fiforpg

To my taste, the Pirx stories read as some of (if not the) most fiction-y Lem in existence. As opposed to the rest: thinly disguised philosophical studies. Sometimes really thinly, as in Golem XIV, or completely naked in Summa Tecnologiae. Other times, the fiction plot is laid thicker, as in Katar (The Chain of Chance), pretending to be a pulpy detective story.

Now, Pirx tales felt less cerebral, and much more human. Full of really tight action, too. Great gateway into Lem, overall.

Protip: check out Cyberiada, philosophy masquerading as a parody, and at the same time a book for children.

I like how the word "meat" is clearly an inaccurate translation of a notion in the language of the conversation, for lack of a better word in human languages. "Organic matter" would be more accurate, but less striking.

Meaning, "meat" is a variation on the "unreliable narrator" theme: the "unreliable language". This is used a lot in Gene Wolfe's Book of the New Sun, where medieval language describes artifacts of a space-faring civilization.

Wasn't really following the subject, but amazed at how tendentious the writing here is. Starting with the title, unsubstantiated claims, really weird turns of phrase, etc. Here's an example:

> not just common, it’s start-up gospel from Altman’s longtime mentor, venture capitalist Peter Thiel

— according to whom? Is it supposed to be common knowledge? Is this even a helpful parallel?

In comparison, reporting on FT on this same topic is a lot more subdued and matter-of-fact.

Given how fond the Egyptian royalty were of their incestuous lifestyles, it is rather surprising that their tombs still did not end up being the go-to reference for all kinds of nasty genetic deviations. On the other hand, this note does not mention that the woman came from any sort of noble family, and the ordinary people of Egypt presumably did not engage in inbreeding to the same degree, their bloodlines being of no importance.

Very pretty. Looks like one of Gustave Doré's illustrations for Paradise in the Divine Comedy:

https://commons.wikimedia.org/wiki/File:Dor%C3%A9,_Gustave_-...

Complex numbers are algebraically closed, reals are not. This means, if you write a polynomial with complex coefficients, it will have (only) complex roots. Analogous statement for the reals isn't true.

You have a point in that to understand any particular subject well, it makes sense to read more than one book on it, at least to compare the different perspectives.

Also worth noting that Strang has a couple of similar linear algebra books, so we might not even be discussing the same text.

About avoiding determinants to the degree that this book does: while I agree it makes sense to delay introducing them, the goal should not be avoidance but clarity. The way author has to bend himself backwards here when dealing with eigenvalues isn't great either.

I would recommend Strang for a healthy balance in handling determinants.

Yep. Huge kudos to the author for making it available, but the PDF does feel sloppy with all the bright colors and images. In science textbooks, less is more.

Compare this to the very latest edition of Stewart's calculus, which now uses even more pastel, subdued colors for diagrams.

What better hobby to pick for those cold winter evenings, than to do some integrals!

Edit: I can recommend this book for a self-guided study

https://archive.org/details/zeldovich-higher-mathematics-for...

The author was a Soviet nuclear physicist (who participated in the creation of the H-bomb), so his main point isn't rigor. It can be a nice change of perspective from standard American texts.

Qpdfview is my daily driver for reading documents on Linux. Supports tabs, search, highlighting.

If you want something still more lightweight, Zathura would be the way to go. It can be a tad too minimalistic, but great for LaTeX with vimtex, and for an occasional quick document, the startup times are phenomenal.

Yep. An obligatory hat tip to lervag — his vimtex plugin* is a beast.

*Which you are most likely using, since it integrates with Sumatra out of the box. And with MuPDF. And Skim, etc. It's cool like that.

> Chatgpt would have no problems introducing the well-ordered principle

Yes, well, that is part of what I was trying to say. The statement of the principle is not important outside of the structure you are building when following one particular proof, or reading a book (so, following several proofs).

You could do just as well with Zorn's lemma or axiom of choice as you would with the well-ordering; what if your course introduces one of these, but not the well-ordering principle, and then asks to solve this particular exercise? In that case, the gist of the exercise would actually be to re-derive, say, the (axiom of choice)=>(well-ordering) implication for the natural numbers. A point that would be thoroughly lost on chatgpt without the course context.

Establishing a proof of a statement in mathematics means giving a series of steps of the form

A(1) && A(2) && ... && A(n) && B => A(n+1),

where each of A(i) has been proved earlier, B is one of the axioms with which you are working, and => means derivation using some fixed rules. The axiom list for B is context dependent, so that a journal paper may be using an extended set of the form "everything already known by the community, given a reference", etc. A textbook will use lower level textbooks mentioned in the introduction as lists of such contextual axioms.

The IMHO biggest issue with this chatgpt proof is that even though correct in principle, it really misses the context of your exercise: it does not really know if e.g. the well orderedness principle had been introduced already, which exact definition of the natural numbers is being used (Peano, intuitive?), etc.

