We all have a fascination with the idea of time travel, much like what we see in popular fiction. In films, we have mostly witnessed people sitting in a large, heavy machine and travelling hundreds of years into the past or future. However, this is not the case. Now scientists have come up with another experiment using quantum entanglement to simulate the activity- the strange way that quantum particles can interact, as per Gizmodo Newsletter. The concept found its way in the 2018 movie 'Ant-Man And The Wasp'.
The latest study was a Gedankenexperiment, a term used by Albert Einstein to refer to theoretical investigations carried out in place of actual experiments which are helpful for probing the boundaries of physics, such as particle motion at the speed of light. However, the team's latest work in Physical Review Letters describes a simulation that contains "effective time travel." The phenomenon wherein the properties of two or more quantum particles are determined by one another is known as quantum entanglement. Since the entanglement of two particles occurs on a quantum level, factors like their physical distance have no effect on the interaction. Hence, understanding the characteristics of one entangled particle provides knowledge about the other.
A possible time-travelling method known as closed-timelike curves was investigated in a recent study. The curve is the arc formed by a particle throughout its lifetime in spacetime that runs backwards. In the experiment, scientists subject photonic probes to a quantum interaction, with the aim of producing a quantifiable outcome.
They may ascertain what input would have produced the best outcome based on that outcome. However, since the outcome was the consequence of a quantum operation, the researchers may adjust the quantum probe's values through entanglement to get a better result even if the operation has already taken place, as opposed to being stuck with a less-than-ideal outcome, as per the Gizmodo Newsletter.
Through the study, scientists found that the time travel effect would happen once every four times, or at a failure rate of 75 per cent. The researchers proposed delivering a lot of entangled photons and using a filter to verify that the photons with the revised information got through while sifting away the outdated particles in order to solve the high failure rate.
David Arvidsson-Shukur, a quantum physicist at the University of Cambridge and the study's author told the outlet, "The experiment that we describe seems impossible to solve with standard (not quantum) physics, which obeys the normal arrow of time. Thus, it appears as if quantum entanglement can generate instances which effectively look like time travel."