Nov 302019

Not a day goes by in Ottawa this autumn without news of yet another service interruption with our brand new light rail transport system.

You’d think that reliably operating an urban rail network is not exactly high science in 2019; especially considering that 60 years earlier, this town had an extensive network of streetcars, which operated reliably for 68 years.

Sadly, that network fell victim to the myopic urban planning trends of the postwar years, which also saw streetcar networks destroyed, or at the very least, severely diminished, as in the case of my city of birth, Budapest, where, for instance, a once popular streetcar line was replaced by an overpass carrying vehicular traffic to an already congested downtown core.

And now we have an LRT that is made unreliable, in part, by a risk-averse culture in which an entire urban transportation system is shut down because of a single door’s failure to close properly.

 Posted by at 10:46 am
Nov 172019

The other day, I used an analogy to describe the likely result of trying to understand a scientifically or technologically complex issue from the media, from political pundits.

Imagine you lived your entire life in a windowless room, but you heard that outside your room, there is this thing called the sky, and it has a color. But you hear conflicting opinions. One side insists that the sky is red, absolutely red, has never been anything other than red, redder than a boiled lobster’s arse as a matter of fact. The other side tells you that the sky is, and has always been, green and anyone who ever said that it was red is a liar, a cheat, committing a crime against humanity.

So by carefully considering both sides, cautiously and meticulously balancing the conflicting views, you finally arrive at the conclusion that the color of the sky is… What exactly?

Chances are that you will never guess its true color.

But wait, it gets even worse. In real-life debates, it is not always red-sky vs. green-sky. Sometimes it is red-sky vs. blue-sky. That is to say that at least some of the time, one side will, in fact, be representing the truth (or at least a reasonable facsimile of the truth.) By giving both sides a balanced opportunity to convince you, then, you are in fact farther from the truth than you would be if you had simply picked the right side in the first place. But how would you know which side is right?

In the end, you’d have to make an actual observation or read the scientific or technical literature, instead of listening to pundits. But this puts you in a difficult situation. Stuck between the red-sky and the green-sky side, you’ll learn what it’s like not to have any friends. But getting stuck in the red-sky vs. blue-sky debate makes it even worse, because now the red-sky folks will see you as just yet another diehard biased blue-sky fan, while the blue-sky folks will think that you are one of them, that you bought into their religion instead of arriving there by way of sound reasoning, and the moment you actually contradict some aspect of their dogma, you will be branded a traitor or worse.

Welcome to the post-truth world.

 Posted by at 3:04 pm
Nov 102019

Last night was the 30th anniversary of the beginning of the demolition of the Berlin Wall.

It was a momentous event. I spent days glued to CNN, watching things unfold and wondering if I was witnessing the beginning of a new world order or prelude to nuclear Armageddon.

Yet here we are, three decades later, alive and kicking, and still no world war in sight (though looking at global politics in the past decade, I cannot say that I am not worried.)

For now, though, here is a nice picture with which to celebrate, courtesy of a Twitter account dedicated to giant military cats.

 Posted by at 9:48 am
Nov 032019

OK, these days I tend to have mostly liberal political views. Trump gives me the creeps. Though not with great enthusiasm, but I rooted for Trudeau over Scheer. More broadly, I prefer a welcoming, open, tolerant society over one that is isolationist and xenophobic. I prefer a comprehensive social safety net even at the expense of higher taxes. And as a middle-aged white man, I am not the least bit worried that I am being marginalized by women or visible minorities; quite the contrary, my concern is that both women and minorities still often face prejudice and stereotypes, and have to fight uphill battles.

But every once in a while, I run into things that just make me want to root for Trump. As in, “in your face, you clowns”.

Like, when, a license plate that clearly alludes to a Star Trek meme is suddenly banned because some social justice warrior finds it offensive.

A perfectly ordinary English word is now banished from Manitoba license plates because it happened to remind someone of the sad history of aboriginal Canadians.

