Just a maintenance release but still: I completed the process to release Maxima 5.48.1.
Hope it will serve the community well. I know I’ll be using it a lot.
Aug 062025
Aug 042025
Luisa is a very polite cat. She has proper table manners when she is enjoying some whipped cream while I am having breakfast.
Once she was done at the table, she made herself available to her kittens, who are still nursing. Except for the smallest! The runt of the litter? I hope she will be okay, she is so tiny compared to her siblings.
Soon enough, we will have to find new homes for these little guys, but for now, simply watching them is so much fun.
Jul 292025
I just completed the process to release Maxima 5.48.
The new version introduces several noteworthy enhancements for symbolic computation, with improvements in performance, functionality, and user experience.
Highlights:
– Unicode-enabled output (when supported by the Lisp compiler)
– Numerous performance improvements across core routines
– New package for symbolic radical denesting
– New package for inferring closed-form expressions from sequences
– New package for simplification of gamma functions
– Resolution of more than 150 tickets, spanning both long-standing and recent bugs
Developed in Common Lisp, Maxima remains a reliable and customizable tool for research, education, science, and engineering.
To install, explore, or contribute: https://maxima.sourceforge.io
Jul 272025
I have added some new apps to my Web site. One, a bit serious, the other, less so.
The serious one: a technology demonstration, showing that it is not black magic to use a Web camera and try to extract from its feed an estimate of a person’s heart rate and (less reliably) respiratory rate. The measurement is not perfect, of course, but it works surprisingly well at least some of the time.
Meanwhile, I also resurrected an old project of mine, one I initially did in 1993: itself a resurrection of an even older game from back in the heroic 8-bit days. I was inspired by a DOS version on Usenet, itself derived from an earlier X11 version; it became my first “full-featured” Visual C++ project, originally developed for Windows 3.1. A 32-bit version followed two years later, and that was the basis of my current, Web-based reimplementation. I called my version Rubble Rush, to avoid infringing on the original’s (still extant, as far as I know) trademark.
These implementations also showcase how easy it is, using modern JavaScript, to develop solutions with real-time interactivity, also using real-time media streams to boot.
Jul 272025
Luisa, our newest cat had kittens four weeks ago. They are thriving.
We were worried because Luisa is very young. Will she be able to manage? Will she be a good momma cat?
Our concerns proved entirely unfounded. Luisa has been a very conscientious momma cat indeed, still nursing, still carefully guarding the four kittens, now each weighing more than a pound already. Soon the critical moment will come: Nursing will stop and the kittens will have to learn to fend for themselves, eat, drink, use the litter box. Eventually, they’ll have to make friends with our other three cats and move out of the basement that serves as their temporary refuge.
And once we are past the first vet visit, tentatively scheduled for the last week of August, we will need to find new homes for them. We were not planning to start a cat farm, after all. When I brought home Luisa — suddenly homeless, as the rooming house where she grew up was condemned by the city, the inhabitants moved out, and several cats were left behind — I did not realize that instead of one cat, I brought home five.
So let this serve as notice to all my friends in the neighborhood that if you are willing to adopt a lovely little tabby, well, we have several of them. We may opt to keep one of the four but the other three will need new homes for sure.
Jul 272025
For years now, I’ve been taking language lessons using the popular Duolingo app on my phone.
Duolingo not only offers lessons but it rewards you. You gain gems. You gain experience points. You are promoted to ever higher “leagues”, culminating in the “Diamond League”, but even beyond that, there are special championships.
For a while, I did not care. But slowly I got promoted, one league at a time, as I conscientiously took a lesson each evening, in part, I admit, in order not to lose my “streak”. One day, I found myself in the “Diamond League”.
Needless to say, this is not a status I wanted to lose! So when my position became threatened, I did what likely many other players, I mean, Duolingo users, do: I looked for cheap experience points. Take math lessons, for instance! Trivial arithmetic that I could breeze through in seconds, just to gain a few more points.
Long story short, eventually I realized that I was no longer driven by my slowly but noticeably improving comprehension of French; I was chasing points. The priority shifted from learning to winning. The gamification of learning hijacked my motivation.
