Misadventures in AWS: Misusing aws-nuke for Configuration Exports | December 12 2025, 16:29

Just for laughs. I asked Gemini how to export the entire AWS configuration for local analysis, and they recommended using the aws-nuke command for permanently deleting everything, but if you add a dry-run flag, you’ll get the configuration… and someone actually follows such advice 🙂 and then we wonder

Two Weeks on Linux: From Mac to ArchLinux+KDE Bliss | December 12 2025, 16:24

Two weeks on Linux, wildly satisfied. After a Mac. I specifically have a setup of ArchLinux+KDE/Plasma 6.5. Everything here is customizable. For instance, I made a program from scratch in half an hour (no lie, thirty minutes) using Gemini that translates selected text to English or corrects errors if the selected text is already in English when ScrollLock is pressed. There seems to be an app for every situation in life, at least in my field. Everything flies (even though this is an Intel i9 285K/64Gb). I just enter a folder that contains 470,000 files, and it opens instantaneously. I’ve never seen anything like this anywhere else. I launch IntelliJ Idea, and there is practically no delay between clicking the icon and the editor being ready with the loaded project. All devices connected perfectly, unlike with the Mac, for which there are simply no drivers for my HP LaserJet 1018 and I need to perform tricks.

Now I occasionally switch to a Mac, and it drives me crazy that the hotkeys are different. Of course, they can be reconfigured for Mac, and probably I will do that. Muscle memory builds up, and switching quickly doesn’t work out. I miss iMessage a bit – I’m used to writing and responding to messages from the computer. Apple iMusic works, through a browser.

Overall, the impression is very good so far.

Unleashing the Power: RTX 5090 for Advanced AI and Digital Art Creations | December 01 2025, 01:39

Nvidia RTX 5090 32Gb! Happy as an elephant. Installed ArchLinux and CUDA. Planning to soon get smart about boosting transformer deep neural networks and have a bunch of ideas for digital art based on concepts other than diffusion models.

Performance: Just ran a test, model GPT_OSS_20b_UD_Q4_K_XL generates 350 tokens per second with a context of 131072 tokens. That’s roughly an A4 page in a few seconds. Gemma3 27B – 55 tokens per second. Qwen3_30B_A3B_Q6_K – 259 tokens per second.

The Inner Mechanics of Old Rotary Phones | November 25 2025, 00:59

When I was little, I used to take apart old telephones many times, and only now, in my grey years, I realized that I never wondered how they worked. And they worked in a very interesting way.

Let’s start with the dial. The phone is connected to the network by two wires. The dial is a rotary one. When you wind up the disk, the contacts are blocked, and when you release it, the disk returns backward and delivers a series of interruptions/pulses to the line. But how was it made to return at a constant speed (which is 10 pulses per second)?

It operated based on a centrifugal friction governor. The mechanics (gearbox) accelerated the governor’s axle to thousands of revolutions per minute. Two weights with friction pads (consider them brakes) were seated on the axle. The centrifugal force pressed them against the stationary drum, creating a braking effort. This is a direct heir to Watt’s centrifugal governor, allowing the mechanism to work stably regardless of how sharply you released the disk.

Next. The Central Office connected you with a friend. You both speak at the same time, and sound is transmitted there and back through two wires—why two wires and not four, you understand? Well, okay, but why don’t you hear yourself too loudly, since the microphone sends the sound there, from where the “speaker” hears it?

I couldn’t answer quickly. Went googling. So, it turns out that a special differential transformer was responsible for this. There, the current from the microphone branches off: part goes into the line to the friend, and part goes into the “balance circuit” (a chain of a resistor and capacitor inside the phone), mimicking the line resistance. The transformer coils are wound in opposition: the magnetic flows from the current in the line and the current in the balance circuit mutually annihilate themselves in the coil that goes to the speaker. Engineers purposely adjusted the balance not perfectly, leaving a “local effect” – a quiet sound of one’s own voice, so the phone wouldn’t seem “dead.” But the incoming signal from the friend has nothing to unbalance it (silence on your side), so it freely passes to the speaker.

