Tag: Education

Historical Insights into the Legendary Seven-League Boots | July 17 2025, 16:42

Here you have the real “fast-walking boots” or, as they were called in Europe, “seven-league boots,” France/Germany, 19th century. Remember, Mr. Ogre in “Sleeping Boy” wore them. You wouldn’t be mistaken to say that they were difficult not only to run in, but even to walk in. Why are they called “seven-league” then?

This is interesting. Actually, their original name in French is „bottes de sept lieues (seven-league boots), and in German — Siebenmeilenstiefel (seven-league boots), from which the name came into Russian.

Regular postal communication in France started in the 15th century when postal stations with horses for exchange were built. The distance between the stations initially was 7 leagues/lieues (about 30-35 km).

Transportations were performed by coaches that had from 4 to 6 horses. The coachman managed them, and on the lead horse sat the ‘fourrier,’ who set the pace of the journey. The work of the fourrier was more dangerous, as in the event of an accident he had more chances of being injured, falling under the carriage wheels or being crushed by a falling horse compared to the coachdriver.

Therefore, fourriers were entitled to special tall and sturdy boots, which, according to some data, were attached to the saddle (but this is not certain). When mounting, he would wear these boots. That is, in these seven-league boots they didn’t even walk, but sat.

These boots were sewn from several layers of treated leather, with wooden soles and iron inserts. In such boots, it was difficult to fall from the saddle, even if one fell asleep, and if one fell sideways, they could withstand the weight of a horse, protecting the rider from serious injuries.

Naturally, such large and heavy boots, which were often dried by the fire, raised questions among children, and the fourriers, smoking their pipes and smiling, would tell them about the magical seven-league boots that one could put on and leap seven leagues in a blink. Undoubtedly, one of these children must have been Charles Perrault 😉

From Forbidden Fruit to Linguistic Roots: The Curious Case of Currants and Smorodina | July 17 2025, 13:09

You know, 99.9% of Americans have never tried blackcurrant. It was legally banned here in 1911 because blackcurrants carried a disease that killed pine trees. And along with it, gooseberries and Kinder Surprise were banned too. It even got to the point where in the USA, purple Skittles are grape-flavored, while in Europe, they taste of blackcurrant.

But today I am thinking about something else. I wondered why in Russian blackcurrant is called ‘smorodina,’ and in English, it’s called ‘currant.’ It turns out that ‘smorodina’ is related to the word ‘smrad,’ which meant a strong smell because, according to our ancestors, it smelled bad. ‘Smrad’ used to mean any strong smell. I don’t know how unpleasant it was for them, but this differentiated it from gooseberries, both of which grew along rivers, hence in Ukrainian and Polish, it’s also called ‘porzeczka’ and ‘porichka,’ especially the red and white varieties. To me, gooseberries even smell stronger.

The English name is also interesting. The English ‘currant’ stems from the Middle English ‘rayson of Corantes’ (‘grapes from Corinth’), where ‘Corantes’ is a distortion of the Greek city Corinth. In the Middle Ages, small dried grapes were actively imported into England from Greece (specifically the region around Corinth) and these dried berries were called ‘raisins of Corinth,’ which later shortened to ‘currant.’ Originally, ‘currant’ referred specifically to raisins, dried grapes (essentially, small raisins). And it still means that in some places.

But then a shift in meaning occurred. Later, when shrubs of the Ribes genus (currant bushes), specifically Ribes rubrum (red currant) and Ribes nigrum (black currant), began to be cultivated in Northern Europe, they were given the same name, since their berries were also small and dark like the Greek raisins. Thus, the word ‘currant’ came to be used to denote both currants and gooseberries 🙂 but later on they were differentiated. Yes, gooseberries and currants turned out to be related both biologically and etymologically.

And do you remember the fairy tale about the good heroes and warriors Dobrynya Nikitich, who fought the three-headed Chudo-Yudo on the Kalinov Bridge spanning the River Smorodina? Well, that river, Smorodina, marked the boundary between the world of the living (Yav) and the world of the dead (Nav).

Exploring the Slug: An Unusual Imperial Unit of Mass | July 15 2025, 20:52

Have you ever heard of a unit of mass measurement called a slug? In the US, it does exist, even though it’s less common nowadays. American physics and engineering textbooks for students, especially where they want to clearly differentiate between mass (slug) and weight (lbf), tend to use the imperial system with its feet and the like. It simplifies F = ma in the imperial system without introducing extra coefficients.

1 slug is the mass that accelerates by 1 ft/s² under the force of 1 pound-force (lbf). Thus, a slug accelerating at 32.174 ft/s² “weighs” 32.174 pounds-force (lbf). 32.174 ft/s² is our 9.8 m/s², just in feet.

A “slug” is, on one hand, a slug (a slow-moving mollusk without a shell), and on the other hand, a heavy piece of metal or a bullet (like a shotgun slug – a large-caliber cartridge). In the context of the unit of mass, it’s not about mollusks, but rather about a “heavy lump.” But it’s still funny when they write “mass equals 5 slugs.”

