No one has yet succeeded in time travel — at least as far as we know — but the question of whether such a feat would be theoretically possible continues to fascinate scientists.

As films like The Terminator, Donnie Darko, Back to the Future, and many others show, navigating in time creates a lot of problems for the basic rules of the universe: if you go back in time and prevent your parents from meeting, for example, how can you exist? For going back in time in the first place?

It’s a massive scratch known as the “grandfather paradox”, but now physics student Germane Topar, from the University of Queensland in Australia, says he’s come up with how to “squared the numbers” to make time travel possible without the paradoxes.

“Classical dynamics says if you know the state of a system at a particular time, that can tell us the entire history of the system,” Topar says.

“However, Einstein’s general theory of relativity predicts the existence of time loops or time travel – where an event can be both in the past and in the future itself – theoretically turning the study of dynamics on its head.”

What the calculations show is that spacetime can adapt itself to avoid paradoxes.

To use a topical example, imagine a time traveler traveling into the past to prevent the spread of disease – if the mission was successful, the time traveler would not suffer from a disease that would travel back in time to be defeated.

Tobar’s work suggests that disease would still escape in another way, through a different path or in a different way, to remove the contradiction. Whatever the time traveler does, the disease will not stop.

It is not easy for non-mathematicians to research Tobar’s work, but it considers the effect of deterministic processes (without any randomness) on an arbitrary number of regions in the space-time continuum, and shows how both curves are similar closed time (such as predicted by Einstein) can correspond to Free Will Grammar and Classical Physics.

“The math has been verified – and the results are science fiction stuff,” says physicist Fabio Costa from the University of Queensland, who led the research.

The new research solves the problem with another hypothesis, which is that time travel is possible but time travelers will be restricted in what they did, to prevent them from creating a paradox. In this model, time travelers are free to do whatever they want, but contradictions are not possible.

Although the numbers may work, bending space and time to get to the past is still a long way off – the time machines that scientists have devised so far are so highly conceptualized that they currently only exist as computations on the page.

We might get there one day – Stephen Hawking certainly thought it was possible – and if we did, this new research suggests we’d be free to do what we wanted the world to do in the past: it would reset itself accordingly.

“Try as much as you can to create a paradox, events will always adjust themselves to avoid any paradox,” Costa says. “The range of calculations we’ve discovered shows that time travel with free will is logically possible in our universe without any paradox.”

Enregistrer un commentaire

Plus récente Plus ancienne