Electric Semolina

I hope that most school children get to see that sprinkling iron filings around a bar magnet produces a pattern which shows the shape of the magnetic field around the magnet. It’s a very simple, yet useful, way of making something invisible, visible. What many school children won’t get to see is that you can do something very similar with electric fields, using semolina instead of iron filings. The picture above is from a demonstration I showed my year 13 (A-level) students last week – the instructions for how to set it up can be found at the Practical Physics site.

A tip: it’s lovely for the students to see this for themselves, but the apparatus is tiny so use a camera to project it onto your whiteboard as well. I forgot to take my webcam into school so I used my phone to take a photo and put that up on the whiteboard so we could look at the demonstration closely and discuss it. I encouraged my students to take photos too, as I did when we investigated magnetic fields – I’m not convinced getting students to draw what they see is terribly useful in this case. What do you think?

Performance range

I keep forgetting that this blog can be about performance skills as well as, you know, demos. Here we go (this really starts around the 40 second mark):


Not science. Not a demonstration. But look at the range of ways Wilde says ‘Shut up!’. Impressive.

ScienceDemo blogger Elin Roberts has an exercise/game (once memorably, if incongruously, played in the library of the Royal Institution) called ‘Sandeels.’ The construction is that all participants are puffins, and that puffins have very limited vocabulary and topics of conversation. Specifically, the only thing they ever discuss – and the only word they know – is ‘sandeels.’ Players take a card which specifies an emotion or mood, and have to perform that emotion using only the word ‘sandeels.’ Ian Simmons’ ‘cantankerous’ puffin is a sight to behold.

These sorts of exercises are useful for exploring our range as performers, and they help us think about the details of how we deliver demonstrations.

Meanwhile, in Abu Dhabi…

As may have been mentioned, I’m in Abu Dhabi for a month helping train the hundreds of science communicators who will staff the Science Festival here in November. It’s a huge project run by Edinburgh International Science Festival – exhausting, but tremendously rewarding.

This week, one of the universities with which we worked was a teacher training college. As I found last year, it’s a pleasure to work with tremendously capable Emirati women and introduce them to perhaps a slightly different way of interacting with their audiences. The parallels and differences between science communication and conventional classroom practice are fascinating.

At one point we found ourselves discussing demonstrations, and how they might best be used. “Ask the audience to predict what they think’s going to happen!” cried one happy participant. “Yes!” continued another, “Then observe what actually happens, and ask them to explain why.”

Predict/Observe/Explain, it turns out, is quite the thing at this particular college. Cool.