Month: May 2008

Fun with the Van der Graff and Animoto

A study of concentration

We had the usual fun with the Van der Graff today. The weather was rather accommodating, and it tallied nicely with the last class before the long weekend.

I have never got a student’s hair to stand up dramatically, but i was drying the canvas belt with a hairdryer when I realised I could help things along a little by aiming it upwards into Fania’s hair. It loosened up the hair very nicely and the show was much more impressive as a result. I also got a student to hold up a mirror so Fania could see for herself what everyone else was laughing at.

I have seen a few examples of Animoto and how it does a pretty cool job of presenting photos, so I thought I’d head on over and check it out.

It really is pretty impressive, and very user-friendly. There might be a couple of thinks I would change, but then again that may just be me not familiar with the program.

It allows for automatic uploading to youtube, which was a pleasant surprise. The free version limits the clip to 30 seconds, so I might just invest in the longer version to check it out.

This is a clip I uploaded last year

 

When is a kilogram not a kilogram?

Many physics students will be familiar with the fact that the prototype kilogram is kept in a high-security vault in Paris. What I didn’t realise was that the mass of this specimen is changing, albeit very slightly.

So here’s the question; if this is the one and only true version of the kilogram, and it loses mass, doesn’t it still stay a kilogram?

And doesn’t that mean that other copies, which would have been correct originally, are now wrong?
(I think in fact that they may all be losing mass slightly.)

Something very unscientific about all this . . ., no wonder physicists are embarassed about it.

Seems a bit like when kids make up the rules of a game, and when it turns out that these don’t suit the leader of the gang, he just changes them.

Which seems as good an excuse as I am likely to get to show Eddie Izzard – Do you have a flag?