Posted on 01/14/2025 11:01:23 AM PST by Red Badger
Time travel has long captured the human imagination, from its appearances in science fiction fantasies to its profound implications in modern theoretical physics. Now, a recent study by Dr. Lorenzo Gavassino, a theoretical and mathematical physicist at Vanderbilt University, delves into the enigmatic nature of time travel involving time loops to examine their profound implications for quantum mechanics, entropy, and human experience.
Dr. Gavassino’s findings, published in Classical and Quantum Gravity, present a strikingly different picture of time travel. They reveal that traveling through such time loops would prevent many classical time travel paradoxes, including the infamous “grandfather paradox.”
“It is often assumed that, in a Universe with Closed Timelike Curves (CTCs), people can ‘travel to the past,'” Dr. Gavassino writes. “On the surface, this seems to be an obvious implication, since (on sufficiently large scales) one may view a timelike curve as the worldline of a hypothetical spaceship traveling across the spacetime. However, to confirm that this is an actual journey to the past, we must first discuss what happens to the passengers (i.e., to macroscopic systems of particles) as they complete the roundtrip.”
“For example, consider the following question: ‘Can Alice meet her younger self at the end of the journey?’ Answering this and similar queries ultimately boils down to determining the statistical evolution of non-equilibrium thermodynamic systems on CTCs.”
Einstein’s theory of general relativity proposes that time travel to the past might be theoretically possible under specific conditions, such as exotic spacetime geometries like traversable wormholes, cosmic strings, or faster-than-light travel.
However, even if such phenomena were achievable, scholars have long grappled with the logical contradictions time travel introduces. In particular, the paradoxes associated with foreknowledge of the future render time travel implausible.
The consistency paradox is often considered the cornerstone of these time travel conundrums, which asks what happens if a time traveler alters the past in ways that prevent their existence.
Commonly known as the “grandfather paradox,” the consistency paradox has been a staple of science fiction, frequently explored in stories about time travel. For example, in the 1985 film Back to the Future, the main character, Marty McFly, accidentally creates a paradox that prevents his parents from meeting, jeopardizing his own existence.
In his recent paper, Dr. Gavassino offers a provocative solution to time travel’s biggest logical challenges. According to him, in a universe with closed timelike curves (CTCs), the laws of quantum mechanics would inherently erase many time travel paradoxes.
Dr. Gavassino’s study reveals that any system traveling through a time loop experiences a reset in entropy and memory, ensuring that causality remains intact and preventing contradictions like the grandfather paradox from arising.
At the core of Dr. Gavassino’s research lies the concept of closed timelike curves (CTCs), theoretical paths within spacetime that loop back to their origin.
Closed timelike curves could only exist under highly exotic conditions predicted by Einstein’s general relativity. These conditions include phenomena such as traversable wormholes, where a stable tunnel between distant points in spacetime is maintained using negative energy or exotic matter to prevent collapse.
Similarly, rotating spacetimes, like those described by the Gödel metric, suggest that intense angular momentum on a cosmic scale could create paths that loop back in time.
Cosmic strings, hypothesized one-dimensional defects formed during the early universe, could also theoretically generate CTCs if they moved past each other at near-light speeds or rotated rapidly, distorting spacetime enough to permit time loops.
Another possibility involves Kerr black holes, where the extreme rotation near their event horizons could theoretically enable closed paths in time, though such regions are likely unstable due to singularities and quantum effects.
These scenarios require conditions far beyond what is naturally observable or technologically achievable, including negative energy density or exotic spacetime geometries. Likewise, these theoretical constructs face significant challenges, such as energy requirements, stability issues, and the potential invalidation of causality, making the natural or artificial creation of CTCs an extraordinary challenge.
Nevertheless, Dr. Gavassino used a mathematical model of a spaceship traveling on a CTC to examine such a journey’s physical and quantum dynamics. His analysis revealed that systems traveling along these curves undergo a spontaneous quantum restructuring, including discrete energy level adjustments and entropy inversions. This ensures that all internal states and systems reset to their original configuration by the end of the loop.
One of the study’s most remarkable discoveries is the erasure of memories for individuals or systems traveling on a CTC. Memory formation, closely tied to the increase of entropy over time, is inherently unstable on a CTC due to the reversal of the entropic arrow of time.
As entropy decreases during the journey’s second half, all processes—including memory retention—reverse, leaving the traveler unable to recall their experiences within the loop.
This phenomenon ensures that no observer within the loop can interfere with their past or create causal paradoxes, as their memory and internal states are effectively “reset” upon completing the journey.
In simple terms, time travel may be theoretically possible, but Dr. Gavassino’s findings reveal that altering the past is fundamentally impossible.
Entropy plays a pivotal role in understanding the physics of time loops. In ordinary systems, entropy—the measure of disorder—steadily increases, providing a clear arrow of time.
However, Dr. Gavassino’s findings show that CTCs impose a periodic constraint on entropy, requiring it to return to its minimum value at specific points along the loop.
This phenomenon aligns with the Poincaré recurrence theorem, which predicts that finite, isolated systems will eventually return to their initial states. In the case of CTCs, this return occurs at regular intervals, dictated by the curve’s properties.
Dr. Gavassino’s research demonstrates how quantum mechanics ensures the self-consistency of time loops. The study shows that the energy levels of systems traveling on CTCs are quantized so that all processes remain coherent and self-correcting.
For example, an unstable particle that decays into smaller components during the journey is observed to spontaneously reassemble into its original form as the journey nears its end. While counterintuitive in ordinary thermodynamics, this behavior is a natural consequence of the quantum constraints imposed by the CTC.
