In a world first, physicists have successfully made light appear to move backwards and forwards in time simultaneously.
The physics of time can be mind-bending to say the least, but now two independent teams of scientists have achieved something never seen before by making light appear to move forwards and backwards in time simultaneously – a phenomenon known as a ‘quantum time flip’.
To achieve this, the physicists used a special type of optical crystal to split a photon, an elementary particle which is essentially a small ‘packet’ of light.
The ‘time flip’ achieved results as a consequence of two principles of quantum mechanics.
Quantum superposition enables particles to exist in multiple different states at the same time until observed, while CPT (charge, parity and time-reversal) symmetry dictates that any system of particles will obey the same laws of physics even if their charges, spatial co-ordinates or movements through time are flipped.
In the future, experiments such as this could help to open up the door to a new world of quantum discoveries.
“A nice way to put it is to say that our experiment is a simulation of exotic scenarios where a photon might evolve forward and backward in time,” Oxford University physicist Giulio Chiribella told Live Science.
“What we do is an analogue to some experiments that simulate exotic physics, such as the physics of black holes or time travel.”