Yes, it seems that resistance is indeed futile. When SJWs arrive, you will be assimilated. And you will not even be allowed to say so, because the word itself gets banned and you’re only allowed to use words from the list approved by Ministry of Tolerance or whatever.

Darn it, let me present my own, slightly modified version of this license plate, appropriate for this occasion I believe:

Just to make it clear, it is not my intent to make light of the suffering that Canada’s aboriginal population experienced for many generations. The cultural genocide, sexual abuse, forced assimilation, broken up families, broken lives, economic deprivation, not to mention all the things that are still going on, from chronic unemployment and inadequate medical care to the lack of clean drinking water (in a supposedly first world country!)… These are all real tragedies, tangible problems and it is Canada’s shame that they remain largely unsolved in 2019.

But none of these problems will be addressed by this cottage industry of phony outrage over ridiculous things like a dictionary word on a bleeping license plate or the words of a 1940s popular song. If anything, letting people supply their own context and find offense in everything achieves the exact opposite. It cheapens genuine, real concerns and subjects them to ridicule, ultimately harming the very people that these fearless warriors of political correctness are pretending to defend. In reality, of course, that’s not what they are doing. Rather, they are Trump’s counterparts on the opposite end of the political palette: narcissistic poseurs, infantile hypocrites playing the self-aggrandizing role of valiant defenders of the faithful.

 Posted by at 2:15 pm
Oct 232019

World, please say hello to my Donald Trump letter generator, which allows you to create and print letters in the style of the free world’s fearless leader’s most recent missive to the Turkish President.

Here is one example. Guess the date is a little off; the meme generator always uses today’s date.


[All processing is done by your browser. No information is sent to my server.]

 Posted by at 10:08 am
Oct 112019

I just saw the news: Alexei Leonov died.

Leonov was a Soviet cosmonaut. The first man to ever take a spacewalk (which, incidentally, nearly killed him, as did his atmospheric re-entry, which didn’t exactly go as planned either.)

Leonov was also an accomplished artist. Many of his paintings featured space travel. Here is a beautiful picture, from a blog entry by Larry McGlynn, showing Leonov with one of his paintings, in 2004 in Los Angeles.

So Leonov now joins that ever growing list of brave souls from the dawn of the space age who are no longer with us. Rest in peace, Major General Leonov.

 Posted by at 2:01 pm
Oct 112019

I just came across this XKCD comic.

Though I can happily report that so far, I managed to avoid getting hit by a truck, it is a life situation in which I found myself quite a number of times in my life.

In fact, ever since I’ve seen this comic an hour or so ago, I’ve been wondering about the resistor network. Thankfully, in the era of the Internet and Google, puzzles like this won’t keep you awake at night; well-reasoned solutions are readily available.

Anyhow, just in case anyone wonders, the answer is 4/π − 1/2 ohms.

 Posted by at 12:10 am
Sep 302019

One of the few news shows I still watch is Reliable Sources on CNN, a weekly backgrounder on Sundays.

Yesterday, Robert De Niro was interviewed in one segment.

He certainly did not hide his opinion about Fox News. Gave me a good chuckle, too, but then I remembered why he was saying what he was saying and it no longer felt funny at all.

 Posted by at 9:26 am
Sep 172019

I just came across the name of an artist, a painter, that I never heard before: Vilhelm Hammershøi (1864-1916) of Denmark.

Amazing paintings. Here is one example.

I find the subdued, melancholic atmosphere of his works irresistible. If I had the talent (which I most decidedly lack), this is what I would paint.

 Posted by at 3:43 pm
Sep 162019

Very well, I’ve been had. I lost all my bitcoin savings.

Don’t worry, it was not much. Approximately 0.0113 bitcoins. Just over a hundred US dollars at current exchange rates. And it’s not like I didn’t know from the onset that something fishy was going on. Of course I was not planning to hand over my hundred bucks to a scam artist, but I figured the learning experience was worth the risk. I had no idea how things would play out, except for one thing: I knew I was not going to get richer, but my risk was limited to my meager bitcoin holdings.

