We may never see practical time travel in our lifetimes, if it's possible at all. However, a team at the University of Queensland has given the Doc Browns of the world a faint glimmer of hope by simulating time travel
on a very, very small scale. Their study used individual photons to
replicate a quantum particle traveling through a space-time loop (like
the one you see above) to arrive where and when it began. Since these
particles are inherently uncertain, there wasn't room for the paradoxes
that normally thwart this sort of research. The particle couldn't
destroy itself before it went on its journey, for example.
As you might have gathered from the "simulation" term, sci-fi
isn't about to become reality just yet. The scientists haven't actually
warped through time -- they've only shown how it can work. It could
take a long time before there's proof that whole atoms and objects can
make the leap, let alone a real-world demonstration. Should you ever
step into a time machine, though, you'll know where it all started...
and ended.