12 slugs equal 1 blob (image of blob attached). Blob is a version of slug, but based on inches instead of feet. It has fun slang names – slinch, slugette, snail.

I also read about the British Thermal Unit — the amount of heat needed to heat 1 pound of water by 1°F. Converting BTUs to calories or joules results in a quite awkward number.

AI-Powered Smart Glasses: Revolutionizing Real-Time Discussion and Information Access | July 15 2025, 20:19

Here’s what would be great to do with AI – a system that reads the screen, listens to what’s being discussed on the call, including what you say, and what is said to you, and _on the screen_, and better yet, directly on smart-glasses, gives pop-up tips and hints that help you timely ask a counter-question or request a clarification, or respond to a question directed at you. Not just for passing interviews, although that would also be nice, but for more effectively conducting discussions — from technical to commercial ones.

In the case of smart-glasses, you could enjoy this without a computer in front of your eyes. I’m just afraid of having to send absolutely everything that happens around you to the cloud, analyze it, and return it in real time, which is technologically challenging (=expensive).

Such a system would be no less useful for conducting interviews than for passing them. For example, you ask someone a question, they start to respond, and then the system suggests — aha, it seems they are struggling with this topic. Let’s ask this question. Then you decide whether to ask this or something else. Why not? It’s convenient. Of course, the interviewee could employ the same system, and then it would not be simple.

Right now, I’m flipping through a book by Johannes Itten on color, and I think about how I miss dynamic illustrations and commentary. I’ve reached Piero della Francesca and for the life of me, I can’t recall what his paintings are like. This is where smart-glasses would come in handy. You look at a word, snap your fingers, and around it appear pop-up windows with contextual illustrations, comments, and links to detailed information, which you can visit now, or save to read later. It would be possible to ask any question verbally while looking at the text segment it pertains to and get an answer not verbally, but in a pop-up window that you can quickly close if you didn’t find anything new, or perhaps add a clarification by voice, after which the content in the window updates.

If I had smart-glasses, I would experiment with this. It seems straightforward.

Pearls and Mother-of-Pearl: Nature’s Fascinating Defense Mechanism | July 14 2025, 20:58

I realized that I don’t know much about pearls and started reading up on them today. It turns out that pearls are formed as a natural defense by oysters to irritation: when a micro-particle (a grain of sand, a piece of shell, or a microorganism) gets into the shell, the oyster begins to cover it with layers of nacre. Nacre (nacre) — the inner layer of shells, thin layers of calcium and protein. Interestingly, nacre and pearls are essentially the same in composition. The word “nacre” comes from German and means “mother of pearl” (Perlmutter). A single layer of nacre can form several times a day to several weeks, and it takes up to 2 years for a full pearl to form.

Wild pearls are extremely rare (one in 10000), as not all mollusks are capable of producing them — only some species can. There is also black pearl, found only in the southern part of the Pacific Ocean, and the colors of natural pearls vary from white and grey to green, blue, and red.

Most of the pearls on the market are cultured: humans manage to “trick” the oyster by placing a bead or a piece of fabric inside the shell so it starts the process of covering it with nacre. In other words, to put it simply, almost all the pearls in the market have a plastic bead inside, and nacre is just a thin “skin” around it. Cultivation of pearls occurs on special farms, where oysters are provided ideal conditions for growth and are regularly cared for. The mortality rate of mollusks after transplant is between 10-40%.

Pearls can burn: this is an organic material (97% calcium and 3% water and proteins), and it does not withstand high temperatures, it also dissolves in vinegar.

It turns out, edible oysters also produce pearls, but they are not as shiny.

The Multi-Functional M1 Helmet: Beyond Battlefield Protection | July 14 2025, 02:26

Today I learned from the museum that in field conditions, soldiers used the steel body of the M1 helmet as makeshift dishware: they boiled water, shaved, washed clothes, etc. The helmet consisted of two parts: a steel outer body and a separate inner plastic or fiber liner (liner), which could be worn separately (for instance, for ceremonies). By the way, it was in military service from the beginning of WWII until the 1980s.

Exploring the Technological Marvels of Tesla’s Full Self-Driving Capabilities | July 11 2025, 03:59

I read various engineering blogs about Tesla’s autopilot (FSD) — simply because for the last month and a half I’ve been almost constantly riding as if in a taxi — you set the destination and hardly ever need to intervene, the car travels from point A to point B completely independently. This is certainly the future.

Such systems exist not only at Tesla. For example, Mercedes has one (Drive Pilot). Others only help in traffic jams at best. Though Tesla seems to be the only one that works on all roads.

So, returning to engineering curiosities. Tesla has an AI model production on its “farm” called Dojo — an exaFLOP supercomputer on Tesla chips. Videos from cameras are fed into it, and it trains models that are then sent out for autonomous operation across the entire fleet of Tesla cars.

The FSD architecture comprises about 48 specialized neural networks, trained on Dojo, which together form about 1,000 different prediction tensors. Tesla is gradually moving from modular networks (object recognition + planning) to end-to-end training — directly converting video frames into steering trajectory/action. This is akin to a “black box” — the neural network learns directly from human behavior, without manual tuning of knobs; an extremely cool engineering solution, but, I suspect, complex to debug.

