People count things with words. Yet some internal features of number systems in human languages are fascinating.

Number systems come in a great variety of shape and form. English’s base-10 system is quite unusual in its regularity, as systems in human languages go. French mixes decimal and vigesimal forms …

An absolutely stunning feature of the lambda calculus is that it allows us to define functional recursion without using recursion. That is, the concept of recursion is fundamentally a by-product of being able to reproduce multiple copies of a function’s input in its output.

In other words, the “essence …

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There’s this guy I know, and this guy, and this guy

Most published scientific articles display two or more authors. This does not necessarily mean that more than one person was involved in writing the article. The “author list” of scientific articles, like marriage in traditional cultures, is usually decided by unwritten political rules rather than love and the personal preferences …

A recent XKCD post makes fun of frequentist statisticians and hails Bayesian statisticians for their superior skill at predicting trivial outcomes. This comic makes it look like only Bayesian approaches are sane and reality-compatible when predicting outcomes. This annoys me. There is no need to invoke Bayes’ theorem and Bayesian …

We have in our office this awesome networked multi-function laser color printer able to churn out hundreds of pages in a few minutes. It’s also our coffee corner at work. Which means I spend time quite often next to it. And therefore that I see stuff coming out of …

In 2011 Alan Kay gave a talk/lecture on Programming and Scaling at the Hasso-Platner-Institute Potsdam. The take away is that you have to be creative and step out of the box to design new software that is both very simple and very powerful. The Cairo compositing system is his …

So there’s this bunch of friends who wanted me to play Scrabble with them. I’d like to play with them. Unfortunately, my relationship with words does not involve decomposing them into individual letters: I learn and use them as a whole, not an assembly of their parts. So …

Men and women hired as scientific researchers soon after their doctoral graduation are often labelled “post-doc” by their peers, their organization, or even themselves. This label is misunderstood by everyone, even researchers themselves, because it has different definitions in different organizations and no clear definition outside of these organizations. It …

September 5th, that was last week. Photos and videos were made. But I was not really there.

(It was reminded that I write a lot. It is thus fitting that I would deliver an epilogue in writing as well.)

“the clothes were really nice. the event was impressive.”

I am …

An epilogue to the past few posts, also published as chapter 16: “What now?” Who will constructs computers of the future, and how? I’m not sure yet, but we can start with a few statements.

Innovation in computer architecture, while necessary, is not a task that can be carried …

General-purpose computers are, like stem cells for living organisms, key to the perpetuation of computer engineering. Here’s why.

Sometime between 1992 and 1996, CALC was written. CALC was a graphing program: the user would interactively enter on the keyboard the definition of a function and the coordinates of a …

As I argue in the intro to this book, the advent of general-purpose computers has altered the limitations of the human condition in ways both unforeseen and still poorly understood.

In the middle of the 20th century, something exceptional in the history of mankind happened: a universal tool was invented …

The words “computer science” seem to mean different things. Some use it to talk about making web pages, others to talk about computational complexity theory or category theory. As I argue in the intro to this book, it’s more than the combination of both. Here’s why.

The term …

What is “science” exactly? What is “innovation” in technical fields? Here’s my take, from the intro to my recent book.

The traditional purpose of the fundamental sciences is the acquisition of new knowledge pertaining to observed phenomena, in an attempt to describe “what is.” In parallel to the discovery …

A dear friend yesterday shared his quest to sharpen his understanding of philosophical concepts by studying their opposites. Like one can better understand light by acknowledging darkness, it seems to him that much is to be learned about wealth, power, comfort, safety and liberty by considering what they are not …

Distraction is pleasurable, but there are many ways to waste time reading stuff online. There’s the useless stuff, and there’s the stuff that makes you stupid. In contrast, choose wisely and balance useful stuff with stuff that makes you smarter and more creative.

For example: web comics are …

Recently I have published a book. This could not have happened without the help of a few special people, whom I thus profusely thank at the beginning. Yet this simple expression of gratitude has raised unexpected questions, some from people close by, that make me wonder what picture of me …

It was an ideal moment.

We saw the bus leaving as we crossed the street. Twenty minutes to kill, at least ten with nobody around.

Content after a productive day. Content from a clement weather, the kind where it is pleasurable to be outside. Carefree, confident in success to come …

Het binnenbad was gesloten. Als we toch naar buiten moeten, dan liever onder de schaduw dan onder de zon met schreeuwende kinderen?

Wij liggen naast elkaar, onder een boom. Jij leest, iets over kwantum mechanica. Ik doe mijn ogen dicht, luisterend naar het geluid van de wind door de bomen …

My friend Julieta [had] this weird idea of writing 25 random facts about herself, and asked some of her friends (including me) to do the same.

