Marc Gallant

November 5th, 19972024-08-24

Remember, remember the fifth of November, 1997. Rocking on the radio (yes, people were still listening to radio) was Elton John's update to Candle in the Wind and Aqua's Barbie Girl. Titanic was just about to become the biggest movie of all time. And at 8:17 PM, yours truly was settling down to write page one of his life story. What follows is a transcription of a journal entry I wrote that day as a reflective 12-year-old:

8:17 P.M. November 5th, 1997

Today I went to MacDonalds for lunch
with all of my classmates. We also went
to The Maritime Museum of The Atlantic
which was a lot of fun. At the start we
got to see a film about Nova Scotia
in the past and then we went on a
tour of the whole Museum. At the end
we went into this room where we pretended
we were fishing, The guy that worked
at the museum told us to close our
eyes and imagine all the fish, thats
when he sounded this huge foghorn
that probably scared everybody, including
me! After school I went to my friends
Scott's house, We played magic cards
and a bit of soccer and I had a
lot of fun.

Hiran: 68

Can you imagine working at "MacDonalds" when 25 sixth-graders randomly show up? As a parent myself it makes me feel old when I recall things in my childhood that would never happen today for my kid. To be honest, I doubt they'd even do the foghorn thing. Luckily, kids these days probably still go to Scott's house to play magic and a bit of soccer. As for the addendum, Hiran was my best friend growing up, but his 68 is a bit of a spooky mystery, seeing as he moved away three months before this was written. Finally, don't hold your breath for my next journal entry, sadly this was the only one I ever wrote.

Sci-Fi2024-04-20

I am an avid reader of science fiction, usually having a book on the go at all times. I thought I would write down my favourites so far. I would love for some of these to be replaced in a future update of this list, because that would mean I found something I truly loved. Also, something, something, really difficult to narrow down, blah, blah, blah, the usual sentiments when trying to make list, etc.

7. Replay (1986) by Ken Grimwood

I've read multiple books that have tackled the question of "What would you do if one day you woke up in your past?". That is, one day you wake up as your own younger self, keeping all the memories of your older self. In Replay, we see this happen on a cycle, where the protagonist lives their life over and over again. The book examines the psychological stages a person might go though in this situation, and how that would affect the type of life they'd live. Sure it's fun to be mega rich, but does that lead to loneliness and fleeting personal connections? Is being famous worth it? What happens if you have children that you love and you know you'll die without seeing them grow up? It's a fantastic read that I come back to every few years. And I won't lie I've taken a quick look at the "unlikely" sport results in my past.

6. The Player of Games (1988) by Iain M. Banks

This book takes place in Banks' fascinating Culture series, a disconnected collection of novels taking place in a shared universe. Trust me, if you've ever thought "I would love to live in that universe" with regards to a book or movie, the Culture is the epitome of this. Imagine a post-scarcity interplanetary society that provides practically limitless comforts and experiences to everyone for free. It has overcome nearly all physical limitations on life such as death or disease, and the day-to-day life of its citizens can be anything they want; from living indistinguishable-from-life VR experiences, to transferring your conscienceness to a different body or species, to just partying all the time. I could have selected one of many of Banks' Culture novels for this list, but I decided on The Player of Games because it was my introduction to the Culture. Like most of the books in the series, much of it takes place on the fringes of the Culture, namely its interactions with other civilizations. A Culture citizen uses infinite leisure to become a master of what is essentially futuristic board games. He becomes enlisted by Special Circumstances (the CIA-like organization within the Culture) to "interfere" with a society whose hierarchy is based largely on an extremely complex game. The writing, the ideas, the characterization, and a gentle exposure into the vastness of the Culture makes this a wonderful introduction to first-time readers of Banks' masterpiece series.

5. Speaker for the Dead (1986) by Orson Scott Card

While working at a bookstore in my teens, I witnessed a wide array of people buying Card's Ender's Game. Men, women, young, old, it seemed to strike a chord with everyone. So naturally, I read it and loved it. On the shelf sat other books by Card, including Ender's Shadow (an excellent retelling of the events of Ender's Game from Bean's perspective) and Ender's Game's sequel, Speaker for the Dead. I've read that Card wrote Ender's Game as a prequel before developing his initial intention, Speaker for the Dead. People looking for more of the same will find Speaker a little jarring. It follows Ender as he comes to terms with the xenocide he committed, trying to learn for and speak for the mostly extinguished species. In this role, he begins a spiritual movement of speaking for the dead, which is an honest and deeply personal account of the life of the deceased. He travels to a remote planet on the request for a speaker and becomes deeply involved with inhabitants, quickly becoming entangled between what appears to be a conspiracy among the alien and human inhabitants. This was certainly a book that I spent a lot of time thinking during and after I read it. It's truly Card's masterpiece.

