Martijn Hendriks
Gradually, then suddenly (white version), 2009

Still from a single channel altered video of a 1965 studio performance by Bruce Nauman, 1 min 59 sec

The existence of wormholes, shortcuts through spacetime, is still hotly debated.  Stephen Hawking gave a lecture touching on the possibility and the implications of traversable wormholes.  In theory, they would allow quick travel in space to even the most remote galaxies (you wouldn’t actually be travelling faster than the speed of light, but you would beat light to your destination, because it had to travel all the way around). More baffling still, they would allow time travel too. Hawking stated that if you could travel from one side of the galaxy to the other in a matter of a week or two, you could return through another wormhole, and be back before you started your journey. The theory only allows travel back in time, and only to the moment of the initial creation of the time machine.  Hawking again: a time machine will be built someday, but has not yet been built, so the tourists from the future cannot reach this far back in time.

– Based on a text by Brooke Ballantyne –