This is a repost from a previous entry, updated after 3 years. Deleted text from the previous version is mentioned for reference but stricken …

Should functional programming be taught early in computer science curricula? For example as the first topic upon entering higher education? I have often thought about this and could “feel” it was a good idea without being able to articulate why. I was mostly stuck with ideas that it “fosters and …

Larry Sanger, co-founder of Wikipedia, has recently argued his perceived increase of anti-intellectualism among geeks. By denouncing anti-intellectualism, he turns into an anti-anti-intellectualist. However I don’t like his picture of “intellectualism”, here’s why.

By “anti-intellectualism” Sanger means: 1) disrespect towards the role of experts 2) disinterest in books …

Je bent er niet voor opgevoed. Je plannen omvatten kinderen, een huis, een hond. Je kijkt naar mij, en ik zie in je ogen dat je niet ziet hoe ik erbij zou kunnen passen.

Je hebt misschien vooroordelen over de “levensstijl” dat het impliceert. Ik heb je een keer een …

You, there. You have exposed some rusty cogs in my thoughts processes, and I friendly despise you for that. The rest of the engine has awakened again by the way, after so many years of dusty oblivion; I guess I should thank you for that. But today there was something …

When you expressed last Friday your interest in my opinion about you trying to decide how to shape your future, I felt honored. Many thanks for trusting me; although I don’t believe you should trust me too much on this.

My musings from the past few days were an …

Two days ago, we considered together the difficulty to move forward, and we mulled over the question of “why.” Yesterday, I presented you the four-base model I had used so far to recognize the drive in other people.

You see, one aspect of my crisis is that I am not …

Yesterday, we saw that answering your “why” may be an important step to decide what you are going to do next. If you are anything like me, chances are it’s difficult for you too. Did you know different people have quite different answers to it?

Together, we recalled our …

What now? That was the question that kept a friend and myself busy over the telephone for about an hour yesterday.

We found that there are two main criteria to consider: who you interact with, and why you do what you do. We found also that “what”, “where” and “how …

Lately I have been entertaining myself in the evening by playing and replaying Diablo 3.

The general goal of the game is to save the world against evil forces; the means to achieve this goal is to slay said evil forces repeatedly, using combinations of magic, dexterity, strength, vitality and …

How to organize your contact list, 21st century-style.

Orkut, Hyves, Facebook, Google+… They all try it and fail.

Did you ever have to decide whether your best buddy at work should be labeled “Friends” or “Work”? Or whether your brother-soon-to-be-co-founder should be “Family” or “Work”? Or whether your best-friend-closer-than-your-brother should …

All manners of self-help and “life hacking” sites promote programs and techniques to expand one’s boundaries of self-awareness or otherwise improve one’s compatibility with the real world (as opposed to the fantasy world that most people have built in their head). I think they are all unnecessary; there …

Ever wondered how to put a network to good use with sound matters? Here’s how it’s done at my place.

A simple setup looks like this:

This diagram illustrates the use of the Music Player Daemon (MPD, wiki, wiki) on a centralized music library and audio output, with …

Something happened in the world of Minecraft; an opportunity to illustrate my favorite pet peeve against “cloud storage”.

When someone opens their Google Mail interface, they will expect to see the same list of e-mails (or more) as they saw the last time they opened the interface, even possibly from …

I can’t seem to remember this analogy ever been used: digital information as fire.

Imagine our ancestors: before flint was discovered, humans were dependent on lightning, lava and spontaneous ignition to initiate fire. Then when flint was discovered, it wasn’t discovered by everyone: some groups of humans had …

The question “top or bottom?” can be answered with “versatile,” to mean “either, depending on circumstances.” Another possible answer is “interleaved.” Here’s an argument that the proper answer should be “both” to maximize satisfaction.

Quoting from Wikipedia:

The main options [when replying to email] are interleaved posting, also called …

What criteria should one use to pick a job?

Most people would answer a combination of skills, salary and commute time.

My personal experience taught me that it is whom you work with, not what you do, how much you get nor where, which matters most.

It’s just a …

You probably wish you had seen the fine print on the package.

The hazard warnings were clearly indicated, in big letters. Annoyance awaits a particular human trait, or so you’d heard. Bullying, then discrimination, the occasional gratuitous violence, inequality before the law, administrative hassles, and whatnot. You heard the …

I had a shitty week-end.

Maybe not the shittiest week-end ever. There were two light point, namely the impromptu water art session on Saturday night and two hours of dance classes on Sunday. Just for that it was not all that bad.

Nevertheless, except for these few light hours, I …

Something is up, this is not my “normal” self. Lately I wake up often to vivid dreams; with rich imagery and rich scenarios, diversified in place, duration, characters, intensity, atmosphere, colors, moods. I did not use to dream this much.

Last night was an itinerary through a series of houses …

The scene takes place during daytime, at the frame of a door giving to a veranda in a wooden house. This must be a public place for there were a number of strangers around us. Two friends and I. Talking about past and recent achievements, one of them highlights that …