Jan 292026
 

A few days ago, I was in for a shock. Something I held as absolutely true, something that seemed self-evident in general relativity turned out to be blatantly wrong.

We learn early on that there is no dipole gravitational radiation, because there is no such thing as intrinsic gravitational dipole moment. Gravitational radiation is therefore heavily suppressed, as the lowest mode is quadrupole radiation.

Therefore, I concluded smartly, an axisymmetric system cannot possibly produce gravitational radiation as it does not have a quadrupole mass moment. Logical, right? Makes perfect sense.

Wrong.

What is true is that an axisymmetric system that is stationary – e.g., a rigid, axisymmetric rotating object with an axis of rotation that corresponds to its symmetry axis – will not radiate.

But two masses in a head-on collision? They sure do. There is even literature on this subject, some really interesting papers going back more than half a century. That’s because there is more to gravity than just the distribution of masses: there’s also momentum. And therefore, the gravitational field will have a time-varying quadrupole component even as the quadrupole mass moment remains zero.

So I took it upon myself to calculate a simple, pedagogical case: two masses on a spring, bouncing back-and-forth without rotation. A neat, clean, nonrelativistic case, which can be worked out in an analytic approximation, without alluding to exotics like event horizons, without resorting to opaque numerical relativity calculations.

Yes, this system will produce gravitational radiation. Not a lot, mind you, but it will.

Once I understood this, I had another concern however. Over the years, surely I must have written answers on Quora promoting my flawed understanding? Yikes! How do I find those answers?

Oh wait. Not too long ago, I built a RAG: a retrieval augmented generation AI demo, which shows semantic (cosine similarity) searches using the totality of my over 11,000 Quora answers up to mid-2025 as its corpus. That means that I can interrogate my RAG solution and that would help me find Quora answers that no keyword search could possibly uncover. So I did just that, asked my RAG a question about axisymmetry and gravitational radiation, and presto: the RAG found several answers of mine, three of which were wrong, one dead wrong.

These are now corrected on Quora. And this exercise demonstrated how RAG works in an unexpected way. Note that the RAG answer is itself wrong, in part because it is faithfully based on my own incorrect Quora answers. Garbage in, garbage out. In this case, though, it meant that the same cosine similarity search zeroed in on my most relevant wrong answers. In an almost picture-perfect demonstration of the utility of a RAG-based solution, it saved me what would likely have amounted to hours of fruitless searching for past Quora answers of mine.

 Posted by at 3:33 am
Jan 282026
 

It was 40 years ago today that the Space Shuttle Challenger exploded some 70 seconds after liftoff, a result of a faulty O-ring design in its solid rocket boosters, combined with an aggressively accelerated launch schedule overriding concerns about freezing temperatures.

It was also one of three tragedies during what is sometimes described as NASA’s “week of tragedy”. The Apollo 1 fire, which killed three astronauts 59 years ago, happened on January 27, and then there is of course the Columbia disaster, which took place on February 1, 2003.

 
 Posted by at 2:25 pm
Jan 282026
 

The other day, my friend John Moffat called me. He told me about a letter that he received the day before. An old school letter, paper-in-an-envelope, brought by the mailman.

A letter from the Prime Minister of Canada.

In these sad days, we have to question the authenticity of everything but no, this letter was the real thing: an actual letter, on embossed letterhead, with a handwritten signature.

I don’t know what prompted the Prime Minister’s office to send this letter to John. I refuse to speculate.

The letter itself stands on its own. It is a very dignified recognition of John’s amazing (and amazingly long!) career as a physicist, and a true note of appreciation that he decided to live his incredible life in this great country, Canada.

Congratulations, John. Perhaps you deserve more recognition. You definitely deserved this. And keep up the good work. I am rooting for you: perhaps I’ll be there when you celebrate your 100th birthday, still in good health and good spirits, still working on MOG/STVG, your nonlocal quantum field theory, your complexified manifold proposal and other intriguing ideas!

 Posted by at 2:32 am
Jan 272026
 

I have been thinking a lot (who hasn’t?) these days about the state of the world, in particular the United States.

Many people I know would like to see Trump gone. Can’t blame them. Unfortunately, I think the mess is deeper, and older than Trump’s presidency. Indirect roots go back decades. Trump is a symptom, maybe an accelerant, but not the cause. And even if he were to vanish tomorrow, the problems would remain.

Looking at the totality of events, from Minneapolis to Venezuela, from Davos to Mar-a-Lago, I realized that I am looking at a system that is under stress. Complex systems neither slide into chaos slowly nor crash instantly: they may reach the point of no return yet show only few outward signs of impending collapse until it actually happens.

