Jet Propulsion

Jet propulsion is motion produced by passing a jet of fluid (e.g. air or water) in the opposite direction to the direction of motion. By conservation of momentum, the moving body is propelled in the opposite direction to the jet.

A number of animals, including cephalopods, sea hares, arthropods and fish have convergently evolved jet propulsion mechanisms. These have been artificially mimicked by the jet engine.