Galileo proved 388 years ago why human giants can't exist
388 years ago, Galileo worked out why human giants can't exist
In 1638, Galileo Galilei demonstrated that scaling up a human body would be physically impossible: bone strength grows with the square of size, but weight grows with the cube. This means a giant's bones would snap under its own mass. The same principle explains why elephants have thick legs, why insects can walk on walls, and why tiny humans like Lilliputians are equally implausible.
Clearly then if one wishes to maintain in a great giant the same proportion of limb as that found in an ordinary man he must either find a harder and stronger material for making the bones, or he must admit a diminution of strength in comparison with men of medium stature; for if his height be increased inordinately he will fall and be crushed under his own weight.