The_suffocated

The compass button slightly confuses me. I thought the arrow in anticlockwise direction was intended to turn the map anticlockwise, but it actually works like a GPS navigator, i.e., it works as if I turn my car to the left and the direction ahead is always the upward direction on the map.

What is a nested equation?

It was Joseph Fourier, the Fourier in Fourier transform, who showed the then 11-years-old Jean-François Champollion a copy of the Rosetta stone.

Near the end of the article:

  > As impressive as the video is, there is no word whether this product is ready for market or not.

The Nazi salute is called the “Bellamy salute” ( https://en.wikipedia.org/wiki/Bellamy_salute ), which actually was an American invention.

The concept is interesting, but the watch looks ugly and the dial is too small to be useful.

I think this is not a biology-only phenomenon. I have the impression that chemistry and mathematics are also not taught well in many (if not most) high schools. Physics education in contrast seems to be in better shape.

Yes, it's a fun piece of art. I don't think this was meant to be practical. It was probably just an interesting experiment or proof of concept.

What does the “SO” in the article refer to?

The MathJax part.

May I ask how to create a Mathematics Stack Exchange clone without JS?

I think in the Soviet bloc, "higher mathematics" referred to mathematics taught at higher institutions (i.e. universities or technical institutions at the same level). This usage is a bit different from that in the Commonwealth of Nations (see https://en.wikipedia.org/wiki/Further_Mathematics for instance). As for the current text, while it does mostly cover high-school calculus, some portions of it (e.g. contour integration, analytic functions and Dirac delta function) are definitely outside high-school curricula. As the authors indicated in the preface, the intended audience of this book include high-school students, high-school teachers and first-year college students.

Is the existence of basis in every vector space really useful? I think in analysis, people mostly work with Schauder basis rather than Hamel basis. I am not aware of any important result that uses the existence of Hamel basis in an infinite-dimensional vector space. This is not a criticism about your comment, but an honest question.

> "...but I don't think the CCP is so crudely trying to eliminate languages."

Last time I checked, less than half of the population in Guangzhou knew how to speak Cantonese.

I don't think the introductory paragraph of the Gibbs Phenomenon article is bad. Quite the contrary, I think it's well-written. The opening sentence in the Taylor series article is terrible, though, but it's at least factually correct. True horror occurs when there is a major mistake. Incidentally, I encountered one such mistake just an hour ago. In the Encyclopedia of Mathematics published by Springer, there is an article entitled "Schur determinant lemma" (https://encyclopediaofmath.org/wiki/Schur_determinant_lemma), which says that the determinant of a block matrix (in Matlab's notation) [P Q;R S] is det(PS-RQ). But this in general is wrong unless PR=RP. The result that "Schur determinant lemma" or "Schur determinant formula" refers to is actually det[P Q;R S]=det(P)det(R-SP^{-1}Q) (provided that P is invertible).

The article hasn't mentioned the sizes of the cubes, but the linked journal paper shows that the typical size is 2.3cm x 2.5cm x 4cm, which is about (but slightly thicker than) the size of a rubber/eraser. So, the shape is more like a rectangular cuboid than a cube.

I understand nothing in the paper, but this is cool.

If you define determinant as volume, how do you define volume? I agree that it's pedagogically sound to motivate the notion of determinant by the volume of a parallelepiped, but using volume as the definition of determinant just doesn't sound right.

And strictly speaking, determinant is not volume because the former is dimensionless. It is the scaling factor of the volume when a geometric entity is transformed by a linear map.

You are right. I did learn this term in high school decades ago but have forgotten it. Thanks for the explanation.

> For years, I thought the CIA was the prime mover of the coup, but I was wrong.

I think the CIA was indeed the prime mover of the coup, at least according to the CIA's official history. Derbyshire, the person who was in charge of SIS's Iran branch, came up with the idea of a coup, but the Brits had not the capacity to pull it off and so they asked the CIA for help. The whole operation was very well documented by the declassified report entitled "CIA Clandestine Service History, Overthrow of Premier Mossadeq of Iran, November 1952-August 1953", which is downloadable from

https://nsarchive2.gwu.edu/NSAEBB/NSAEBB28/

What is the current state of REPLs for Nim? If I remember correctly, Nim had an official REPL a long time ago, but it was abandoned a few years back.

This bug reminds me of the plot of the 1996 Japanese crime story "Subete ga F ni Naru" (The Perfect Insider).

Not sure about oxygen respirators, but some civil organizations in Hong Kong have been 3D-printing filter cans for 3M 6200 face-piece respirators since mid-February, amid shortage of surgical face masks. The designs of the filter cans are modified so that, instead of using 3M's particulate filters, one cuts a surgical face mask into many smaller pieces and inserts only one piece of them into the filter can in each use.

Of all time travel stories I know, the one with the most consistent and logical view on time travel isn't Steins;Gate, but Murai Nikki (Future Diary).

IMHO, Steins;Gate hasn't clarified what time travel really represents. When one travels from one world line to another, does the previous world line still exist? Is time travel a travel between parallel universes, a complete rewrite of history in the _same_ world, or something else?

In the first Steins;Gate anime, it seems that time travel means a rewrite of history (i.e. the conventional type of time travel in science fictions), but in Steins;Gate 0, time travel seems more like jumping between parallel universes.

The article's title is VERY misleading. After the fifth covid-19 case was confirmed in Taiwan (around Jan 25), the Taiwanese government had already banned all mainland Chinese tourists from entering the country. In February, even non-citizen children and mainland Chinese spouses of Taiwanese were forbidden to enter. That Taiwan had implemented a travel ban at a very early stage is a crucial factor for keeping the number of infections low.

> Working from home will be mandatory... due in part to government restrictions.

What government restrictions? Not sure about South Korea, but to my knowledge, there aren't any government-mandated measures in Hong Kong or Japan that require non-government employees (except school teachers) to work from home. It's up to businesses to decide what they should do.

Am I the only one who has misread the title as "Amazon has 150M prime NUMBERS"? I thought that the article was about some weird practice of reusing prime numbers for encryption ;-D

> I explained my app. "Since senior citizens are not good at swiping," I said, "I made it possible for them to play by tapping."

I have a similar experience. A few years ago I implemented a traditional Chinese dominoes game on Android for my grandma. (To date she still plays the game every night for two hours.) When I let her tested the game, the first thing I observed was that she was poor at dragging the dominoes to the table. So, I quickly changed dragging to tapping. (Tap a dominoe once to choose it and tap the table once to play it. To cancel a wrong choice, tap the chosen dominoe again.)

> Judeo-Christian dogma is “foreign and cool“ and the writers eventually admit it

Any reference?

Thanks for the link. The price difference is huge. Around 16:20 in the programme -- if one ships a 3/4-pound package across the US, the USPS has to charge the shipper $4.76 for the "last mile", but if the same package is imported from China, the USPS can only charge China Post for $1.39 according to the UPU reimbursement rates.