Good, there are some concerts that I missed and most of the performers are dead or retired.
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Posted on 10/24/2025 8:44:59 PM PDT by Red Badger
Here’s what you’ll learn when you read this story:
* Time travel is deterministic and locally free, a paper says—resolving an age-old paradox.
* This follows research observing that the present is not changed by a time-traveling qubit.
* It’s still not very nice to step on butterflies, though.
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In a peer-reviewed paper, a scientist says he has mathematically proven the physical feasibility of a specific kind of time travel. The paper appears in Classical and Quantum Gravity.
Germain Tobar and Fabio Costa, both of the University of Queensland at the time of the paper’s publication, worked together on the study. In “Reversible dynamics with closed time-like curves and freedom of choice,” Tobar and Costa say they found a middle ground in mathematics that solves a major logical paradox in one model of time travel. Let’s dig in.
The math itself is complex, but it boils down to something fairly simple. Time travel discussion focuses on closed time-like curves (CTCs), something Albert Einstein first posited. And Tobar and Costa say 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,” their paper concludes.
In a statement, Costa illustrates the science with an analogy:
“Say you travelled in time, in an attempt to stop COVID-19's patient zero from being exposed to the virus. However if you stopped that individual from becoming infected, that would eliminate the motivation for you to go back and 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. It would mean you can time travel, but you cannot do anything that would cause a paradox to occur." Some outcomes of this are grouped as the “butterfly effect,” which refers to unintended large consequences of small actions. But the real truth, in terms of the mathematical outcomes, is more like another classic parable: the monkey’s paw. Be careful what you wish for, and be careful what you time travel for.
Tobar explains in the statement:
“In the coronavirus patient zero example, you might try and stop patient zero from becoming infected, but in doing so you would catch the virus and become patient zero, or someone else would. No matter what you did, the salient events would just recalibrate around you. Try as you might to create a paradox, the events will always adjust themselves, to avoid any inconsistency.” While that sounds frustrating for the person trying to prevent a pandemic or kill Hitler, for mathematicians, it helps to smooth a fundamental speed bump in the way we think about time. It also fits with quantum findings from Los Alamos, for example, and the way random walk mathematics behave in one and two dimensions.
At the very least, this research suggests that anyone eventually designing a way to meaningfully travel in time could do so and experiment without an underlying fear of ruining the world—at least not right away.
So, of all the possible scenarios to illustrate how time-travel-induced paradoxes would not happen (because Time itself, would somehow "heal" the flow of history and force a similar outcome), he chose COVID!
It's obvious that a time-traveller visiting, say, 1923 Munich during Hitler's famous "Beer Hall Putsch" and detonating a 5-megaton nuclear warhead there would result in an outcome that could not be somehow "healed."
Regards,
Lol, nope, that woulda be3n a doub,e whammy if it had been
Good, there are some concerts that I missed and most of the performers are dead or retired.
I’d like to wade that stream by Sutters mill the year before the first guy discovered the gold. 😏
It appears you could not change the past to much effect.
However, you could obtain lots of information about the past which is much more accurate than the information currently available.
You might bury treasure or know about buried treasure, which you might recover in the future. Think about the possibility of “saving” some of the ancient texts which have been lost.
There may be things which were cheap, and durable, in the past which are worth a great deal today, as collectibles. Even just 200 years ago, if you could obtain first editions of now extremely valuable documents, and place them where they would be preserved and hidden, might prove worth while.
Thomas Jefferson lost an “invaluable” collection of notes on Indian languages was stolen and most dumped in the James river.
A time traveler might make a substitution or simply photograph the notes before they were destroyed.
Maybe it’s already been done...how would YOU know?
Sure, maybe it has already been done... but until an example is publicly demonstrated, a math proof does nothing for me.
There are unlimited ways in which it theoretically *could* be demonstrated.
For example, if a spacecraft crash-landed on earth tomorrow and it contained some evidence that it had been launched in 2185, that would constitute some level of proof.
Or if someone today said, “Hey, I went back in time to 1925, and I can prove it. I went into the office of The New York Times and I placed a small classified ad on page 48 saying that 100 years from today the president of the United States will be named Donald John Trump.” And then you went to a library obtained old microfilm images of the NYT for October 25, 1925, and such an ad was indeed on page 48. That would be proof of concept.
“You might bury treasure or know about buried treasure, which you might recover in the future.”
That is the plot of the Crichton novel “Timeline”. The movie sucked. The book was great..............
He’s planning to speak at a seminar to explain it last week.
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