US Visa Freeze for 75 Countries Amid Public Charge Concerns | January 14 2026, 15:23

If Fox News is to be believed, the US State Department is indefinitely suspending the processing of all types of visas for citizens of 75 countries, including Russia. Supposedly these measures will come into effect on January 21, 2026, and will remain in force until the department completes a full reassessment of verification procedures. It is stated that exceptions to this rule will be extremely rare and possible only after a thorough completion of all checks.

The reason is the aim to tighten the fight against “potential burdens on the American social security system”. Consular officers must deny visas to those who may become a “public charge”. Age, health status, English language proficiency, and financial situation are among the criteria.

P.S. Curious why there are so many chairs. Ten minutes ago, I sent Nadya a message on iMessage (!) “let’s buy a chair for mom on Ozone” after discussing chairs with mom on Signal. It seems like iMessage has not been known for leaking topics. Before this, I had no interest in chairs at all for many many years. Either advertising networks adapted quickly or it’s such a coincidence, I don’t know.

Harnessing GPU Power Beyond Machine Learning: A Data Processing Experiment | December 13 2025, 01:16

Torturing my supercomputer. Illustration that the GPU is not just for machine learning and some complex math.

My script takes a thick English dictionary (Webster) and multiplies it by 30, creating a list of 12 million words. Then, the algorithm looks through all 12 million words and replaces all the vowels with asterisks using regex. To add more load, a “word length” column is added, and then we take words longer than 10 letters and find the most frequent (top 5).

So, in Python this is

df[‘masked’] = df[‘text’].str.replace(r'[aeiou]’, ‘*’, regex=True)

df[‘len’] = df[‘masked’].str.len()

res = df[df[‘len’] > 10][‘masked’].value_counts().head(5)

and this code is executed first through the main processor, then through a GPU.

The main processor (I have the top-tier Intel i9 285k) completes this task in 24 seconds, while the Nvidia RTX 5090 does it in 0.51 seconds. That’s a 46 times difference!

[Pandas CPU] Top Patterns:

masked

s*r w. sc*tt. 23280

s*r t. br*wn*. 23220

j*r. t*yl*r. 16140

bl*ckst*n*. 10860

b***. & fl. 10830

Name: count, dtype: int64

[Pandas CPU] Computation Time: 23.5596 sec.

Transferring data to GPU…

Transfer complete in 1.16s

— Running Benchmark: cuDF GPU —

[cuDF GPU] Top Patterns:

masked

s*r w. sc*tt. 23280

s*r t. br*wn*. 23220

j*r. t*yl*r. 16140

bl*ckst*n*. 10860

b***. & fl. 10830

Name: count, dtype: int64

[cuDF GPU] Computation Time: 0.5108 sec.

TOTAL SPEEDUP: 46.12x

Comparing US and Russian Higher Education Systems through Credit Hours | December 10 2025, 17:35

Regarding education in the USA and the USSR/Russia. My degree in the USA is evaluated as a Master of Science degree in Computer Science. My younger colleagues say that a Russian university degree is rarely recognized as a Master’s these days, and often hardly qualifies even for a Bachelor’s. I decided to look at the numbers and was very surprised.

To earn a bachelor’s degree in the USA, you need to spend about 2000 hours in classrooms/laboratories. In terms of credits, this equals 120 credit hours. One credit usually equals 1 hour (50 minutes) of lectures per week for a semester (15 weeks). Laboratory work has a different coefficient (often 2–3 hours in the lab count as 1 credit), so the actual number of classroom hours is slightly higher (closer to 2000+).

So, my diploma states that I spent 7908 hours in classes over five years. That’s four times more than the typical student in the USA. Based on the numbers, it turns out that I spent about 2000 hours on math, physics, and English alone over five years, with a total of 42 subjects.

A colleague shared that in his Russian bachelor’s diploma there are 3140 academic hours, which is twice as less. And can you share how many hours are in your diploma?

Year of graduation, university, specialty, and the number of hours? I’m curious about the range of variation.

Navigating Complexity: The Challenge of Wikipedia’s Expert-Driven Content | November 26 2025, 01:06

Wikipedia has one big problem. Well, or we have it with Wikipedia. If you go to almost any Wikipedia page about a relatively complex mathematical or physical concept, you often suddenly don’t want to read it any further. Formally everything is correct there, but the explanation is given through concepts, often even more complex than the concept being explained. Besides, there is often a lot of unnecessary information — what is formally/academically/taxonomically part of the topic, but essentially “pollutes” the first impression.

This problem arises because the authors of Wikipedia (often mathematicians) prioritize rigor and completeness rather than didactics and comprehensibility.

In the English-speaking environment, this is sometimes called “Drift into pedantry”. Articles are often written by experts for experts, not for those who are trying to learn the subject from scratch.

Let’s take, for example, a “tensor”. Imagine a student who has heard that tensors are used in machine learning (Google TensorFlow) or physics and wants to understand the essence.

What the reader expects (intuition): “A tensor is a table of numbers (or some sort of data container) that describes the properties of an object and correctly changes if we rotate the coordinate system”

What Wikipedia provides: “A tensor (from Latin tensus, ‘strained,’ as per the classical layout of mechanical stress at the sides of a deformable cube, see illustration) — is a layout (arrangement in space) of numbers (components), used in mathematics and physics as a special type of multi-index object, possessing mathematical properties.” The article immediately starts listing ranks, covariance and contravariance of indices. This is formally correct but it “pollutes” the first impression.

