How path integrals mirror Feynman's personality traits

Courage, playfulness, analogies, shut up and calculate (calculation instead of words), lots of calculations extending simple rules, numbers instead of philosophy, don't give up easily

The most successful theories of classical physics may be formulated in terms of the principle of least action. We may consider alternative histories \(x_i(t)\) where some observables \(x_i\) depend on time \(t\). The principle says that the action \(S\) which is a functional of the history (a collection of functions) \(x_i(t)\) is minimized for the history that is actually allowed by the laws of physics:\[

\delta S [x_i(t)] = 0.

\] Paul Dirac has been convinced that this elegant formalism of classical physics – based on the concept of the action – should have a correspondingly nice role in quantum mechanics. And he found a good guess. In quantum mechanics, one could perhaps calculate the probability amplitudes for the evolution of \(x_i(t_1)\) to \(x_i(t_2)\) as \(\exp(iS/\hbar)\).

That was nice and Dirac presented some basic argument why the Lagrangian (whose integral over time gives the action) is related to the Hamiltonian but he didn't do much with this idea. It looked too heuristic to him.

Paquette vs Yin on the love-hate relationship between math and physics

In 2014, a few Nobel prize winners such as Sheldon Glashow along with the climate skeptic Richard Lindzen, Intelligent Design advocate David Berlinski etc., and a notorious moron Tim Maudlin have teamed up to create an online journal,

Inference-review.com,

a quarterly which is almost as influential as TRF now and where essays on the philosophy of science and reviews of books are regularly posted (I guess that there exists a printed journal, too). There must be lots of deep and inspiring texts over there but I have only learned about them today (although I may have been informed about the plans to establish it by one of the founders already in 2010) which is why my exposure to that journal may start at a somewhat random place (a metaphor for a point that will be made at the very bottom of this blog post).

Not too much time ago, Caltech string postdoc Natalie Paquette posted an essay

A View from the Bridge

that views mathematics and physics as peacefully co-existing traders. In the past, mathematics was helpful for physics. As you may have heard from Brian Greene, me, or someone else, their main relationship got mostly reversed due to the ability of string theory to produce gems that are cool from the mathematicians' viewpoint. She wrote an interesting review about some offspring of string theory that became important in mathematics: topological field theory, Donaldson theory, mirror symmetry, and monstrous moonshine, among others.

Only strings, not branes, can be consistently quantized in the same way

Jee_Jee has asked the following question:

Dear Lubos, thanks for this article. Please excuse my ignorance but could you please briefly explain why we don't find quantization of higher dimensional objects (such as branes) discussed in various standard references? Shouldn't the rules of QM determine the dynamics of branes too? Or may be it is done somewhere but I have not been able to find it.

Well, the reason why this "quantization" isn't discussed in any of these texts is that it is not possible. The question is analogous to the question: "Why don't textbooks of zoology feature photographs of flying elephants that would resemble the flying eagles?" You know, elephants don't fly. In the same sense, there is no "brane theory" that would be fully analogous to "string theory".

You can see a difference between the two situations: most kids can figure out that unlike eagles, elephants don't fly after some time – when they see no flying elephants. Jee_Jee has seen that no counterpart of string theory is being constructed with other objects – but he still believes that this non-existent entity exists. It must have been omitted because string theorists are stupid or they hide some dirty secret or something like that. Why does he believe such a thing instead of making the same straightforward conclusion as the kid makes about the flying elephants?

Top Czech players denounce Serena, her claims on sexism, an official support for her

Czech women don't have much tolerance for the so-called feminism. Many of us love America, some of us know it rather well, but people were getting increasingly familiar with the kind of shocking arrogance by women that was selectively encouraged by the pathological ideology of feminism.

The shocking events that were often started in the U.S. include the incredible witch hunt named #MeToo. A very recent event that shows a similar point was a hysterical meltdown of Ms Serena Williams, currently the #16 top female tennis player (WTA), with an umpire.

Czechia is a tennis superpower, one of the 3 countries that won the Davis Cup and Fed Cup on the same year, one of the most successful countries in these cups, and a cradle of numerous #1 players such as Lendl, Navrátilová, Kvitová, Plíšková.

Tim Gowers' conceptual thinking sucks

Four days ago, I discussed – and many of us talked about – the retroactive silent erasure of Ted Hill's already published article from an electronic journal because the paper implies conclusions that are considered politically undesirable. The focus was on the sociology and dirty politics.

Here I want to focus on the content of Ted Hill's paper (read on the arXiv) and the quality of its arguments and counter-arguments, especially those from Tim Gowers, a famous mathematician. Another famous mathematician, Terry Tao, wrote just three paragraphs whose main purpose seems to be to express some loyalty to the powerful leftwingers in his environment.

Petrov, Bashirov look suspicious to me

A week ago, I mentioned Petrov and Bashirov, two Russian nationals that were named as suspects in the Skripal poisoning case. I was mocking the British accusation but now I must say that the two Russian guys' defense looks even stranger and locally comical to me.

Read the transcript of an RT interview (The Telegraph)

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90-second video excerpt from that Margarita Simonyan interview; for full interview, see the bottom

It's really the cathedral that made me laugh. Just to be sure, I do realize that none of the feelings I have may be considered terribly strong evidence. People have different interests. And most importantly, if these two men attempted to poison Skripal and/or his daughter, it doesn't mean that the Kremlin or any other Russian authority is involved.

Article 7 against Hungary is an effeminate version of the 1956, 1968 invasions

When I returned home from a trip, one of the first news that appeared on the displays was that the European Parliament has voted to launch Article 7 against Hungary: 448 for, 197 against, 48 abstained.

