Tag: science

Gold and Gadgets: Tracing Global Influence and Metal Monopolies | October 14 2025, 03:13

Rajesh Exports states on their website that they process 35% of the gold mined on the planet. Of course, they are exaggerating, but overall, India and Rajesh do shape the market. It turns out that 11% of all the gold on the planet is adorned on Indian women. Additionally, it was found that in 1947, 70% of all mined gold was in the USA. From 1934 to 1970, it was legally prohibited for private individuals to own gold in the USA. Approximately 22% of all the gold ever accounted for on the surface of the Earth has been mined from a plateau in South Africa called the Witwatersrand. And if you consider all the gold mined throughout history, it would amount to less than an Olympic swimming pool.

China buys up silver, with India not far behind. Interestingly, platinum is significantly used in the production of catalytic converters for vehicles – almost 40% of the global production goes there. China, of course, holds much of this production.

Practically every smartphone, tablet, or touchscreen monitor that we use is coated with a thin layer of indium tin oxide (ITO). This material has a unique combination of properties: it is almost completely transparent while also conducting electricity excellently. This allows the screen to register your touches.

Although lithium is now strongly associated with batteries, historically and still today, a significant portion of it is used in the production of glass and ceramics.

From Vision to Bookshelf: Launching “Recommender Algorithms” | October 13 2025, 11:54

Finally, I have released a book! It is called Recommender Algorithms — it contains more than 50 recommendation algorithms with mathematical explanations, detailed descriptions, and code examples.

It all started early in the spring in Germany, when I attended the ACM conference and made the first sketches of the book’s structure, analyzing reports on the RecSys stream. And now, six months later, the book has been published.

Why did it appear? Because there is no single, accessible source either online or in print where the recommendation algorithms of various types and purposes are thoroughly examined. There are articles focused on narrow aspects, but to collect and systematize the developments — from fundamental to the most recent — until now, it seems, no one has managed to do it for some reason. Maybe no one needed to. Suddenly, I found I needed to. I don’t know if I succeeded, but I am eager for your feedback.

Available on Amazon and Barnes and Noble. There is a Russian automatic translation (surprisingly, but very decent), but I do not know how to sell it yet.

https://www.testmysearch.com/books/recommender-algorithms.html?FB

(This is not my only book, but today — just about this one.)

Decoding Solr and Lucene: Engineering Insights and Algorithms | October 06 2025, 17:11

Preparing a book for publication on Solr&Lucene. What do you think about publishing such a translation on Amazon? 🙂

The book is about algorithms and under-the-hood engineering. I haven’t seen books from this angle yet, maybe someone will find it interesting.

When Pigs Outsmart Technology: The Failure of Precision Feeding in Large Farms | October 05 2025, 17:01

Today I learned how scientific achievements fly under a pig’s tail when faced with reality.

There’s this thing called precision feeding in pig farming. The gist is: a pig has an RFID chip attached to its tag (actually to its ear), and when it wants to eat, it sticks the tag into the feeder – and a special sensor reads its data and dispenses exactly as much feed from the machine as it should, also recording in a database how much and when it was given. If the pig sticks its tag in too early, the feed machine won’t dispense any. The idea is to reduce feed costs, improve growth and health of the animals, and lessen environmental pollution (less uneaten feed).

It seems like a great idea. However, such a system doesn’t work where there are large populations – it only works in specialized productions with few pigs, where almost all are known by name.

Why doesn’t it work on a large scale?

Because pigs are very cunning and quickly adapt. One pig inserts a tag, and then the one higher in the hierarchy chases it away and eats what isn’t meant for it.

Whole classes of oppressed arise, whose role is to insert the tag so that the authorities can gorge themselves. In the end, chaos ensues and no precision is achieved.

This is how pigs oppose technological progress.

The Surprising Origins of the Word “Tumbler” for Drinking Glasses | October 05 2025, 15:32

In our language, glasses are called tumblers. I decided to find out why, because a tumbler is essentially an acrobat.

