The World's Biggest Gear Reduction by designer and maker of prototypical machines, devices and tools Daniel de Bruin.
This machine visualizes the number googol. That's a 1 with a hundred zeros. A number that's bigger than the atoms in the known universe. This machine has a gear reduction of 1 to 10 a hundred times. In order to get the last gear to turn once you'll need to spin the first one a googol amount around. Or better said you'll need more energy than the entire universe has to do that. That boggles my mind.