I’ve actually read about this in a Biography about Tesla, apparently Twain would come over to Tesla’s place sometimes and they would mess with all the crazy inventions. :D

Side note: These don’t have motors. They’re completely momentum/wind-powered and literally just wander around beaches unsupervised like giant abstract monsters.

The Brachistochrone This animation is about one of the most significant problems in the history of mathematics: The Brachistochrone Challenge:

If a ball is to roll down a ramp which connects two points, what must be the shape of the ramp’s curve be, such that the descent time is a minimum?

Intuition says that it should be a straight line. That would minimize the distance, but the minimum time happens when the ramp curve is the one shown: a cycloid.

Johann Bernoulli posed the problem to the mathematicians of Europe in 1696, and ultimately, several found the solution. However, a new branch of mathematics,Calculus of Variations, had to be invented to deal with such problems. Today, calculus of variations is vital in Quantum Mechanics and other fields.