Over at Boing Boing, Charles Platt has a story about a new space propulsion system being developed at California State University at Fullerton:

Ever since H. G. Wells imagined a gravity-shielding material in “The First Men in the Moon,” space enthusiasts have fantasized about ways to achieve thrust without any need for reaction mass. Unfortunately, it seems impossible.

Or is it?

Personally, I’m not so willing to use the word “impossible” anymore. In October of this year, at the laboratory of Dr. James Woodward in California State University at Fullerton, I watched a very small-scale experiment that was surprisingly persuasive.

Unlike all the “free energy” scams that you see online, Woodward’s device does not violate basic physical laws (it does not produce more energy than it consumes, and does not violate Newton’s third law). Nor is Woodward withholding any information about his methods. He has written a book, published by Springer, that explains in relentless detail exactly how his equipment works–assuming that it does, indeed, work. He published his theory in Foundations of Physics Letters, vol. 3, no. 5, 1990, and he even managed to get a US patent — number 5,280,864, issued January 25, 1994.

I first heard about him in 1997, when I interviewed him for Wired magazine. His results were tentative, then, and he was cautious about making claims. “I have biweekly paranoia attacks,” he told me, “and then I try something else to see if I can make this effect go away.”

Almost twenty years later, the situation has changed. Dr. Heidi Fearn, a theoretical physicist who specializes in quantum optics at Fullerton, has done the math that she believes can justify Woodward’s experimental evidence. Wikipedia now has a substantial entry about the Woodward Effect. The Space Studies Institute is championing the cause, inviting tax-deductible donations.

If a small amount of thrust really can be created using a power input but no reaction mass, the principle could be applied to correct orbital variations in satellites. If the effect turned out to be scalable, it would be a major game-changer for human spaceflight. Of course, this is a big “if”; but I think Woodward’s idea shows more promise than any other alternate systems of propulsion. It would be infinitely more attractive than rocket motors.

The concept is based on the possibility of changing the mass of an object. Changing mass? How can that make sense? The answer is linked with the general theory of relativity.