I am tempted to embed the video of this thing in action, but it really is worth [a trip to the site] to get a look not only at the device but a behind the scenes look at the making of the film.
> This is a 2000-year-old analog computing device reconstructed out of Lego. It predicts solar and lunar eclipses, accurate to within two hours — all using plastic gears. Andy Carol, its designer, builds mechanical computers out of Lego as a hobby. He made this device basically because Adam Rutherford, an editor and producer at Nature, dared him to. When Adam heard that Andy had actually built the device, he called me and said, “Well, clearly we have to make some sort of film about this thing now.”