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" Next time you see gears on some sort of poster take a close look. Every now and then, some graphic designer threw them on there to symbolize cooperation and synergy, but if you actually think about the way that gears work, it will become immediately clear that they couldn&amp;#039;t actually move.\u00A0  As the folks at Numberphile explain, this isn&amp;#039;t unique to closed systems of three gears, it&amp;#039;s true of any closed system that contains an odd number of gears. Sure, they&amp;#039;ll work if they are in a line, but if they loop around they&amp;#039;d just cancel each other out. So can you make a closed system of three gears that would actually turn? Yes you can, but they will look weird.\u00A0        As Numberphile illustrates, the trick is to change the shape of your gears so have anything but flat, circular, planar ones. Worm gears? Sure! Donut gears? Why not! Square gears? All systems go. The solution is, in essence, to just add another dimension.\u00A0 Of course if you want to get really weird with gears, these are just a few of many, many options. But next time you see a poster with three gears that won&amp;#039;t turn, just imagine how awesome a trio of donut gears would look instead.\u00A0  Source: Numberphile "^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.popularmechanics.com/technology/a21286/working-systems-of-three-gears/>