By the way, it is claimed that Tesla has switched from C++ to Python. And that this shift to end-to-end training has made 300,000 lines of C++ code unnecessary, where various corner cases and rules for resolving different scenarios were accounted for — now it’s at the model level.

Tesla has abandoned radar and ultrasonics, switching to purely camera solutions (Vision Only) with “Hardware 4” (HW4, FSD Computer 2): 16 GB RAM, 256 GB flash memory, performance 3–8× higher than HW3.

Assess the performance: 22 milliseconds to create a 3D scene with cars, pedestrians, cyclists around — information is collected from 8 cameras 36 times per second.

85 ms for the entire cycle from receiving the image to changing the plan and commands to the wheels. Fantastic!

More than 4 million Teslas on the roads collect data daily, and in the FSD Beta version, more than a billion miles of autonomous driving have been recorded. This “live” dataset is used to train networks on the most real-world scenarios, including rare “edge-case” incidents (strange accidents, road conditions, etc.).

In June 2025, Tesla for the first time delivered a Model Y from the factory in Austin to a customer’s home without a driver or remote operator — fully autonomously. This is very cool.

The Vision network not only analyzes the current frame but also stores features from previous ones (at a distance of ≈1 m). This allows it to remember recently crossed markings/signs, even if they have already left the field of view – very similar to human memory.

Treasures in Translation: A Glimpse into Rare Russian Reprints | July 09 2025, 01:27

Nadia from Russia just brought me three books I ordered. “The Art of Color” by J. Itten, “Americans and Everyone Else” by I. Kurilla, and this one, Holodkovsky’s commentary on his translation of Faust. Interestingly, it seems that these commentaries are not available in Russian.. to be more precise.. in modern Russian. There is a reprint of the original 1914 edition, created based on a high-resolution electronic copy that was manually cleaned and processed, preserving the structure and spelling of the original edition, and it seems it was not translated into modern Russian. However, there are no difficulties in reading the reprint.

Exploring the Bubble Method of River Level Measurement at the Potomac | July 06 2025, 19:38

How would you measure the water level in a river? A float? A pressure sensor? Something else? Yesterday, I discovered how it’s done here on the Potomac, and it turned out to be not at all what I had imagined. The USGS engineers are great—they educate passersby by posting a diagram of the operation.

A tube is lowered into the river through which air is supplied in bubbles (through a bubble orifice). A special pressure sensor (Pressure Transducer) measures the air pressure in the tube that is necessary to release the bubbles from it. The higher the water level in the river, the more pressure is required to push the air into the water—because the air pressure in the tube is directly related to the depth of the water (according to Pascal’s law). The bubble method works well even if there is floating debris or ice in the river, which may interfere with other sensors (such as ultrasonic ones). Since the sensor does not contact the water, it always remains dry and clean. Additionally, to prevent data distortion, the system includes an air dryer (Air Dryer), which removes moisture from the air and prevents condensation.

The accuracy of such systems is 1-2 cm in water level for rivers with shallow depths.

Interestingly, the readings are transmitted not through the mobile network, but via satellite.

Lost in Translation: A Midnight Encounter at Ashburn Station | July 06 2025, 17:28

Yesterday late, around 10-11pm, I was returning from Washington by metro. At the exit of Ashburn station, a relatively well-dressed guy approaches me and asks how to get to Route 7 from the station by bike. I start to answer, then he asks me if I happen to speak Russian. My accent gave me away (damn, how did he know exactly?)

I open the map on my phone, start explaining it to him, go right here, then left, then right, a 45-minute ride. It’s night outside. The dude’s on a bike. He doesn’t have a phone — something is broken or dead. But the most interesting thing, he doesn’t know the address where he needs to go. And Route 7, by the way, is 497 km long, but he obviously meant a segment about 30 km near the metro, but it was still not clear where he needed to go in that section.

In the conversation, it turned out that he knows how to get to the place where he stopped (friends?), from the local Russian-speaking Protestant church, called New Life. I feel I’m explaining to him, he’s overall ready to go alone in the dark without navigation, but from his feedback, I understand he didn’t get it, and at the first turn, he’d go wrong. And at that time, there was absolutely no one on the streets, it’s a neighborhood and data center area (the largest in the world, by the way), very safe, but absolutely deserted. I tell him — my car is parked at the metro, let me give you a lift if that’s the case, it’s no trouble for me.

His name is Edik. He wrecked his car a week ago because he liked to drive “with a breeze”. He regrets it because now he doesn’t understand what to buy a new one with. Lives in Baltimore, came to our area because there’s some Mongolian holiday tomorrow. What? I ask, what the hell is a Mongolian holiday. Turns out he’s from Mongolia, lived there before moving to the USA. Russian family, school at the Russian embassy. Speaks Russian without an accent, and fluent in Mongolian. Illegal. Apparently, he came to the USA on a tourist visa and stayed. Works in a store somewhere near Baltimore. Deep in debt. Apparently, a few adventures weren’t enough and he went to Virginia by bike mixed with metro and buses.

I hope he made it home from the church.