vttoth

I am a software developer and author of computer books. I also work on some problems in theoretical physics. For more information, please visit my personal Web site at http://www.vttoth.com/.

Good-bye, Alexei Leonov

History, Space No Responses »

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.

Nerd sniping

Humor, Physics No Responses »

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.

De Niro’s opinion on Fox News

Politics, Television No Responses »

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.

Amazing paintings by Vilhelm Hammershøi

Art No Responses »

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.

Bitcoin fraud

Computer Security, Internet, Personal No Responses »

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 blockchain.com. 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 blockchain.com. 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 blockchain.com 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 blockchain.com; with the appropriate cryptocurrency software, they can recreate the wallet and empty it.

Which means that my entire blockchain.com 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.

Dilbert and the consultant

Computers, Personal, Programming No Responses »

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.

So this is how the planet is killed…

Environment, Politics No Responses »

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.

How not to manage a transcontinental data network

Computer Security, Internet No Responses »

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.

That Brexit disaster

History, Internet, Politics No Responses »

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.

No leader of my free world

Humor, Politics No Responses »

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?

Imaging extended sources with the solar gravitational lens

Astronomy, Personal, Physics, Space No Responses »

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.

Tears in rain

Film No Responses »

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.

Was Apollo 11 not PC enough?

History, Politics, Space No Responses »

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.

Moon shot

History, Space No Responses »

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.

The Great Radio Bonfire

History, Radio No Responses »

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.

Galileo down

Space, Technology, Transportation No Responses »

Jul 152019

Galileo is the world’s third global satellite navigation system, built by the European Union, operating in parallel with the American GPS system and Russia’s GLONASS. It has been partially operational since 2016, with a full constellation if satellites expected to enter service this year.

But as of early Monday, July 15, Galileo has been down for nearly four days, completely inoperative in fact:

As of the time of this writing, no explanation is being offered, other than one article mentioning an unspecified issue with Galileo’s ground-based infrastructure.

It really is difficult to comprehend how such a failure can occur.

It is even more difficult to comprehend the silence, the lack of updates, explanations, or any information about the expected recovery.

Thank goodness I am not claustrophobic…

Handyman, Personal No Responses »

Jul 032019

There is always a first time for everything.

I have spent more than 56 years on this planet so far, but today was the first time that I managed to lock myself in a bathroom.

I was heading to see my dentist, in a bit of a hurry when I went to the bathroom one last time and slammed the bathroom door. (I was angry because I missed the bus that would have taken me to my destination comfortably.) When I was trying to exit the bathroom, the doorknob did not function. It rotated freely, and the door remained stuck.

My wife was fortunately at home. Unfortunately, the doorknob on the other side of the door didn’t do a thing either.

I was trying to force the door open using makeshift implements. My wife was trying to do the same from the other side.

After a few minutes, I realized that I would not be able to make it to the dentist on time, so I phoned their office. They were very nice and understanding. What they thought about me is another matter.

After another fifteen minutes I was ready to give up. I resigned myself to having to spend half the afternoon in a tiny bathroom (a tiny powder room, really) as I called our condominium manager for help.

But just then, while I was talking to our condo manager, my wife succeeded. With the help of an axe and a kitchen knife, she was able to force the door open. I was free! And the door was not damaged too badly either.

Grabbing my screwdriver, I disassembled the door lock. I found that an essential part, the spindle, became detached from the knob to which it is normally attached, and ended up completely inside the other knob. Thus it could no longer perform its essential function of actuating the latch. The problem was trivial to fix.

Thank goodness I was not alone at home. Thank goodness my wife didn’t give up so easily and managed to free me. And thank goodness I am not claustrophobic.

Darmok and Jalad at Tanagra

Politics No Responses »

Jul 012019

I have been thinking about this supposedly historic meeting between Trump and Kim at the DMZ.

One TV talking head criticized Trump’s last-minute invitation. “These meetings should be preceded by months of preparations by experts,” he said, or something to this effect. I remember, I was actually waking down the stairs towards my kitchen as I exclaimed, “Those experts had 65 years at their disposal.”

In short, I am not going to blame Trump for trying something different. Trying, of course, is not the same as succeeding.

