Apr 062021

World, please say hello to Freddy.

Freddy has been with us for more than two years now. He is a very funny cat. Strong-willed, to be sure; he might even bite you if he disapproves of your behavior. (No, he has not bitten off any fingers or earlobes yet.) And he likes… green peas. Or kernels of corn. And like one of our past kitties, Pipacs, Freddy also stole a freshly cooked potato from the kitchen not too long ago.

Last but not least, I should mention that his favorite toys are small pompoms. We have many of those, on account of my wife’s knitting. So I have a box of pompoms right here, next to my desk. Freddy often shows up here and, after carefully sniffing the pompoms, selects one, takes it from the box, puts it down on the floor and sits down proudly next to it, quietly meowing a few times. That is my cue to pick up the pompom and throw it down the stairs, with Freddy sprinting after it. Often, he then spends a good half hour playing with that pompom.

He also occasionally plays with his somewhat larger buddy, Rufus. I suppose Rufus looks just like a big gray-and-white pompom…

 Posted by at 9:33 pm
Apr 052021

My success story of the day involves two cups.

A few days ago, I heard my wife grumbling loudly in the kitchen. I went downstairs to see what was wrong. She showed me a pair of cups, a teacup, inside which there was one of our brand new espresso cups.

And when I say inside, I mean wedged inside. Firmly and utterly stuck, quite impossible to remove.

We tried to separate them using force, but they wouldn’t budge. We obviously didn’t want to break either cup. Not that they are terribly expensive but the teacup, well, we’re quite fond of these teacups and as for the espresso cup, it was brand new, I only just purchased the set off Amazon a few days earlier.

Force failed to do the trick so we tried to be clever. Use some oil to make it slick? Nope. Dishwasher detergent? That didn’t work either. I tried holding the outer cup, upside down, under hot water in the hope that thermal expansion might loosen the smaller cup inside; nope.

Nonetheless we thought that a temperature difference might help, so we filled the cups with water and put them in the freezer. Once the water was frozen solid, we took them out and placed them in a pot of boiling water. Again, the hope was that the high heat would cause the larger cup to expand, while the ice keeps the smaller cup cold, allowing it to fall out. Nope.

After this experiment failed for the third time earlier this afternoon, I sat down with the cups in hand and once again, tried brute force. The outer cup was still quite hot to the touch, the inner cup still quite cold and this may have helped; suddenly, I felt them budge, and after one more pull, they were separated, completely undamaged.

I was… absolutely delighted. Later I remarked to my wife that we humans are creatures of simple pleasures. Never mind the animations I completed just today using gravitational lenses of arbitrary shape. Never mind the work I am doing on another project on payment processor integration, or yet another project involving Microsoft Teams. (Yes, I multitask. Virtual desktops can be quite handy.) All of that is fun, sure, but it’s having been able to separate these poor cups without breaking or damaging them that really made my day.

 Posted by at 9:33 pm
Apr 032021

My beautiful wife is getting really good at this.

She just made this kalach (kalács), Hungarian style braided sweetbread/eggbread, on account of Easter.

It is absolutely yummy for breakfast. Might work for lunch and dinner, too, if you ask me.

Yes, it has raisins in it. I love kalach with raisins.

 Posted by at 1:05 pm
Mar 192021

I remembered something today. A set of playing cards.

I never had a card deck like this but some of my grade school classmates did. This was the (very) early 1970s in communist Hungary. It was through these cards that I first learned of the existence of luxury sports cars, supercars like Ferrari, racecars like Lotus.

It was cards like these:

These were not some imports from the decadent West. Not subtle imperialist propaganda. These cards were produced by the state-owned Playing Card Factory (yes, that was the name of the company!) and they were much coveted by many 7-year olds. Like me.

But now that I think back, it makes me wonder: Exactly what were they thinking? I mean, this was a bleeping communist dictatorship (of the goulash variety, but still). What on Earth did they think they were doing, these self-appointed masters of agitprop, poisoning our young, impressionable minds with such blatant Western consumerist propaganda?

Ah, the sweet irony.

 Posted by at 9:28 pm
Mar 162021

Somebody just reminded me: Back in 1982-83 a friend of mine and I had an idea and I even spent some time building a simple simulator of it in PASCAL. (This was back in the days when a 699-line piece of PASCAL code was a huuuuge program!)

So it went like this: Operative memory (RAM) and processor are separate entities in a conventional computer. This means that before a computer can do anything, it needs to fetch data from RAM, then after it’s done with that data, it needs to put it back into RAM. The processor can only hold a small amount of data in its internal registers.