Here is how it began. I became acquainted with an Neale H. Spark* on Quora. At first, we exchanged some private messages, in part about some of the answers I wrote. But soon, he started talking about the business he is in, cryptocurrency. He seemed legit: I looked him up. A cryptocurrency expert, member of a listed cryptocurrency company’s advisory board. He asked if I wanted to invest some bitcoins into cloud mining, because supposedly, I can make “8% a day”.

OK, red flags are up. Nobody, and I mean nobody, is paying you 8% daily interest. That this was a scam, of that I had no doubt, but I just couldn’t resist: I had to understand how the scheme worked.

It so happened that I actually had some bitcoins, those 0.0113 BTC, in a bitcoin wallet. So what the heck… let’s play along.

As soon as I agreed to become his victim (not that he called me that, mind you), this Mr. Spark kindly set up a “mining enabled” bitcoin account for me at He provided me with all necessary details and soon enough, I was able to manage the account. I then transferred my bitcoin holdings from my other wallet to this one.

And within 24 hours, I received about 0.0008 bitcoins. And again, 24, 48, 72 hours later. I was told by Mr. Spark that this money is not completely free money: that there will be a “mining fee”, which sounded odd because how can they charge any fee to my bitcoin account? But you know what, let’s see what happens. Indeed, after about a week of regular, daily payments, four days ago I actually got charged about 0.0008 bitcoins. But the payments continued: after two more payments, my bitcoin holdings were getting close to double my initial investment.

Meanwhile, Mr. Spark called me several times on the phone. It was always a bad connection, suggesting to me that he was using a VoIP phone, but for what it’s worth, his calls came from a California number consistent with his place of residence. He was advising me that I should invest a lot more; that investors who put in a full bitcoin or more (that would be $10,000 US) are doing much better. I told him that I’d think about it. He asked when I might make my decision. I said he’d be the first to know. He did not sound happy.

Indeed, the phone calls stopped and for the past two days, I received no e-mail notification of payments in my bitcoin wallet either. So earlier today, I went to check the wallet, and whoops: all my bitcoins are gone. The wallet has been zeroed out two days ago.

I sent this Mr. Spark a Quora message but I am not expecting a reply. On the other hand, I think I can reconstruct what actually happened, so my bitcoins were, after all, well spent: I did learn some intriguing details.

For starters, I am pretty certain that the Quora account doesn’t actually belong to the real Neale H. Spark. I tried to find information online about Mr. Spark but I was unable to locate a valid e-mail address or social media account. The person is undoubtedly real, mentioned in a 201█ press release by G█████ T███████████ as a newly minted member of their advisory board. But Mr. Spark seems like a rather private person with little visible online presence.

The Quora account was only created about a month ago. It has very low activity.

The aggressive sales tactics seemed odd from a noted expert, and represented another indication of fraud. But how exactly was the fraud committed?

Here is how. It all started when “Mr. Spark” kindly set up that “mining-enabled” Bitcoin wallet for me on I knew something was not kosher (what exactly is a “mining enabled” account, pray tell?) but in my ignorance of the technical details of cryptocurrency wallets, I could not quite put my finger on it. When I received the account info, everything checked out and I was able to secure the account, restricting transactions with two-factor authentication and even by IP address.

However, unbeknownst to me, “Mr. Spark” must have copied down the wallet backup phrase: twelve words. The company warns me: Anyone with access to my backup phrase can access my funds. What I didn’t know is that the backup phrase can be used anywhere. They need not access the wallet through; with the appropriate cryptocurrency software, they can recreate the wallet and empty it.

Which means that my entire wallet was compromised from the onset. Never mind the steps that I took, setting up two-factor authentication and all… It was never really my wallet to begin with.

