative statement has to hold because the "existence of entanglement", which is dual to it, isn't an observable, either.

Thursday, October 08, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Post-communist Europe has no reason for gratitude for Cold War emigration

Days after the Nobel peace prize winner Barack Obama has flattened the Afghani hospital of a fellow Nobel peace prize winner, Doctors Without Borders, the prospective Nobel peace prize winner Angela Merkel has made some new insane statements meant to increase her chances to beat Tunisia's National Dialog Quartet (unlikely!) and win the 2015 Nobel peace prize for having caused the worst migration wave in Europe since the end of the Second World War.

The Telegraph has reported her offensive claims in the article

Angela Merkel attacks east European leaders for ignoring their past over refugees
Before I get to her explicit statements, I want to dedicate a few paragraphs to a meme that has been mentioned on this blog but as far as I remember, it was never a major topic of a blog entry. Some people say that the post-communist countries should support the immigration from the Muslim world because the citizens of these countries have been allowed to emigrate to the West during the Cold War years and these Eastern countries should therefore repay the debt.

This suggestion is insane. The countries have nothing to be grateful for. On the contrary. The emigration has stripped our homelands of some gold in the human capital.

Wednesday, October 07, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Syria, Microsoft, Norway and kids, VW solutions, Czechs in Lebanon

There are tons of ongoing events outside physics that are happening and that would normally be discussed in separate blog posts. Let me reduce the number of blog posts where these heavily unphysical topics appear and consolidate my comments.

Russians in Syria

My most recent entry about Syria was posted hours before the Russian lawmakers okayed an operation in Syria – which was followed by the ongoing airstrikes that started just several more hours later. The bombing videos remind me of what we were watching in the early 1990s when Bush 41 was showing Saddam that the occupation of Kuwait wasn't a good idea.

It's obvious that the Russian intervention is making a difference – and a much bigger difference than the year(s) of the U.S. alleged campaign. I think that the data make it extremely probable that the U.S. was just "pretending" to be fighting against the Islamic State. Russia has already destroyed a significant portion of the tanks, command centers etc. It is implausible that this won't make a difference on the ground rather soon. It's like playing chess so that one piece of your enemy is artificially eliminated after every move.

Tuesday, October 06, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Neutrino oscillations aren't near the top of particle physics

The 2015 Nobel prize in physics went to Takaaki Kajita (University of Tokyo, 1/2) and Art McDonald (Queen's University, Ontario, Canada, 1/2), for their discovery of the neutrino oscillations – which may also be interpreted as the discovery of the neutrino mass. Congratulations!

I don't think that I know the Gentlemen in person. Of course, I know their achievements in cooking. A fajita is a flavored meat strip. And it's sensible that fajitas got the prize along with the hamburgers. McDonald's restaurants have repeatedly saved my life, for example in Santa Cruz, California. While I was at Harvard, I often walked a mile towards the Central Square, away from the hard core of the People's Republic of Cambridge which de facto bans corporations such as McDonald's. (This attitude of the pompous far left-wing bigots offends my nationalist feelings as well – McDonald's only became a big chain when it was bought by Ray Kroc, 1902-1984, a Czech American whose father was born 10 miles from my home.)

But back to the prize. It's a prize in particle physics and one that is totally legitimate but I am sure that lots of top particle physicists will be left a bit unexcited by that prize, too. For example, Nima Arkani-Hamed – who, as a Westerner, is primarily Canadian, just like McDonald – has explicitly stated that neutrino physics – something that the Fermilab has pretty much promoted to the core of the institute's activities – isn't an adequate flagship for the particle physics enterprises in a country that is as great as the U.S. I have always shared this view.

Monday, October 05, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Frank Wilczek's book on beauty

Spoiler: this blog post is full of spoilers'

Ann has sent me Frank Wilczek's new popular book, "A Beautiful Question" (thank you again, Ann!) and it is very nice, entertaining, multi-dimensional, and mostly correct. The question reads "Is the Universe built upon beautiful ideas?" and Wilczek's highly secret answer is a combination of the letters Y, E, S.

If you don't know the name, Frank Wilczek is a Twitter follower of mine. (You probably despise honors but he is also a 2004 Nobel prize winner.)