This remains true even today; sure, modern processors have a lot of on-chip cache but conceptually, it is still separate RAM, it’s just very fast memory that is also physically closer to the processor core, requiring less time to fetch or store data.

But what if we abandon this concept and do away with the processor altogether? What if instead we make the bytes themselves “smart”?

That is to say what if, instead of dumb storage elements that can only be used to store data, we have active storage elements that are minimalist processors themselves, capable of performing simple operations but, much more importantly, capable of sending data to any other storage element in the system?

The massive number of required interconnection between storage elements may appear like a show-stopper but here, we can borrow a century-old concept from telephony: the switch. Instead of sending data directly, how about having a crossbar-like interconnect? Its capacity will be finite, of course, but that would work fine so long as most storage elements are not trying to send data at the same time. And possibly (though it can induce a performance penalty) we could have a hierarchical system: again, that’s the way large telephone networks function, with local switches serving smaller geographic areas but interconnected into a regional, national, or nowadays global telephone network.

Well, that was almost 40 years ago. It was a fun idea to explore in software even though we never knew how it might be implemented in hardware. One lesson I learned is that programming such a manifestly parallel computer is very difficult. Instead of thinking about a sequence of operations, you have to think about a sequence of states for the system as a whole. Perhaps this, more than any technical issue, is the real show-stopper; sure, programming can be automated using appropriate tools, compilers and whatnot, but that just might negate any efficiency such a parallel architecture may offer.

Then again, similar ideas have resurfaced in the decades since, sometimes on the network level as massively parallel networks of computers are used in place of conventional supercomputers.

Gotta love the Y2K bug in the header, by the way. Except that it isn’t. Rather, it’s an implementation difference: I believe the PDP-11 PASCAL that we were using represented a date in the format dd-mm-yyyy, as opposed to dd-MMM-yyyy that is used by this modern Pascal-to-C translator. As I only allocated 10 characters to hold the date in my original code, the final digit is omitted. As for the letters "H J" that appear on top, that was just the VT-100 escape sequence to clear the screen, but with the high bit set on ESC for some reason. I am sure it made sense on the terminals that we were using back in 1982, but xterm just prints the characters.

 Posted by at 12:54 pm
Mar 142021

The next in our series of papers describing the extended gravitational lens (extended, that is, in that we are no longer treating the lensing object as a gravitational monopole) is now out, on arXiv.

Here’s one of my favorite images from the paper, which superimposes the boundary of the quadrupole caustic (an astroid curve) onto a 3D plot showing the amplitude of the gravitational lens’s point-spread function.

I was having lots of fun working on this paper. It was, needless to say, a lot of work.

 Posted by at 9:18 pm
Jan 282021

Every once in a while, strange coincidences occur that make me wonder if we live in a simulation after all.

Take today. Just moments ago, I ran across a tweet by Trump’s former director of communications (for 10 days), Anthony Scaramucci:

I found the reference to Max Headroom amusing; it’s been a while since I last saw any mention of this once iconic television series (which I happened to like very much.)

But then, no more than two minutes later, I ran across a Quora question that I was asked to answer, only to find an existing answer (good one, incidentally) that begins with a quote:

What exactly are the odds that I run across two completely unrelated Max Headroom references within minutes of each other?

Of course the fact that Max Headroom was an AI personality living its own virtual existence is just icing on the proverbial cake…

 Posted by at 8:27 pm
Dec 152020

A very nice article about our work on the Solar Gravitational Lens was published a few days ago on Universe Today, on account of our recent preprint, which shows quantitative results assessing the impact of image reconstruction on signal and noise.

Because the SGL is such an imperfect lens, the noise penalty is substantial. However, as it turns out, it is much reduced when the projected image area is large, such as when an exoplanet in a nearby star system is targeted.

While this is good news, the Sun’s gravitational field has other imperfections. We are currently working on modeling these and assessing their impact on noise. Next comes the problem of imaging a moving target: an exoplanet that spins, which is illuminated from varying directions, and which may have varying surface features (clouds, vegetation, etc.) Accounting for all these effects is essential if we wish to translate basic theory into sound scientific and engineering requirements.

So, the fun continues. For now, it was nice to see this piece in Universe Today.

 Posted by at 11:08 pm
Oct 312020

The ghosts of Halloween have not completely forsaken us.

Here is the driveway of one of our neighbors tonight:

I doubt there will be many trick-or-treaters, but it was nonetheless good to see this. I especially appreciated the lit candle that turned a jack-o-lantern into, well, an actual jack-o-lantern. But it is really the other pumpkin that looked truly frightening. Thank you, neighbor!

