Why did cannons shatter European walls but barely dent Chinese ones?

Answer: Stone fractures; rammed earth absorbs energy by deforming

Stone fractures; rammed earth absorbs energy by deforming ✓ — Correct! European walls were solid stone — when a cannonball hits, the impact creates fractures that propagate through the brittle stone, eventually collapsing whole sections. Chinese walls had a 10-20 m thick rammed-earth core faced with brick: the earth deforms locally on impact, absorbing kinetic energy without crack propagation. French heavy artillery shattered 1,000-year-old French castle walls in the 1450s. Early Chinese cannons against Ming walls just made dents.

Chinese walls were taller, so cannonballs flew over — Wrong. Chinese walls (12-21 m tall) and major European walls were comparable in height. Cannon trajectories were flat at siege range — height didn't matter; material response did.

Chinese gunpowder was weaker than European gunpowder — Wrong. Ming gunpowder was actually similar in composition to European. The difference was on the receiving end: brittle stone fractures, ductile rammed earth deforms. It's a materials science problem, not a chemistry problem.