A perpetual motion machine is a device that can power itself. So how come we aren’t using perpetual motion to power the world? To travel to other stars? To create free energy for all of humanity? The simple answer is that a perpetual motion machine is impossible. According to the laws of physics, it is utterly impossible to receive more energy than the amount you put in. The Solarbotics DIY Perpetual Motion Machine is probably the closest we’re ever going to get.