Tag: Engineering

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.

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.

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.

Childhood Curiosity and the Mysteries of Soviet Electrical Engineering | September 23 2025, 17:00

I remember being puzzled as a child by who the idiot was that decided to make the radio plug exactly the same as the one for 220 volts. This radio plug was supposed to go into a radio socket.

As a child, I used to disassemble and “improve” almost everything electrical in the house (I hadn’t graduated to electronics yet). Of course, I got shocked many times by the outlet, but to my surprise, the old Soviet phone could also give a shock. When a call came in, the voltage in the line would jump from 12-60 volts to 120 volts 🙂

I also had an interesting experience with Christmas lights. For a younger schoolchild, it was unclear why Christmas lights could shock you since they used the same bulbs that I connected to a flat “Planeta” battery. I had to learn the technicalities 🙂 By the way, those square flat batteries have disappeared; they used to be everywhere.

Inside the High-Tech World of USB-C Cables: More Than Just Wires | September 22 2025, 22:50

It turns out USB-C cables are sometimes whole computers inside the odd form factor of a wire. Watching a video where guys from Adam Savage’s dissected an Apple Thunderbolt 4 cable ($130) using a CT scanner, explaining its internals, and comparing it to a similar cable for $12.

The cable connector contains a complex system that includes a full-fledged processor, two power supplies, and many other components. The processor splits data into multiple parallel streams and converts them into differential signals that travel through twisted, intertwined pairs of wires. The system sends two signals simultaneously, but in mirror-opposite directions. This helps protect the signal from interference (from vacuum cleaners, mobile phones, etc.). Indeed, the circuit board inside is nine-layered.

On the internal circuit board, there are interesting serpentine/wavy tracks with sizes in fractions of a millimeter. It turns out, Apple engineers intentionally made them longer to match the overall length with the neighboring longer tracks (because they include turns). This is necessary for the signals to reach the processor absolutely simultaneously, down to the nanosecond.

The cable itself inside is made up of many individually shielded smaller coaxial cables. There are more than a dozen of them.

The cheap cable lacks this smart electronics, no active components inside. It just has connectors and wires.

But the coolest thing – the guys post such scans in the video description as a link to a viewing program. There you can rotate and examine everything on your own. I’ll put it in the comments

Living in the Valley of Data Centers: The NSA’s Gigantic Utah Facility | September 20 2025, 20:06

I live right in the valley of data centers, like 80% of internet traffic goes through us (a dangerous place!). I drove by one of them today, and later at home, while Googling stuff about data centers, stumbled upon the NSA’s data center in Bluffdale, Utah.

It serves as a data repository for the U.S. intelligence community. Capacity — something like 5 trillion terabytes. 5,000,000,000,000,000 gigabytes. Back in 2013, it was 100-1000 times less, but 12 years have passed, Moore’s Law and all that. Hard drives in data centers usually have a lifespan of 3-5 years. Meaning, since the launch of the data center, they have all been replaced several times with obviously greater capacity.

It is expected that the data center will be able to process “all types of communications, including the full content of private emails, mobile phone conversations, internet browsing, as well as all types of personal data: parking receipts, travel itineraries, purchases in bookstores, and data of other transactions made using digital technologies.”

The amount of data this facility is able to store is, of course, classified, but estimates “several yottabytes”. Yottabyte = 1000 zettabytes = 1,000,000 exabytes = 1 trillion terabytes. To store all the books ever written in any language would require just 400 terabytes.

In 2013 it consumed no less than 65 MW with a potential of 100 MW. Water — ~1.5–1.7 million gallons (5.7–6.4 million liters) per day for cooling servers. The water is treated with chemicals (to prevent corrosion) and discharged, leading to criticism in arid Utah — especially amid the record heat from 2022–2025 and the shortage of fresh water. There’s no closed-loop system, and it remains a “hot” topic in local discussions.

Exploring the Evolution of Inflight Entertainment: The Forgotten eXport Connector | September 14 2025, 13:24

We’re taking off. I’m wondering what kind of connector this is. Googling it. About 10 years ago, the Panasonic IFE multimedia system (which seems to have been used on B773ER and A333, I’m on a Boeing 777ER) featured a new port named eXport. It was a 9-pin mini-DIN connector for iPods. You could buy an adapter cable made by Griffin that essentially served as a bridge between the 9-pin mini-DIN and the 30-pin dock connector of iPods. Do you remember such connectors on iPods? And do you remember iPods at all? This cable allowed you to charge the iPod, control it via the IFE system, and transmit media from it to the IFE system. Time flies so fast. Looked up when the airplane was made – 14 years ago. That is, 14 years ago it still made sense to integrate a proprietary connector into the seats that essentially worked only with iPods.

I’m not even writing about RJ-45 above. White-orange orange, white-green blue, white-blue green, white-brown brown

Update from a page that has been gone for ten years, but the archive org remembers everything

And how does all this work? Here are some visual materials for clarity and facts from Panasonic (…about the biggest and highest-flying accessory for iPod in the world (as someone from Apple put it)

1. Allows audio and video signals to be transmitted from a passenger’s iPod to the IFE system, while also providing power and charging the iPod.

2. The eXport solution consists of two main components: the eXport connector (installed in the seat) and the eXport cable (connects the iPod to the eXport connector).

3. The crew will provide the eXport cable to passengers during the flight.

4. The solution is the world’s first Apple-certified Made for iPod” and Made for iPhone” solution, specifically designed for commercial airliners.

5. Natively supports Apple authentication technology.

6. In the near future, Panasonic will introduce additional functionality that will allow two-way communication between the iPod and the IFE system.

7. Supports both iPod and iPhone (in airplane mode”).

The reason a special cable is needed is that Apple does not allow video to be transmitted via USB. The only alternative would be to have three RCA connectors and an AC power socket onboard. But it’s expensive (installing an AC power system) and not worth the extra weight. Plus, it takes up legroom under the seat. Moreover, having three RCA connectors is a lot of ‘ports’ (red, yellow, white), which can confuse passengers (imagine a night flight in a darkened cabin). It only increases the workload on the crew, who are responsible for safety and comfort, not tech support.”