The US military is considering testing the principle behind a type of space drive which holds the promise of reaching Mars in just three hours. The problem is, as New Scientist explains, it's entirely theoretical and many physicists admit they don't understand the science behind it.
Nonetheless, the so-called "hyperdrive" concept won last year's American Institute of Aeronautics & Astronautics award for the best nuclear and future flight paper. Among its defenders is aerospace engineer Pavlos Mikellides, from the Arizona State University in Tempe. Mikellides, who reviewed the winning paper, said: "Even though such features have been explored before, this particular approach is quite unique."
The basic concept is this: according to the paper's authors - Jochem Häuser, a physicist and professor of computer science at the University of Applied Sciences in Salzgitter and Walter Dröscher, a retired Austrian patent officer - if you put a huge rotating ring above a superconducting coil and pump enough current through the coil, the resulting large magnetic field will "reduce the gravitational pull on the ring to the point where it floats free".
The origins of this "repulsive anti-gravity force" and the hyperdrive it might power lie in the work of German scientist Burkhard Heim, who - as part of his attempts to reconcile quantum mechanics and Einstein's general theory of relativity - formulated a theoretical six-dimensioned universe by bolting on two new sub-dimensions to Einstein's generally-accepted four (three space, one time).
As New Scientist explains, Heim's two extra dimensions allowed him to couple together gravity and electromagnetism, and permits conversion of electromagnetic energy into gravitational and vice-versa - something not possible according to Einstein's four dimensions, because "you cannot change the strength of gravity simply by cranking up the electromagnetic field".
Heim, then, proposed that "a rotating magnetic field could reduce the influence of gravity on a spacecraft enough for it to take off" - an idea which caught the eye of Wernher von Braun when it was first proposed in 1959 and the rocket scientist was working on the US's Saturn launch vehicle.
After the initial excitement died down, however, Heim moved on to other projects and his hyperdrive theory slowly gathered dust until the arrival of Walter Dröscher in 1980. Dröscher expanded on Heim's work, in the process reactivating two further dimensions the latter had originally discarded. Thus "Heim-Dröscher space" was born - an eight-dimensional concept of which Dröscher says: "If Heim's picture is to make sense, we are forced to postulate two more fundamental forces."
The said extra forces are: "A repulsive anti-gravity similar to the dark energy that appears to be causing the universe's expansion to accelerate"; and a second resulting from the "interaction of Heim's fifth and sixth dimensions and the extra dimensions that Dröscher introduced". Crucially, it "produces pairs of 'gravitophotons' - particles that mediate the interconversion of electromagnetic and gravitational energy".
The groundwork done, Dröscher then teamed up with Häuser to produce the award-winning "Guidelines For a Space Propulsion Device Based on Heim's Quantum Theory."
So far so good - in theory. However, as NS notes: "The majority of physicists have never heard of Heim theory, and most of those contacted by New Scientist said they couldn't make sense of Dröscher and Häuser's description of the theory behind their proposed experiment."
Furthermore, Dröscher and Häuser's proposed practical experiment to prove their theory requires "a magnetic coil several metres in diameter capable of sustaining an enormous current density" - something which the majority of engineers say is "not feasible with existing materials and technology".*
So, Mars in three hours? As NS puts it: "Dröscher is hazy about the details", but "suggests that a spacecraft fitted with a coil and ring could be propelled into a multidimensional hyperspace" where "the constants of nature could be different, and even the speed of light could be several times faster than we experience". Then, he says, a quick three-hour jaunt to Mars would indeed be on the cards. ®
*Roger Lenard, a space propulsion researcher at Sandia National Laboratories in New Mexico does think it might be possible, though, using an X-ray generator called the Z machine which "could probably generate the necessary field intensities and gradients".