A Physicist Has Discovered Math That Makes 'Paradox-Free' Time Travel Plausible

Re:A Physicist Has Discovered Math That Makes 'Paradox-Free'... by setr on Saturday September 26, 2020 @10:47PM (#24603818)

>Tobar's work suggests that the disease would still escape some other way, through a different route or by a different method, removing the paradox. Whatever the time traveller did, the disease wouldn't be stopped.

At least scifi-plotwise, the problem with this model of time travel is that it assumes arbitrary events are marked as "important", but from the perspective of the timeline, all events should be equally important -- or rather, none of them are.

And if every event is important, and must happen (in some fashion, even if you somehow stop it) and must be maintained... then you can travel to the past, and do nothing at all. Because everything must stay the same.

If you imagine that some key events are so special as to deserve recognition for maintenance, then there must be some author to this grand narrative

IMO the only time structure that has a chance of a plothole-free narrative is multi-universe (time travel = pick a universe thats exactly the same but delayed to point of interest, out of infinite selection). If you want to get real fancy, homestuck-style multitimelines hopping back and forth between each other

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Re:A Physicist Has Discovered Math That Makes 'Paradox-Free'... by aeternum on Sunday September 27, 2020 @12:06AM (#24604152)

It seems to me that determinism is the simple answer to this. If we're all basically just actors playing out a predefined movie then time-travel is just a loop within that movie.

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Re:A Physicist Has Discovered Math That Makes 'Paradox-Free'... by setr on Sunday September 27, 2020 @02:33AM (#24604662)

Forgot about that model - one timeline, but your time traveling was always a part of it - this also is functional, but plotwise usually just amounts to a twist rather than something more interesting (i suppose tenet is a bit of an argument against that)

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Re:A Physicist Has Discovered Math That Makes 'Paradox-Free'... by sktguha on Sunday September 27, 2020 @02:55AM (#24604775)

interesting thought

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Re:A Physicist Has Discovered Math That Makes 'Paradox-Free'... by thisiszilff on Saturday September 26, 2020 @11:26PM (#24603991)

I don't think that every event is equally important or that any event is "special". Rather, the avoidance of paradoxes is. You just have to ensure the alternate history you get with respect to an action (or an event) doesn't preclude that event from happening. So if you go back to stop a disease from escaping a lab in Texas, that doesn't stop the disease from escaping two months later from a lab in California. The key is the avoidance of paradoxes.

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Re:A Physicist Has Discovered Math That Makes 'Paradox-Free'... by setr on Sunday September 27, 2020 @02:30AM (#24604652)

The problem is, assuming the butterfly effect, anything you change could trigger the paradox -- and the further you go back, the less work you need to do find a trigger.

I mean you can't even cause the timeline in which you decide to go back to change; your memory would either have to be altered to match [a paradox: which memory was "first"? Neither] or you'd have a memory from a timeline that never existed [does that count as a paradox?]

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