4. Exhalation: Stories (2019) by Ted Chiang

Exhalation is Chiang's second collection of short stories, this time spanning material published from 2005-2019. Many people's introduction to Chiang is the movie Arrival, and intellectual first contact film based on a story from his first collection, Stories of Your Life and Others. Chiang is the opposite of that kind of author that does one thing well and all their books are similar. Each of his stories are wildly different and imaginative. I had no idea what universe I was being plunged into when I started a story, but I always came away satisfied. The highlights for me in this collection were The Merchant and Alchemist's Gate, a cause-and-effect time travel story set in medieval Baghdad, The Truth of Fact, the Truth of Feeling, which explores the effect human memory has on people's lives, and Omphalos, an alternate universe where young Earth creationism is demonstrably true, and a scientist's discovery in humanity's role in God's plan. All of these stories presented ideas I was eager to discuss with others, and I always recommend Chiang to anyone looking for a foray into science fiction without the committment of a full novel (or, as is becoming more common, a full series of novels).

3. Project Hail Mary (2021) by Andy Weir

When I know I am going to read a book (e.g., a new release by one of my favourite authors), I always go in completely blind. I don't read a single word about the book before jumping in. This book rewards readers taking this approach. The book opens with the protagonist having lost his memory and slowly piecing together his solitary life. Having not read anything about the book beforehand, I got to experience this journey in parallel, whereas anyone who read the dustcover would know certain plot points before they are discovered by the protagonist. That isn't to say I didn't enjoy this book on a re-read, where the mystery of discovery became excitement for my favourite parts of happen. Anyway, as you can tell, I am revealing very little about this book because it's such a treat to learn about. Also, this book is particularly well-suited to the audiobook format, so if that's your thing it comes highly recommended. I enjoyed this adventure so much that I don't doubt I'll continue to re-read (or re-listen) to it in the future.

2. Rendezvous with Rama (1973) by Arthur C. Clarke

Although many people consider Childhood's End to be Clarke's magnum opus, I always come back to the slow burn that is Rendezvous with Rama. In short, it is the story of an alien spacecraft passing through our solar system, which appears to be long-dead and/or abandoned. Because of a lack of notice, a crew on a ship that just so happens to be nearby is tasked with exploring it. Rendezvous with Rama explores the effect of definitive proof of alien life on humanity, both at a personal level for those exploring the craft, and at a societal level to those experiencing it second-hand from Earth. Something about this story just feels so real. Of all the human-alien interactions I've read in sci-fi, this one feels the most plausible. If you enjoy the book, check out the BBC radio adaptation. I recently learned that my favourite director, Denis Villeneuve, will be making a film based on the book. Along with Project Hail Mary, I'm not sure I have ever been so excited for an upcoming film.

1. Children of Time (2015) by Adrian Tchaikovsky

So many times while reading this book did I pause and just admire the writing. Tchaikovsky's prose sometimes just makes me smile. It's like the literary equivalent to listening to music and that one note sends shivers down your spine. If there was ever a book I would like to read with a highlighter in hand, ready to immortalize my favourite passages, this would be it. Wonderful writing aside, the plot of this book is awe inspiring. It follows the parallel plots of an interstellar ark starship that is adrift in time and space, and a terraformed planet seeded with intelligent life by long-dead(-ish) humans. As the starship spends generations looking for a new planetary home, we witness the evolution of a new species on the terraformed planet. I was absolutely engrossed in both stories and absolutely loved the obvious research and what-if-isms Tchaikovsky obviously took great care to develop. These intertwined stories revolve around each until a very satisfying conclusion, bringing together both stories and resolution for both. The first time I finished this book was on an airplane, and I just sat there, staring out the window for the rest of flight, pondering what I just read.