A sad apolitical example is Chernobyl: The reactor’s fate was sealed when they removed the last few control rods, but for another minute and a half, everything seemed normal. They could even conduct the test that was the whole point of the exercise that ultimately led to disaster. When the operators finally pressed the famous AZ-5 shutdown button, triggering a series of explosions, it was just the closing act of a play that already had a predetermined outcome. Button or no button, the reactor was already primed for a thermal excursion and eventual explosion.

A replica AZ-5 button sold by the Chornobyl shop.

What is common in these cases is that the moment of no return represents the last moment in time when the system could still redundantly absorb or redistribute stress. It does not collapse instantly afterwards: things may start to SNAP, but it takes a while before the failure of individual pieces turns into a cascading collapse. Meanwhile, those in charge may still be under the illusion that they are in control, when in reality, the system is already in an irreversible, runaway state.

In that light, I think I might be able to put my finger on the precise moment when the US reached the point of no return, the first SNAP. It was early summer 2024, when the system failed to sentence Trump despite the criminal convictions. It was, quite simply, too slow. From that moment onward, America’s famed system of “checks and balances” could no longer keep up with events. The system broke even though from the outside, it still appeared, still appears to be functioning. It’s only now that the SNAPs are becoming a cacophony, with new outrage happening every day.

What we now have in the US – ICE effectively above the law, the militarization of federal enforcement even against local authorities, unilateral presidential action on everything from wars to tariffs with no checks on presidential power, weaponization of institutions of law enforcement, open corruption (e.g., Trump’s cryptocurrency, Venezuelan oil money to Qatar) – will not go away with Trump. There will be others – people who will be more determined and more talented than Trump! – exploiting these things. The system, which has been under stress ever since (at least) the days of Gingrich is, in my reading, broken already, and no event will magically repair it. To my untrained eye, I’d say the US ceased being a free democracy sometime in 2025 and became a hybrid regime, a “competitive authoritarian” state. Internationally, as Carney observed, Pax Americana is history: Instead we have a new world order that in many ways resembles the years before 1914, though hopefully with a saner outcome. (I am not terribly optimistic. As Carney said, you’re either at the table or you’re on the menu. That’s not a prescription for sanity.)

So… I cherish the past 80 years. It’s been an incredible period in human history. But I think it’s come to an end.

 Posted by at 4:22 am
Jan 132026
 

His views were notably controversial, especially in these troubled, polarized times. But his cartoons delighted millions, myself included.

Rest in peace, Scott Adams. Along with Catbert, we mourn you.

 Posted by at 2:49 pm
Jan 092026
 

Been a while since I blogged about politics. Not because I don’t think about it a lot… but because lately, it’s become kind of pointless. We are, I feel, past the point when individuals trying to raise sensible concerns can accomplish anything. History is taking over, and it’s not leading us into the right direction.

Looking beyond the specifics: be it the decisive US military action to remove Maduro in Venezuela (and the decision to leave Maduro’s regime in place with his VP in charge), the seizure of Russian-flagged tankers, yet another Russian act of sabotage against undersea infrastructure in the Baltics (this time caught red-handed by the Finns), the military situation in Ukraine, the murder of a Minnesota woman by ICE agents, more shooting by US customs and border protection agents in Portland…

Never mind the politics of the day. It’s the bigger picture that concerns me.

Back in the 1990s, I was able to rent a decent apartment here in Ottawa, all utilities included, for 600-odd dollars. It was a decent apartment with a lovely view of the city. The building was reasonably well-maintained. Eventually we moved out because we bought our townhome. The price was well within our ability to finance.

Today, that same apartment rents for three times the amount. Our townhome? A similar one was sold for five times what we paid for ours 28 years ago. Now you’d think this is perfectly normal if incomes rose at the same pace, perhaps keeping track with inflation. But that is not the case. The median income in the same time period increased by a measly 30%, give or take.

This, I daresay, is obscene. It means that a couple in their early 30s, like we were back then, doesn’t stand a chance in hell. Especially if they are immigrants like we were, with no family backing, no inherited wealth.

In light of this, I am not surprised by daily reports about rising homelessness, shelters filled to capacity, food banks struggling with demand.

What I find especially troubling is that we seem hell-bent on turning cautionary tales into reality. For instance, there’s the 1952 science-fiction novel by Pohl and Kornbluth, The Space Merchants. Nowadays considered a classic. It describes a society in which corporate power is running rampant, advertising firms rule the world, and profit trumps everything. Replace “advertising” with “social media”, make a few more surface tweaks and the novel feels like it was written in 2025. When the narrative describes the homeless seeking shelter in the staircases of Manhattan’s shiny office towers, I can’t help but think of all the homeless here on Rideau Street, just minutes away from Parliament Hill, in the heart of a wealthy G7 capital city.

