A machine that never stops always grinds

Perpetual motion machine: the impossible invention

For centuries, inventors have tried to build a machine that keeps moving itself. According to the laws of physics, such a "perpetual motion machine" cannot exist. But that doesn't stop inventors from trying it anyway.

The greatest inventor in history is called Lukas and is a train driver. If only it really existed. The hero from Michael Ende's famous children's book about Jim Knopf and his friend Lukas succeeds in what people have been striving for for centuries: He builds a functional perpetual motion machine - a machine that moves by itself, i.e. without any external drive. To do this, he attaches magnetic stones in front of his steam locomotive, which attract the vehicle and set it in motion.

But according to the laws of physics, a perpetual motion machine cannot work: Because a machine can only convert energy (such as fuel) into another form (such as movement), but never generate it itself.

The perpetual motion machine: an impossible invention?

On top of that, a little energy is lost with every conversion - among other things as heat when machine parts rub against each other. Therefore, at some point there will be a standstill again.

These findings have formed the foundation of thermodynamics, the theory of heat, for around 150 years. But that doesn't stop people to this day from designing all sorts of apparently constantly moving devices.

As early as 1150 AD, the Indian mathematician Bhaskara designed a wheel that was supposed to turn forever thanks to a shift in weight (similar to the design above), but actually stopped after a few turns, slowed down by the friction on its own axis.

The belief in the perpetual motion machine lives on

During the Renaissance, European philosophers, naturalists and engineers became more interested in the constant movement out of nowhere. Dozens of curious designs with hammers and levers, wheels, weights and counterweights were presented. Some devices initially seemed to work, but were always exposed as fraudulent - such a flywheel from 1717 that was actually covertly cranked.

Nevertheless, the belief lives on: In 2007 Irish entrepreneurs presented a wheel that should turn by itself. It didn't move an inch.