The big warning sign was when the crook first processed a “mining fee”. I did not understand the details, but I knew that something was wrong. No third party can take money from your bitcoin wallet, “mining enabled” or otherwise. Yet at the same time, I continued to receive small payments, so I was still waiting for the other shoe to drop.

I guess eventually “Mr. Spark” decided that I am unlikely to invest more into his scheme, but more likely, I was not his only or biggest victim. You don’t set up an elaborate scam like this, with a fake social media account, fake phone number and all to just steal a hundred bucks from someone. (That would be a less effective, and certainly more risky, way of making money than working at minimum wage.)

There is the usual, “if it’s too good to be true” lesson here: Nobody is going to pay you 8% interest a day. OK, I knew that. I also knew that cloud mining is a very risky proposition, the returns are not spectacular and fraud is rampant. I didn’t have to spend a hundred bucks to learn this.

But there is also a valuable technical lesson. I had zero experience with cryptocurrency wallets in the past, and thus I did not realize that anyone setting up the wallet basically has a permanent, irrevocable key to that wallet. And when a sum, however small, goes missing from your bitcoin wallet, it is a guaranteed indicator that the wallet is compromised.

There is also another other thing that I did not realize until today. Namely that the Spark account on Quora is almost certainly a fake, an impersonation. In fact, it was not until I actually asked myself, “how can this chap commit such fraud under his own name?” that I came up instantly with the obvious answer: he didn’t. Rather, a scamster used the name and credentials of a respectable but social media shy expert to set up shop and rip off his victims. That I did not think of this possibility earlier is a consequence of my prejudice. I had very low expectations to begin with, when it comes to people in the speculative cryptocurrency business. So neither the cheap VoIP line nor the pushy behavior raised additional red flags: I was wondering what scam the real Neale Spark was dragging me into, I did not expect to be dealing with an impostor.

*Name altered to protect the privacy and reputation of the person who was impersonated.

 Posted by at 7:49 pm
Sep 132019

My favorite cartoons are Kliban’s cats, but the Dilbert comic strips represent a close second.

Today’s Dilbert offers a perfect demonstration why.

I could actually be the consultant that Dilbert’s pointy-haired boss is looking for. Over the years, I learned one very important thing about this business: As a consultant, my job is to offer my best advice to my customer, but then whatever decision they make, it’s theirs to make, not mine. My job is to continue supporting them to the best of my abilities.

In my career, I have seen customers make bad decisions that destroyed their projects. I offered my advice. When it was ignored, I did not take it personally. Neither that nor judging the customer are part of my job description. That is not to say that I do not feel regret, or that I did not often second-guess myself: Could I have offered better advice? Could I have been more convincing? Why was my advice not accepted?

But judging? Nope. That would be rather unprofessional.

 Posted by at 12:02 am
Aug 222019

The rainforest of the Amazon burns, like it never burned before.

Image credit: NOAA

And nobody gives a flying fig.

I am officially done. I am in my fifties. I don’t have children. I don’t frigging care what the planet will look like 50 or 100 years from now. I don’t plan to be a jerk: I won’t intentionally pollute, but from now on, I no longer care either. If those who are (much) younger than I, those who have children who will inherit this planet are unconcerned, why on Earth should I worry?

The fact that there is no global outrage, no emergency session of the Security Council, no economic sanctions, no threat of an international intervention, just (apart from social media and a few published articles) deafening silence tells me all I need to know.

Screw the planet, my fellow inmates living on this planet are telling me, and finally, I listen.

 Posted by at 11:20 pm
Aug 212019

I am reading an article in The Register about a major Internet outage that occurred last December, when a handful of rogue packets managed to clog up a backbone network for more than a day and a half, blocking even VoIP 911 calls.

There are two rather frightening aspects of this fiasco. Both rather horrifying, as a matter of fact.

First, that in this day and age, in late 2018, a backbone service provider can still be brought to its knees by something as simple as a malformed packet. What on Earth are you doing, people? Have you heard of penetration testing? Fault tree analysis? Auditing your equipment and system software? Or have these essential steps been dropped just so that you can report some cost savings to your shareholders?