The book describes the history and recent developments in "generalized physics" and is nicely built around the condensation nucleus called "beauty". It's possible but sometimes, one can see that the presentation of the topics is a bit stretched. Is the history of physics a history of beauty? The answer is as ambiguous as in the case of history of physics as the history of light. Yes, no, a little bit, perhaps. Well, the beauty is great if you see it in the laws of Nature. But if you don't see it, it's likely that it's your fault, not Nature's. A person's sense of beauty is only a good guide to understand Nature if the person has a good sense of beauty, one that is correlated with Nature's. ;-)

Saturday, October 03, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Metaphysics is needed, should face competition, too

Days ago, I discussed Lawrence Krauss' tirade slinging mud at the concept of a theory of everything.

I have also mentioned another text in the same issue of the e-magazine, Life Is a Braid In Spacetime, by Mad Max Tegmark, but I think that it's even more vacuous than his well-known texts about the Mathematical Universe. His text is equivalent to: There is a spacetime. Something is mathematical about it. Sometimes it's the future, sometimes it's the past. If one is a bird, he can look from a bird's perspective. If he is a frog, he may have a frog's perspective.

If it won't be raining, we won't get soaked. (The previous sentence is from a popular Czech children's song that was the template for Smetana's The Moldau ;-) and that I began to use as a symbol of tautologies and "easy prophesies".)

Life is complicated. World lines of living things are complex, too. Yup but where's the beef, Max? Thed text is like Gigi's Puzzle in the Fio Bank's TV commercial: Which of us is me: he... or me...? – He [while each solver points at a different man]. – The solver #1 is a moron moron, the solver #2 is an imbecile moron.

Thursday, October 01, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

The trouble with Krauss' criticism of TOE has published a rant by a fanatic named Lawrence Krauss,

The Trouble with Theories of Everything.
Most of it is an attempt to explain the important idea that most theories we use in physics are effective theories that are optimized for certain scales – for phenomena whose typical energy or typical length belongs to a certain fuzzily defined interval. It would be great if someone were explaining this important point, an unsung scientific revolution, as Krauss correctly calls it.

But he stops short of doing it right – and goes well beyond that, too. The insights about the renormalization groups aren't the goal of his tirade. Instead, they are just some new tools in Krauss' lame attacks against state-of-the-art theoretical physics.

Anti-diesel hysteria emulates witch hunts in Salem, MA

HTTPS: a technical detail: allowed me to activate and I did so. The HTTPS URLs are no longer redirected; they are safe. Some widgets may be missing in HTTPS but I guess no one will miss those. ;-) HTTP works as it did before.
This text is a continuation of the Volkswagen story.

Petrol engines and diesel engines are comparably important. In the U.S., diesel isn't too popular but in Europe, the percentage of diesel engines in newly sold vehicles has actually surpassed 50%. The fuel economy of the diesel engines has traditionally been better (you may see lots of 2-liter diesel cars that run on less then 4.5 liters per km); but the diesel cars end up being a bit more expensive. Petrol and diesel engines have comparable bodies of supporters, however.

Environmentally, the two groups of engines are roughly similar but the details are very different. Diesel engines produce – and the producers have to care about – particulate and NOx emissions. NOx is harmful to the human health, especially lungs. As far as I can say, the most important measurements are the measurements of the NOx concentration at the most contaminated places of our cities. We know that the NOx concentrations have dropped considerably in recent decades.

Wednesday, September 30, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Trouble with The Core Theory

A sweet New England reader has sent me a copy of Frank Wilczek's new "beautiful" book (thanks so much, Ann!) and I will discuss many ideas from that book when I finish reading it, which won't be too soon.

But I want to spend a few minutes with one isolated proposal of Wilczek's, one that was also endorsed by Sean Carroll. Frank wants to rename "The Standard Model" – a term that was coined by Steven Weinberg who also wrote the final version of its "weak" part – as "The Core Theory". And he wants to "include" the Einstein-Hilbert action to it, too.

Would I agree with that?

Russia's imminent solution of Syria's problems?

The following text was written hours before the Russian lawmakers okayed the airstrikes in Syria. Those began just a few hours later.

The U.N. General Assembly has listened to many talks. Obama wants to remove Assad because that leader has already been labeled as politically incorrect in the U.S.; Putin wants to keep him because he's the head of the only significant force in Syria that has a chance to defeat the extremists. You may see a difference between a rational politician and a politician with hay filling his skull.

I do believe that it must be an easy, straightforward task for a power to destroy ISIS. The U.S. failures in doing so indicate that Obama's White House doesn't actually want to do so.