Now about the microphone. At that time there were no transistors in phones, but the signal was loud. The secret is in the design of the microphone, it’s carbon. Essentially, it is a box with carbon powder and a movable diaphragm. The sound from your mouth compresses and decompresses the powder, changing its resistance. The microphone does not generate current but modulates the powerful current coming from the Central Office. Essentially, it worked as an amplifier. Over time, the charcoal compacted, and the audibility dropped—hence the habit of tapping the handset to “shake up” the powder.

The speaker was normal, electromagnetic. Although not quite. If there were only an electromagnet inside (without a permanent magnet), the phone would horribly distort the voice. An electromagnet attracts iron regardless of the polarity of the current. If you supply a sine wave (voice), the diaphragm would be attracted during both the positive and the negative half-waves. Result: the frequency of the sound would have doubled, and you would hear not the voice of a friend, but an unintelligible high-frequency buzzing. The permanent magnet solves this problem: It creates “preload.” The diaphragm is always attracted to the magnet with medium force. When the “plus” of the signal arrives, the magnetic field strengthens and the diaphragm flexes more. When the “minus” arrives, the field weakens and the diaphragm springs back.

In modern speakers, the force strictly depends on the direction of the current. Plus pushes, minus pulls. Therefore, the frequency doubling, which old phone engineers feared, physically cannot occur here. The diaphragm doesn’t need “preload” by a magnet, it just needs to hang in peace.

Interestingly, the principle of old electromagnetic capsules (metal diaphragm + “anchor”) is used now in the most expensive in-ear headphones—google “balanced armature headphones” (prices around $500).

The voltage in the telephone network was negative – minus 48/60 volts. Plus was grounded, and the “live” wire was the minus. Why? It turns out, this is protection against electrochemical corrosion. The cables lie in moist earth. If there were a “plus” (anode) on the wire, upon insulation damage, copper would dissolve (electrolysis) and the cable would rot. With “minus” (cathode), metal ions, on the contrary, tend to settle on the conductor from the soil, which prolonged the cable’s life by decades.

Exploring the Fascinating Properties of Glass | November 21 2025, 23:58

I got carried away with the topic of glass and learned so many interesting things, so I’m sharing. It all started when I read about the supercritical state of matter – it turns out that the line separating liquid and gaseous states on a pressure and temperature graph at some point breaks off, and beyond that lies a state of matter that is neither here nor there. I started reading about states (phases) of matter and stumbled upon the fact that glass is essentially a state between liquid and solid. It flows, just very slowly. This myth is popular thanks to observations of medieval windows, where the glass is often thicker at the bottom, which was attributed to “flowing” under the influence of gravity, and it was even mentioned in school textbooks. In reality, glass is an amorphous solid with extremely high viscosity at room temperature, and it does not flow noticeably even over billions of years; the uneven thickness of old glass panes is explained by production technologies, when the thicker edge was installed at the bottom for stability.

I delved into the topic of glass further. It turned out that the reason why glass can be transparent is rooted in quantum mechanics, specifically in the electronic structure of the material, not because of the density of particles. The essence is that for an electron to absorb a photon, it must transition from one energy level to another, but in silicon dioxide, the width of the band gap is so large that the energy of visible light photons is physically insufficient to make this “jump.” As a result, light simply cannot interact with the electrons and goes straight through the material, while higher-energy ultraviolet radiation can overcome this barrier and is thus absorbed by glass.

It also turned out that melted glass conducts electricity. Moreover, the mechanism of conductivity fundamentally differs from how metals conduct electricity. In a copper wire, current is a flow of free electrons. In cold glass (an insulator), electrons are tightly bound, and ions are locked in the solid lattice. But when you heat glass to the molten state (usually above 1000 degrees for silicates), thermal energy breaks the rigid bonds of the lattice, and glass becomes a liquid, with ions gaining freedom of movement. The current in molten glass is the physical movement of charged atoms (ionic conductivity), not just “flowing” electrons.

