Cool article in New Scientist...
After publishing the mass formulae, Heim never really looked at hyperspace propulsion again. Instead, in response to requests for more information about the theory behind the mass predictions, he spent all his time detailing his ideas in three books published in German. It was only in 1980, when the first of his books came to the attention of a retired Austrian patent officer called Walter Dröscher, that the hyperspace propulsion idea came back to life. Dröscher looked again at Heim's ideas and produced an "extended" version, resurrecting the dimensions that Heim originally discarded. The result is "Heim-Dröscher space", a mathematical description of an eight-dimensional universe.
From this, Dröscher claims, you can derive the four forces known in physics: the gravitational and electromagnetic forces, and the strong and weak nuclear forces. But there's more to it than that. "If Heim's picture is to make sense," Dröscher says, "we are forced to postulate two more fundamental forces." These are, Dröscher claims, related to the familiar gravitational force: one is a repulsive anti-gravity similar to the dark energy that appears to be causing the universe's expansion to accelerate. And the other might be used to accelerate a spacecraft without any rocket fuel.
This force is a result of the interaction of Heim's fifth and sixth dimensions and the extra dimensions that Dröscher introduced. It produces pairs of "gravitophotons", particles that mediate the interconversion of electromagnetic and gravitational energy. Dröscher teamed up with Jochem Häuser, a physicist and professor of computer science at the University of Applied Sciences in Salzgitter, Germany, to turn the theoretical framework into a proposal for an experimental test. The paper they produced, "Guidelines for a space propulsion device based on Heim's quantum theory", is what won the AIAA's award last year.
Claims of the possibility of "gravity reduction" or "anti-gravity" induced by magnetic fields have been investigated by NASA before (New Scientist, 12 January 2002, p 24). But this one, Dröscher insists, is different. "Our theory is not about anti-gravity. It's about completely new fields with new properties," he says. And he and Häuser have suggested an experiment to prove it.
This will require a huge rotating ring placed above a superconducting coil to create an intense magnetic field. With a large enough current in the coil, and a large enough magnetic field, Dröscher claims the electromagnetic force can reduce the gravitational pull on the ring to the point where it floats free. Dröscher and Häuser say that to completely counter Earth's pull on a 150-tonne spacecraft a magnetic field of around 25 tesla would be needed. While that's 500,000 times the strength of Earth's magnetic field, pulsed magnets briefly reach field strengths up to 80 tesla. And Dröscher and Häuser go further. With a faster-spinning ring and an even stronger magnetic field, gravitophotons would interact with conventional gravity to produce a repulsive anti-gravity force, they suggest...
At the moment, the main reason for taking the proposal seriously must be Heim theory's uncannily successful prediction of particle masses. Maybe, just maybe, Heim theory really does have something to contribute to modern physics. "As far as I understand it, Heim theory is ingenious," says Hans Theodor Auerbach, a theoretical physicist at the Swiss Federal Institute of Technology in Zurich who worked with Heim. "I think that physics will take this direction in the future."
It may be a long while before we find out if he's right. In its present design, Dröscher and Häuser's experiment requires a magnetic coil several metres in diameter capable of sustaining an enormous current density. Most engineers say that this is not feasible with existing materials and technology, but Roger Lenard, a space propulsion researcher at Sandia National Laboratories in New Mexico thinks it might just be possible. Sandia runs an X-ray generator known as the Z machine which "could probably generate the necessary field intensities and gradients".
For now, though, Lenard considers the theory too shaky to justify the use of the Z machine. "I would be very interested in getting Sandia interested if we could get a more perspicacious introduction to the mathematics behind the proposed experiment," he says. "Even if the results are negative, that, in my mind, is a successful experiment."
Whether this can be made practical is another question...
More here, and here especially. Here's some definitions, etc... (also look here).