It's a nuclear option allowed by the Treaty of Lisbon (a treaty that turned the European Union into a new Soviet Union a decade ago) that starts a process that may end up with the annihilation of Hungary's voting rights within the EU and/or all the financial inflows from the EU, among other sanctions. I hope and I still understand the situation so that Poland will ultimately be capable of vetoing all these plans (Article 7.2 still requires a unanimous vote in the European Council which has folks from all EU member states) but I am no longer sure. The EU could preemptively remove the Polish and Hungarian votes in the European Council and squeeze everyone else.

The same article has been launched against Poland – not by the European Parliament but rather by the European Commission (the "government of Europe"). Hungary considers the vote to be a fraud, a petty revenge for Hungary's asylum and immigration policies, and – as Orbán said – an insult to the Hungarian history. A Fidesz MEP called the decision "legally invalid" because voting rules were breached.



"The Mézga [Mr Badluck's] Family", here the theme music with Czech lyrics (orig. here; in Czech, the main characters got native Czech names), is the most famous Hungarian cartoon for my and somewhat older generation. It's a clear counterpart of The Simpsons except that the Hungarian show was 20 years older (1969-1978). The Simpsons were first aired in 1989. I think that (not only) Yankees should watch a couple of cartoons like that to get rid of the incorrect idea that the world would be impossible without the U.S.

The development wasn't quite unexpected but it's still infuriating to see that it has actually taken place. Most Czech voters must have been shocked what sort of unreliable allies in the Visegrád Group Czechia is. Ten Czech MEPs voted against the proposal to harass Hungary, nine MEPs have supported it. So a majority is against the proposal but the majority is infinitesimal. There are 4 deputies for billionaire PM Babiš's ANO movement among the 9 traitors – and, thankfully, zero MEPs for the center right ODS. The social democrats were perfectly diverse: 1 yes (the proposed minister of foreign affairs Poche), 1 no, 1 neutral, 1 absent.

French education minister: kids must learn Arabic

My countrymates are somewhat obsessed with watching the collapse of the politically Western civilization in the geographically Western Europe – we really need to distinguish these two types of the adjective "Western". One of the most recent shocking developments has something to do with France and the languages.

The French minister of education Mr Jean-Michel Blanquer has brought an ingenious new idea: French kids should learn Arabic (RT, Google News, original).

Why string theory is quantum mechanics on steroids

In many previous texts, most recently in the essay posted two blog posts ago, I expressed the idea that string theory may be interpreted as the wisdom of quantum mechanics that is taken really seriously – and that is applied to everything, including the most basic aspects of the spacetime, matter, and information.

People like me are impressed by the power of string theory because it really builds on quantum mechanics in a critical way to deduce things that would have been impossible before. On the contrary, morons typically dislike string theory because their mezzoscopic peabrains are already stretched to the limit when they think about quantum mechanics – while string theory requires the stretching to go beyond these limits. Peabrains unavoidably crack and morons, writing things that are not even wrong about their trouble with physics, end up lost in math.

Other physicists have also made the statement – usually in less colorful ways – that string theory is quantum mechanics on steroids. It may be a good idea to explain what all of us mean – why string theory depends on quantum mechanics so much and why the power of quantum mechanics is given the opportunity to achieve some new amazing things within string theory.

Harvard, Google, NSF, Springer, and others need a vigorous rat control

Electronic tools make it easier for dishonest SJW terrorists to perform Stalinist purges

Nick has told us about a troubling – but no longer unprecedented – story described in Quillette.

Academic Activists Send a Published Paper Down the Memory Hole

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See also: Hot Air, Reason, Power Line Blog, The Daily Wire, Tim Gowers, Terry Tao

Ted Hill (*1943) is not only a veteran from Vietnam but also a famous mathematician who has done probability theory and wrote a well-known paper on Benford's law (about the frequency of first digits of numbers), among many others.

OK, he has clearly done politically neutral things most of his life. And his way of talking about the "discrimination" of women make him another feminist in my eyes. It just happened that he wrote a paper about the statistical differences between sexes. The main topic of a paper he co-authored was the wider statistical distribution of men's IQ and other quantities relatively to the female counterparts.

Woit and probability in quantum mechanics

Peter Woit is a veteran physics hater. His website has regularly served the most idiotic anti-physics garbage and it has attracted some of the world's šittiest mammals to its comment section for almost 15 years.

It would have been natural for Woit to be a leader of the anti-quantum zealots, too. String theory is the power of quantum mechanics applied to the realm of gravity. If one is claimed to be "bad", the other must be "bad", too. But for some reasons, Woit has avoided the discussions about the foundations of quantum mechanics. He wasn't inclined to join various branches of the anti-quantum zealots.

Musk's weed, crypto drop, Skripal assassins, Jones Twitter ban, Chemnitz

First, in the early trading, the Tesla dropped over 9%, to $254, before recovering some losses to a 6% drop around $264 now (that's still a 30% drop from a post-tweet local minimum near $380 exactly one month ago). In the previous days, a Mercedes' Tesla killer SUV and Goldman Sachs restored "sell" rating were quoted as the reasons.

Today, the most quoted reason for that drop was an Elon Musk who smoke weed. My hyperlink points directly to the relevant place of the 160-minute-long Joe Rogan interview. He's surely not repelled by this stuff but it wasn't even something that Musk initiated – he was given the weed by the host – but it's enough to erase over $4 billion from the Tesla capitalization? It's just amazing.

The fundamentals play almost no role here. Well, just to reveal all the public interpretations, the BBC and others have a different explanation of the drop of the Tesla stock price, an executive's exit. There have been many Tesla exits in recent years so I wouldn't think it's a terribly sensible reason for such a huge drop, either.