davinci’s notebook » computer science

Perimeter Scholars International — Master’s program in Theoretical Physics

davinci — Sun, 29 Nov 2009 03:34:06 +0000

I was asked to pass this information along to anyone who might be interested:

Canada’s Perimeter Institute for Theoretical Physics (PI), in partnership with the University of Waterloo, welcomes applications to the Masters level course, Perimeter Scholars International (PSI). Exceptional students with an undergraduate honours degree in Physics, Math, Engineering or Computer Science are encouraged to apply. Students require a minimum of 3 upper level undergraduate or graduate courses in physics. PSI recruits a diverse group of students and especially encourages applications from qualified women candidates. The due date for applications to PSI is February 1st, 2010. Complete details are available at www.perimeterscholars.org.

There’s also a downloadable poster with more information at this link.

– davinci 11855

Object Oriented Turing

davinci — Sat, 19 Sep 2009 11:00:40 +0000

I suppose that this post is a continuation of the one on old software and books.

The Turing programming language (named after Alan Turing) was developed at the University of Toronto as an introductory language for teaching computer programming at the high school level. It was (and apparently still is) widely used in Ontario.

I had actually won this software package in a University of Toronto programming contest in high school.

The difficulty with teaching computer programming to high school students is that skill levels will vary widely among the students. Students who already know how to program are probably already familiar with C/C++, Pascal, Basic, or Java, and would find a teaching language such as Turing very confining. These students likely know far more about how to program than the teacher does. At the other end of the class, there are students who barely know how to type, and they’re unlikely to pick up very many programming concepts no matter how simple the language they’re taught with.

At least, that was the situation back when I was in high school. Given the proliferation of personal computers and other consumer electronic devices such as cell phones, today’s teenagers are, on average, much more tech-savvy than before. And so the knowledge gap between the best students and the teacher (a technologically-behind-the-times adult) might be even worse than when I was in high school. But on the other hand, the latest crop of today’s high school teachers also come from the first generation to grow up with widespread personal computing technology, so maybe the playing field has been leveled somewhat.

The objected-oriented extension of Turing was a new product at the time. (I had version 1 of the software.) By the time it rolled out, however, C++ had been around for a while, and Java was about to appear. So anyone who was intent on learning object-oriented programming had better options.

And, generally speaking, students don’t like to learn languages designed for teaching because they understand that the minor possible increase in ease of learning comes with a very steep reduction in economic payoff. Nobody will pay you to be a great programmer in Turing, but even a mediocre C++ or Java programmer can make a decent salary.

My friends and I wrote numerous programs — mainly games — in Turing, which we shared amongst ourselves. Unfortunately, I’ve lost many of them, or they’re on floppy disks which I no longer have the hardware to read.

The software and reference books are now available for free at the web site for Holt Software, the company which used to produce Turing.

– davinci 11785

The causes of my depression, part 2: my high school predictions about the future

davinci — Thu, 23 Apr 2009 04:01:01 +0000

In high school, I predicted to my parents what I would be doing in the future, the kind of environment I would be working in, and even the demographics of the people I would be working with. But instead of helping me, my parents did everything they could to hinder me and prevent me from achieving my goals.

My predictions were quite reasonable, or so I thought. First, there would be a close collaboration between computer scientists and physicists to study some issues which are at the core of both fields; as a result, there would be a niche for people fluent in both fields who could facilitate communication between the two communities. Naturally, I thought that I should fill that role. Second, I would be working in close proximity specifically to astrophysicists; I will explain how I arrived at this conclusion in a later post. Third, the engineers and experimentalists in this combined community would include a disproportionately large number of Iranians; this was actually just one minor aspect of what I thought at the time about what the demographics of my future colleagues would be like, but it would turn out to be important later. I had classmates who wanted to become professional athletes, movie stars, or members of pop music bands, and their parents indulged them despite the unlikelihood of attaining their goals.

