Let’s be frank: in the world, not a large number of individuals truly believe in the possibility of temporal journeys. Regarding this topic, there are several objections of a strictly scientific nature, yet some of them are quite understandable even to the average person. The most renowned is the grandfather paradox. The essence is that a traveler, having gone to the past, might kill their grandfather there before he meets their grandmother. Consequently, this individual themselves could not come into being. But they do exist! Hence the deduction: traversing time is impossible.
Scientists from Australia propose forgetting about this and other paradoxes that alter the future. According to their study, featured in the journal Classical and Quantum Gravity, time travel is feasible. And without any logical inconsistencies!
The Cosmos Possesses “Pliability”
The article by physicists Germain Tobar and Fabio Costa from the University of Queensland might alarm with its title alone—”Reversible Dynamics with Closed Timelike Curves and Free Will.” Fear not, reader. It suffices for you to grasp that closed timelike curves (CTCs) are geometric constructs in spacetime, whose trajectories return to the starting point not only by coordinates but also by time. They were first discussed when examining Albert Einstein’s equations of general relativity. At that point, researchers hypothesized that loops could emerge within the temporal dimension under specific conditions.
But what about that persistent problem of time travel—the paradoxes? The Australians, Tobar and Costa, assert they have pinpointed a solution. The core of their intricate calculations (the paper is scientific!) can be distilled into a simple and compelling precept: The Universe possesses a particular “pliability.” It functions like a stubborn accountant who detests discrepancies in financial records and seeks to correct them upon discovery. Should you endeavor to create a paradox (for instance, dispatching your own grandfather in the past), the laws of physics will gently yet firmly set you straight. Events will rearrange themselves so that all the “accounts” balance, and cause-and-effect linkages remain unbroken.
The scientists illustrate this through a hypothetical scenario. Suppose you decide to journey back in time to forestall a global occurrence—the COVID-19 pandemic. You intend to locate the “Patient Zero” and prevent them from contracting the coronavirus from an animal (or a lab sample, it matters not). According to classic understandings, a paradox arises here: if you succeed, the pandemic won’t occur, and you would have no reason to depart from a hypothetical 2025 for a trip back to 2019.
“But, according to our model, no matter how hard you try, the crucial events will simply restructure around you,” explains Germain Tobar, one of the paper’s originators. “For example, you might avert the ‘Patient Zero’s’ infection, but you yourself contract the virus and become that very ‘Patient Zero,’ or someone else you didn’t account for will become it. This means, however you strive to generate a paradox, occurrences will invariably adjust to avoid any contradictions.”
This implies the pandemic will happen anyway. It is just that its specifics will be different.
Instead of the “Butterfly Effect”—the “Monkey’s Paw”
Thus, the time traveler does not become a helpless spectator—their will remains intact at a local level. They can act in the past, and upon returning to the present, may even tick a box: I tried!
The difficulty, however, is that their actions will not yield the substantial outcome—the one they were hoping for (preventing the pandemic, eliminating Hitler, or similar). The results of these actions will always be interwoven into the already existing macrocosm’s history.
Biophysicist Alexander Levich.
On the edge of fantasy. At Moscow State University, they unraveled the mysteries of teleportation and time machines
The study’s authors maintain that this resembles not the “butterfly effect” (in Ray Bradbury’s tale, the demise of a butterfly in the distant past transforms the world of the far future), but a different literary trope—the “monkey’s paw.” In the eponymous short story by English author W.W. Jacobs, a magical artifact resembling a mummified monkey’s paw grants wishes, but this brings about unforeseen consequences, completely different from what the petitioner anticipated.
Additionally, the researchers note that their theory is supported by quantum experiments where particles, interacting with their preceding versions, fail to generate contradictions.
So, there is positive tidings: time voyages are theoretically plausible, and it is conceivable they might someday become actual reality. But there is also unfavorable news: these voyages will not unfold as depicted in Hollywood blockbusters. If you board a time conveyance and venture into the past, you will be unable to influence subsequent events as you might desire.
Be prepared for the Universe to prove more obstinate than you. Or, perhaps more aptly put—more sagacious.
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