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When Seth Lloyd first pitched his idea for a quantum time loop, he didn’t consider all of the consequences. For one, he didn’t expect to receive countless emails from would-be time travelers pleading for help. He jokes that if he could restart time, “I probably wouldn’t do it.”
Unfortunately, Lloyd, the MIT physicist, won’t be looking back at the years that have passed. Spoiler alert: no one is going back in time during this article. But what about particles? That’s another question.
Physicists have long hypothesized a theoretical pathway to the past, called a time loop, but it has long been considered impossible, plagued by impracticalities and inconsistencies. But now Lloyd and other physicists are beginning to show that in the quantum world, looping back in time is not only possible, but experimentally feasible. In other words, we may soon be effectively attempting to send particles back in time.
If it works, it could potentially be possible to send, if not people, then at least messages in the form of quantum signals back in time. More importantly, studying this phenomenon could get to the heart of how cause and effect actually works, what quantum theory means, and perhaps how we can create successor theories that more fully capture the true nature of reality.
In physics, time loops are more precisely known as closed timelike curves (CTCs), which first appeared in Albert Einstein’s theory of general relativity…
Source: www.newscientist.com
