Props
Sometimes, life takes a little push . . .
A propeller is a product of basic mechanics - three or four inclined planes attached to a wheel and then a source of power. Force is applied and as the prop turns it pushes against the water and the vessel it’s attached to moves.
It doesn’t take much effort to move things forward, if a motive force is applied evenly, and with consistency.
That last sentence applies to propellers, too. Keep pushing. Propel.
When we stop, we die.