Woodward effect

The Woodward effect is a hypothesis proposed by James F. Woodward, a physicist at California State University, Fullerton, that energy-storing ions experience transient mass fluctuations when accelerated. The hypothesis is considered to be without merit by respected theoreticians. However, if these doubts are unfounded it is conceivable that the Woodward effect could be exploited in spacecraft engines that would not have to expel matter to accelerate. Several groups of researchers have therefore conducted experiments designed to prove or disprove the existence of the effect. The subject has even been lampooned in a cartoon.

Spacecraft Engine Concept

A basic problem with spacecraft design is that they must either expel matter to accelerate, rely on the pressure of the stellar wind or rely on planets to provide gravity assist. Rocket propellants will eventually run out, and the stellar wind and planets can only be used within a Planetary system. If a spacecraft is to keep accelerating as it travels further into interstellar space, it needs some other motive force.

If the Woodward effect were real, and if an engine could be designed to exploit it, the basic concept would be that the engine would pull ions when their mass was lower, and push them when it was higher. The result would be steady acceleration. Woodward has published a paper on the effect that was presented at the NASA Breakthrough Propulsion Physics Workshop in 1997 and is available on his university's website and has applied for a patent on engines based on the effect This has generated some interest in the media.

Wormholes and Stargates

Woodward has stated on The Space Show that theoretically, if the device can be built robust enough to handle sufficient amounts of power, the device should be able to generate wormholes with flat enough throats to resemble stargates seen in Stargate SG-1 and other science fiction, enabling instant transit between points in space-time.

Criticism

Conservation of Momentum

One typical criticism is the claim that the Woodward Effect violates Conservation of Momentum and thus is a form of Perpetual Motion Machine. Woodward answers this by explaining that as Mach's Principle says that inertia results from the gravitational influence of the entire universe upon any given mass that creates resistance to its acceleration, that any device that enables mass fluctuations to derive acceleration in this manner is using the mass of the universe as the reaction mass. The whole universe is the "system" in this device, and thus momentum is conserved.

Mathematical Disagreements

A paper by J.H. Whealton published by the U.S. Department of Energy Office of Scientific and Technical Information on 4 September 2001 raised serious doubts about the mathematical foundations of Woodward's theory, noted that his experimental results can be explained in terms of force contributions due to time varying thermal expansion, and stated that a laboratory demonstration produced 100 times the Woodward effect without resort to non-Newtonian explanations. Whealton's math, however, has been criticized by Woodward as demonstrating a fundamental misunderstanding of the effect.

Related Theory

Woodward's hypothesis is related to Dennis William Sciama's formulation of Mach's principle, a rather vague concept propounded by the philosopher Ernst Mach which Albert Einstein viewed as something along the lines of "inertia originates in a kind of interaction between bodies". Woodward uses the term "Mach Effect" for his hypothesis. The fluctuations in mass are hypothesized to result from gravity / inertia-based Wheeler-Feynman radiation reactions.

The hypothesis is also related to the Nordtvedt effect proposed by Kenneth L. Nordtvedt from Montana State University, who observed that some theories of gravity suggest that massive bodies should fall at different rates depending upon their gravitational self-energy. This would violate the strong equivalence principle that the laws of gravitation are independent of velocity and location, a principle considered fundamental by many theoretical physicists. The Lunar Laser Ranging Experiment has shown that if the Nordtvedt effect exists at all, it is extremely weak.

Experiments

• In 2004, John G. Cramer, Curran W. Fey, and Damon V. Cassisi of the University of Washington reported that they had conducted tests of Woodward's hypothesis, but that results were inconclusive.

• On January 20, 2006 Paul March and Andrew Palfreyman reported experimental results at an American Institute of Physics conference. Test results exceeded Woodward's predictions by one to two orders of magnitude.

• In 2006, researchers at the Austrian Research Centers reported results of a study of the effect using a very sensitive thrust balance. Results did not seem to be in full agreement with the findings claimed by Woodward and collaborators. However, given the importance of the subject the researchers recommended further tests.

These results should, of course, be considered in the light of J.H. Whealton's previously cited report.