For his father’s 75th birthday, Dave Johnson has built what may be the most awesome birthday present ever created: a machine that dispenses rare earth magnets.
It’s called, oddly enough, “Magnet Machine.” The machine, manipulates a chain of rare-earth magnets, slicing the end off and moving it through the air using a series of arms before dropping it back onto the end of the chain to start the process again. It’s not quite a perpetual motion machine, since that would violate the laws of known physics, but it’s still pretty cool to watch.
Johnson says that the machine demonstrates a principle called eddy currents. “Watch how slowly the magnet falls through the aluminum tube compared to falling through air,” his description on the YouTube video for the machine says. “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.”
(I also can’t help but be reminded of a running gag in the third book of Douglas Adams’ “Hitchhiker” books: “Life, The Universe, and Everything.” “Eddie’s in the space-time continuum, is he?”)
The number 75 also keeps popping up in the creation of this machine. First, as I mentioned previously, the device was created for Johnson’s fathers 75th birthday. And that’s not all. “Astute viewers equipped with video analysis software and way too much time on their hands might find that the magnet drops 75mm from the tip of the slicer until caught by the lifter, and that the lifter then drops it through a 75mm long aluminum tube.” You’ll probably start seeing 75 everywhere, just as you start seeing 42 after reading “The Hitchhiker’s Guide to the Galaxy” or 23 after reading “The Illuminatus! Trilogy.” It’s obviously a conspiracy!