But it really is the second point that I find particularly upsetting. To quote, “the nodes along the fiber network were so flooded, they could not be reached by their administrators”.

Say what? Are you telling me that you had no alternate means to access your nodes? Like, you know, something as crude and simple as a dial-up port with a command-line based management interface? I mean, this is something even my little home office network used to have, and when I dropped it last year, reacting to rising landline costs and the fact that I no longer used that data/Fax phone line at all, I did so because I have dual network connections. To learn that a major backbone provider doesn’t have the kind of redundancy that I take for granted for my own little network is disconcerting, to say the least.

I suppose I should stop rambling now, though. Truth to tell, I am ignorant as to how CenturyLink’s actual network is configured, and I certainly never managed a fiber optic backbone network. I am simply reacting to the main points of The Register‘s article even though I cannot independently confirm its veracity. In my defense, The Register‘s articles tend to be well written and accurate. Even so, criticizing from a position of ignorance is never a smart thing to do.

Nonetheless, if The Register is correct, this really is not how a transcontinental data network should be configured and managed. This also seems to be the FCC’s conclusion.

 Posted by at 5:04 pm
Aug 202019

I have been reading dire predictions about the increasingly likely “no deal” Brexit that will take place this Halloween.

Today, I ran across two things that drove the point home for me more than anything else.

First (actually, this came second, but let me mention it first), this warning by GoDaddy to their UK-based customers who happen to hold a .EU Internet domain name:

And then there is this: An article from three years ago by a Fedja Buric (judging by the name, probably from the region) who offers a sobering comparison between the breakup of Yugoslavia and Brexit.

It may have been written back in 2016, but I think its dire warning is even more relevant today, now that a no-deal Brexit is rapidly becoming a near certainty.

 Posted by at 9:00 pm
Aug 112019

Dear American friends: please stop calling your President “the leader of the free world”.

I live in what you call the free world but Trump is no leader of mine. I have not elected him. He does not represent my values.

On the contrary, he seems hell-bent on destroying the values that I consider fundamental to the free world. He already managed to drag his own country down (though arguably, other politicians and long-term partisan trends played an equally important role) so that it no longer qualifies as a full democracy on The Economist’s democracy index. Why would the rest of the free world want him to lead us down the same path?

 Posted by at 12:41 pm
Aug 072019

Yesterday, we posted our latest paper on arXiv. Again, it is a paper about the solar gravitational lens.

This time around, our focus was on imaging an extended object, which of course can be trivially modeled as a multitude of point sources.

However, it is a multitude of point sources at a finite distance from the Sun.

This adds a twist. Previously, we modeled light from sources located at infinity: Incident light was in the form of plane waves.

But when the point source is at a finite distance, light from it comes in the form of spherical waves.

Now it is true that at a very large distance from the source, considering only a narrow beam of light, we can approximate those spherical waves as plane waves (paraxial approximation). But it still leaves us with the altered geometry.

But this is where a second observation becomes significant: As we can intuit, and as it is made evident through the use of the eikonal approximation, most of the time we can restrict our focus onto a single ray of light. A ray that, when deflected by the Sun, defines a plane. And the investigation can proceed in this plane.

The image above depicts two such planes, corresponding to the red and the green ray of light.

These rays do meet, however, at the axis of symmetry of the problem, which we call the optical axis. However, in the vicinity of this axis the symmetry of the problem is recovered, and the result no longer depends on the azimuthal angle that defines the plane in question.

To make a long story short, this allows us to reuse our previous results, by introducing the additional angle β, which determines, among other things, the additional distance (compared to parallel rays of light coming from infinity) that these light rays travel before meeting at the optical axis.

This is what our latest paper describes, in full detail.