Or how about a computer game from the golden era of 8-bit computing, one of the gems of Infocom, the leading company of the “interactive fiction” (that is, text adventures) genre? I am having in mind A Mind Forever Voyaging, a game in which you play as the AI protagonist, tasked with entering simulations of your town’s future 10, 20, etc., years hence, to find out how bad policy leads to societal collapse. When I read their description of the city, I am again reminded of Rideau Street’s homeless population.

In one of his best novels, the famous Hungarian writer Jenő Rejtő (killed far too young, at 37, serving in a forced labor battalion on the Eastern Front in 1943, after being drafted on account of being a Jew) has a character, a gourmand chef, utter these words: “The grub is inedible. Back at Manson, they only cooked bad food. That was tolerable. But here, they are cooking good food badly, and that is insufferable.” The West is like that today. It’s not “bad food”: our countries are not dictatorships, not failed states governed by corrupt oligarchs, but proper liberal democracies. Yet, I feel, they are increasingly mismanaged, unable to deliver on what ought to be the basic contract between the State and its Subjects in any regime.

What basic contract? Bertold Brecht put it best: “Erst kommt das Fressen, dann kommt die Moral“, says Macheath in Kurt Weill’s Threepenny Opera: “Food is the first thing, morals follow on.” A State must deliver food, shelter, basic security, a working infrastructure, and a legitimate hope that tomorrow will be better (or at least, not worse) than today.

A State that fails at that will itself fail. A State that succeeds at this mission will survive, even if it is an authoritarian regime. In fact, if the State is successful, it does not even need significant oppression to stay in power: it will, at the very least, be tolerated by the populace. (I grew up in such a state: Kádár’s “goulash communist” Hungary.) The liberal West may only forget this at its own peril.

What happens when the basic contract is violated? People look for alternatives. They may become desperate. And that’s when populist demagogues arrive on the scene, presenting themselves as saviors. In reality, they have neither the ability nor the inclination to solve anything: they feed on desperation, not solutions.

In contrast, successful States, liberal democracies and hereditary empires alike, share one thing in common: the dreaded “deep state”. That is to say, a competent meritocratic bureaucracy, capable of, and willing to, recognize and solve problems. A robust bureaucracy can survive several bad election cycles or even generations of bad Emperors. Imperial China serves as a powerful example, but we can also include the Roman Principate and later, Byzantium. Along with other examples of empires that remained stable and prosperous for many generations.

No wonder wannabe despots often target the “deep state” first. A competent meritocratic bureaucracy, after all, stands in their way towards unconstrained power. Thinning out the ranks, hollowing out the institutions is therefore the top order of the day for the would-be despot. It’s not always true of course. Talented despots learn to rely on the competent bureaucracy as opposed to eliminating it. But talented despots are not myopic populist opportunists. They are that rare kind: empire builders. Far too often, the despots we encounter lack both the talent and the vision to build anything. They just exploit the pain, and undermine the very institutions that can alleviate that pain.

This is what we see throughout the West in 2026. Even as the warning signs get stronger—among them rising wealth and income inequality, an oligarchic concentration of astronomical wealth in just a few hands, rising homelessness, decaying infrastructure, an increasingly fragile health care system, rising indebtedness, lack of employment security—there appears to be way too little appetite for meaningful structural solutions. Instead, we get easy slogans. “It’s the damn immigrants,” says one side while the other retorts with a complaint about “white supremacism,” just to name some examples, without implying moral equivalence. The slogans solve nothing: they do create, however, the specter of an “enemy” that must be eliminated, an “enemy” from whom only the populist can protect you.

One of the best records of one of my favorite bands, Electric Light Orchestra, was the incredibly prescient concept album Time, released in 1981. In addition to predicting advanced, well-aligned AI in such a way that feels almost uncanny in detail (“She does the things you do / But she is an IBM / She’s only programmed to be very nice / But she’s as cold as ice […] She tells me that she likes me very much […] She is the latest in technology / Almost mythology / But she has a heart of stone / She has an IQ of 1001 […] And she’s also a telephone“) they also describe a future that is… hollow: “Back in the good old 1980s / when things were so uncomplicated” – in other words, when Western liberal democracies still understood how to deliver on that basic contract, Brecht’s “basic food position“.

 Posted by at 1:03 am