Choosing what kind of scientist to be

Scientists often identify themselves with a particular discipline, irrespective of what they might actually be working on at that moment. In my case, although my work connects with physics and mathematics, I describe myself as a computer scientist. I’m definitely not a physicist and I don’t know enough about mathematics to be a mathematician (though I do like to pretend sometimes), but the real reason I consider myself to be a computer scientist is because that’s what I studied as a student.

I don’t recall making a decision to become a computer scientist, I just gravitated to what I thought was cool. When I was a kid I wanted to be surrounded by computers, like in Batman’s Bat Cave. I didn’t have any idea what those computers would actually do. My first experience with an actual computer was in school, around grade 6 or 7, programming a TRS 80 in BASIC. In high school I took computer classes and found that I was good at it, and eventually I had a couple of computers of my own to surround myself with. And there were computer games, which put hooks in me and reeled me in like nothing else. I have fond and vivid memories of experiences that were programmed for me by someone else.

I knew that I wanted to study computer science as an undergraduate before I started. I didn’t really know all that much about computer science, but it didn’t matter — I loved computers and never seriously considered a different subject.

As an undergraduate I took many computer science courses, but one of them really grabbed me and took my interest to a new level. It was a course on theoretical computer science: automata theory, grammars, Turing machines, and so on. Having taught such a course myself many times since then, I’m well-acquainted with the lack of interest many have in this subject, but to me this was the coolest stuff I’d ever seen in my life. The course was taught by Professor Ker-I Ko, who I thought was probably the coolest person I’d ever met in my life — like a wizard possessing arcane knowledge. One of the research results Ker-I Ko is well-known for is that, for any chosen level of the polynomial-time hierarchy, there exists an oracle relative to which the hierarchy collapses exactly to that level. I’m sorry, but it just doesn’t get cooler than that.

Sometime after the course finished, Ker-I Ko agreed to supervise me for a summer of independent study, and then allowed me to take a couple of graduate courses with him during my final year as an undergraduate — one on computability theory and one on complexity theory. I loved it all and wanted to learn more. Before this I took my studies seriously enough, but only worked as hard as I needed to get good grades. Now I was hanging out in the stacks reading everything about theoretical computer science I could.

As a graduate student I initially worked on computational number theory, which I found to be fascinating but wasn’t particularly good at. Then I discovered quantum computing. It was 1994, and Peter Shor had just discovered his now-famous quantum algorithms for factoring and computing discrete logarithms. I read Shor’s paper, along with every other paper on quantum computing I could find, and was totally hooked — quantum computing took coolness to an entirely new level. So I completely dropped what I was working on, started thinking about quantum computing, and haven’t stopped.

Sometimes students ask me what field they should enter, what classes they should take, what topic they should study as a graduate student, and so on. My response is to ask them what they find to be most cool. For me there was never really a choice to make — it was clear and had nothing to do with career prospects, getting a job, or anything at all beyond the subject itself. I couldn’t imagine working in a field that I didn’t find to be truly fascinating. Of course, what’s fascinating varies from person to person, so I tend to think that the only effective way to navigate is to follow your heart and do what you love.

And as educators we should not forget the importance of teaching others about the things that captured our hearts. Not everyone will be interested, but some will see what we saw — and perhaps their paths forward will be illuminated.