Music2024-02-24

Early Days

Do you like country music? I am fine with it. At a young age, my family fished out Garth Brooks' The Hits on our drives to PEI, and I'll admit to bobbing my head to Callin' Baton Rouge and solemnly appreciating its haunting conclusion, The Dance. But it wasn't long after my sister handed me a mix tape of Gen X hits that I decided I was too cool for country. Get out of here Billy Ray Cyrus, hello1Hello, hello, hello Oasis. Suddenly I found my jam (technically, jams), with my favourites being Green Day, the Canadian-renamed Bush X, and The Age of Electric's Remote Control. Before long I got a Sony Walkman for Christmas and pilfered my sister's copy of Dookie, and with a couple spare AAs in hand, Shania Twain was drowned out by Longview on the road. This was the best song in the world. They were allowed to swear.

Teenage Years

I was in high school during what is now considered the golden age of emo and post-hardcore. And how fortunate to be part of this without the digital preservation of today's social media. But yeah, my CD collection was highlighted by Saves The Day, Thursday, Taking Back Sunday, Senses Fail, and Silverstein. I even played in a band, despite a lack of talent. But that wasn't going to stop me.

Perhaps even more interesting here was my frame of mind when it came to music. Here is a direct quote from my LiveJournal, circa 2003:

Have you ever noticed that music is a huge part in defining a person? I feel bad for those "I like everything" people. It's so great to have bands you love and shows to look forward to. I hate it when people just let muchmusic decide what their new favourite song is going to be. Unfortunately, this kind of music is all about "hoes and tricks" and "air force ones".

It's too bad that since rap is cooler than everything I like, those who like rap are cooler. I mean I've never seen Boys Night Out on muchmusic so they have to suck. What was I thinking? This was all fueled by when my sister said, "I can't believe you listen to this crap", and she then took out my CD and put in some Outkast. Thank you for saving me.

Early Adulthood

Here is where I quickly ate my teenage words and music was pushed more towards the "pleasant background noise" part of the spectrum, because now I had Adult Responsibilities. I still spun my favourites, but some indie rock, classical, and even jazz began to find its way into my Spotify Wrapped.2Yeah, no, streaming wasn't a thing yet. But I did move from CDs to an iPod Nano! I believe dubstep was my thing for a while there. But music was something I listened to when I had a long walk to university, a long bus ride to work, or I put on in the background while studying. And sadly my guitar spent this time in its case under my bed. Sure, I didn't really care for rap or country or whatever, but I wasn't posting diatribes on Facebook about it.

Today

Something happened to my frame of mind during the pandemic. If I were to summarize it, it would be along the lines of "be more chill". This shift has invaded my entire outlook on life. Car cuts me off? Maybe they are in a desparate rush. Dropped my lunch on the floor? Something, something, spilled milk. People love rap, country, or today's pop? Cool, just be you. I am also not so naive to think that I am alone in this transformation, or that it even has anything to do with the pandemic. Maybe it's just called getting old. My eight-year-old's taste in music is all over the place, probably because he has access to more than just a cassette of Dookie. And hey, maybe sometimes I am back in those long car rides, this time to bobbing my head to Astronaut in the Ocean, Thunderstruck, or even Justin Bieber. Not gonna lie, I genuinely like Miley Cyrus' Plastic Hearts. But there's always room for me to sit down, lean back, and let the poetry of Saves The Day's Stay What You Are take me away.

Tetris Attack2024-01-20

I was less than a week away from being on my own for the first time. In a few days, I'd be packing up everything and making the long 14 hour drive to Ottawa with my Dad to start university. But today I was puttering around a flea market, eyeballing things and wondering if an 18 year old needed them to survive. Did I need an iron? An ironing board? How do you use an iron? Why is it called an iron? Oh my god, what is fabric softener? But then, like many kids who grew up in the '90s, I abandoned all thoughts of irons and laundry when I saw the table selling Nintendo games.

When I was a kid, the Super Nintendo Entertainment System (SNES) was king. From the memorable Christmas morning circa 1993 when my brother and I spotted it wrapped under the tree, through the frantic calls to Sobeys' video and game rental department to see if they had Uniracers in yet, to the illegal wraparounds in NHL '94, my small group of friends were under its 16-bit spell.

Venus Video closing in my hometown was a blessing in disguise. Yes, seven year old me missed the free small bags of popcorn, but it opened a VHS-sized hole in our community. And that hole was filled by Hollywood Video. After winning a keychain by spinning the grand-opening prize wheel1Disappointing, I really wanted the snap bracelet., I beelined for the double rack (both sides) of freshly unpacked SNES games. Oh, the games! More than double compared to Venus Video's meager offering. What were these games I had never seen? Cool World? Joe & Mac? Actraiser? Mom, this is gonna take a while.

