Sure, I found this blog post that describes it pretty well: http://somethingsurprising.blogspot.com/2011/11/feynmans-shaft-passer-in-reality.html http://someth

Sure, I found this blog post that describes it pretty well: http://somethingsurprising.blogspot.com/2011/11/feynmans-shaft-passer-in-reality.html http://somethingsurprising.blogspot.com/2011/11/feynmans-sha... But basically, it was something that was posted recently on HN, about how Richard Feynman (famous physicist) happened upon a mechanism designed in WWII to avoid mines being detected by trip wires between boats, by allowing the trip-wire to pass through the shaft-passer