There are two mutually exclusive theories. According to one, the original tumbler glasses had a rounded or slightly convex bottom, which allowed them to “rock” or “tumble” (to tumble), but not tip over completely. So, a tumbler in this sense is kind of like a “weeble.” According to the other, they were specifically made so they could not be put down on the table open, because, say on a ship, they could tip over and the valuable rum would spill out.

Exploring the Chaos Game: Creating Fractals From Randomness | October 04 2025, 15:32

I read something interesting today. About fractals. If you take any three points that form a triangle, and then a fourth point anywhere, and subsequently throw a dice, the faces of which are assigned to the first three points. Next, you move from the current point towards the point corresponding to the result on the dice and place a new point halfway; this becomes the new current point. After many iterations, the points start to form the Sierpinski triangle – the one shown in the attached picture. Intuitively, you would think the triangle should be fully filled because it involves random movements in three directions from a randomly chosen point, but no. Moreover, it works even if the starting point is inside the future empty triangle (yes, a few points will disrupt the picture, but that’s it). If you start our experiment with five or six points instead of three, different shapes will form – see the attached picture. This graphical method is called the Chaos Game.

By the way, it may seem obvious, but in case you wondered — all the presented figures have zero area.

If you take two triangles and with a probability p move towards random vertices of the first, and with (1-p) towards random vertices of the second, you end up forming a Barnsley fern (picture №2).

I love such things because they seem like magic at first glance 🙂

(It’s a kind of problem from the same class as the synchronization of metronomes)

Understanding Jerusalem Syndrome and Its Global Counterparts | October 01 2025, 16:10

Listening to Sapolsky in the background, he mentioned Jerusalem Syndrome. It’s when a deeply religious American Baptist from the southern USA, having saved money and prepared, arrives in the Holy Land and sees that Jerusalem is just another city: traffic jams, smog, noise, pickpockets, McDonald’s—everything like that. And then—an interesting feature—in all cases, the person tears up sheets, takes off their clothes, and suddenly finds themselves on the streets of Jerusalem, dressed as if in a toga, begins to preach on the streets, calling for a simpler life and all that.

A psychiatric team arrives, takes the person to the hospital for a few days, everything becomes clear, they send him back home, and he never encounters this syndrome again.

Each year in Jerusalem, about up to many dozens of cases are recorded. It’s a recognized syndrome, about which scientific articles are published.

Sapolsky says that if hotels in Jerusalem always had, for example, checkered sheets instead of white ones, which seem to “invite” one to don a toga, it would help prevent the crisis.

But amusingly, there’s a twin brother of this disorder, the Paris Syndrome, which for some reason mainly affects the Japanese. Japanese tourists come to Paris because they are attracted by the culture, language, literature, and history of France, as well as the landmarks of Paris. However, once there, they encounter difficulties such as a language barrier (surprise surprise!), differences in mentality, and disappointment from the reality of Paris not meeting their expectations.

There’s also a milder version called the “Florentine Syndrome.” This often happens during a visit to one of the 50 museums in Florence, the cradle of the Renaissance. Suddenly, a visitor is overwhelmed by the depth of feeling the artist has imbued in the artwork. At this point, they acutely perceive all emotions, as if transported into the space of the image. Victims’ reactions vary up to hysteria or attempts to destroy the painting. Despite the syndrome’s relative rarity, guards in Florentine museums are specially trained on how to deal with its victims.

Overall, be careful with syndromes when you’re traveling.

PS. This image was made for me by google. In the second image, a guy in a tie tells a tearful girl 脆培, which seems just a meaningless set of characters, something like fragile culture. But when I asked ChatGPT, it told me it resembles 脱げ (nugu) — undress 🙂 if you ask Google Gemini to redo it, Google gives the same picture, where he’s also shouting 暁は, but at the same time, he has already taken off his shirt. But that’s also unclear what 暁 – it’s dawn. Generally, with Japanese, LLM is bad. I’ll leave the second image in the comments. By the way, there are several differences there, you can play a game to find ten differences. They are amusing

Introducing the AI-Powered Text-to-Diagram Generator | September 30 2025, 20:57

While working on a book, I realized what kind of product I’m missing. It’s an AI diagram generator based on textual descriptions.

