Month: May 2024

Surdin and Semikhatov Interview Severinov | May 19 2024, 03:42

Seems like I have a lot of posts today, sorry about that. Nice format. In Russian. Surdin (an astronomer) and Semikhatov (a physicist) are quizzing the guest (in this case, Severinov) on his topic. Since both are educated, the level of questioning is generally pretty good (with rare exceptions).

The first two-thirds are filled with a lot of interesting stuff from Severinov (mostly high school level, but still). In the last third, Semikhatov jumps in with quantum theory and totally outshines Severinov.

Listening to the rest of it now. They’re discussing Student’s t-test – it’s about statistical significance. Just a brief mention, no big deal. I decide to check out some details on Wikipedia and find something amusing:

“…This test was developed by William Gosset to assess the quality of beer at the Guinness company. Due to confidentiality obligations (the Guinness management considered the use of statistical methods a trade secret), Gosset’s article was published in 1908 in the journal ‘Biometrika’ under the pseudonym ‘Student’.“

A380 landing | May 19 2024, 02:14

We have an international airport nearby, and planes are almost always in the sky (plus, even closer by, a small airfield where small private planes are constantly taking off and landing). And I’ve noticed something interesting several times—a plane virtually hanging in the air. Just driving along, you look up—at some point in the sky, there’s a plane. Look up a few seconds later, and it’s exactly in the same spot!

Yes, it’s almost always flying almost directly towards me, so the angular velocity is not noticeable. But again, there are many planes flying, and I have something to compare it with. Encountered it again today, but I went the extra mile and checked on flightradar to see what this four-engine aircraft was.

I investigated. It was an Airbus A380—the largest airliner in the world. It’s just big, the wings are huge, and with a strong headwind, and specifically the one I saw was decelerating to 155 km/h according to flightradar24 while approaching for landing. But the following B777 also landed at a similar speed, give or take. The difference is, the B777 is significantly smaller than the A380 (30% shorter in fuselage height and nearly 20% in wingspan), and the same visual angular size for A380 appears at a higher altitude, where angular velocity is lower. Meaning, I saw the A380 when it was further away than I am used to seeing Boeings, and therefore its speed seemed very slow.

Perhaps, in addition to this, there might be a headwind. It can really drastically reduce the plane’s speed relative to the ground. Here I’m “out of my depth” and don’t know what pilots do when landing against the wind.

While I was figuring this out, I read that apparently, the A380 engages its thrust reversers (which direct the engine’s thrust forward) quite late, when the speed drops to 80 km/h. Although a fully loaded Airbus A380 weighs 573 tons, its braking system does not rely heavily on reversers. They are not a mandatory element for airliners, and on the A380, they are installed only on the two inner engines.

Although reversers help slow down the A380, their contribution to braking is not as significant as on most airliners, including the Boeing 747, where thrust reversers do significantly reduce the braking distance compared to brakes and spoilers.

It turns out, A380’s main braking effort is performed by huge Honeywell composite brakes on 16 of the 20 main landing gear wheels. The brakes on the A380 are equipped with a car-like anti-lock braking system. The aerodynamic braking, thanks to 16 large spoilers on the wings, which create drag and reduce lift, also plays an important role. Reducing lift improves mechanical braking, increasing pressure on the wheels.

The A380 slows down from cruising speed of 500 knots (926 km/h) to a complete stop within a few minutes thanks to the overall design of the plane. The descent begins at cruising altitude at about 0.85 Mach (1235 km/h). Below 10,000 feet, the speed decreases to 250 knots (463 km/h), and on the approach glide, the plane moves at 180 knots (333 km/h). The A380 crosses the landing threshold at 140 knots (259 km/h) and touches down at 130 knots (240 km/h).

By the way, here’s how beautifully the landing gear of the A380 extends:

Chinese Names in Latin Script: how to pronounce | May 18 2024, 19:25

I’m currently reading Liu Cixin’s “The Dark Forest,” and I realized that I don’t understand how to pronounce Chinese names transcribed into Latin script, like Quang or Xin. I decided to educate myself on the topic and dug up some information. Below is a little guide for the similarly curious, who were perhaps too lazy to figure it out themselves.

