Late yesterday, Elon Musk finally unveiled the Hyperloop: A partially evacuated tube, where pods floating on air bearings and accelerated by linear motors will travel between San Francisco and Los Angeles in under 30 minutes, at around 760 mph -- just under the speed of sound. While this sounds exciting, it's important to bear in mind that the Hyperloop -- if this hypothetical mode of transport is ever built -- serves a very niche need and will probably have almost zero effect on 99% of the world's population.