Last week I did the beer foam decay experiment with one of my first year classes. If a couple of students bring their own lap tops we now have enough computers for one each so instead of using the sticky tape and pen method described they can take a video and analyse it with loggerpro. It means that all the data collection and analysis can be done in class. I usually supply some crisps to go with the non alcoholic beer but since it was right after lunch I thought they wouldn't be hungry. The problem with these analogy experiments is that students can sometimes miss the point, I wonder how many of my students now think that beer is radioactive. Or that it should be poured very quickly and drunk out of tall glasses.