Why It Took So Long to Invent the Wheel
by Natalie Wolchover
Date: 02 March 2012 Time: 06:24 PM ET
Wheels were invented circa 3,500 B.C., and rapidly spread across the Eastern Hemisphere. CREDIT: James Steidl | Shutterstock |
The tricky thing about the wheel is not conceiving of a cylinder rolling on its edge. It's figuring out how to connect a stable, stationary platform to that cylinder.
MORE: http://www.livescience.com/18808-invention-wheel.html
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