Andrew Birkett’s blog

Model checking has been on my list of “stuff to understand” for a long time. It’s one of the few ‘formal methods’ which gets noticeable positive press. This month’s Communications of the ACM had a big article about it, of which I understood very little. However, it prompted me to search t’internet and this introduction to model checking which, shockingly, has an actual worked (ableit trivial) example. Now I am enlightened!

This morning, I did an guest lecture for the Advances in Programming Languages course at Edinburgh University. I’ve talked at the University before, as part of the SPLS seminars. So, when I met Ian Stark again at ICFP and he invited me to talk to his class, I jumped at the chance.

Partly, I just love doing talks. But, specifically, I thought it would be a good opportunity to share some of the stuff I’ve learned over the last 12 years since I left uni. I’ve interviewed lots of graduates over the years, and I’ve seen how they adapt to working in industry. I’ve seen grads grow into world class software developers, and I’ve observed some of the common traits and interests that the best of them have.

And so my talk split into three themes. Firstly, I explained why I think learning languages is a worthwhile use of one’s precious/finite time. Secondly, I explored which languages give you the biggest bang-for-buck in terms of expanding your world view. And, finally, I used erlang as a concrete example to explore both the design pressures that influence a language, and to ‘cherrypick’ the key ideas from the language.

My aim was not to convince anyone to use Erlang day-to-day. My aim was to demonstrate that you can expand your mind by seeking out new ideas. Much like riding a bicycle, once you’ve seen a new way to look at the world you never forget it. And Erlang, operating in the difficult realm of high availability software, was full of good examples.

It’s pretty cool to be asked back to the University you graduated from, and to have the chance to share your thoughts with the next generation of students. Thanks to Ian Stark and David Aspinall for inviting me back to the Uni.

When I visited the Royal Institution in London recently, there was obviously something ‘going on’ in the building. After checking out the official exhibit in the basement, I explored the building by following the staircase up past an interesting succession of portraits. I could hear a professional sounding talk coming from somewhere, and saw several stressed stagehands running from a room packed with scientific props to a door leading to a backstage area.

This, then, would be the world-famous Royal Institution Christmas Lectures! They’re now being shown on TV as I speak. I didn’t want to get in the way of the stagehands and their precious cargo, and so I beat a hasty retreat back downstairs.

However, I noticed today that the RI website says that the christmas lectures are held at 6pm. But I visited there at around 3pm. So how come I managed to overhear a lecture?

Turns out, these slick tv productions don’t “just happen”. I found an article by a previous xmas lecturer which explain the painful reality. Each lecture is preceded by at least a gruelling day and a half of rehearsals and planning. It’s more like a stage show than a simple lecture – the cameras, sound guys, lighting and stagehands all need to figure out what they’ll be doing and when they’ll be doing it. And the lecturer needs to figure out where to look, who to talk to *and* remember their words! Seems like working with children & animals is the least of their troubles.

Having watched the first lecture on TV now, I’m left wondering how they got two donkeys up to the lecture theatre. Did they walk up the stairs? Do they have a lift – and, if so, would you get into a lift with two donkeys?!

And so I leave the Royal Institution, home of Michael Faraday and Humphry Davy, by contemplating the deepest question of science: Donkeys and staircases. Staircases and donkeys.

I recently got the NASA When We Left Earth DVDs, and I thought “great, I’ll be able to watch them during my Seattle trip”. So, I put them into the hotel DVD player tonight .. and got a “cannot play” error. Arg, the dvd’s will be region 2 (europe) and the player is region 1 (US). So, despite this being a completely legal, paid for copy of the DVDs which I brought with me, I cannot watch them! Grr!

What does one do to stay awake in Seattle after getting up at 3am, 14 hours of travelling and an 8 hour timezone shift? In my case, grab a coffee (how native) and head to the awesome Seattle Public Library. Without much of a plan, apart from staying awake. As it turns out, I randomly stumbled upon an archive of Communications of the ACM dating back to the very first edition, in 1958.

1958 was a strange old world. Things considered newsworthy: buying a new computer (as in, ‘Foo University has purchased an IBM 456 with 2048 bytes of memory’), upgrading the memory in your existing computer (particularly when you are building said memory from scratch yourself). Other articles included puzzles similar to chess end-games – ie. implement [trivial operation] using only 6 bytes of IBM xyz machine code but without using any jump operations.

I skipped forward to November 1976, the month I was born. An article by Jim Gray on db locking in which it’s necessary to define the term ‘transaction’ explicitly. The previous month, there’s an early paper about texture mapping by Jim Blinn with lots of pretty pictures. Again, it’s enlightening to see ‘basic’ stuff being laboriously explained .. for example, why you get aliasing effects if you sample the texture naively. But wasn’t “basic stuff” back then; it was the frontier of knowledge.

Only the flight across, I was reading a biography of Oliver Heaviside. The book covers both his physics work and also the world, time and society that he lived in. In particular, it’s fascinating to read about how resistant (sic) “practical” electrical engineers were to the new-fangled mathematics-wielding theoreticians who had started to dominate the field. There were many vocal engineers who were quite sure that they didn’t need “all that maths stuff”.

For every success story celebrated and enshrined in today’s textbooks, there were many other forgotten voices arguing against that viewpoint in the publications of the day. I’m sad that almost every textbook I read at university missed out all of this rich tapestry – instead they provided a neatly cut-and-dried distillation, devoid of any human context. To me, real science was. and presumably still is, a process of muddling around in a sea of uncertainty and conflicting schools of opinion. I seemed to learn about the abstract scientific method (very useful!) but not so much about the day-to-day struggles of real scientists. Much later, I found my way to Thomas Kuhn and biographies of Faraday, Maxwell, Boltzmann, etc. And there I found a much more interesting picture, crucially explaining the ideas in their original context.

So it’s nice to be able to go back to the original sources and imagine what it might’ve been like to be a ‘computer person’ in 1958 .. to see what kind of ideas were thinkable in that time, to see who was prodding at the boundaries, and to see how much is recognizable today.