 Posted by at 7:53 pm
Oct 302020

I don’t usually write about such matters, but a letter like this one is always a nice one to get even when there is no raging pandemic:

Let this serve as a public service reminder: If you are, like me, in your fifties, especially if you are a male, with a sedentary lifestyle (spending your days in your office chair), perhaps overweight: You are at risk. Early detection may mean the difference between surviving to a ripe old age in good health vs. dying before you get to enjoy life as a pensioner.

 Posted by at 5:53 pm
Oct 182020

I rarely remember my dreams. It was therefore striking when this morning I woke up from a vivid dream. In my dream, I visited my long dead grandmother’s old apartment, except that she was very much alive, sitting in front of a desk facing the window of her room. I stood at her doorway, not wanting to get any closer, COVID-19 and all. I said to her that we should keep our distance, and at first she nodded but then, bah, she approached me anyway with the intent to hug and kiss me. Not having any better ideas, I quickly held up the sheet of paper or book or whatever it was that I had in my hands, so that instead of kissing each other on the cheek, we ended up kissing through that paper object. I truly was worried that if we are careless, we risk her frail health.

In actuality, my grandmother, who was born in 1901, passed away 26 years ago. I was wondering what prompted this dream. Then I realized: last night, I saw an image on Twitter, a 1908 Canadian painting titled Mrs. Davies at the Sewing Machine, by Albert Henry Robinson.

Not quite the same as my grandmother’s room, but it has the same vibe, same atmosphere.

What an unusual dream.

Yes, I loved my grandmother very much. But I don’t think I ever saw her using a sewing machine.

 Posted by at 12:46 pm
Oct 092020

So I try to start a piece of software that accesses a classic serial port.

The software locks up. The process becomes unkillable. Because, you know… because. Microsoft has not yet discovered kill -9 I guess.

(Yes, I know that unkillable zombie processes exist under Linux/UNIX, too. But in the past 25 years, I remember exactly one (1) occasion when a Linux process was truly unkillable, hung in a privileged kernel call, and actually required a reboot with no workaround. On Linux, this is considered a bug, not a feature. In contrast, on Windows this is a regular occurrence. Then again, on Linux I have fine-grained control and I can update pretty much everything other than the kernel binary, without ever having to reboot.)

Ok-kay… this means Windows has to be restarted. Fine. At least let me check if there are any Windows updates. Oops… error, because an “update service is shutting down” or whatever.

Oh well, let’s restart. The browser (Edge) will remember my previously opened tabs, right?

After restart, another program tells me that it has an update. Clicking on the update button opens the browser with the download link. Fine. Just checking, in the browser history all my previously opened tabs (lots of them) are still there. Good.

Meanwhile, Windows Update does come to life and tells me that I need to restart my system. Couldn’t you freaking tell me this BEFORE I restarted?

Oh well, might as well… restart #2.

After restart, let’s open the browser. History… and all my previously opened tabs are gone. The only thing the bloody browser remembers is the single tab that contained the download link for that application.

@!##%@#!@. And @#$$!@#$@!$. And all their relatives, too. Live or deceased. And any related deities.

Oh well, let’s restore the bleeping tabs manually; fortunately, I also had most of them opened in Chrome, so I could reopen them, one by one, in Edge. (Maybe there’s a more efficient way of doing this, but I wasn’t going to research that.)

Meanwhile, I also restarted Visual Studio 2019. It told me that it had an update. Having learned from previous experience, I shut down a specific service that was known to interfere with the update. It proved insufficient. When Visual Studio was done updating, it told me that “only one thing” remains: a teeny weeny inconsequential thing, ANOTHER BLOODY RESTART.

Because, ladies and gentlemen, in the fine year of 2020, the great software company Microsoft has not yet found a way to UPDATE A BLEEPING APPLICATION without restarting the WHOLE BLEEPING WORLD. Or at the very least do me a bleeping failure and warn IN ADVANCE that the update may require a restart.

My favorite coffee mug survived, but only just barely. I almost smashed it against the wall.

So here we go… restart #3.

It was nearly two hours ago that I innocently tried to turn on that program that required access to the serial port. Since then, I probably aged a few years, increased my chances of a stroke and other illnesses related to high pressure, barked at my beautiful wife and my cats, almost smashed my favorite mug, lost several browser tabs but also my history in some xterm windows, and other than that, accomplished ABSOLUTELY NOTHING.

Thanks for nothing, Microsoft.

And I actually like Microsoft. Imagine what I’d be saying if I hated them.