The idea is that the master document for the diagram is text. This textual description can be (and should be) quite detailed, so the generated diagram exactly matches the author’s vision. The diagram itself is not edited. That is, it can be edited – moving circles around, but ideally, after making changes, the system should update the text, generating from which will result in what the user adjusted.

The result — the diagram — should correspond as closely as possible to the description. If it does not match the description because, for example, it’s impossible to make a triangle with three obtuse angles, the system should do its best and provide a verbal response about what didn’t work. The user can then modify the task so that the system complies and produces the diagram correctly.

But then we understand that the author might have randomly achieved something that they liked with their flawed text. And if regenerated, it might turn out differently, and not necessarily better. Therefore —

You could ask the system to generate a diagram description from the diagram, which, if inputted back into the diagram generator, would result exactly in what the description was generated from. Yes, this description would be more verbose and complex, but it would more reliably describe the result.

So, from this point, you are no longer working with the diagram. You are working with text. If a diagram is needed — you simply compile the text into a diagram and it turns out as needed. But you don’t even work directly with the text. You work with this diagram-description text through an LLM, asking it to add some block, and the text changes, but changes in a way that everything doesn’t suddenly shift.

The final diagram should be in an object form, from which raster (PNG) or vector (SVG, EPS) images can be created.

It would also be great if such a system could take existing diagrams or diagram templates so that it could borrow styles and existing conventions on how to display what.

So, these are my fantasies. If anyone has ideas on how to implement this — let’s discuss 🙂

The Ingenious Mechanics of Modern Fuel Pumps | September 28 2025, 13:36

With the purchase of a Tesla, there’s sudden interest like a fuel nozzle understanding that the tank is full. And a couple of other interesting findings on the topic.

There used to be an awkward problem at gas stations. Customers didn’t know when their tank was full and gasoline often spilled over. Engineers came up with a genius solution.

Inside the fueling nozzle, there’s a thin tube that pulls air from the car’s tank into a special membrane chamber (if you look at the “nozzle,” there will be two holes) When you press the trigger, fuel flows until the tube is submerged in gasoline (which means a full tank) and the air flow stops.

This creates a vacuum, which pulls three little steel flaps into the center of the mechanism, instantly releasing the trigger and cutting off the fuel supply.

By the way, approaching the diaphragm valve in the channel there is a compartment with a small ball inside. If for some reason the fuel nozzle falls out of the tank, the ball will block the vacuum channel, provoking a sharp increase in vacuum – and triggering the process described above.

It also turned out that the diesel nozzle is larger in size so it cannot be mistakenly inserted into a gasoline tank. But the opposite mistake can happen. Although they could have invented a different design that would work both ways from the start.

When a tanker refills an underground reservoir, the valve automatically closes when the tank is nearly full, and the gasoline vapors are sucked back into the tanker through another hose, where it condenses back into liquid fuel.

And it also turned out that if you drive away with the hose still in your car, there will be no fireballs, spilled fuel, or toppled gas pump. The hose connecting the nozzle to the pump is designed to disconnect into two parts when a certain force is applied. Next time you are at the gas station, pay attention to the metal connector on the hose. That is the break point. When the hose disconnects and you drive away, the area of the hose breaks, built-in valves in the hose cut off the fuel, but, of course, the pump will not operate for some time until everything is put back to normal again. Interestingly, this risk is considered and damage is minimized.

Oh, and here’s something for those who haven’t driven in New Jersey. By law, it’s prohibited to refuel your own vehicle. At all gas stations, there are attendants who do it for you.

The Optical Illusion of the Changing Purple Dots | September 27 2025, 23:44

An interesting trick. To color the circle dark purple, you simply need to look at it and it will instantly change color. However, to revert it back, you just need to stop looking at it, and it will return to its original appearance (though you’re likely to look at another circle instead)