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)
I decided a while ago to write a book on recommendation algorithms. With mathematics, code examples, a repository, etc. English, of course.
Accordingly, I am looking for volunteer reviewers who are knowledgeable in the field. Also those who have experience with print-on-demand on Amazon.
There’s already about 200 pages of content. About three months of work left. Working title Recommender Algorithms in 2026: A Practitioner’s Guide. Roughly half of it is still in draft form, with the first 80 pages about 80% complete.
I’ve built a mechanism to publish in HTML and PDF simultaneously. The HTML version is fully functional, with navigation. The navigation block reflects the current section, and as you scroll, it shifts to the one in front of the reader. Clicking on a section, of course, teleports you to what you clicked on. It’s all completely automatic.
So far, I have only one car model and brand that can deploy airbags not at the moment of impact, but a moment earlier, so that by the time of the impact, it’s not too late to do so. We’ll see what the news shows, but tests indicate that this thing works better than the traditional method. Reality might turn out to be harsher, but we’ll keep an eye on it.
It’s also interesting that the car started to receive new exciting features after purchase. I never had this experience before. What you bought it with, you lived with, and sometimes you could go to the dealership for something new, and it usually involved replacing something physical.
The previous update (not very useful to me, but maybe to someone) was about automatic detection of children and animals in the cabin. And if it turns out they were left inside while the owner left, the car does not turn off the climate control. And of course, it screams into the app that this is not a good thing to do.
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
I made a gift for myself yesterday and bought Airpods Max. I already had Sony WH1000XM3, but I didn’t quite grow to like them. They don’t perform well with multiple devices, especially Macs, and although I find the sound quality decent, I prefer the sound in the Airpods, initially thinking it was due to the codecs, which indeed are a bit chaotic. Sony supports all – SBC, AAC, aptX, aptX HD, and LDAC. Apple devices (Mac, iPhone) do not support aptX and LDAC. Of all the advanced codecs available to Sony, the only one Apple devices can utilize is AAC. Exactly the same codec found in Airpods. But the sound to the ear is noticeably different.
Regarding the new ones, I realized I would be earning an eternity plus still, of course, I decided to buy used. For popular items, if you have a lot of time, you’ll definitely find some in excellent condition and for half the price. And here’s what I found out in the process: nine out of ten “half-price” headphones are fakes. The same situation applies to Airpod earplugs. Sometimes they are of very high quality, but like any counterfeit, they have serious flaws, but as many reviews say, the average ear won’t notice the difference, as counterfeiters don’t skimp on the audio path.
Eventually, I watched a ton of videos on how to distinguish fakes from genuine ones, and managed to buy Airpods in perfect condition yesterday for $180 when their price is $500.
Interestingly, checking the serial number on Apple’s website is no longer a cure-all because they’ve learned to reuse serial numbers from stolen ones. Most importantly: never buy a sealed box. Its outer part is counterfeited such that it can only be differentiated by the slightly less neatly wrapped film. In unpacked “ears,” the differences are more noticeable. The main thing – the headphones must pair with the computer using Apple’s proprietary protocol, which the counterfeiters have not yet been able to replicate.
Popup on iPhone upon first connection: Genuine — with a “Connect” button. Fake — no button, connects via Bluetooth settings.
The material of the headphones — should be metal. Fake — plastic, because metal is more expensive to manufacture. Snap your fingers on them, there should be a specific sound (try it in the Apple Store) — but most importantly, it should be the same on both sides. On the fake, it’s different and distinct.
The material inside the box: Genuine — cardboard (possibly recycled). Fake — plastic. Although cardboard is sometimes used too. An unreliable indicator.
Wrapping of the headphones: Genuine — in paper material. Fake — in plastic or without wrapping. Also unreliable.
Case — Interior material: Genuine — soft, changes color when touched, has text. Fake — hard, does not change color. This is quite a reliable aspect, because fakes will not use more expensive leather.
Noise when shaking: Genuine — noiseless. Fake — the button moves, noise is heard. Ear cups: Genuine — strong magnets, do not fall off. Fake — weak magnets, easily detach or fall off. Screws inside the cups: Genuine — dark. Fake — silver or light. This only works if you have seen the genuine ones. The difference is impossible to describe in words.