For transcription into Russian, there is the Palladius system (Google it if you speak Russian). Generally, all of the information below is from there and from the Pinyin system (a romanization system for Chinese).

In general, most letters can be pronounced more or less (very roughly speaking) as in the English alphabet, except that the voiceless consonants p, t, k (for example) come with aspiration, but there are exceptions:

* q — pronounced like the Russian “ч” or the English “ch” (as in the word cheese) with a light aspiration. For example, Qiang is read as “Ч’ань”. Other names: Qing, Qin.

* x — resembles the soft Russian “ш/щ” or the English sh/sch. For example, Xia is pronounced as “Ща”. Other names: Xin, Xiu.

* r — something between r and zh/ж. In the Palladius system, ran is prescribed to be read as zhàn (жань), and rang as zhan (жан), and rao as zhao (жао). In Pinyin, it’s written that r is read as in red with a slight zh hue.

* z — like “ds” in the word “reads”.

* c — like the Russian “ts” as in “cats”.

Therefore, Xi Jinping is read as Си Цзиньпин. And Dèng Xiǎopíng is cyrillicized as Дэн Сяопин.

In Chinese names, the last name comes first, followed by the given name. For example, in “Li Wei,” “Li” is the surname, and “Wei” is the given name. Máo Zédōng, the name here is Zédōng, not Mao. Or Dèng Xiǎopíng, where the given name is Xiǎopíng. In the case of the author of “The Dark Forest,” Liu Cixin, the given name is Cixin.

However, I learned that addressing Chinese people by their full name is impolite and even rude. According to Chinese etiquette (in China), it is customary to address by last name, adding a title of social status/position (engineer, doctor, professor, academic, ambassador, teacher, master, foreman, director, etc.) or a general salutation (Mr., Comrade, Ms.). For example, Mr. Wu (in Chinese: Wu xiansheng), Ms. Zhang (in Chinese: Zhang nüshi). But that’s there, in China. In the case of international teams, where someone like Li Wei is a frontend developer, of course, it’s normal to write “Hi Wei.” But not “Hi Li.”

By the way, Chinese people often change their names when moving out of China. Jackie Chan, for example, was 成龙 (Chéng Lóng) back home, Bruce Lee was 李小龙 (Lǐ Xiǎolóng).

Janet Fish | May 18 2024, 15:25

Janet Fish is an American artist. Today is her birthday, she is 86 years old. She has an interesting still life technique and a very recognizable style!

I remind you that similar posts are grouped under the tag #artrauflikes, and on beinginamerica.com in the “Art Rauf Likes” section, you can find all 58 of them (as of now), unlike Facebook, which forgets (or ignores) almost half of them.

Jianwu Tan | May 17 2024, 13:35

Chinese artist Jianwu Tan boasts a varied portfolio, each piece showcasing his mastery in knowing when to restrain and when to embrace photorealism. His body of work spans several series including Tibet, ballerinas, nudes, and portraits.

I remind you that similar posts can be found grouped under the tag #artrauflikes, and on beinginamerica.com in the “Art Rauf Likes” section, where all 58 of them (to date) are available. This is in contrast to Facebook, which tends to forget (or overlook) nearly half of them.

Richard Schmid | May 16 2024, 20:33

Richard Schmid is an amazing contemporary artist, whose books (specifically “Alla Prima II”) I often feel tempted to buy, but the price is quite high even for used copies (~$150-200), so I still haven’t bought it yet. For me, it’s still very expensive. By the way, in the book, he shows the process of creating his works layer by layer.

I remind you that similar posts are grouped under the tag #artrauflikes, and on beinginamerica.com in the “Art Rauf Likes” section, you can find all 58 of them (as of now), unlike Facebook, which forgets (or ignores) almost half of them.