Inward-pointing scanner, cloud chamber from FMCG


Here are a couple more excerpts from The Fat Man and Circuit Girl show. In the first clip, Jeri converts an optical flatbed scanner so that it rotates around an object (like her FACE!) and scans inward.

In the second, she makes a cloud chamber with a toy tank (a tank in a tank) to move the Americium 241 (taken from a smoke detector) radiation source around. In the resulting cloud chamber, you can see alpha emissions, background radiation, and the effects of magnets on alpha radiation. It’s amazing that all you need to create such a cloud chamber is little more than a clear plastic tub, some magnets, a rag with alcohol on it, some dry ice, and a bright light source (oh, and the radioactive material). Nice to see our pal Steve Davee in the vid.

The Fat Man and Circuit Girl

2 thoughts on “Inward-pointing scanner, cloud chamber from FMCG

  1. says:

    I love that show!

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Gareth Branwyn is a freelance writer and the former Editorial Director of Maker Media. He is the author or editor of over a dozen books on technology, DIY, and geek culture. He is currently a contributor to Boing Boing, Wink Books, and Wink Fun. His free weekly-ish maker tips newsletter can be found at

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