Rocket Science
Rockets are spectacular examples of Isaac Newton’s third law of motion: that to every action there is an equal and opposite reaction. For instance, throwing hot gas out of its engines at high speed (the action) thrusts a rocket off its launch pad and into space (the reaction). But having to carry the propellants needed to create the gas (the reaction mass) is a pain, for at any given moment during a flight, the action has to propel not only the rocket itself, but also all of the remaining, unburnt propellant. Most of the effort expended in a rocket launch is therefore directed towards lifting propellant. As a result, even the most modern rockets start off with a mass that is more than 90% propellant. The unrealistic fantasy of rocket scientists is therefore an engine that needs no propellant. And that is precisely what Roger Shawyer, a British aerospace engineer, claims to have invented.