The fact that certain people are alive is absolute proof that no one in our timeline ever invents time travel.

#TimeTravel #paradox #alive #GrandfatherParadox #timeline #multiverse

   
#TimeTravelTuesday #ThoughtExperiment: Many #Worldlets?

or in other words, fractions of #World, not the whole World. #TimeTraveler #theories often involve splitting or multiplying #universes. Time Travel events divide #spacetime into two near-identical clones. Grandfather lived or did not, you did not meet yourself or you did. But if we think this through further, its scope might not be quite so universal as typically presented.

Take 3 heavenly bodies: Mother #Earth, the #AlphaCentauri triple star system (at 4+ light years away), and #Polaris, the #NorthStar (at 400+ light years away).

Now we program our #TimeMachine to take us back one year (#retrograde) where we meet ourselves. Hi selves! This all takes place in one year. There's the original us, there's us leaving the present, and there's us meeting our past/original selves a year earlier — standard #boilerplate #scifi #movie #script.

Alpha Centauri will have to wait another 3 years before any of this information can get to there. This is related to the concept of a #lightcone which expands at the speed of light. This doesn't sound quite so much like birthing a twin universe, does it? Now what about the North Star? It will have to wait 433 years for news of our Time Travel event(s). And that's still pretty much in our tiny #celestial neighborhood.

The point is that the effects of such events are largely localized and rapidly diluted as we move farther away. This still has its paradoxical problems, but it doesn't quite feel like the whole universe dividing into two — maybe part of it (a universelet? a subuniverse?) Possibilities are that in moving further out in space-time, the effects of a Time Travel incident may be 'blurred out', as are anomalous numerical samples in the law of large #numbers. If one pours a cup of coffee into a lake, it doesn't change the color of the lake. There is a brief chaotic #glitch before it is no longer measurable.

It is tempting to imagine space-time as "stitching" itself back together. (Glitch & stitch?) Such speculations are related to #StephenHawking's "chronology protection conjecture" of 1992. And along with #blackholes, #entanglement, and other #quantum phenomena, if Time Travel is possible, then we should be looking for it at every scale. We could be surrounded by time-traveling particles everywhere all the #Time.

🔗 https://Wikipedia.org/wiki/Many-worlds_interpretation … #ManyWorlds
🔗 https://Wikipedia.org/wiki/Temporal_paradox#Consistency_paradox … #GrandfatherParadox
🔗 https://Wikipedia.org/wiki/Light_cone … #LightCone
🔗 https://Wikipedia.org/wiki/Time_travel#Absence_of_time_travelers_from_the_future … #TimeTravelTheory
🔗 https://Wikipedia.org/wiki/Law_of_large_numbers … #LawOfLargeNumbers
🔗 https://Wikipedia.org/wiki/Chronology_protection_conjecture … #ChronologyProtectionConjecture

#Community #TimeTravel #Research #GlitchInTime #Kronodon

WRITER FUEL: The grandfather paradox is just one of the thorny logical problems that arise with the concept of time travel. But one physicist says he has resolved them.

https://www.limfic.com/2025/03/28/writer-fuel-physicist-claims-to-have-solved-grandfather-paradox/

#LimFic #LiminalFiction #WriterFuel #Writers #Authors #WritersofMastodon #StoryIdeas #TimeTravel #GrandfatherParadox

 
A #Scientist Claims He’s Solved a Major Time Travel Paradox

#SciFi fans know that (#retrograde) #Time #Travel breaks basic #logic. If #interdimensional #transport is to be pursued, then logic may have to be violated.

Gavassino's new #study doesn't so much remove the #GrandfatherParadox, as it suggests how higher #physics could provide a workaround.

🔗 https://www.PopularMechanics.com/science/a63395644/time-travel-paradox-solved/
🔗 https://Wikipedia.org/wiki/Temporal_paradox
🎓 h/t @cosmiclibrarian

#Community #TimeTravel #Research #science #quantumphysics #Kronodon

The most well-known example of the impossibility of traveling in time is the grandfather paradox or self-infanticide argument: a person who travels in the past and kills his own grandfather, thus preventing the existence of one of his parents and thus his own existence. A philosophical response to this paradox would be the impossibility of changing the past, like Novikov self-consistency principle (if #grandfatherparadox

https://www.indexacademic.ro/pdf/grandfather-paradox-in-time-travel/

When reading maths or physics texts, I often struggle with ambiguities none of my peers seem to be seeing. Here's an example about time travelling.

People say, if you could move faster than light, then you'd move backwards in time.

To me, this is ambiguous, but most just go on and say that that would cause problems with causality, and destroy the universe.

What? Let me be more explicit:

If a spaceship moves near the speed of light, time _on it_ would move slower, and if it, after a reasonably long journey, would return to earth, its clocks would say, "we've been underway for a few months". But they would find themselves on earth where a decade had passed.

So if that spaceship could travel #fasterThanLight, its crew would not have started the journey yet by a few months, but the clocks on earth would still have measured a decade!

See what I mean? I run into problems like these all the time, still struggling, while people are already discussing the #GrandfatherParadox.

I wanted to write a short toot about how the #GrandfatherParadox could be resolved using ideas from #QuantumMechanics but I read that this point has already been made years ago and isn't at all an original idea.

Basically, I figured that you should be able to interfere with your own timeline without any problems. You can #TimeTravel back in time and prevent yourself from getting born is fine. It that doesn't affect "your own" timeline.

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