Friday, 7 April 2000


Listening to:

The white album by the Beatles.

I was wondering about the physics of bomb blasts the other day, perhaps prompted by the news of an explosion in an army barracks in Londonderry. If you’re not close enough to an explosion to be affected by the heat released, nor any flying bits of shrapnel from the bomb and its casing, how does the shock wave affect you? (Not well, I'm ready to believe, but I’m looking for a bit more detail than that).

What’s a “shock wave” anyway? It’s just air, innit? Does it do its damage by lifting you off the ground and slamming you into nearby buildings, or does the impact of the wave do damage in itself? I guess the latter must be the case. A famous IRA bomb in London caused plate glass windows on buildings within a large area to shatter, but you could explain this with the first hypothesis by noting that the windows were fixed into position and couldn’t react to the force of the explosion by flying away.

And if I’m behind a sturdy post-box (they’re big steel things in Britain), does that shelter me from the effects? At all?

Or am I underestimating the area of effect of the heat and shrapnel? Is this how a bomb does most of its damage? All these questions, and no real answers.

On a cheerier note, I was a happy customer of the Parkside pool this morning. I had a good swim, and emerged feeling simultaneously refreshed and pleasantly exercise-tired.

I was going to have a rant about anti-intellectualism and anti-education attitudes today (predictable stuff coming from an academic I suppose), but I think I've probably wittered on for long enough already, and I have two bug reports to deal with.