Researchers from the University of Queensland opined on the matter in late-2020. U.S. counterparts have taken Europe’s research several steps further.
This article is based on technology and science postings, and related media reports. All linked information within this article is fully-attributed to the following outlets: The University of Queensland, Business Insider, IFL Science, Germain Tobar, Classical and Quantum Gravity, Google.com, Space.com, NASA.gov, and Wikipedia.org.
Time travel is no longer a science fiction trope and in fact has not been for several years. Modern science, however, has been slow at times to release their theories and findings on the matter due, in part, to expected ridicule from the general public.
In her September, 2020 article, entitled “Time Travel is Theoretically Possible, New Calculations Show. But That Doesn't Mean You Could Change the Past,” Susie Neilson of BusinessInsider.com reported on a then-recent conclusion: "Events readjust around anything that could cause a paradox, so the paradox does not happen," Germain Tobar, the study's author and a student at the University of Queensland, told IFLScience. His work, published in the journal Classical and Quantum Gravity last week, suggests that according to the rules of theoretical physics, anything you tried to change in the past would be corrected by subsequent events. Put simply: It's theoretically possible to go back in time, but you couldn't change history.
As validated by a cursory Google search, Tobar’s conclusion received a great deal of attention states-side, and also ridicule.
On balance, Space.com published “Is Time Travel Possible?” in December, 2021, which referenced and reiterated the thoughts of one of our stalwart physicists: Although many people are fascinated by the idea of changing the past or seeing the future before it's due, no person has ever demonstrated the kind of back-and-forth time travel seen in science fiction, or proposed a method of sending a person through significant periods of time that wouldn't destroy them on the way. And, as physicist Stephen Hawking pointed out in his book "Black Holes and Baby Universes" (Bantam, 1994), "The best evidence we have that time travel is not possible, and never will be, is that we have not been invaded by hordes of tourists from the future."
It is noted that Hawking wrote his book in 1994; the Queensland conclusion was derived 16 years later.
Let us explore further.
Time Travel and Modern-Day Research
An April, 2022 article published by TheConversation.com, entitled “Time Travel Could be Possible, But Only With Parallel Timelines,” written by Barak Shoshany, Assistant Professor of Physics at Canada’s Brock University, offered yet another take on the time travel conundrum: After working on time travel paradoxes for the last three years, I have become increasingly convinced that time travel could be possible, but only if our universe can allow multiple histories to coexist. So, can it? Quantum mechanics certainly seems to imply so, at least if you subscribe to Everett’s “many-worlds” interpretation, where one history can “split” into multiple histories, one for each possible measurement outcome – for example, whether Schrödinger’s cat is alive or dead, or whether or not I arrived in the past.
The author follows with a note that he and his students are developing a “concrete theory” of time travel which is compatible with Einstein’s Theory of Relativity.
In the U.S., no less an authority than NASA commented on the issue, while referencing that clocks on airplanes and satellites travel at different speeds than those on earth: Yes, time travel is indeed a real thing. But it's not quite what you've probably seen in the movies. Under certain conditions, it is possible to experience time passing at a different rate than 1 second per second. And there are important reasons why we need to understand this real-world form of time travel.
The NASA article delves heavily into Einstein’s work, which is strongly related to the their own findings.
For a brief on Einstein’s Theory of Relativity, upon which much of modern-day science as it relates to the possibility of time travel is based, see Wikipedia page here.
Whereas “Back to the Future’s” Doc Brown may take issue with the fact that most scientists presently seem to agree we cannot alter the past, recent questions — as elucidated primarily in Shoshany’s article, above — regard the possibility of building a time machine made of “exotic matter,” being material we have yet to discover, or perfect.
The work of the world’s scientists continues.
Thank you for reading