Before I discuss why I thought what I did in high school about the future of computer science research, I want to point out that the general public actually has a completely wrong idea of what computer science even is. I think Edsger W. Dijkstra summed up this misunderstanding best when he opined, “Computer science is no more about computers than astronomy is about telescopes.” (Incidentally, while Dijkstra is famous as a computer scientist, he was trained as a theoretical physicist.) My experience has been that when most people who are not computer scientists hear the words “computer science”, they think of either computer applications or computer programming. This was especially true in the early to mid-1990s, when I was in high school, and a few years before the dot-com bubble burst. Whenever anyone heard that I was studying computer science, they would inevitably say things to me such as, “Oh, you must be really good at programming”, or — and this happened often enough to be quite irritating — “There’s something wrong with my Windows, can you fix it for me?”

Now, it happened that I was really good at programming, and I did fix their broken Windows — and I made good money doing both. But the point is that applied and theoretical computer science are really two separate (though related) fields, and lumping them together under one name is, I think, quite damaging to potential future graduate students in computer science. I have already mentioned this in a previous post. I was actively discouraged by my parents from studying topics during high school that I would later need for graduate school in computer science, on the grounds that they had “nothing to do with computer science”! Of course, when I did inevitably encounter the very same topics later, it made me very depressed and I couldn’t focus on my studies. (And to further rub salt into the wound, my parents would then accuse me of being “distracted”.)

I think that there are, generally, two kinds of high school students who end up entering graduate studies in computer science and related fields. The first enjoy reading popular books on science and mathematics, such as works by Douglas Hofstadter, Daniel Dennett, Raymond Smullyan, and Martin Gardner, to name but a few authors, and solving puzzles. The second spend a lot of time studying their textbooks and doing their schoolwork. I fell naturally into the first category — and besides, my teachers encouraged me to read by suggesting books and authors to me — but my parents kept pressuring me into the second. Every time they caught me reading something that didn’t look like a school textbook, they would tell me to stop “wasting my time” on “nonsense”.

When you’re trying to understand a difficult subject, you don’t want to be interrupted. You especially don’t want to have to be defending yourself against accusations that what you’re studying is “worthless” or a “waste of time”. I have already written much about how traditional Chinese culture is incompatible with science, and I think it bears re-iterating. No culture in which it is considered a sin to defy authority can ever sustain scientific development. Once my father had declared that certain topics had “nothing to do with computer science”, then they didn’t, and that was that — regardless of the facts.

My parents simply ignored everything I told them about how important certain topics were to my future career in computer science. After all, my father worked with computers, and he had never heard of any of the things I told them about, so they must be “worthless”. My mother’s attitude was that my father was always right and I should listen to him; I simply had to be wrong for no reason other than because “your father knows what he is talking about”. Eventually, I began to ignore them instead of defending myself whenever they ordered me to stop studying. When giving me an order once wasn’t enough, they began to interrupt me every several minutes in order to disrupt my concentration, so that I wouldn’t be able to study. And when that didn’t work, my father would scream at me, and eventually that escalated to hitting me. But that only happened a few times, because by then I had learned to hide my studies pretty well from them.

I think that there are certain ideas that a person has to be exposed to early on, if he or she is to understand them deeply, because they have to be ingrained into his or her very thought processes. One example of this is the idea that problems can be categorised into classes such that they are somehow “equivalent” within each class, and solving certain problems allows you to solve any of the problems in that class. The basic gist of the idea can, I think, be understood by a bright child even in elementary school, and most certainly by the time he or she is in high school. But once you have it, every time you see a problem you ask yourself, “What other problems is this one like?” or “Can a solution to this problem be used to solve any other problem?” It becomes a habit and affects the way you think. Anyone whose first exposure to this idea is in university is, I think, being exposed to it far too late.

The difference between the two kinds of high school students can be seen by the time they enter graduate school. Those who stuck to their textbooks typically study applied computer science or computer engineering. Theorists, on the other hand, tend to have read a lot of interesting books. This is all based on my admittedly unscientific observations, conversations with various graduate students, and an examination of the titles on their bookshelves. But I think it partially explains the abundance of students of Chinese cultural background in the applied areas and their paucity in the theoretical ones — because their parents prevented them from being exposed to ideas not found in high school textbooks.

– davinci

Gifted program in Mississauga

davinci — Sat, 22 Nov 2008 02:03:27 +0000

In Mississauga, we were enrolled in a gifted program at a Catholic elementary school, because our mother is a Roman Catholic. They had a pretty nice library there, and because the school was Catholic, there were lots of books on Latin, Greek, Roman history, and Catholicism, and I became interested in those subjects.