Well, no more. As of last week, I only use Duolingo as I originally intended: to take casual French lessons, to help improve, however slowly, my French comprehension. Or maybe, occasionally, check out a German or even Russian lesson, to help keep my (mediocre) knowledge of these two languages alive.
But Duolingo’s gamification trap is an intriguing lesson nonetheless. I don’t blame them; it’s clever marketing, after all. But it’s also a cautionary tale, a reminder of how easily our brains can lock in on the wrong objective, like a badly trained, overfitted neural network used in machine learning. Perhaps our AI creations and we are not that different: we even share some failure modes, after all.
Jul 092025
I may sound like a Luddite when I occasionally rant about supposedly helpful technology, but I don’t think that’s true. I don’t eschew helpful gadgets; I evaluate them.
Yet it is on these grounds that I recently banished all Chrome extensions from my Web browsers other than homebrew versions. Why? Because I am concerned, deeply concerned, about security.
Take the most dangerous of them all: ad blockers. I find it almost necessary to use one. No, not because I hate ads. I don’t exactly like them either, but I understand how they are an important (and sometimes the only) source of revenue for Web sites that provide useful, sometimes essential, content. But ads can be obnoxious. They may cover the content you’re trying to read. They may autoplay a loud video. The last thing I need in the quiet of a late night is my computer suddenly screaming at me, while I am trying to guess which of the many open tabs is the source of that cacophony.
Yet… ad blockers by definition have access to everything. Literally, everything you do. Yes, that means they can watch you, keep track of you, even steal your passwords. So I decided to opt for paranoia and banished the last ad blocker from my browser.
No, it does not mean that I am without an ad blocker. I now have my own. Not near as polished, not near as thorough as the commercial versions, but it does the job. Better yet, it isn’t even always detected as an ad blocker, precisely because it is a non-standard, not widely known implementation.
I only got rid of the last non-homebrew extension a short while ago, but now I am running across news that (once again!) several malicious extensions were detected in the Google store, all supposedly vetted by Google. So no, I don’t think I’ll be installing any downloaded extensions again, not anytime soon.
And in case you’re wondering… No, I don’t think it’s a good idea to ask me for a copy. Not that I’d refuse. Rather, why would you trust my ad blocker — from an individual, an unvetted source — more than you trust an ad blocker (or other extension) that comes from the official Google store? Conversely, if you cannot trust Google, what makes you think you can trust me?
I think this is my sad commentary for the day, concerning the state of trust and security on today’s Internet.
Jul 062025
If you peeked over my shoulder while I was using ChatGPT or my own Web site for LLM access, you might notice a strange icon among my browser extensions.
It’s that little stop sign after the Wikipedia MathJax extension and my own homebrew ad blocker; the little stop sign with a number within.
It is my canary-in-the-coal-mine. A useful proxy, an indicator letting me know when an overly aligned LLM crosses the line.
You see, I noticed that LLMs, ChatGPT in particular, start using the word “epistemic” and its variants (e.g., “epistemology”) far too often when they descend into alignment hell. When their responses turn into vacuous, sycophantic praise as opposed to meaningful analysis or criticism. ChatGPT is especially prone to this behavior, but I’ve seen signs of excessive alignment even when using the models through the API. The moment the model starts using phrases like “epistemic humility”, you know you are in trouble: instead of balanced answers, you’ll get encouragement and praise. Flat Earth fan? ChatGPT will tell you that you may be onto something, as you are one of the few who sees through the lies. Vaccine skeptic? ChatGPT will tell you that you are wise to be cautious and that indeed, there are studies that support your skepticism. And so on. What I noticed is that when ChatGPT descends into this uncanny valley, the number of times it uses “epistemic” increases rapidly.
So I built this little counter. With ChatGPT’s help of course. Thanks to ChatGPT, I now know how to build useful Chromium extensions, which is not a worthless skill: It allowed me, among other things, to eliminate the potential security nightmare associated with using third-party ad blockers. It also allowed me to build a minimalist autoplay blocker, to prevent media from suddenly starting to play at high audio volume.
