The science fiction canon is thick with ideas about how to make faster-than-light travel possible. Some writers favor wormholes, some filmmakers go in for time dilation, some graphic novelists use warp drives that folds space time up — the list of possibilities, unencumbered by physics, are endless. But one of the genre’s classic tropes for making interstellar travel possible is worth a second look: hyperspace. This blurred line visual shorthand for interstellar travel is not science fact, but it isn’t purely science fiction either.
Hyperspace is accessible to ships that have hyperdrives. Exactly what that means, presumably varies from fictional universe to fictional universe — there aren’t a lot of details given. But the larger questions remains, what is hyperspace? How does it physically operate? And is hyperspace something that could be real? In the normal four dimensions that make up spacetime as we know it, the shortest path between two points is a straight line, and the fastest way to travel across that distance is to move at the speed of light. Nothing moves quite at the speed of light other than, well, light.
So, time to ditch Newtonian physics.
What if you weren’t limited to 4D spacetime? The idea of hyperspace is based on the presumption that there is a separate region of spacetime beyond the limits of four dimensions. Hyperspace seems to allow ships to foreshorten the shortest distance between A and B. Perhaps in the fourth dimension, time is indiscreet and jumps between points in such as way that it allows a ship to achieve movement without velocity. Maybe the physics of hyperspace work differently such that a ship’s propulsion has compounded effects. Maybe the speed of light ain’t shit.
There are some theories of hyperspace that are tied to speculative yet supported science. Some physicists, after all, believe there are several more dimensions past the four we know of. These higher dimensions could make it possible for hyperspace to exist.
That sounds like bullshit, but it isn’t, depending on how you feel about string theory, the idea that the physical world is made up of a framework of tiny, one-dimension string particles that shape spacetime and interact with one-another to form what we might call existence. An offshoot of string theory, called superstring theory (think: Lutheranism), suggests that there could be 10 dimensions because of the way strings warp time and space around themselves. The four dimensions we know actually conceal six other dimensions that are curled up. The manifolds that make up these dimensions are apparently less than 10^-33 centimeters across, so obviously they are smaller than what our most powerful microscopes can see. If, however, we found a way to interact with these dimensions, we might be able to access the properties that make up an invisible hyperspace that is simply another layer of the universe.
There are other parts to how hyperspace would work based on what we already know about the physics of the universe. For one, hyperspace wouldn’t look like a streak of white lights moving outwardly, but rather would be more of a bright glow. The Doppler effect — in which faster speeds would cause light to transform into longer wavelengths — would take effect and cause light from the stars to be stretched into the x-ray spectrum, and thus invisible to our eyes. Moreover, the background microwave glow of the universe would actually become visible! Space would look incredibly different at that sort of speed.
It’s unclear that we need to master faster-than-light travel in order to make interstellar travel a reality, but if we ever manage to finally interface with the supposed higher dimensions that exist in the universe, hyperspace could be the key that makes the rest of the galaxy, and possibly the universe, our oyster.