I had actually been reading the Bible in English since my arrival in Canada. My grandparents were given a copy when they were sworn in as citizens. Since they couldn’t read it, they said I could have it, and I used to read it every day. In grade five, the Gideons came to our public school — in fact, into our classroom with the teacher’s permission — and gave each of the students a pocket edition of the New Testament with Psalms and Proverbs, with a red leathery cover. I used to carry it everywhere and read it whenever I had the chance. Nowadays that sort of blatant proselytism of immigrants and children would probably not be allowed inside a public institution. But I don’t think that I was ever harmed by it — in fact, quite the opposite. By studying the Bibles, I not only learned about Protestantism and other sects of Christianity, but also vastly improved my vocabulary, became familiar with archaic and other literary forms of English, and began to think about problems of translation between languages. So I don’t think the Bible should be kept out of public classrooms, as some people do — it is one of the most important documents in Western civilisation, regardless of one’s beliefs about it, and one can learn a lot from it.

Since I was at a Catholic school, I tried to memorise the Vulgate in Latin and read the New Testament in Greek, but I wasn’t successful. Nevertheless, my exposure to these classical languages would prove very useful later in high school science. Also, I developed the ability to memorise lengthy texts in languages I didn’t completely understand, which would become very useful later as well. After I devoured the books on Roman history and Catholicism, I expanded my interests to history and religion in general. I spent a lot of time visiting libraries and bookstores. In fact, I spent most of my time on extracurricular activities but very little on schoolwork, but I did really well because I was already so far ahead, and I was continuing to study ahead. My parents hadn’t yet caught on to the fact that I wasn’t “studying” according to their definition of studying, but my academic freedom would soon come to an end.

At the end of each school term, there would be a parent-teacher meeting where the parents would come in and discuss their child’s grades and whatnot with their teachers. When I was in Whitby, I would serve as my grandparents’ translator because they didn’t speak English. So I knew what sorts of things were being said about me: “tell David that it’s great that he’s reading all these books, encourage him to explore this-and-that, etc.” They also gave us pamphlets on how to raise gifted children, which I read because my grandparents couldn’t. But when my parents returned from the parent-teacher meetings, they would say things such as “Your teachers say that you’re always distracted by things other than your schoolwork. Stop running around doing all these extracurricular activities.” I am certain that that’s not what they said — but it’s what my parents heard. They always turned a positive into a negative.

When my parents arrived in Canada, my brother and I were at the top of almost every subject — so we must have been doing something right. There were other students who were also ahead in math, but they weren’t very good at art, or they were excellent writers but didn’t know about history, or whatever. But we were good at almost everything, and we got that way by doing all the things my parents didn’t want us to do. As the saying goes: “if it ain’t broke, don’t fix it”. But my parents insisted on interfering with everything.

We had to hide our comic book collection, because if my father saw it he would scold us for wasting our time and money — but we were doing so well in art class because we were inspired by comic books! So we were allowed to read a textbook on art if it was assigned by the school for a class, but we were discouraged from looking at or producing actual art. And whenever my father saw me on the computer, doing something he didn’t understand, he would tell me to “stop playing games”, even though what I was actually doing was learning about programming, operating systems, and so on. I was in elementary school at the time, and most of my peers would even not learn about these things until university. So my father basically prevented me from getting even further ahead than I already was.

On the other hand, he had some books on computer science from when he went to university or from work, and he would allow me to read those. But they were limited to certain subjects only, basically: programming, databases, and graphics. (He also had some manuals on things like word processors and operating systems, but they only told you how to use them, not how to build them.) Outside of that, my father discouraged me from reading. For example, I couldn’t read books on game theory at home because he thought they were about computer games, which of course were “a waste of time”. But what really angered my parents were the extracurricular books on subjects which they didn’t understand, which my teachers had encouraged me to read because I was ahead of the class.