 Posted by at 1:18 pm
Sep 222020

My favorite Twitter accounts: @PossumEveryHour, @RaccoonEveryHr, @RatsEveryHour,@ekichoTAMA, @evilbmcats, @giantcat9. I also love the Facebook Bird Misidentification Page. I think I should limit my social media consumption to these groups. For mental health, you know.

 Posted by at 8:13 pm
Sep 122020

I have a travel radio.

It is a SONY ICF-SW1. It is an amazing little radio, probably the nicest radio ever made by anyone. It looks more like jewelry than a radio.

It is an immensely capable universal receiver, with continuous tuning in the AM band between 150 and 29995 kHz, and in the FM band between 76 and 108 MHz. About the only shortcoming that was mentioned by its critics is that it is a shame that such a radio does not offer the ability to selectively pick modulation schemes (e.g., narrowband FM, SSB).

I bought this radio maybe a quarter century ago, back in the 1990s. (So I guess it qualifies as an antique, despite the fact that there really are no comparable receivers out there that I know about.) I thought about buying one for quite some time but at first, I refrained as the radio was quite pricey. But one day, while waiting for my flight back home at Budapest Airport, I could not resist anymore: I saw the radio at the duty free shop and bought it.

Come to think of it, it must have been 1993 or earlier, because as I recall, the radio was already in my possession when I visited Beijing in the fall of ’93. As such, it began to show signs of age, its sound quality deteriorating because of aging electrolytic capacitors.

A few months ago, I purchased a capacitor kit off eBay, in the hope that I might be able to repair the radio. In fact, I began the repair job back in the summer, starting with taking the radio apart; not an easy task by itself, as it requires not just the removal of countless screws, not just carefully separating snap-together parts of the radio’s case without causing damage, but also desoldering several wires.

Back in the summer, I successfully replaced two capacitors but then I put the radio aside. It was hard work, and very easy to make irreversible mistakes working on submillimeter scale parts with a soldering iron. As I attempted to replace a third capacitor last night, I managed to rip up a small patch of the printed circuit board. I was able to repair the damage with a piece of wire, but this was the point when I said, enough is enough; “do no harm” should be my mantra, and I certainly do not wish to destroy this beautiful little device. So I decided to forego the rest, in the hope that the two largest capacitors that I replaced (the third was a backup capacitor for the microprocessor, to keep it powered while replacing batteries) would be sufficient. I did, however, replace the display backlight: the original backlight was a low-luminosity green LED, which I replaced with a modern, high-luminosity white LED that I received as part of the kit.

Putting everything back together was a challenge, too, and not just because the light didn’t work at first (bad soldering on my part). Ultimately I managed, though I ended up with four surplus screws with no place to go. (I think I know where they’re from, but they are redundant, and there’s no way I am going to take this radio apart again just to put those screws back in.) And much to my surprise, the radio works, and its sound quality indeed improved noticeably.

As I was studying the circuit diagram of the radio, I kept wondering what possessed SONY to produce a little marvel like this. This radio is insanely complex, with its multiple circuit boards in an absolutely tiny package. The number of distinct parts (each carefully labeled in the service manual with replacement order numbers) is astonishing. Was it a labor of love? Were they showing off? Probably both.

 Posted by at 12:20 pm
Sep 102020

In the last few days, I was:

  1. scolded in one Facebook group, when I commented on a post and made a mention of other personalities (who are not directly connected to the topic of the group), intended to serve as examples showing that the issue being discussed was a much broader one;
  2. had a repost of mine of a funny image to a humor group unceremoniously deleted, for supposedly reposting “ad nauseam” something that I have not yet seen in that group since I became a member a few months ago.

Yes, I know, discussion group moderation is a thankless task. Been there, done that.

But, as I often reminded all-powerful witches and wizards in our favorite MUD (Multi-User Dungeon) games, there is no point overdoing the policing. It sucks away the fun for everyone. By all means, step in and police blatant violations… but also be wise and know when it is more appropriate not to notice things, even when they technically qualify as infractions. The goal, simply put, is to make things fun for everyone, not to enforce rules at all costs. In short, rules exist for our convenience, not the other way around.

If only people were this conscientious when it comes to pandemic-related rules for social distancing and wearing masks… Rules that are there, you know, because they actually save lives?

Oh well. Done ranting for the day.

 Posted by at 1:13 pm
Sep 032020

Tonight, Slava Turyshev sent me a link to an article that was actually published three months ago on medium.com but until now, escaped our attention.

It is a very nice summary of the work that we have been doing on the Solar Gravitational Lens to date.

It really captures the essence of our work and the challenges that we have been looking at.