Over the next few years, when Parent-Teacher conferences came back clean or my parents needed me "not here" for a weekend, I found myself in front of that rack of games at Hollywood Video. New titles were buried in holds, so I made do just working my way through the classics. And one day that meant bringing home a puzzle game2Not popular with 12 year old boys. Trust me, ask the closest pre-teen. called Tetris Attack.

Don't let the name fool you. The name and theme of the game was changed from the original Japanese market to appeal to us Westerners. There are no falling tetrominoes here. It's somehow even simpler than that, you just move a cursor around and switch the position of two tiles to make lines of three-or-more matches. But somehow from this simplicity is a game of immense skill with a endless supply of just-one-mores. I loved it. Then Monday rolled around and back it went, no longer needed to keep the kids in the basement during my parent's soirée.

At a mature 18 years old,3lol puzzle games were cool now, so when I saw Tetris Attack on that flea market table for $5 I bought it immediately, dusted off my SNES, and packed it for my upcoming foray into adulthood. Later, after being eyeballed by my roomates, the SNES found its way to our common room. And so began the great Tetris Attack outbreak of 2004. Before long, high scores were scribbled on the walls, March Madness style tournaments were drawn up, and we all lived and died by the utterings of Yoshi and his friends. We had positioned the TV near the door to our suite and passerbys soon took notice of the shouts of the group of teenagers huddled around the 20" CRT TV. Before long, the same sounds could be heard from other rooms as newly delivered eBay purchases found their way to Glengarry House.

One day as I exited the elevator and stomped towards room 808, I heard the exciting fanfare of someone nailing a large chain. Poking my head into an unfamiliar room, I saw the comforting glow of Tetris Attack engrossing a group of strangers. As a smile spread across my face, one of them asked, "want to try?". Sure, I thought. Puzzle games are cool.

Gear Acquisition Syndrome2023-11-26

Buying things is easier than getting good at something. And, at least briefly, it can sometimes feel just as good as well. Gear acquisition syndrome (GAS) is the retail therapy that fuels hobbyists to endlessly pursue the perfect camera, bike, guitar, tool, etc., or to just build up a "respectable" collection of these things. I am too young to know how much this inflicted hobbyists in the pre-internet days, but surely this is problem has been amplified by a constant barrage of blog posts, review videos, discussion forms, and social media where people show off their goods and congratulate each other on buying stuff.

My hobby is guitar, which sometimes feels like an entire industry fuelled by GAS.1See what I did there. It's a retail attack from several angles at once: guitars, amplifiers, pedals, plugins. This is my first gear-based hobby where I have that toxic combination of some disposable income and my inherent "heavily research before you buy" attitude. So I got some serious GAS for a while there. I was wheelin' and dealin' on Kijiji. The local store knew me by name. The worst part is I spent much of the time I could have used playing guitar fuelling my GAS instead.

I finally got the GAS under control though a number of experiences and realizations:

• I watched old videos of myself when I had vastly different gear and realized it sounded not so different compared to my current gear.
• I want to sound like me. I was always adjusting new gear to sound like me.
• I played in a live show and realized that most of the nuance of different gear doesn't really translate well in that environment, and the audience sure as hell doesn't know or care.
• I went to concerts and felt like the range of gear that the musicians used didn't sound so different than mine. The players themselves made the gear sound good.
• I saw one of my favourite musicians use pretty basic gear and sound awesome.
• I realized I didn't want to be part of a system of unchecked consumerism.

So I've now been focusing on figuring out a way to produce my few core sounds as simply as possible for recording, practicing, and playing with others. I'm also not being too picky about live sound based on my experiences above. I'm nearly there, at which point I'm going to sell my excess gear then ban myself from certain websites that are GAS pumps. Then I will, you know, actually play my guitar.

Going for Yahtzee2023-10-28

My wife and I were playing Yahtzee when the inevitable decision arose. She only had Large Straight and Yahtzee left open and her first roll turned up

The tempation of Yahtzee (and a chance for the bonus Yahtzees) was too much for her. A misstep? Should she have kept 3-4-5 and gone for the Large Straight instead? Anyway, she went for Yahtzee but it was not to be. As she sketched that familiar zero on the scorecard, she pondered: "what if I just always went for Yahtzee?". Well, those who know us aren't surprised that it didn't end there. Let the great experiment begin!

