Physicists at the University of Queensland in Australia have used photons - single particles of light - to simulate quantum particles travelling through time and study their behaviour.
They were hoping to find out more about whether time travel would be possible at the quantum level - a theory first predicted in 1991.
In the study, the researchers simulated the behaviour of a single photon that travels through a wormhole and interacts with its older self. This is known as a closed timelike curve - a closed path in space-time that returns to the same starting point in space but at an earlier time. Their study is published in Nature Communications. Read more.