But maybe the failures are due to a complete incompetency and the characteristically American misunderstanding of geography outside the U.S. border. For example, the result of a half-a-billion-dollar U.S. program to train Syrian opposition warriors is that there are five ("5", using digits) troops left who may want to fight. Wow, what an army.

At any rate, Russia seems increasingly active in Syria and its contributions may accelerate very soon. Russia has a naval base in Tartus. Lots of weapons and humanitarian aid have been brought there, perhaps the most Western port in Syria, as well as Lattakia. So far, it's only Assad's forces that are stronger thanks to Russia but Russia may offer a more direct military aid, too. So far, Russia has been refusing the idea of its ground troops operating in Syria, however.

Tuesday, September 29, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

Enrico Fermi: a birthday

Enrico Fermi was born 114 years ago, on September 29th, 1901, in Rome. He died on November 28th, 1954 in Chicago, thanks to the stomach cancer. He was most likely the second most important Italian physicist after Galileo Galilei (check this list). Apologies to Rovelli, Dorigo, and others who would place themselves above Fermi and maybe Galileo.

When he was 17 and he was entering the college in Pisa, he wrote an essay about a Fourier-series analysis of solutions to the partial differential equation describing... waves on a string. The examiner interviewed Fermi and determined that the essay would have been good enough for a PhD in Pisa. That was probably no overstatement because the analysis was largely equivalent to a big part of the first or second chapter of any string theory textbook.

Before he was 20, he learned quantum mechanics so well that he was already hired to lead a seminar on it. He went on to master the tensor calculus and GR later. At some moment, he wanted to study mathematics but switched to physics rather soon.

Aspects of Merkel's suicidal policies

While the Central European ex-socialist countries are presented as villains by most of the Western "mainstream" media and e.g. Hollande's suggestions that we could very well be expelled from the EU for having a different opinion are being amplified by those not-so-independent sources of information, the opinions about the migrant wave and the role of top Western European leaders such as Merkel and Hollande are very, very different in countries like Czechia.

Recently, Angela Merkel has dedicated much more energy to selfies with illegal migrants than to work for her Vaterland. Click the image for hundreds of other selfies. 1.6 billion folks with their cameras are still waiting for their selfies – and to be fed and entertained by the German government for the rest of their life.

The Schengen area – the European Union's unified visa zone – seems to be failing. Ten days ago, Politico.EU presented their list of politicians who are responsible for the bad condition of the Schengen area. It's Assad, Orbán, Erdogan, Bush 43, Obama, Cameron, smugglers, Le Pen, Ayoub el-Khazani, Nemmouche, Afewerki, and al-Baghdadi. Some of the contestants' presence makes sense, others (e.g. Orbán and Le Pen in particular) are absolutely preposterous.

Monday, September 28, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

No-transmission principle, antiholographic LQG

I want to mention two recent conceptual, not too technical papers about the connection of holography to seemingly local theories.

Today, Netta Engelhardt and Gary T. Horowitz released their paper

Holographic Consequences of a No Transmission Principle
which argues that whenever a gravitational spacetime dynamics is described by quantum field theories, their background spacetimes have to overlap for them to be able to influence each other and transfer energy. This assumption seems to imply
  1. ban on certain bounces
  2. ban on the resolution of certain black hole singularities
  3. ban on traversable wormholes
Here, the third ban seems to be right and desirable and the first two are "plausible" so if you judged their principle by its selected consequences, you could be tempted to say that it should be a correct one. However, this is not a logically valid method to decide about the validity of a claim. If a claim implies some correct implications, it doesn't mean that the original claim is correct, too. ;-)

Saturday, September 26, 2015 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

LHC13: the first inverse femtobarn collected

In the Wall Street Journal on Thursday, David Gross and Ed Witten promoted Nima's Chinese \(100\TeV\) collider. But let's back to the LHC.

In 2012, at the \(8\TeV\) center-of-mass energy, the Large Hadron Collider has collected something like 27 inverse femtobarns of data per detector out of which about 20 inverse femtobarns is being analyzed by the papers.

The 2015 collisions at \(13\TeV\) were rather slow but if you look at the LHC luminosity chart of the LHC control panel, you may see that the LHC tends to nicely collect about 0.1/fb i.e. 100/pb at a time – in a fill that lasts 11 hours or so. The data is currently being collected at the rate about 100/fb/year i.e. 3000/μb/sec.