What’s the secret to skipping a stone?
Secrets of successful stone-skipping
French physicists built a stone-skipping machine and found the magic angle: about 20 degrees.
To study skipping stones properly, physicists in France built a machine that fires a flat disc at a pool of water at exactly controlled speeds, spins and angles, then filmed each bounce at high speed.
The best tilt between stone and water was about 20 degrees. Go much steeper or flatter and your stone sinks with a sad little plop. A lakeside hobby, solved.
Twenty degrees, a flick of the wrist, and a quiet lake.