Physics students at the University of Leicester designed a concept for fully operational deflector shields, but there's one problem: they'd blind whoever they protect.
Those fancy light shields they use in Star Wars to protect themselves against laser attacks aren't necessarily the stuff of science fiction after all. According to three fourth-year physics students at the University of Leicester, not only is the technology scientifically feasible, the science behind the principle is already in use today.
The Star Wars deflector shields are a sort of force field that surrounds an object, such as a fighter craft, Death Star, or a ground base, and deflects laser blasts — the primary munition used in the Star Wars universe. The students worked from the assumption that surrounding an object with a field of super-hot plasma, held in place by an electromagnetic field, would work in the same way. The denser the plasma, the higher the frequency of electromagnetic radiation (the laser blasts) would be deflected.
And something similar already exists — in the form of the Earth's own ionosphere. "The Earth's atmosphere is made up of several distinct layers, one of which is the ionosphere. The ionosphere is a plasma, and extends from roughly 50km above the surface of the Earth to the edge of space," student Alexander Toohie explained. "Just like the plasma described in our paper, it reflects certain frequencies of electromagnetic radiation, in this case radio frequencies. Radio communications and RADAR can be beamed upwards toward the sky where it will be reflected back down toward the Earth. This method can be used to send communications over the horizon where radio transmissions would not normally be capable of reaching, much like using a mirror to look around a corner."
There are a few problems, though. The first is that the magnetic field would have to be pretty strong to hold the plasma in place — requiring a larger generator than could fit on, say, an X-Wing. The other is that the shield deflects electromagnetic radiation — which includes, well, light. This would leave whoever was inside the shield unable to see anything outside.
However, all is not lost: the students proposed a more practical application for the technology. "Another possible application of this principle may be for trapping radiation inside a shell of plasma rather than excluding it," Toohie said. "This may be useful for applications that require incredibly high temperature environments, such as experimental fusion reactors."
The full paper can be read for free online in the Journal of Physics Special Topics.