Can Trump succeed? Can this meeting be the beginning of something meaningful, like Captain Picard’s meeting with the Tamarian captain, who was speaking in the allegorical Tamarian language in that famous Star Trek: The Next Generation episode?

Or, far more likely, is it just a misguided attempt by a narcissistic world leader who grossly overvalues his own skills at personal diplomacy, reminding me of the last Kaiser of Imperial Germany, Wilhelm II?

I am not optimistic, but for what it’s worth, I am rooting for Trump. If he succeeds, the world becomes a slightly better, slightly safer place.

Bill 21 vs. SJWs

Canada, Film, History, Politics, Religion No Responses »

Jun 182019

So on the one hand… here I am, praising Canada for being true to its values, only to learn yesterday that Quebec’s provincial legislature approved a ban on “religious symbols”. Not once in my life did I worry when I was being served by a person wearing a kippa, a cross, a turban or a headscarf that nature that they might discriminate against me. Should I have been? Perhaps naively, I always felt privileged to live in a society in which persons wearing kippas, crosses, turbans or headscarves were welcome, even into positions of authority. But now I am worried that a person whose religion demands wearing a kippa, a cross, a turban or a headscarf will not be allowed to serve me anymore. And that’s even before I look at the more hypocritical aspects of the bill.

But then, I learn that south of the border, social justice warriors scored another “victory”: at Bowling Green State University, Ohio, they managed to get the name of silent era film star Lillian Gish stripped from the university’s Gish Film Theater because a student union protested on account of her role in the rather racist 1915 silent classic Birth of a Nation.

I fundamentally disagree with the idea of judging the past by the standards of the present. I dare hope that our societies are becoming better over time, and thus our standards are higher, but it is grossly unfair to the memory of those from generations ago when they are judged by standards that did not even exist at the time. But putting all that aside… isn’t it obvious that such acts of cultural intolerance (committed, ironically, in the name of tolerance) are just oil on the fire? That those who are behind the rise of xenophobia, nationalism, racism and intolerance will see such acts as proof that their grievances of valid, that it is truly they (and by “they”, I mean mostly middle-aged or older white men) who are being prosecuted here?

Are these truly the only choices out there? Xenophobic nationalism and Islamophobia vs. social justice militants? Where have all the sane people gone? Please come back wherever you are and help put an end to this madness.

Huawei and end-to-end encryption

Canada, Computer Security, Internet, Politics No Responses »

Jun 132019

The news this morning is that former PM Jean Chrétien suggested that Canada should stop the extradition proceedings against Huawei CFO Meng Wanzhou, as a means to win back the freedom of the two Canadian hostages in China, Michael Kovrig and Michael Spavor. (Yes, I called them hostages.)

The case against Huawei runs a lot deeper, however, than the financial fraud Ms. Meng is alleged by US authorities to have committed.

There is also the question of espionage, including the possibility that Huawei’s 5G equipment cannot be trusted because of firmware or hardware level backdoors.

I repeatedly encountered the suggestion that this issue can be trivially remedied by using end-to-end encryption. Unfortunately, end-to-end encryption, even if properly implemented (ignoring for the moment our own Western governments’ recurrent pleas to have built-in backdoors in any such encryption algorithms), solves only part of the problem.

It still allows Huawei to steal metadata, such as where calls are routed or the amount and nature of data traffic between specific endpoints. Worse yet, no encryption prevents Huawei from potentially sabotaging the network when called upon to do so by the Chinese government.

For this reason, I reluctantly came to the conclusion that the US ban against Huawei is justified and appropriate. It must, of course, be accompanied by a suitable increase in spending on researching 5G communications technologies, because otherwise, we risk shooting ourselves in the foot by banning the use of equipment that is technologically superior to the available alternatives. This is a new situation for the West: The last time the West faced a great power adversary that matched Western scientific and technological capabilities was in the 1930s, with Nazi Germany.

As for Ms. Meng, I think the suggestion to suspend the extradition process is wholly inappropriate. It would signal to the world that Canada is willing to suspend the rule of law for the sake of hostages. However strongly I feel about Messrs. Kovrig and Spavor, however strongly I desire to see them released, this is not a price Canada should be willing to pay.

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