 Posted by at 9:10 pm
Jul 242019

Rutger Hauer was a Dutch actor. He is best known perhaps for his role in the science-fiction cult classic Blade Runner, in particular for his improvised tears in rain soliloquy, spoken by the character Roy Batty just before his death:

I’ve seen things you people wouldn’t believe. Attack ships on fire off the shoulder of Orion. I watched C-beams glitter in the dark near the Tannhäuser Gate. All those moments will be lost in time, like tears in rain. Time to die.

I just learned that Hauer himself died a few days ago, after a brief illness, at age 75.

 Posted by at 6:55 pm
Jul 192019

The world is celebrating the 50th anniversary of one of the most momentous events in human history: the first time a human being set foot on another celestial body.

It is also a triumph of American ingenuity. Just as Jules Verne predicted a century earlier, it was America’s can-do spirit that made the Moon landing, Armstrong’s “one small step” possible.

And today, just like 50 years ago, their success was celebrated around the world, by people of all nationality, religion, gender or ethnicity.

But that’s not good enough for some New York Times columnists.

Instead of celebrating the Moon landing, Mary Robinette Kowal complains about the gender bias that still exists in the space program. Because, as we learn from her article, this evil male chauvinistic space program was “designed by men, for men”. Because, you know, men sweat in different areas of their body and all. Even in the office, temperatures are set for men, which leaves women carrying sweaters.

Sophie Pinkham goes further. Instead of celebrating America’s success on July 20, 1969, Pinkham goes on to praise the Soviet space program in a tone that might have been rejected even by the editors of Pravda in 1969 as too over-the-top. Because unlike America, the Soviets put the first woman in space! Their commitment to equality did not stop there: They also sent the first Asian man and the first black man into orbit. Because, we are told, “under socialism, a person of even the humblest origins could make it all the way up.”

Just to be clear, I am not blind to gender bias. We may have come a long way since the 1960s, but full gender equality has not yet been achieved anywhere: not in the US, not in Canada, not even in places like Iceland. And racism in America remains a palpable, everyday reality. Back in 1969, things were a lot worse.

But to pick the 50th anniversary of an event that, even back in the turbulent 1960s, had the power to unify humanity, to launch such petty rants? That is simply disgraceful. Or, as the New York Post described it, obscene.

The New York Post also makes mention of one of the female pioneers of the US space program, Margaret Hamilton, whose work was instrumental in making the Apollo landings possible. Yet somehow, neither Pinkham nor Kowal found it in their hearts to mention her name.

I have to wonder: Are columnists like Pinkham or Kowal secretly rooting for Donald Trump? Because they certainly seem to be doing their darnedest best to alienate as many voters as possible, from what appears to be an increasingly bitter, intolerant, ideological agenda on the American political left.

 Posted by at 6:49 pm
Jul 162019

Fifty years ago today, fifty years ago this very hour in fact, at 9:32 AM EDT on July 16, 2019, Apollo 11 was launched.

Moonbound Apollo 11 clears the launch tower. NASA photo

And thus began a journey that, arguably, remains the greatest adventure in human history to date.

I was six years old in 1969, hooked on the novels of Jules Verne. With Apollo 11, Verne’s bold imagination became the reality of the day.

 Posted by at 9:25 am
Jul 152019

In 1929, probably just weeks before the great stock market crash, people were entertained by the sight of thousands of burning radio sets.

Some suggested that the apparent zeal with which these poor radios were burned had to do with the fact that they were obsolete regenerative receivers, notorious sources of radio frequency interference.

But no, the pictures make it clear that many of these old radios were simple tuned radio frequency (TRF) sets, not regenerative units. Besides, it was not until the early 1930s that superheterodyne receivers began to dominate the market.

No, this was just good old capitalism. People were encouraged to trade in old, “obsolete” radios and purchase new ones. And the wanton destruction of the old sets became a public spectacle.

One can only wonder about the amount of toxic smoke that was produced by this stunt. Not that anyone cared back in 1929.

 Posted by at 10:40 am