Yahtzees are overpowered. Like the game-ending 150 points gained by catching the golden snitch, the glory and game-ending power of Yahtzees—especially bonus Yahtzees—is tantalizing. For those unfamiliar with the "real" rules of Yahtzee, a bonus Yahtzee not only nets you 100 points (single-handedly equalling a typical bonus-gained upper section in a single turn), but you also get to score in another box. Bonus Yahtzee of fours? Also put 20 in the fours row. Fours row is full? Feel free to mark 40 in Large Straight. Basically at this point you're Victor Krum.

So it's clear Yahtzees are where the big points are available. So why not go for Yahtzee every time? And how often can you expect to get them? To answer the former, it depends if you're playing to win or playing for the high score. Sure, you're going to crush it sometimes, but Yahtzees are elusive outcomes. Will your opponent just cruise to victory with a boring 272? There's only one way to find out!1Well, no. You can use probability theory to solve this problem as well. But, that's not a family friendly activity. We approached this from two angles. First we recruited friends and family to gather the outcomes from as many trials of the following experiment as possible:

Record the number of rolls it took to get a Yahtzee. Always "go" for the number shown on the greatest number dice (i.e., switch numbers if necessary), re-rolling all the dice if they all have different values. Break ties arbitrarily.

Somehow we have enough friends and family that go along with our nonsense, so we managed 308 trials. But guess who has no choice but to do as many trials as we want? My trusty old Lenovo ThinkPad. I threw together some Python code to run some trials as well. And by "some" I mean one million. So were the human trials necessary? I mean, why are MLB umpires still used to call balls and strikes? It's a human thing. Anyway, here are the results.

So there you have it. If you go for it every time, your odds of rolling a Yahtzee on any given turn are about 1-in-22 (I'm trusting the computer's 4.55% on this one). Given that you only get 13 turns, the boring approach of filling the score card out the old-fashioned way is probably best if you're trying to defeat an opponent. On the other hand, screw that. Gimme some of those sweet, sweet, bonus Yahtzees!

Circle of Protection2023-09-23

The year was 1997 and I was unstoppable. My Serra Angel had been cast early thanks to the lucky draw of a Sol Ring. This majestic angel was alone in the skies above the battlefield, her aptly-named Holy Strength a pious omen of the imminent smitening to come. But the helplessness didn't stop there for my 11 year old opponent. A surge of adrenaline struck as I drew my secret weapon: Empyrial Armor. Let's see him deal with a 9/10 flyer coming at him every turn, making a mockery of his laughable fielding of a Pearled Unicorn and Prodigal Sorcerer. I bubbled with the smugness of a Video & Arcade Top 10 champion, for victory was all but assured. I could practically hear Nicholas Picholas (is that his real name?) awarding me a Toronto Blue Jays prize pack. But then my opponent did something unthinkable. He committed a major faux-pas that would reverberate through the hallway of the elementary school in which our battlefield was perched. He slapped down Circle of Protection: White on the dusty floor.

All zero people watching our duel gasped. How could he? A Circle of Protection? He was making a mockery of our sacred pact. Circle of Protections were banned.

Joe Posnanski once wrote that baseball is best when you're 10 years old. But it's not just baseball; for at 10 years old, my baseball was Magic: The Gathering. And I even played baseball at the time. Back then this was still the frontier of the card game and was barely a rung above Dungeons & Dragons on the keep that to yourself scale of nerd indulgences of the '90s. But at 10 years old, you're old enough for your first deep dive into an obssession that your newly lengthened attention span can support. It's a magical time when school, siblings, and taking showers are just a distraction until you can really live. For me, that was on the battlefields of dusty floors, carpet rugs, and kitchen tables. I planned decklists and combos in my mind and fantasized of pulling a Jester's Cap from my booster pack, as my Mom scoffed at me wasting my birthday money.1 I once bought a second-hand Royal Assassin for $10 and my Mom nearly fainted. ("$10 for a single card? Are you crazy?") I think many people can think back about whatever fascinated them when they were 10 years old and can relate to my burgeoning awareness of the pleasures in this world. Whether it was Polly Pockets, the Titanic, or Super Mario RPG: Legend of the Seven Stars, we all went all-in to the bewilderment of our, and in my case, boomer parents whose presumed childhood cup-and-ball obsession failed to draw the appropriate parallels. And, I think, we all try to capture the magic of this time in adulthood,2 We are currently nearing the peak of markets targeting millenial's chase for this feeling, speaking as someone who rocked a TMNT backpack. but can only grasp at wisps of nostalgia because baseball is best when you're 10 years old.

