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Dave Johnson’s magnet machine has a lot of fascinating details:

This machine manipulates small spherical rare earth magnets. slicing one at a time from the end of a long chain, moving it around a bit, then dropping it back to re-connect at the tail end of the chain.

It also demonstrates a little snippet of science called eddy currents. Watch how slowly the magnet falls through the aluminum tube compared to falling through air: the falling magnet generates an electrical current in the tube, and that current in turn generates a magnetic field that opposes the movement of the magnet, slowing it down dramatically. See if you want more.

[Via Dug North’s The Automata Blog]

John Baichtal

John Baichtal

My interests include writing, electronics, RPGs, scifi, hackers & hackerspaces, 3D printing, building sets & toys. @johnbaichtal

  • Ren Tescher


  • Matt Richardson

    Be sure to watch the video through the 1:18 mark to see how the magnets make their way through the inside of the machine; it’s quite amazing!

  • Charlie Visnic


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