Noise cancelation (ANC): Genuine — activates only on the head. Fake — works in any position (even on a desk). Of course, it’s also poor, but detecting this is difficult unless you have the fakes on hand.
We must also check for Spatial Audio. It requires an accelerometer inside. Of course, fakes do not install one – it’s almost unused and why unnecessarily make the design more expensive. But in Spatial, it is used (you move your head – the sound shifts back and forth).
In short, when I was traveling yesterday, I was almost sure I wouldn’t buy anything. But — I got lucky.
Speaking of the Airpods themselves, they have some drawbacks that have been known for several years. I’m okay with them. The headphones are heavier than they could be, they don’t fold as they might, they bump against the chin when worn around the neck, and it’s not very comfortable to wear them that way, the price is high (but okay for used), strange case, and the protective case is huge, half the size of a backpack. Among the very important pros for me — support for multiple devices and perfect integration with Apple devices, good noise cancellation (almost like Sony’s), premium materials, and perfect build quality.
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.
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.”
Came in to eat some sushi
It was supposed to be crab
Great idea indeed. A carriage drove past me, delivered a passenger, returns to base.
The day after tomorrow, I am flying to Amsterdam (and then to Turkey), and I remembered that I had an unanswered question to myself about how baggage scanners work at the airport. Of course, I knew that it was essentially computer tomography, X-rays and all that, but I wanted more details. And below is the response as to why they ask you to take out water, and why sometimes they do not.
It turns out that modern scanners can not only see the shape of objects but also determine what material they are made of. How does a regular scanner work? Dense materials (such as metal) absorb a lot of radiation and appear bright or opaque in images. Less dense materials absorb little radiation and appear dark. Hence laptops, for example, had to be taken out — not because the scanner couldn’t recognize them, but because their dense components (battery, boards) could be used to hide other prohibited items behind them. So, it has long been not just scanners, but computer tomography — in essence, the bag or suitcase is scanned from all sides, then a 3D image is created. It seems like everyone knows this.
But I mentioned that they understand the materials items are made from. How?
It turns out that the scanner uses dual-energy X-ray technology. It scans the object with two beams of rays of different energy levels (high and low). Since materials absorb radiation differently depending on the energy of the ray and their atomic composition, the system analyzes this difference. Based on the absorption ratio of the two beams, the effective atomic number Z — a key characteristic, a kind of “elemental fingerprint” of the substance, is calculated.
The problem is that this “fingerprint” of water (~7.4) and many explosives are almost identical. This is precisely why water was banned. Relying only on this parameter would mean receiving a huge number of false alarms.
Here is where computer tomography (CT) comes into play. The scanner creates an accurate three-dimensional (3D) model of the contents of the bag. From the 3D model, the system obtains the exact volume (V) of each object. Based on data on the absorption of X-rays, its mass (m) is calculated. Then it’s simple: ρ=m/V.
That is, the system does not make a decision based on one parameter. It plots each detected substance on a two-dimensional graph with axes “Z — density.” On this graph, water and explosives, having almost the same atomic number, occupy completely different positions due to different densities.
And that’s precisely why water can sometimes be carried through. Smart machines simply do not mark it as something significant, but still identify it as water. Then procedures follow. If the airport has updated the machines, but not the procedures, they will ask to dispose of the water. But also, not all machines are updated everywhere, and at the same airport, it depends on which line is open at the moment.
The cost of such a scanner is $300-400 thousand.
The scanners for people work differently. They use millimeter waves. They pass through clothing and reflect back from the skin. Water absorbs them significantly, so they penetrate only a couple of millimeters. The system registers the reflected signal and constructs a three-dimensional map of the body surface and objects under the clothing. But it does not show this — instead, it displays a simplified contour of a person and shows on it what ML found unusual. Therefore, by the way, many try to carry various items inside themselves, knowing that such a scanner absolutely cannot see it.
Hi, I'm Rauf Aliev. 