Tag Archives: electromagnetism

Not The Alom Shaha Motor

One of the great joys in my life is to come across a new science demo, particularly if it’s an elegant, simple one. I can take credit for introducing one of my favourite science communicators, Michael de Podesta, to this demo of the motor effect. Michael kindly calls it the “Alom Shaha Motor” but I can only wish that I came up with this idea myself. Jonathan and I have made a film about this, but here’s Michael’s own, elegant, simple film of the demo.

Eddy currents

Alom and I are filming at the moment, hence things being rather quiet around here. However, the above caught my eye. This demo is typically done with a long length of copper pipe, and the magnet takes many seconds to fall through. It’s effective on a stage.

The tall narrow pipe, however, is precisely the wrong shape to film, and on video the demo doesn’t work so well. This shorter length of fatter pipe, with an appropriate magnet, has more impact on camera.

Same principle, same demo… but different treatments for different audience contexts. So, lessons for us all:

  1. Don’t assume that the way you’ve seen a demo performed is the best way. Always look for improvements.
  2. It’s not just the demo that matters, it’s the way you use it.

That separation of ‘content’ and ‘treatment’ is, for me, an absolutely key concept.

Tip of the hat to my dad for sending this in.