Back-of-the-envelope Physics (Trusted Source)

The phrase "back-of-the-envelope physics" refers to the art of using rough, order-of-magnitude estimates and basic physical principles to solve complex problems or check if an idea is feasible. These calculations, often called Fermi problems , emphasize intuition over precise decimal places. The Coffee Shop Singularity

He stopped. According to his scribbles, the cable was holding less than 10% of its capacity. It was perfectly safe. "So why is it making that sound?" he muttered. Back-of-the-Envelope Physics

Ten minutes later, the girder was safely back on the ground. A single bolt had sheared halfway through. The phrase "back-of-the-envelope physics" refers to the art