The implications of these findings could be profound. Unlike the chaotic and paradoxical time travel scenarios often depicted in science fiction, the findings suggest that time travel via CTCs operates under strict quantum mechanical rules that prevent disruptions to causality. Any deviations in entropy are reversed, memories are erased, and the system returns to its starting state without contradictions or inconsistencies.
This framework provides a stable, albeit unsettling, model of time travel in which classical paradoxes such as meeting a younger version of oneself or altering the past are inherently avoided.
The study also delves into the nature of reality within a time loop. At the point of minimum entropy on a CTC, causality appears to break down entirely. Complex systems, including living organisms, can seemingly “fluctuate into existence” without a clear origin, consistent with quantum statistical mechanics.
For example, a book might appear without an author, or a person might possess memories that have no logical basis in the system’s macroscopic history. These low-entropy states exist in isolation, disconnected from traditional causal chains, yet they fit within the broader framework of quantum mechanics.
While the study does not claim that interacting with one’s future or past self is impossible, it frames such encounters unconventionally. Any older version of a person encountered in a time loop would likely have no causal relationship to the younger version due to the resetting of entropy and memory. Such an “older clone” might emerge from the random fluctuations at the loop’s minimum entropy point, carrying no verifiable link to the timeline of the younger self.
Dr. Gavassino’s work offers a unique perspective on time travel, grounding these speculative ideas in the rigorous framework of quantum mechanics.
While closed timelike curves remain purely theoretical, their implications challenge and expand our understanding of time, causality, and the laws of the universe.
This research highlights that if time travel were ever possible, it would not resemble the whimsical journeys of popular culture but instead operate as a highly constrained and self-consistent quantum process.
Ultimately, while the possibility of traversing through time may not be as far-fetched as once thought, one crucial takeaway is clear: the past is permanent.
No matter how advanced our understanding of spacetime becomes, the laws of physics appear to safeguard causality, ensuring that history remains unchangeable. Time travel may one day allow us to observe and experience the past—but rewriting it will forever remain out of reach.
Probably not. For one thing we don’t know how much it costs. It might never become anything other than really expensive. Also there’s a lot of people that don’t travel now. Like even a little bit. There are people that never leave their burrow of NY. People in England are notorious for never getting more than 20KM from their town, except for maybe on a party bus that follows their football team. Add in the fact that in any future that could have time machines our present is a 3rd world country, the freaking stone age, how many modern tourists go to stone age villages in middle of nowhere Africa now. I mean would you really want to travel back in time to before antibiotics exist? That version of the world any injury can be life threatening? I’ve got a co-worker that broke his ankle on a trip to a “less civilized” part of the world, it was really rough until he could get back to the states and real medicine. It could happen and just never be cheap or convenient or popular much less all 3.
“Ultimately, while the possibility of traversing through time may not be as far-fetched as once thought, one crucial takeaway is clear: the past is permanent. “
I have had leftist claim to me, “There is no past beyond our memory of it.
You also have to account for motion of the earth and the sun. Let’s say you go back in time, say 100 years,....maybe it could be done ...but then when you get there...you’ll be at least a partial light year away with no way to get to Earth of the past. You’d have to travel in a spaceship to get there and you’d have to find it as there is no assurance that when you went back 100 years, that you would be in the same place that you were when you left 2025 so that you could track it to the place it was in 1925. No way to know if the time jump won’t spatially leave you 100 years past but in a distant galaxy and no way to go home!
Nonsense...Superman absorbs the inertial energy disruptions onto himself and no one dies....
Well it’s just as good an explanation as the stuff Engineer Scott and Spock come up with on Star Trek to save the universe’s women from all being kissed by Captain Kirk...all at once!
He is outside of all those constructs. He created them and visits whenever and wherever He wants.
I can believe in time travel, but a DeLorean reaching 88mph is impossible.
Eventually, he meets more and more of his selves in the same timeline. And as each has a regular lifespan, they are different ages. Some of his selves he gets along with, some not so much. Sometimes he lives with several of his selves.
He even has orgies with his selves, which is really weird. He says it feels good, as he knows how to pleasure himself.
I think the author might have been gay, but perhaps he was signaling that homosexuality is really a form of self-love.
I actually came up with a good scientific explanation for how Superman can fly. He physically does it. He physically moves the atoms of his muscles to provide motion towards whatever direction he wants to go. That changes the mass of his body to provide lift, direction, and speed. I haven’t seen this idea anywhere online.
You know how sometimes you have dreams when you fly?
This is exactly how I fly in my dreams.
I just thought earth life gave him gastric problems.
EWWW!
Super Brown Snail Trails!
What a business that would be, transporting people back to fix their pasts. I would definitely take my dishwashing money from the restaurant in 1979 and put it on Apple. And I would never date L——, not even for the first time.
When I have that kind of dream I don’t fly so much as levitate and glide along at a slow pace instead of walking. And for some reason it always takes ***INTENSE*** concentration on my part, a supreme act of will to leave the ground.
I like how you think
Well, they don't exist separately. Time, itself, does not exist according to Quantum Theory. However there is space-time. But QT is above my head even though I find it fascinating.
Jesus said “Before Abraham was, I am.”
Figure that one out.
“To a liberal, history started at breakfast this morning.” - Ann Coulter..............
“There is no past beyond our memory of it.”
“We are unburdened by what has been.” - K. Harris.............
I would settle for just being able to erase some memories..................
Hey! I dated her!
She had a face that would stop a clock!................
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