Summer has started and I have a bit more time to think about things. It can get a bit hectic during semester so you end up like the proverbial hamster on a wheel: running to stay still. Also, the weekend before last I had a pile of marking while last Saturday I was running an Open Day. This time I have a whole weekend off!

So, I have a little more time to think. I am thinking about a phenomenon called “self-averaging”. It is best to explain what this is via an example. The density of water is self-averaging which means that if I take a litre of water and divide it into two half litres, then the density of both will be the same and the same as the original, i.e., 1 gram (or about 30 billion trillion molecules) per cubic centimetre. This is actually less trivial than it sounds. If the molecules were arranged in a fractal this would not be true.

So, the two half litres of water each have the same density, but I work on freezing, so do they freeze at the same temperature? I think it will depend on how pure the water is, but maybe not. As I discussed in an earlier post, water does not freeze at 0 C.

It may be than one half-litre would freeze at, say, -3C while the other freezes at -5 C. A scientist I have talked to at MIT has done experiments with his PhD student, not on water but on the crystallisation of aspirin. The aspirin you buy in a pharmacy is crystalline so people study how drugs like aspirin crystallise.

I emailed him to suggest how to take variations in crystallisation from sample to sample into account. He emailed me back the next day to say that it didn’t work. So I replied that it was research, and so sometimes you try things and they work …. and sometimes they don’t.

Of course I was disappointed but most ideas you have in scientific research turn out not to work. As Einstein said: “If we knew what it was we were doing, it would not be called research”, and when you do not know 100% what you are doing, then you will not be right 100% of the time. The secret is not to worry if you guess wrong. You just try something else the next day.

Then the day after, he emailed again to say that there was a problem the first time they did the analysis and when they fixed this, it worked really well! Maybe my summer thought is right after all. I hope so, predicting how the world works is what a good summer for an academic scientist is all about.