Re: [math-fun] Microwave ovens

Those little 2-stroke glowplug model airplane engines are completely symmetrical: since they don't have any electrical ignition, there's no way the piston & combustion chamber can know which direction the propeller is going. More than once when I was trying to start mine, it kicked back & ran backwards, which didn't do good things to the airplane it was attached to... BTW, Shannon was an avid unicyclist, who I believe cycled the hallways at MIT. (Most) Unicycles are also completely symmetrical; I assume that Shannon was good enough to unicycle backwards. At 10:29 AM 1/27/2014, meekerdb wrote: A two-stroke engine will also run backwards.