I have become so rusty, I just don’t keep on top of it and haven’t done for years. Doing some preparation last night for something has reminded me of this. I was thinking, it would’ve been so easy to keep up to scratch if I’d wanted, so why haven’t I? There was one thing I did recently which I did genuinely enjoy, for the OU astrophysics course, we had to make a composite spectrum of quasars, filtering out the quasars you wanted, downloading all the data and then importing to excel to make the composite. It took ages to do by hand, I wrote some java which hit their database, ran sql and did the rest. It was great because it meant you could play around, for instance I was able to pull out quasars with low emissions in certain lines, see how their overall composite looked and compare it to normal quasars.