The illustration at the very top is captioned like this: “Mechanical stress, deforming a cube with faces perpendicular to the coordinate axes, in classic elasticity theory is described by the Cauchy stress tensor, which links 2 indices: the normal vector to the face with the stress vector T (force per unit area); there are 3 directions of normals and 3 directions of stress components, which gives a 2nd rank tensor 3×3 — consisting of 9 components.”

Formally — not a single error. In fact — it’s a wall of text that requires knowledge of linear algebra just to read the definition.

It’s as if you asked “What is an apple?”, and you were responded with: “An apple is a fruit of plants from the subfamily Amygdaloideae or Spiraeoideae, featuring an epicarp, mesocarp, and endocarp, often participating in Newton’s gravitational experiments.”

On one hand, it seems like with the emergence of LLM, Wikipedia is no longer necessary. There are conditional LLMs like ChatGPT, which essentially paraphrase everything that is in Wikipedia in the required form. But they do it because they were trained on Wikipedia, and undoubtedly Wikipedia was given much more weight during training than other internet junk. If there was no Wikipedia in the training set, it would be much more difficult. Meanwhile, Wikipedia is constantly edited, and LLM and Google use it exactly when answering questions.

Therefore, on the one hand, it seems to me that it is high time for Wikipedia to transition to generating on the basis of expert-curated data and packaging knowledge in the required format, for example, in the form of questions and answers. On the other, the whole idea of encyclopedia master-data for LLM/RAG is lost.

The paradox is that LLM is, in essence, the only “interface” that was able to read these pedantic definitions of Wikipedia, “understand” them (through thousands of examples of code and articles) and translate them back into humane language. Wikipedia has become an excellent database for robots, but a poor textbook for people.

Crafting the Future of Recommender Systems: A Deep Dive into Algorithms and Implementation | September 26 2025, 21:17

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.

Decoding “Carboy”: A Journey Through Language and Autobiography | August 20 2025, 04:02

Rereading Feynman’s autobiography, this time in English, and my eyes stuck on the word carboy. It turns out that it’s the same as lady jeanne, and the same as demijohn – essentially lady jeanne in French (dame joanne). In short, it’s just a bottle.

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.

Unveiling the Mystery of the Original Declaration of Independence | July 04 2025, 02:36

Tomorrow is July 4th – Independence Day.

I’m currently reading about it. It turns out that the authentic Declaration of Independence is lost to history, and the document labeled “Original Declaration of Independence” in the National Archives is actually a copy.

By the way, about 80% of the text of the declaration lists why the king is bad. Literally. He doesn’t do this, he doesn’t do that, he forgot about us here, he didn’t remember there. It’s just a straight protest of no kings. The last paragraph of the long text essentially says, in sum, forget him. We want to handle it ourselves.

Jefferson prepared the draft of the Declaration of Independence with all the usual revisions—crossed out words, inserts in the gaps, etc., all written in his poor handwriting. This document exists and is very interesting.

The rest of the committee approved the text, and Jefferson then created a fair copy (still in his bad handwriting and just the size of a regular sheet), which was presented to Congress, voted on, adopted, and received its first signatures. This “fair copy” was the real original Declaration of Independence—and it is precisely this one that is lost.

Later, Congress decided that a version suitable for publication was needed—bigger and, of course, not written in Jefferson’s terrible handwriting. For this, they hired a professional copyist. When he made his copy, Congress held a re-signing. This version by the copyist has the label “Original Declaration of Independence” on the back and is the one currently displayed in the National Archives. It was “original” only in the sense that it served as the master copy for printing.

So what happened to Jefferson’s “fair copy,” the genuine original Declaration of Independence? No one knows. It might still be somewhere in the archives, lost among other documents. Or perhaps someone took it home and preserved it, or maybe it was destroyed by time and circumstances, such as when the British burned Washington.

In 1989, a man named Michael Sparks bought an old painting at a flea market in Pennsylvania for $2.48. When he removed the frame, he discovered a rolled-up piece of paper behind it. This turned out to be one of the rare “Dunlap Broadsides”—the first 200 printed copies of the U.S. Declaration of Independence, printed on the night of July 4 to 5, 1776, by John Dunlap.

This find was in excellent condition and was sold at a Sotheby’s auction in 1991 for 2.42 million dollars (and later resold for even more). This isn’t Bitcoin!

A bit about the dates. On July 2, Congress voted for independence. Not the 4th. On July 4, it was formally ratified by Congress, they spent two days making minor formal amendments, having already decided on the substance. No signatures yet. The date on the document, of course, is the 4th. Copies were printed and sent out the next day. Eventually, the ones sent out were signed by the delegates only on August 2.

Three of the first five American presidents died on this day. Jefferson, Adams, Monroe. Jefferson was in fact the father of this declaration, with Adams, they found the time. So maybe July 2nd would be a more appropriate day to celebrate.

Yes, also—technically—America did not gain independence in 1776. It happened only after the signing of the Treaty of Paris (September 3, 1783), when Britain said: “Alright,” and recognized America as a separate state.

If the War of Independence hadn’t turned in favor of America, Washington (like most of the founding fathers) would likely have been executed for treason. But since it turned out otherwise, they picked that day.