There is no part of our bodies that fully rotates--be it a wrist or ankle or arm in a shoulder socket, we are made to twist only so far. And yet there is no more fundamental human invention than the wheel--a rotational mechanism that accomplishes what our physical form cannot. Throughout history, humans have developed technologies powered by human strength, complementing the physical abilities we have while overcoming our weaknesses. Providing a unique history of the wheel and other rotational devices--like cranks, cranes, carts, and capstans--Why the Wheel Is Round examines the...