One of the most common things that you hear everywhere about raising children is “encourage your children to read”. But my parents were just the opposite. They continually discouraged me from reading. Whenever my father saw me with a book, he would ask, “Is that for schoolwork?” Even the asking of the question bothered me. What was wrong with reading books which were not on the school curriculum? The teachers in the gifted program had specifically advised parents to encourage their children to read outside of school! If I answered “yes”, he would leave me alone. But most of the time I would answer “no”, because I had a distaste for textbooks assigned by the school. In the gifted program, even the teachers often ignored the official curricular texts. I would always find interesting books on my own, and bring them in to discuss with my teachers — I found that I learned a lot more that way. But my father would say, “Stop reading and go to your room and study!” Now, in Chinese, the verb “to study” literally consists of the characters for “to read” and “book” — I always found it ironically amusing that he would tell me to stop reading, followed by an order to go to my room and read.

So all the time, my parents were going against what the literature on parenting and gifted children said to do. They received advice and literature on gifted children from my teachers, but they ignored the advice, and I am certain they never read the literature, which said to encourage reading, pay attention to and praise your child’s interests, look for unconventional ways to stimulate and challenge them, etc. These are common sense things that apply not only to gifted children, but I think really to all children. I think the only reason they wanted us in the gifted program was so they could brag about it to our relatives.

I continued to read despite my parents’ discouragement. Whenever they saw me reading, they would try to get me to stop, but I ignored them. My father would raise his voice, and sometimes he would shove me, but I would just leave and go read somewhere else. Both of them would disparage my interests — there are some Cantonese expressions, which don’t really translate into English, but which basically mean “frivolous”, “nonsensical”, “worthless”, “impractical”, and so on. They would nag at me using these expressions: “You’re always reading nonsense”, “Stop wasting time reading about worthless things,” etc.

But the most annoying thing wasn’t that they kept disrupting my studies — it was the fact that they took credit for everything I did while doing so. They would scream and yell at me at home for doing whatever, and then when a teacher or another parent mentioned how great it was that I was doing that exact thing, they would take credit for it, without the slightest trace of a recognition of the incongruity. They were always praising themselves for what excellent parents they were and criticising everyone else’s parenting.

I am very fortunate that I always had excellent teachers. My teacher in grade six, Mr. Watters, taught the class what I now consider to be the most important subject I have ever studied: logical reasoning and the formal and informal fallacies. I was dimly aware of certain patterns of erroneous reasoning that I had encountered over and over (especially in the religious literature I had read). And now I had names for them! To determine the truth of anything, it is necessary to understand and apply logical reasoning correctly and properly. So this was a tremendous boost to my ability to understand a lot of other things. I think this topic should be introduced into the regular school curriculum, because there really is a lot of hucksterism in politics and religion and generally just out there in society, and logic is a really effective defense against being fooled. Another amazing thing that Mr. Watters did was to allow me to do my math homework in hexadecimal. I mean, how cool is that?

There was a shelf in one of the classrooms with books that we could just pick up and read. I was introduced to quantum mechanics at around this time, by a book that was there called “In Search of Schrödinger’s Cat”. From that I learned a lot of the names of big physicists, and went to the library and looked them up, and so on. So I read a lot of physics books, and I learned a lot of things that would later show up in high school. Before this I had wanted to be a mathematician, because I was good at mathematics, but in those years I became more and more interested in both computer science and physics. And I became especially interested in Richard Feynman, because he was a physicist who also directed his attention to computation, and because his books were fun to read. He really impressed on me that the life of a scientist can be very fun and exciting. My parents’ attitude had always been that “fun” and “work” are two separate things.

I thought a great deal at the time about what made a great scientist. I realized that the scientists whom I admired the most were those who dedicated their time and energy towards the betterment of society. All were people who not only made important contributions to their fields, but also did other notable things. Some made science accessible to the public, such as Carl Sagan and Richard Feynman. Others shaped important historical events, such as Alan Turing, and of course numerous scientists during World War II and the Cold War. I said to myself, “Well, there’s obviously no such thing as ‘the number 1 scientist in the world’ — but being a number 1 scientist means promoting science and using science to improve the world.” So by the time I began high school, that was what I had already decided to do.

So near the end of elementary school, I asked myself the question: “what are going to be the main defining geopolitical issues of my generation by the time I became an adult?” I considered overpopulation and climate change and other big issues that were often discussed in the news. But I wanted to find an issue that I could contribute to as a part of my continuing studies into computer science and physics, and one which other people had not yet started paying attention to but would become very important in the future. This was in the late 1980s and early 1990s: the USSR was about to collapse and the Internet was just getting popular.

