Forty years ago today the movie Star Wars opened in theaters, and inspired a generation to study and explore the depths of space. Many people of my age entered into science and engineering fields after first getting excited by the possibilities presented in the entire septet of films.

In honour of the anniversary, I thought I would discuss one of the interesting technologies used in the Star Wars universe. (Which as I wrote in a previous entry, may actually exist in a galaxy far, far away if you believe in certain models of eternal cosmic inflation.). That technology is the hyperdrive system.

In our Universe, with our technology, it is impossible to travel even to our nearest stellar neighbour. Even if we could travel at close to the speed of light, it would take decades to reach another star. In order to cross the entire galaxy, you would have to spend several millenia in transit even with the best technology that we can imagine (excluding of course technologies that rely on unproven physical theories).

And yet in the Star Wars canon, any reasonable spaceship has a hyperdrive system that can be engaged and the ship and occupants can travel from the outer rim to the core worlds in only a few hours. This would seem to violate the laws of physics (and especially when one includes time dilation effects due to the theory of relativity), and yet with some modern physics theories it might actually be a viable technology!

Over the past twenty years, several theories have been developed which include hyperspace - a spacetime whose dimensions are greater than the four that we are aware of (which is the definition of the word hyperspace). The existence of higher dimensions could plausibly explain a number of observed phenomena in nature, including the weakness of gravity relative to the other forces and the existence of multiple generations of particles in the Standard Model. And while a number of experiments have sought evidence of these higher dimensions, so far there is no strong evidence for or against the existence of hyperspace.

In many of these models, our Universe exists on a four-dimensional membrane that floats through hyperspace. Often these models also include other membranes with other properties, and perhaps other Universes. It is also possible that distances are measured differently on other membranes or between the membranes in the hyperspace, and that is where the idea of a hyperdrive becomes possible.

Hypothetically, if hyperspace exists then it could be possible for some future technology to exit our Universe and enter the higher dimensions. At present we do not know how this would happen, because we don't really understand how these membranes form in the first place. However there are some speculative theories in particle physics in which these membranes can form, and which apply a very strong force to keep matter trapped on the membrane, but which do not actually forbid a high energy particle from entering hyperspace. And so it may be possible to construct an entire spaceship that can exit the membrane and enter hyperspace.

And again, in hyperspace distances are different than they are in our Universe. Space itself can become compressed, and so traveling at a sub-light speed in hyperspace a spaceship could cross more distance than traveling at far greater than light speed would on the membrane. 

It then is not entirely impossible that there might be a technology which allows a spaceship to enter hyperspace, travel a short distance at a reasonable speed, and then re-enter the Universe on the other side of the galaxy. And just like the movies suggest, this would actually require careful calculations to prevent the spaceship from re-entering the Universe in the middle of a star or a black hole, since these objects do not exist in hyperspace. The end result would be a civilization that is able to traverse the entire galaxy in just a few hours, by using the properties of hyperspace.

So maybe the technology of Star Wars is not so unbelievable after all...