Don't shoot, shotgun...

3.57pm. After lunch we went back to the lab, and Roy and Kirsten were late back again. I know that there is some stuff going on, but they shouldn't let it spoil their respective lab partners work, i.e., mine and Paul's.

After the four of us presented our results to the tutor Jean (in exactly the same way as we'd done to her in Mallorca), we worked out our value for the Planck constant, which was actually very accurate, and certainly well within the right order of magnitude. I was delighted, practically ecstatic in fact; it's not often one gets the chance to measure one of the most mind-bogglingly small things in physics with extremely basic equipment.

Afterwards by calculating the energy levels, we deduced with Jean's help (and that of a very heavy reference book) what metal had been used in the electrodes, which we think was potassium. The only other candidate would be uranium, and we certainly wouldn't be diffracting with unshielded uranium sources! Potassium it is. One of my favourite metals.

We moved on to the next experiment, and we picked the speed of a bullet experiment. I did this at school, and measured it directly, by measuring the time taken for the bullet to pass through two aluminium foil tapes. But this one is done a completely different way, by measuring the displacement of something fired into.

Paul, looking for a way of finding a way to shoot annoying fellow students

Again Roy and Kirsten were late moving into the other room, and it later turned out that they had a right telling off from the activity tutor, Sarah Webb. I can't say I blame her to be honest but I hope it won't prejudice their satisfactory attendance and participation record.

We weighed six lead pellets (that took some doing, to find five of almost equal weights). The first one managed to miss the target, strange trick when it's about 10 cm in front of the gun, but I think we hadn't loaded it sufficiently tightly. So in the end we got five shots fired correctly before the coffee break, which was great.

Go ahead mongoose... make my day....

We had one pretty funny moment when I fired the gun, and at the same time, Roy threw another pellet at the back of Kirsten. She turned around very rapidly, deeply indignant, saying that we'd shot her! Roy and I laughed so hard that people started to glare, and of course we had to explain that we hadn't, but it was a great moment.