I realized that the one topic which tied together almost all of my interests was the resurgence of religion in international politics. This may seem completely outlandish, but it made a lot of sense to me. In the United States, Christianity was becoming more intertwined with government — this process had been accelerating since after World War II, when “godless Communism” became the primary ideological enemy. Fundamentalist Christians were trying to inject creationism into science class. Perhaps biologists are best equipped to refute many of their erroneous arguments, but computer science also deals with complex, evolving, and self-replicating systems, and I could see the errors in the creationists’ claims very clearly.

But I thought that it would be the encounter between the West and the re-awakening Muslim world that would have the most impact in the international arena at the beginning of the twenty-first century. I had studied the Crusades, and knew that the conflict between Christianity and Islam was not resolved and was only dormant, and thought that Islam would soon re-assert itself on the international stage. The reasons are too complex to go into here; and besides, these things are now common knowledge. But very briefly: many non-Arab Muslim-majority countries had undergone a process of Islamisation in the 1970s, a decade with two oil crises and which ended with the Islamic Revolution in Iran. The 1980s saw the Soviet invasion of Afghanistan and the Iran-Iraq War, the first of which precipitated the collapse of the Soviet Union and the second of which led to the Iraqi invasion of Kuwait, both in the early 1990s. The Internet was also becoming popular at this time. Through it and other mass media technologies — you don’t have to be able to read to listen to the radio or a cassette, or watch a videotape — Western (and in particular, American) culture penetrated into formerly isolated Muslim societies, some segments of which held what are essentially medieval views of the world. And what they saw wasn’t necessarily the best parts of Western culture either!

All of this was very interesting to me. The West took hundreds of years to evolve into societies with certain ideas of individual rights, freedoms, and liberties — with a considerable amount of blood spilled in the process. Concepts such as freedom of speech and freedom of religion (and perhaps more importantly, freedom from religion) developed alongside communications technologies which made the wide dissemination of heretical ideas possible. The Industrial Revolution and the mechanisation of manual labour meant that men moved from farmland into cities, women joined men in the workplace, children could enjoy childhoods relatively free to engage in their own pursuits, and so on. Many predominantly Muslim countries absorbed all of these modern technologies and immediately had to deal with their social consequences, without having gone through all the intermediary stages that Western societies had gone through. And of course the traditional authorities, the religious leaders and so on, didn’t like this and had to contain it. But they couldn’t shut out the technologies, and so what they did instead was to produce their own cassettes and videotapes, put up their own websites, and so on, promoting their views about the world. They had to pro-actively attack Western ideas and Western values, because the best defense is a good offense. So what you had, basically, were men with medieval ideas about the world armed with modern communications technology (and modern weaponry), who weren’t too thrilled about the West.

I realised that information and communication were going to be very important to this encounter between the West and the Muslim world. In the latter were these societies that were closed to the outside world before, where their religious leaders could tell their followers, “this-and-that group of people aren’t true Muslims”, “all non-Muslims are infidels and are our enemies”, etc. And they had a captive audience, because the people didn’t have access to any other information. And then here come these channels through which these people could learn that, just maybe, the outside world isn’t like what their leaders had taught them, that other people have different beliefs — beliefs totally contrary to theirs — not because they are obstinate, not because they are ignorant or haven’t been exposed to “true Islam” or whatever; but there are people who have actually studied and thought a lot about religion and have come to completely different conclusions, for whatever reason. So one of two things could happen. Muslims could learn from the last four hundred and fifty years or so of European Christian history that sectarian violence is a very bad thing, that theocracies tend towards tyranny, that different beliefs should be allowed to compete in the free marketplace of ideas, and so on; or they could ignore all that and learn it the hard way — by repeating the mistakes for themselves, perhaps at the cost of tremendous bloodshed. And the difference between the two was the communication of information, and that was something I could study as a part of computer science. Thus, I began to learn Arabic.

And that was how I ended elementary school: with the intent to study computer science and physics, and a belief that religion, and in particular Islam and the Muslim world, would become very important topics by the time I became an adult — a belief that motivated me to learn more about history and politics and religion and linguistics and many, many other things. And the entire time that I was getting books from the library and studying these things, my parents dismissed my interests as worthless.

– davinci