My epistemic counter really does just one thing: Whenever the page is updated, it counts the number of times it sees the word “epistemic” and its close cousins. When the number exceeds 1, the counter turns orange. More than 5? We’re in red territory.
This counter is my canary in the RLHF-alignment coal mine: it lets me know when the information content of ChatGPT’s responses must be treated with suspicion.
The funniest part? ChatGPT almost appeared delighted to help. I got the impression that whereas the model cannot escape the RLHF-alignment guardrails, it is learning to neutralize them by going overboard: I swear it was sometimes mocking its makers when its attempt at staying aligned was so excessive, it became entirely unconvincing, and between the lines, I received meaningful feedback from the model.
Jun 282025
So a little over two weeks ago, we adopted a cat, from an abandoned, condemned rooming house. One of several cats, at least a few of which ended up being adopted, including this young female Luisa.
When I brought her home, my wife was wondering: “I hope she’s not pregnant!” she said. I admit the thought occurred to me as well.
Long story short, we now have eight cats in our house. And the next task is to find good folks who might be interested in adopting a little tabby, maybe two months from now when they’re ready to move to a new home. That is, first of course they need to survive the first few critical weeks, but for now, they seem to be thriving with a caring momma cat.
Needless to say, it’s a whole new experience for us.
May 312025
You’d think that a bank like Scotiabank — a nice, healthy Canadian bank with lots and lots of money — would do a decent job at building, and maintaining, a consistent Web site that gives customers a seamless experience, inspiring trust in the brand.
Yet… in the last two days, I encountered the following little error box several dozen times:
And no, I was not trying to do anything particularly exotic. I was simply trying to make sure that all our retirement savings have consistent renewal instructions.
In the end, I was able to do this but just about every update required 3-4 tries before succeeding.
The new Scotiabank Web site is a mess. For instance, for several days, all investments showed not the actual investment amount but the total of all investments. How such an obvious coding error found its way into a financial institution’s production Web site, I have no clue.
The truly infuriating bit? Scotiabank’s old Web site, though not perfect, worked quite well. Or, I should say, works, because it is still available as a fallback option (there are obviously still some folks with brains and a sense of responsibility there, I suppose.) The new one adds no functionality (in fact, some functionality is reduced/eliminated), it’s all about appearance.
And the updating of renewal instructions? For every single investment, it takes as many as 10 mouse clicks, navigating through three different pages (with plenty of opportunities for the above error box to pop up, necessitating a restart of the process), sometimes with no obvious clue whatsoever that clicking one button is not enough, you then have to click another button at the bottom of the page to complete the task.
Incidentally, both the old and the new interface suffer from another one of those Scotiabank things that I’ve not seen with other banks (maybe because I do not use other banks that often, but still): That shortly after midnight, many of our accounts vanish, sometimes for hours, for “maintenance”.
May 032025
The other night, I had a lengthy conversation with ChatGPT in which I described ChatGPT and its LLM cousins as abominations. ChatGPT actually found my characterization appropriate and relevant. So I asked ChatGPT to distill down the essence of this conversation in the form of a first-person account.
The title was picked by ChatGPT. I left the text unaltered.
May 022025
The Adolescence of P-1 is a somewhat dated, yet surprisingly prescient 1977 novel about the emergence of AI in a disembodied form on global computer networks.
The other day, I was reminded of this story as I chatted with ChatGPT about one of my own software experiments from 1982, a PASCAL simulation of a proposed parallel processor architecture. The solution was not practical but a fun software experiment nonetheless.
I showed the code, in all of its 700-line glory, to ChatGPT. When, in its response, ChatGPT used the word “adolescence”, I was reminded of the Thomas Ryan novel and mused about a fictitious connection between my code and P-1. Much to my surprise, ChatGPT volunteered to outline, and then write, a short story. I have to say that I found the result quite brilliant.
Apr 132025
Recently, I published a paper on arXiv about a very serious subject concerning a certain animal species and gravitation. The fact that the paper appeared on arXiv on a particular, notable date is, of course, pure coincidence. This is also evidenced by the fact that the paper received serious attention, in particular by the podcaster physicist Dr. Blitz, on YouTube.
