Time Travel Violates Thermodynamics. Here's why

[Kyrian007]

That is, unless the act of time travel creates a divergent timeline that we dont experience

Then, what's really the point of going forward with "time travel" at all. Sure, the person travelling experiences the divergent timelines... but that's from that traveler's point of view. From the point of view of anyone else, the "time machine" is basically a Futurama suicide booth. The traveler goes into it, and is never present on this particular timeline ever again. Might as well make a suicide booth and just say its that kind of time machine, it would have exactly the same effect on this timeline.

I never said it was a good thing, I was just reply to the idea that time travel could exist without current evidence of it.

I mean hell, the divergent timeline theory is how 99% of time travel shows and movies work already. Think of stuff like Back to the Future. Only people in the delorian experience time travel. Everyone else exists as if they lived through the changes because they did.

I mean think about it, unless a time traveler is stupid enough to leave behind incredibly obvious evidence, how would we know they changed the past? Maybe the past used to be different and it's already changed and were living in another timeline already.

Mostly I'm sure we don't live in a universe where time travel is possible because even though the answer would keep changing, we'd all know the answer to one question... "who invented the time machine." Even if someone went back, invented the time machine just to keep it quiet and try and "fix" history... there would still eventually be someone who would eventually abuse it for profit and in some way leave evidence of time travel. And even if someone is successful, the timeline would correct... and that guy that invented it in the original timeline or someone close to his level (say the guy that would have invented it next, or the next guy, or the next guy... on to infinity) would "re-discover" it and invent it again, starting the cycle over. Plus the past is an escape. There are dozens of ways an extinction level event can wipe out humanity... before eventually our sun grows cold and goes out. Time travel isn't possible, because those humans have not already retreated into the past to escape that eventuality. Or it is possible, but human kind won't eventually advance far enough to achieve it before being wiped out.

Actually I'm generally more positive about time travel in terms of the original idea of project Quantum Leap (holograms in a simulated environment) or Steven Baxter's The Light of Other Days (rewinding omnipresent objective recall.) Basically a system where the past can be viewed but not interacted with in any way. They seem more possible to me because there isn't any problems with causality, no chance of paradox. And just like time travel, they are both horrifying in their own ways.

 

[TheVampwizimp_v1legacy]

I think time travel is impossible because it violates the law of conservation of matter and energy. If you displace an object in time, that means that it's physical existence must be overlapping with another moment in which it also exists (since even if a thing is destroyed it's component atoms still exist, or the energy that those atoms represent). This would both remove matter/energy from the present, and add matter/energy to the past or future, whichever direction the object travels, resulting in a change in the total energy of the universe, which is impossible; thus, time travel is impossible.

 

[leison]

The second law of thermodynamics refutes the possibility of creating some devices (perpetual motion machine) and many physics phenomena (more answers [https://assignment.essayshark.com/physics-help.html] can be found on the site). And I agree with the author. The phenomenon of entropy proves the impossibility of traveling through time. But at the same time, we know about the existence of black holes, but don't understand how the processes take place there. We have only guesses. And how the time-space flows there remains inexplicable and the statement about the time travel remains unproven.

 

[stroopwafel]

There are many approaches to the mathematical derivations, which vary in their formality and accessibility, but the most famous and easiest to understand is Einstein's own thought experiment involving a laser reflected by a mirror in a moving train car.

Most of what you wrote went way over my head but I do know about Einstein's theory of special relativity that says time speeds up or slows down depending how fast you move relative to something else. Say, someone inside a spaceship that moves at the speed of light would age much slower than someone on earth. Inside the four-dimensional fabric of space time gravity also bends time as objects inside the fabric move on a curved path and that curvature of space is gravity. Due to time dilation astronauts for example return to earth 38 microseconds younger with every day they spent in outer space.

Going by special relativity the only way for time travel would be to create a wormhole between two points in space-time. But ofcourse, there is no technology to create a wormhole and apparently these collapse very quickly and are only suitable for small particles. Another way would be for a spaceship to move at the speed of light around a black hole and for 5 years in the spaceship 10 years on earth will have passed. I read that even without a worm or black hole it could be possible to time travel at warp speed by bending space time inside a doughnut shaped vacuum by letting focused gravitational fields form a closed time-like curve.

Seems difficult to accomplish but, maybe a few hundred years from now? Black holes in particular would be revolutionary if science could ever figure them out.