concept

The square-cube law

A geometric law stated by Galileo in 1638: as an object scales up while keeping its proportions, its surface area grows with the square of its linear size, while its volume and mass grow with the cube. The consequence for living bodies is profound - weight (which follows volume) outruns bone strength (which follows cross-section), so skeletal stress rises in direct proportion to body length. Double an animal's size and its mass grows eightfold while bone cross-section grows only fourfold: the skeleton must thicken or be built from stronger material. This is the core physical limit on how large and how fast a body can be.