So far, at least as far as we know, no one has succeeded in time travel, but the question of whether such a feat is theoretically possible continues to fascinate scientists.
like a movie The situation is over, Donnie Darko, back to the future Many others point out that time travel poses many problems for the basic laws of the universe: if you go back in time and prevent meeting your parents, for example, how can you exist to go back in time? Initially?
It’s a big surprise known as the Dada Paradox, but a few years ago a physics student at the University of Queensland in Australia, Germain Tober, figured out how to square the numbers to make time travel possible without the paradox.
“Classical dynamics holds that knowing the state of a system at a particular time can tell us about the history of the entire system.” Tober explained in 2020.
“However, Einstein’s general theory of relativity predicts the existence of time loops or time travel – where an event can be both past and future – theoretically turning the study of dynamics on its head.”
Calculations show that spacetime can adjust to avoid paradoxes.
To use a recent example: imagine a time traveler traveling back in time to prevent the spread of a disease – if the mission is successful, the time traveler will have no disease to travel back in time to defeat.
Tober’s work suggests that the disease will still escape in some other way, some other way or other, eliminating the paradox. No matter what the time traveler does, the sickness won’t stop.
It’s not easy for non-mathematicians to engage with Tober’s work, but he examines the implications deterministic process (without any randomness) in any number of regions in the space-time continuum and shows how both Closed time curve (As Einstein predicted) It can obey free will and the laws of classical physics.
“The math has been verified – and the results are the stuff of science fiction.” says physicist Fabio Costa from the University of Queensland, who supervised the research.
Fabio Costa (left) and Jermaine Tober (right). (ho fu)
The research solved the problem with a different hypothesis, which stated that time travel was possible, but that time travelers would be limited in their activities to prevent creating a paradox. In this model, time travelers can do whatever they want, but paradoxes are not possible.
While the numbers may work, bending space and time still has a long way to go—the time machines scientists have built so far are so sophisticated that they currently exist only as calculations on a page.
We may get there one day — Stephen Hawking certainly thought it possible — and if we do, this new research suggests we’ll have the freedom to do what we wanted the world to do in the past: It will adjust accordingly.
“No matter how much you try to create a paradox, events will always adjust to avoid a conflict.” Costa said.
“The mathematical operations we discovered show that time travel is logically possible in our universe without hesitation.”
The study was published Classical and quantum gravity.
An earlier version of this article was published in September 2020.
