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 contraptions and tricks we have devised in order to more efficiently move—and move through—the physical world.