Level 72023-08-05

While I was working in Germany, my workplace had a small English language library. It was mostly stocked with donations, containing what I estimate to be a few thousand books. Luckily for me, it had a sizeable science fiction section, with some authors dominating the collection (presumably favourites of the donors) and scores of out-of-print books from the 1950s to the 1980s. I had a lot of time to read, as I was living by myself in a foreign country and took the tram to work every day. So often on my lunch break, I found myself browsing through the science fiction section, essentially judging the books by their covers.

One thing interesting is the books never changed. Over a year of visits, there were never any new books in the science fiction section. I came to enjoy this lack of option paralysis. Books that I had earlier skimmed over quickly became prime candidates as I read my way through the section. As a result, I read many books that I wouldn't have given a second glance had I had access to the tome of a large public library. One such book was Level 7 by Mordecai Roshwald.

Level 7 is a speculative fiction novel written in 1959, not far after the start of the Cold War. It is about a military officer (whose nationality is never specified) that receives orders one day that require him to enter an underground complex. Shortly afterwards the complex is closed and sealed (to the surprise of the officer) and he is ordered to push buttons that he later learns was his direct participation in nuclear war. The whole war lasts about three hours and then the protagonist is faced with living the remainder of his life on the bottom (seventh) level of the underground complex.

This book is terrifying. I can't imagine reading it at the time of its publication, when its events were a very real possibility, at least more so than today. I can feel the claustrophobia setting in page by page, and with it, the anxiety of the inhabitants. As clues trickle in that reveal the state of humanity and the likely fate of the entombed survivors, it's clear that perhaps those who remained on the surface were the lucky ones.

Several years later I happened across the book at a used book store and bought it at once. Upon re-reading it, I fell into a kind of stupor that I recalled from my first time through. I don't know if I'll read it again.

In some ways this story gives the most realistic picture of nuclear war that I have read in any work of fiction.

Defaults2023-02-17

When I first started developing in Linux, I went all in on the tools and configuration rabbit hole. I heavily configured my .vimrc with all the latest plugins. My tmux.conf had a clock and weather. My .zshrc was full of aliases and plugins. And the crown jewel of my setup was my heavily configured i3 window manager (sans desktop environment, of course). And so on. Everything was under version control and could be configured and installed via scripts. Based on countless reddit subreddits and blog posts, I certainly was not alone. I was zipping around the command line, window splits, sessions, etc.

My setup became more of a hobby then any sort of notion of productivity. That isn't to say I didn't enjoy it. Whether it was learning of new tools on unixporn or tweaking the colours in my .Xresources, heck I was having fun with it. So what if switching between monitors required a custom script or connecting to wifi required puttering around on the command line. Everything was so lightweight!

Eventually I was issued a laptop at work where I was a little more restricted as to what I could do with it. At the same time, I had moved onto other hobbies and wanted to try something a little different. I decided to have a go at really learning the default Gnome desktop. And by defaults I mean just that, I didn't tweak any keyboard shortcuts or any other settings. Rather I learned not only how things were provided out of the box, but also how the desktop was designed to be used (i.e., the Gnome philosophy). It was actually kind of enlightening. At first it was kind of like moving around with one hand behind my back. But to be honest that's what learning vim was like until I stuck with it. And there's something to be said with being able to hop onto anyone else's machine and feel right at home. And although I've toned down the configuration and plugins, I'm still right at home on the command line.

Now, several months later, here I am looking ahead at the new features and improvements in the next Gnome release.

Algorithm Illustrations2023-02-15

I often like to draw illustrations to help communicate an algorithm I am explaining, designing, or implementing. For example, perhaps I am teaching someone how a Kalman Filter works using the popular example of a one-dimensional robot driving towards a wall. For this task I want to use simple program(s) that can do the following:

• Draw lines, arrows, shapes, and other simple geometries
• Easily align the different geometries with snapping, guides, and distributing tools
• Is not overburdened with many features and tools I'll never use
• Label different parts of the illustration with mathematical symbols or equations, preferably using LaTeX
• Edit the math/LaTeX after I've put it in the image to update symbols or fix mistakes

Back when I was using a Mac for everything, my preferred solution was a combination of Omnigraffle and LaTeXiT, which worked wonderfully. But I've sinced moved on to Linux and prefer to use open source software when possible. A good illustrating solution eluded me until recently, when I found it in LibreOffice Draw with the TexMaths plugin (with which I made the above illustration). Success!