Peculiar research co-authored by University of Queensland student Germain Tobar and UQ Professor Fabio Costa, postulates that a particular kind of time travel might actually be possible, according to a report in Popular Mechanics.
The authors of the paper, titled “Reversible dynamics with closed time-like curves and freedom of choice”, argue that they've discovered a “middle ground in mathematics that solves a major logical paradox in one model of time travel”.
With the "time-travel discussion" focused on so-called closed timelike curves, the magazine notes, Tobar and Costa suggest that "as long as just two pieces of an entire scenario within a CTC are still in 'causal order' when you leave, the rest is subject to local free will".
"Our results show that CTCs are not only compatible with determinism and with the local 'free choice' of operations, but also with a rich and diverse range of scenarios and dynamical processes," the paper states.
In a statement cited by the magazine, Costa deployed the analogy of a time traveler seeking to prevent the COVID-19 Patient Zero from becoming infected with the virus, noting how succeeding in that quest would eliminate the traveler's motivation to head into the past to stop the pandemic in the first place.
"This is a paradox, an inconsistency that often leads people to think that time travel cannot occur in our universe. [L]ogically it's hard to accept because that would affect our freedom to make any arbitrary action", he said. "It would mean you can time travel, but you cannot do anything that would cause a paradox to occur."
Tobar further detailed, however, that no matter what a hypothetical time traveler does in the past, “salient events would just recalibrate" around them.
"Try as you might to create a paradox, the events will always adjust themselves, to avoid any inconsistency", he suggested.