A History of the Circle: Mathematical Reasoning and the Physical UniverseThe concept of the circle is ubiquitous. It can be described mathematically, represented physically, and employed technologically. The circle is an elegant, abstract form that has been transformed by humans into tangible, practical forms to make our lives easier. And yet no one has ever discovered a true mathematical circle. Rainbows are fuzzy; car tires are flat on the bottom, and even the most precise roller bearings have measurable irregularities.