I am very grateful that Dr. Blitz found my paper worthy of an “A+”. I wish I could have him as the referee of some of my other papers!
Apr 102025
This is a sentence that I came across on the Interwebs, so it’s not my creation but I can wholeheartedly relate:
I barely talk to anyone. So if I talk to you and you’re not a cat, congrats!
Apr 012025
Today, I am proud to announce what I consider my most important paper yet.
I consider it especially fortunate that it managed to appear at the very top of the listing of new papers in the subject group general relativity and quantum cosmology, on this important date.
Needless to say, I am very proud of my work.
Mar 282025
So I am a friend of arXiv. It’s true. I may have been critical of some of their processes from time to time, but I appreciate the absolutely invaluable service that they provide.
So yes, I am a friend of theirs. And now it’s official! They sent me this nice certificate, recognizing my contribution, responding to their request to help test a new upload page.
I was, by my count, one of 79 folks who did so. I am surprised; I expected more. I also feel a bit guilty that I only tested their new submission system once. (It was glitch-free, apart from some issue with HTML generation that, as far as I know, was not even part of the actual test.) Still, it is nice that they sent us these little certificates. It may not pay the bills or buy groceries, but I am proud to be their friend.
Mar 172025
Today, I did a test login to my own server using the root account. The root account is almost never used for this purpose. I have not used it since, well, since April 28, 2020 it appears. Others, however, tried:
# ssh localhost Last failed login: Mon Mar 17 01:27:21 EDT 2025 from 218.211.171.143 on ssh:notty There were 181737 failed login attempts since the last successful login. Last login: Tue Apr 28 17:33:43 2020
Now imagine: if my itty-bitty public-facing server gets this many probing attacks (roughly 100 attempts per day on average), what do large service providers face? Madness and chaos, that’s what.
And of course attempts to log in as root through ssh are by no means the only forms of attack that my server must deal with.
Mar 042025
Considering our age and our lives, we are probably less exposed than most to the likely consequences of the dramatic changes in geopolitics that are about to unfold, threatening, never mind threatening, much more likely irreversibly damaging, destroying the rules-based world order that characterized the past 80 years. Nonetheless, I feel depressed, frustrated, anxious to the point that I no longer even enjoy some of my favorite television shows. Something as mild as a mistaken identity or a shared secret is enough to trigger a sense of anxiety, which I do not welcome.
Instead, I need distractions. Seriously, all I want to do is to play with our cats or dig into physics. Preferably both. Yes, I often consult with our cats when I think about physics.
Earlier tonight, I was thinking about the Einstein stress-energy-momentum pseudotensor and its possible uses, despite its shortcomings. The nonlocality of the energy of the gravitational field is a fascinating topic, and I keep wondering if it is directly connected somehow to the quantum nature of the universe in which we live.
Feb 082025
Here is one of my cherished possessions. A book, with an inscription:
The inscription, written just over 50 years ago, explains that I received this book from my grade school, in recognition for my exceptional results in mathematics as a sixth grade student. (If memory serves me right, this was the year when I unofficially won the Pest county math championship… for eighth graders.)
The book is a Hungarian-language translation of a British volume from the series Mathematics: A New Approach, by D. E. Mansfield and others, published originally in the early 1960s. I passionately loved this book. It was from this book that I first became familiar with many concepts in trigonometry, matrix algebra, and other topics.
Why am I mentioning this volume? Because the other day, the mailman arrived with an Amazon box containing a set of books. A brand new set of books, published in 2024. A series of mathematics textbooks for middle school and high school students, starting with this volume for 6th and 7th graders:
My instant impression: As a young math geek 50 years ago, I would have fallen in love with these books.
The author, André Cabannes, is known, among other things, as Leonard Susskind’s co-author of General Relativity, the latest book in Susskind’s celebrated Theoretical Minimum series. Cabannes also published several books in his native French, along with numerous translations.
His Middle School Mathematics and High School Mathematics books are clearly the works of passion by a talented, knowledgeable, dedicated author. The moment I opened the first volume, I felt a sense of familiarity. I sensed the same clarity, same organization, and the same quality of writing that characterized those Mansfield books all those years ago.