The green tint you see on the edge of regular glass (as seen in the attached picture) turns out to be caused by iron ions, present as impurities (~0.1%). Sand is a natural material, and removing all the iron from it is difficult and costly. Low-iron glass, which has tens of times fewer iron ions, is used in solar panels, not just because it is more transparent. Iron greedily absorbs the infrared spectrum (thermal energy), reducing the efficiency of the panel. By removing iron, we allow maximum energy to reach the silicon cells.

And finally, the most “mind-blowing” (literally). There are these things called “Prince Rupert’s drops.” If you drop molten glass into icy water, the outer shell of the drop cools and hardens instantly, while the inner part remains liquid. As it cools, the core tries to contract, but the hardened shell doesn’t allow it. As a result, the inside of the drop preserves colossal mechanical stress (up to 700 MPa).

The physics of this process creates a paradox: the “head” of such a drop can withstand being struck by a hammer because the compression of the surface makes it incredibly strong (the same principle is used in tempered glass for smartphones). But just nick the thin tail, and the balance of forces is disrupted, and a wave of destruction moves through the drop at the speed of a bullet (about 1.5 km/s), turning it into glass dust right in your hands.

There’s also something in physics called “metallic glasses” (amorphous metals). If you cool the molten metal at a rate of a million degrees per second, atoms do not have time to arrange into a crystalline lattice and freeze in chaos. Such “glassy metal” possesses unique magnetic permeability and is stronger than titanium, because it lacks crystal lattice defects, which are usually the points of destruction. So glass is a much broader concept than just transparent substance in our windows 🙂

The only example of an object made from this material, amorphous metal, that I’ve encountered is, believe it or not, the iPhone clip.

By the way, that same amorphous structure of glass, which I mentioned earlier, gives it an unexpected advantage — supernatural sharpness. If you take a scalpel made of the best surgical steel and look at it under an electron microscope, its edge will look like a jagged saw. This is inevitable: steel is made up of crystalline grains, and it’s impossible to sharpen it any smoother than the grain size allows.

But obsidian (volcanic glass) when fractured provides an edge only about 3 nanometers thick (about 1/30000 the thickness of a human hair). There’s no magic here, just that glass lacks a crystalline lattice, which would otherwise prevent achieving a perfectly smooth fracture down to the molecular level. That’s why obsidian scalpels are still used in the most complex eye surgeries — the cut is so clean that tissue cells are minimally traumatized, and healing occurs faster.

And one more powerful engineering case — vitrification (glassification). Mankind has chosen glass as the most reliable “safe” for nuclear waste. Liquid radioactive waste is mixed with special additives, melted, and cooled into blocks. The trick is that dangerous isotopes are not just poured inside, they are chemically embedded into the atomic grid of the glass. Glass is chemically inert, it doesn’t rust like metal or decompose for thousands of years. This is perhaps the only material that engineers trust to store hazardous substances on a geological time scale. Yes, it takes about a million years for a discarded bottle to decompose.

And finally. Digging into history, it turns out that the Romans were engaged in nanotechnology 1600 years before we even invented the word. In the British Museum stands the “Lycurgus Cup” (4th century AD). If you look at it under normal lighting, it’s greenish and opaque. But if you place a light source inside the cup, the glass flashes bright rubin red.

Until the 1990s, scientists could not understand how this was achieved. An electron microscope showed: Roman craftsmen added gold and silver, ground to nanoparticles about 50 nanometers in size (about 1000-1800 times thinner than a hair). This size of particles triggers a quantum effect known as surface plasmon resonance: electrons in the metal begin to oscillate such that they absorb some wavelengths of light and let others pass depending on the angle of incidence. The funniest thing is that the Romans did this empirically, “by eye,” and we’ve only just learned to replicate this consciously in photonics. It’s crazy to think you could handle 50 nm gold dust by eye. This moment required additional googling.

It’s unlikely the Romans mechanically crushed the metal to 50 nanometers — they had no such mills.

More likely, they added gold and silver in the form of salts or foil to the molten glass mass. The nanoparticles formed not by crushing, but by crystallization and sedimentation from the melt under very precise temperature conditions (“glass prescription”). This is even more complex chemistry than simple grinding.