And there is so much more to do! Countless more things to tackle: image reconstruction of a moving target, imperfections of the solar gravitational field, precision of navigation… not to mention the simple, basic challenge of attempting a deep space mission to a distance four times greater than anything to date, lasting several decades.

Yes, it can be done. No it’s not easy. But it’s a worthy challenge.

 Posted by at 10:54 pm
Jul 312020

A few weeks ago, Christian Ready published a beautiful video on his YouTube channel, Launch Pad Astronomy. In this episode, he described in detail how the Solar Gravitational Lens (SGL) works, and also our efforts so far.

I like this video very much. Especially the part that begins at 10:28, where Christian describes how the SGL can be used for image acquisition. The entire video is well worth seeing, but this segment in particular does a better job than we were ever able to do with words alone, explaining how the Sun projects an image of a distant planet to a square kilometer sized area, and how this image is scanned, one imaginary pixel at a time, by measuring the brightness of the Einstein-ring around the Sun as seen from each pixel location.

We now understand this process well, but many more challenges remain. These include, in no particular order, deviations of the Sun from spherical symmetry, minor variations in the brightness of the solar corona, the relative motion of the observing probe, Sun, exosolar system and target planet therein, changing illumination of the target, rotation of the target, changing surface features (weather, perhaps vegetation) of the target, and the devil knows what else.

Even so, lately I have become reasonably confident, based on my own simulation work and our signal-to-noise estimates, as well as a deconvolution approach under development that takes some of the aforementioned issues into consideration, that a high-resolution image of a distant planet is, in fact, obtainable using the SGL.

A lot more work remains. The fun only just began. But I am immensely proud to be able to contribute to of this effort.

 Posted by at 7:41 pm
Jul 162020

I met Gabor David back in 1982 when I became a member of the team we informally named F451 (inspired by Ray Bradbury of course.) Gabor was a close friend of Ferenc Szatmari. Together, they played an instrumental role in establishing a business relationship between the Hungarian firm Novotrade and its British partner, Andromeda, developing game programs for the Commodore 64.

In the months and years that followed, we spent a lot of time working together. I was proud to enjoy Gabor’s friendship. He was very knowledgeable, and also very committed to our success. We had some stressful times, to be sure, but also a lot of fun, frantic days (and many nights!) spent working together.

I remember Gabor’s deep, loud voice, with a slight speech impediment, a mild case of rhotacism. His face, too, I can recall with almost movie like quality.

He loved coffee more than I thought possible. He once dropped by at my place, not long after I managed to destroy my coffee maker, a stovetop espresso that I accidentally left on the stove for a good half hour. Gabor entered with the words, “Kids, do you have any coffee?” I tried to explain to him that the devil’s brew in that carafe was a bitter, undrinkable (and likely unhealthy) blend of burnt coffee and burnt rubber, but to no avail: he gulped it down like it was nectar.

After I left Hungary in 1986, we remained in sporadic contact. In fact, Gabor helped me with a small loan during my initial few weeks on Austria; for this, I was very grateful.

When I first visited Hungary as a newly minted Canadian citizen, after the collapse of communism there, Gabor was one of the few close friends that I sought out. I was hugely impressed. Gabor was now heading a company called Banknet, an international joint venture bringing business grade satellite-based Internet service to the country.

When our friend Ferenc was diagnosed with lung cancer, Gabor was distraught. He tried to help Feri with financing an unconventional treatment not covered by insurance. I pitched in, too. It was not enough to save Feri’s life: he passed away shortly thereafter, a loss I still feel more than two decades later.

My last conversation with Gabor was distressing. I don’t really remember the details, but I did learn that he suffered a stroke, and that he was worried that he would be placed under some form of guardianship. Soon thereafter, I lost touch; his phone number, as I recall, was disconnected and Gabor vanished.

Every so often, I looked for him on the Internet, on social media, but to no avail. His name is not uncommon, and moreover, as his last name also doubles as a first name for many, searches bring up far too many false positives. But last night, it occurred to me to search for his name and his original profession: “Dávid Gábor” “matematikus” (mathematician).

Jackpot, if it can be called that. One of the first hits that came up was a page from Hungary’s John von Neumann Computer Society, their information technology history forum, to be specific: a short biography of Gabor, together with his picture.

And from this page I learned that Gabor passed away almost six years ago, on November 10, 2014, at the age of 72.

Well… at least I now know. It has been a privilege knowing you, Gabor, and being able to count you among my friends. I learned a lot from you, and I cherish all those times that we spent working together.

 Posted by at 2:04 pm