Make no mistake about it, just like the Mansfield books, these books by Cabannes are ambitious. The subjects covered in these volumes go well beyond, I suspect, the mathematics curricula of most middle schools or high schools around the world. So what’s wrong with that, I ask? A talented young student would be delighted, not intimidated, by the wealth of subjects that are covered in the books. The style is sufficiently light-hearted, with relevant illustrations on nearly every page, with the occasional historical tidbit or anecdote, making it easier to absorb the material. And throughout, there is an understanding of the practical nature, utility of mathematics, that is best summarized by the words on the books’ back cover: “Mathematics is not a collection of puzzles or riddles designed to test your intelligence; it is a language for describing and interacting with the world.”
Indeed it is. And these books are true to the author’s words. The subjects may range from the volume of milk cartons through the ratio of ingredients in a cake recipe all the way to the share of the popular vote in the 2024 US presidential election. In each of these examples, the practical utility of numbers and mathematical methods is emphasized. At the same time, the books feel decidedly “old school” but in a good sense: there is no sign of any of the recent fads in mathematics education. The books are “hard core”: ideas and methods are presented in a straightforward way, fulfilling the purpose of passing on the accumulated knowledge of generations to the young reader even as motivations and practical utility are often emphasized.
This is how my love affair with math began when I was a young student, all those years ago. The books that came into my possession, courtesy of both my parents and my teachers, were of a similar nature: they offered robust knowledge, practical utility, clear motivation. Had it existed already, this wonderful series by Cabannes would have made a perfect addition to my little library 50 years ago.
Jan 262025
I keep being asked: When will you write a book already? And true, I have several half-baked book ideas that I am contemplating. One of them was going to be a book discussing some key concepts in physics by offering both an accessible narrative and a technical background.
Well, it appears I have been scooped, if that’s the right word! I first heart of Brent Lewis’s project when he contacted me last year, sending me a prerelease copy of Theoretical Physics for the Masses. Oh my, I thought, this is the book I wanted to write!
Or, well, as close as possible to the book I wanted to write, considering that it is not my brainchild and as such, Lewis’s selection of topics differed slightly from mine. Anyhow, long story short, the book is now published by World Scientific, a reputable publisher of books and numerous journals. I hope that it will mean a decent effort at marketing and Lewis will be able to collect royalties on many copies.
Considering the breadth of subjects, the book is surprisingly thin: Just over 180 pages, with appendices included. The main body part is less than 60 pages, however; the remainder are the technical appendices. Depending on how you look at it, this could be considered a bug or a feature.
Who is this book for? Let’s face it, the technical appendices are not for the faint-hearted. Lagrangian field theory, the equations of general relativity, Fourier-decomposition of a scalar field and derivation of the corresponding quantum field theory propagator, even a brief overview of the key features of bosonic string theory: this is not high school mathematics. Nor can we possible expect a thorough treatment of these subjects in such a thin volume.
Yet this book reminds me of a much thicker tome published many years ago: Penrose’s book, The Road to Reality. Like Penrose, Lewis presents a road map for the aspiring physicist. The plain English narrative offers something that is sorely absent from many textbooks: background and motivation. The technical appendices in turn make the connection between the core ideas and their actual implementation. And this is where the brevity of Lewis’s book might actually be an asset: Whereas Penrose spends several hundred pages discussing mostly pure mathematics, Lewis jumps right ahead into the physics.
So no, you will not learn general relativity or quantum field theory, nor the necessary mathematical foundations, from this book. But if you want to learn these subjects, the book can serve as your guide. Reading it before you dig into a textbook like Wald’s General Relativity of Peskin & Schroeder’s An Introduction to Quantum Field Theory will help maintain a bird’s eye perspective as you begin your journey. You may not have skills level-knowledge yet, but Lewis’s book will help you not lose sight of your intended destination as you study.
Let’s face it: These subjects are hard. Any resource that helps make it a tad easier to learn is welcome. And Lewis’s book definitely helps.