The most astonishing thing is not that they did it, but that the ratio of gold to silver was maintained perfectly. Changing the concentration of gold by just 1% would alter the color to something other than pure ruby red. This indicates that the craftsmen mastered the technology incredibly accurately, although they likely did not understand the mechanism. And that they had a heck of a lot of time for all kinds of nonsense;) probably many generations dedicated their lives to experimenting. Because it’s hard to see why all this was necessary.

There’s a beautiful hypothesis (unproven, but popular) that the cup could have been used as a detector. If you pour a different liquid into it (for example, alcohol with impurities or poison), the refractive index changes, and the color of the “flash” might vary.

Exploring Recommender Algorithms Through Interactive Visualizations and Sandbox Simulations | November 11 2025, 05:23

I’ve launched an electronic open source application for my book Recommender Algorithms! It’s a “sandbox” where you can “run” various recommendation algorithms with different settings, and view specific visualizations for each algorithm that help understand how it works. For instance, for algorithms like ItemKNN, SLIM, or EASE, a key visualization is a heatmap of the learned similarity matrix (item-item similarity matrix). This allows you to see which pairs of items the model considers “similar” (or “influencing” each other). For SLIM, for example, a useful “Sparsity Plot” shows that the similarity matrix indeed turned out to be sparse. For associative rule algorithms (Apriori, FP-Growth, Eclat) the visualization is not a graph, but interactive tables with found “Frequent Itemsets” and generated “Association Rules,” which can be filtered and sorted.

Additionally, there is a parametric mechanism for creating a “game dataset” — Dataset Wizard. It works like this – there are template datasets that describe items through characteristics. For example, recipes through flavors. Or movies through genres. The system generates random users with a random set of characteristics from the same set — and there are many sliders to make this distribution more contrasted or complex. Next, a matrix of user ratings of items is created – conditionally, if the characteristics of the user and the item match, then the rating will be higher because “tastes match”; conversely, if they differ, then the rating will be lower. Here too, sliders add noise and scarcity – randomly removing part of the matrix. The characteristics of products and users are not fed into the recommendation algorithm; they are hidden, but they are used to visualize the results.

The third component of the application is the tuning of hyperparameters. Essentially, it’s an auto-configurator for a specific dataset. An iterative approach is used, which is much more efficient than a full search (Grid Search) or random search (Random Search). In short, the system analyzes the history of past runs (trials) and builds a probability “map” (surrogate model) of which parameters will likely yield the best result. Then, it uses this map to smartly choose the next combination to test. This method is called Sequential Model-Based Optimization (SMBO).

The code is open source and will be further supplemented with new algorithms and new visualizations.

Link to the code in the comments.

Link to the site where the code is deployed and where you can check out the application is also in the comments.

The Evolution of the Albanian Virus: From Joke to Cyberthreat | November 07 2025, 14:21

“Hello. I am an Albanian virus, but due to the low level of technology in my country, I cannot do anything to your computer. Please kindly delete one file on your computer and then forward me to other users.”

Here’s the 2025 version. The line they ask to insert into the terminal – echo “” | base64 -d | bash

This line contains curl, pointing to 217.119.139.117 whose result is passed to `nohup bash`. And from this address, a script is loaded, of course obfuscated.

Naturally, no available LLM agrees to decrypt it. But Qwen didn’t mind.

Upon execution, the script gathers information from Chrome, Brave, Edge, Firefox, and others, extracting cookie files, autocomplete history, and system login data, collects crypto wallets like Electrum, Coinomi, Exodus, Atomic, Wasabi, Ledger Live, and others, gathers content from the “Notes” macOS app with attached media files, data from the Keychain (passwords), and also scans the desktop and documents for files of certain extensions. The collected data are archived and sent to a remote server with the IP address 217.119.139.117.

To ensure persistent access, the script creates hidden launch services (LaunchDaemons) with random names, making it difficult to detect. It can download and replace the legitimate Ledger Live application with a modified version.

Such is the Albanian virus)