Ruby is the king

[xoxo]

it exists in any machine. dynamos, flywheels, pendulums, combustion motors, pumps and many more equipment can be prime movers in a machine

the energy that starts the prime mover in a machine still comes from somewhere else and technically that could be called the prime mover and so on adn so on until you reach the big blow-out (perviously known as the big bang) of our universe at which point you still need to ask what is the prime mover of the big blow-out... see where I'm going

for example on the bike, the legs move the peddle, our body moves our legs our body moves through energy gotten elsewhere, either through food or being moved by another object.......