Researchers from several countries have presented their theory on a quantum computer that uses time-travelling particles to perform intractable computations.
Take this news with a grain of salt, and then send that grain back in time to solve a hard computational problem in the present, because a group of scientists believe that time-travelling quantum computers are the future.
Let's get something out of the way first: in our normal, day-to-day lives, time travel remains an impossibility. At the level of quantum physics, however? Well, let's just say it's a definite maybe. The theory of general relativity allows for time-travel to exist, through warps in spacetime we call wormholes. Most of these wormholes are probably just the right size for quantum particle to travel through.
It's under the assumption that it can happen, however, that an international group of physicists are proposing their revolutionary idea: that taking one half of a pair of entangled, quantum particles, then sending it back in time on a theoretically pre-existing time loop could create tremendous computational power. Talk about over-clocked, right? Right? Sorry.
First, you should understand what it means to have entangled particles. Entanglement is the phenomena whereby two or more entities are connected over vast distances (or times), in such a way that to observe one is to simultaneously observe the other. Fans of Mass Effect 3 encountered the technology whenever Admiral Hackett wanted to congratulate Shepard on not ruining the galaxy yet, and the idea has come up in sci-fi a lot since and before then.
The theoretical time-travelling particle would be locked, in that it could not interact with the past while it was back there, evading the "but I murdered my ancestor!"-type problems. "We avoid 'classical' paradoxes, like the grandfathers paradox, but you still get all these weird results," says Miles Gu, is at the Centre for Quantum Technologies in Singapore and Beijing.
Jayne Thompson, a co-author of the study, adds, "Whenever we present the idea, people say no way can this have an effect... the reason there is an effect is because some information is stored in the entangling correlations: this is what we're harnessing."
I'm going to assume this will work exactly like the climax of the Day of the Doctor episode of Doctor Who.
I won't pretend to know any more than what I've already written - nor will I assume any of my simplified explanations are correct. This is a hard problem. What I do know is that someday I may finally have a computer that can play Crysis!
That joke travelled here all the way from 2008. If only I could harness its power...