As a result, the "proof" it provides is primarily name dropping — albeit correct in principle, it still requires filling in the actual argument. So, might be helpful as a hint for a student, but requires the proof to actually be produced.

There are many different physics courses, so which one was that?

In order not to sound solipsistic, I will admit that they all share the subject :P

The big impact books tend to be the ones read in youth. One that I re-read many times was the biography of Robert Wood by William Seabrook (both really fascinating characters):

Doctor Wood, Modern Wizard of the Laboratory

For a more recent, although not nearly as formative read:

The Coddling of the American Mind

Nice construction. Took me a little while to figure out that by oriented ellipse you really mean a fixed curve in 3d, not just a fixed direction of the normal to the plane of the ellipse, which was my first reading. That way orientation takes 3 (real) dimensions + 1 dimension for eccentricity, which gives the 4 real dimensions in CP^2.

How accessible it is to intuition is debatable though :P

I kind of like how certain statistics are observed in relation to a specific culture/country (Canada), a specific vaccine (COVID) in a specific range of years, whence broad conclusions are drawn, which apparently are expected to be universally applicable. Not sure how that implication is made though.

I am trying to think of a reason for why there are many articles announcing the start of a grand initiative, but few that would announce one coming to fruition. Can't quite put my finger on it.

Human history neglects many bright minds, while showering praise on others, whose main achievement occasionally is just that — they managed to get their name attached to a discovery.

On a less bitter note I would like to collectively nominate ancient Greece for the smartest culture that ever existed, and here is a quote from Bertrand Russell illustrating this point:

> The guesses of the Pythagoreans in astronomy, of Anaximander and Empedocles in biological evolution, and of Democritus as to the atomic constitution of matter, provided the men of science in later times with hypotheses which, but for the philosophers, might never have entered their heads.

It is not that Einstein is overrated, but rather that many people entertaining the usual ideas about his genius are blissfully unaware of his contemporaries and their work: Poincaré, Lorentz, Minkowski. Then of course Newton had Hooke, who figured out gravitation for him, and Leibniz who had some of the same insights in calculus.

History of science is richer and more entertaining than the Einstein this and Einstein that — with all due respect to the man.

If I understand correctly, the initial appeal goes back to the early days of measure theory.

Say, a 2-dimensional set is cut parallel to y-axis, and the cuts all have length 1. If the x-coordinates of the cuts themselves have length 1, you know that the 2-dimensional set must be "large". This is because you can integrate the cut length, and tell that it has area 1. (Think of a 1x1 square for an illustration).

In Kakeya's problem, the cuts still have length 1, but are no longer parallel to any one axis. Besicovitch's construction shows, Kakeya set can have very small area, yet contain cuts of length 1 in many directions. This situation is quite different.

This counterexample turned out to be useful in other areas of pure math, some discussed in the wiki entry for Kakeya problem.

Kakeya problem is a beautiful question, and Besicovitch's construction has been really useful in harmonic analysis (Fefferman's The multiplier problem for the ball is a classic example). Still, in the eyes of wider public it must appear uncanny, requiring the Amazon truck analogies, etc.

Reminds me of Vladimir Arnold's comment on the state of modern number theory (presumably talking about density of primes in arithmetic progressions, he says): why would you even want to add primes, they were born to be multiplied?

It turned out to be a nice little piece of fiction, thanks for posting!

From comments in this thread I learn that it is written in the style called creepypasta. Not entirely familiar with the culture, but it felt similar to some indie horror games, such as those Markiplier plays in his YT series "3 scary games".

It does not take a world war to destroy people's lives like that, unfortunately. That is, malevolence is not necessary, incompetence is enough. Both are abundant in autocratic, repressive societies, such as the Soviet Union in this case. Another example that comes to mind is the story of Romanian orphans under Ceaușescu, where thousands grew up in orphanages:

https://en.wikipedia.org/wiki/Romanian_orphans

More broadly of course, half of the Soviet history is that of displaced small nations (see Crimean Tatars, Soviet Greeks, Ukrainians, Poles, etc), where often the fate of an entire ethnic group was not unlike the fate of this man:

https://en.wikipedia.org/wiki/Population_transfer_in_the_Sov...

Should we tell them about the library Genesis?

There was a recent article (Sep 21) in Financial Times, claiming that the F35 stationed in the US were able to only fly in 55% of cases due to various maintenance issues. Maybe they should consider using runways after all :)

Edit: found it, http://archive.today/Ehlag

Do you mean Pascal the person? :P

That (3) is a very interesting issue. My suspicion is, it basically says "knowing logics is good for your well-being".

The skill of logical inference — even at the level of very basic syllogisms — is both very much underappreciated and underdeveloped in the American college population, at least from my personal experience. As good citizens, we all collectively should grab a couple of Martin Gardner's or Lewis Carroll's books off the shelf and give them a good read. I predict it will do much good... and if I'm wrong, it certainly won't do any harm!

Of course, I do think of math as a (meta)language. Maybe my phrasing does not convey that well. So much for using natural language instead of math... ;)