In one minute

Fearn, Zachar, Wanser and Woodward explain the Mach Effect Thruster, a propellantless drive that uses Mach's principle to produce thrust in an accelerating material whose mass-energy fluctuates. The programme tests Mach's principle directly: make an object's mass fluctuate in the laboratory, turn that into steady thrust, and match theory to experiment. The devices run on 100 to 200 watts and currently produce thrusts of a few micronewtons. The theory uses gravitation and advanced waves, so momentum is conserved between the device and the rest of the universe. After reviewing absorber theory from Dirac, Wheeler and Feynman, and Hoyle and Narlikar, they derive Woodward's mass fluctuation formula from first principles in the fully Machian Hoyle-Narlikar theory.

Theory of a Mach Effect Thruster I