Time travel: You can't change the past.

Great Debates
21

Except that it wouldn’t work that way… [sigh]

It was an interesting episode. It just doesn’t really make sense.

(The episodes with impossible transporter accidents are also usually interesting, if not very believable [even with suspension of disbelief].)

22

TVAA: Are you working with the Vorlons…or the Tralfamadorians? (Grin!)

Me, I’m a “many worlder,” myself, and so going back and “changing” the past is harmless: you’re simply altering one infinitesimal slice of “what if” into another.

(Jack Vance, in his story “Rumfuddle,” gives one of the best possible explorations of this idea.)

Trinopus

23

Yep, that’s true, the many worlds theory does away with the collapse of the wavefunction but it creates it’s own problems. In convential measurement theory and the formal mathematics it’s non-detirministic tho’.

The inital variables of a chaotic system might not be significantly effected by uncertainty, take for example one of the classic examples the extinction of woolly mammouths by modelling their population and the population of caveman who hunt them and a few other variables that can be known to a precise degree. Small variations in either population in this model can mean the difference between extinction and survival for woolly mammouths. Chaos is distinct from indetirmninsm, but the behaviour of a chaotic and indetirministic system can appear superficially simlair.

24

TVAA - I don’t think really any Sci-Fi involving time travel really does make any sense. Time Travel stories always lead to paradoxes. I love the stories that embrace the Paradox’s and have fun with them

25

I love time-travel stories too. But what I always run into is: Okay, at some time in the future, time travel is invented, and people can come back . . . here? So–where are they?

I guess this is nullified by the theory that time travel would result in alternate universes. Or the example that reality would change but so would the awareness of all previous realities.

26

In another thread on time travel, someone brought up a theory that essentially said:

  1. Time travel is possible, and will therefore eventually be invented.
  2. Time travelers travelling into the past will start changing their “futures”.
  3. “Downstreamers” (not necessarily the same people, ot the same race, or in the same galaxy…), mercifully unaware of the fact that they are winking in and out of existence, continue, at some point in their futures, to (re?)invent Time Travel, and to send their own time-line’s voyagers back, only to see another time-line biting the dust. Repeat as necessary
  4. Eventually, one of these changes will result in a universe in which Time Travel, while (as we said) possible, never gets discovered/invented by anyone, anywhere, anywhen.
  5. We are on the time line resulting from this ultimate change…

I don’t have the time or patience right now to go back and search for the earlier thread and the (better) exposition of this theory - if anyone really wants me to, please post and I’ll give it some time early next week.

27

Was that
this thread, by any chance?
I already linked to that thread earlier in this one;
I feel like I am stuck in some kind of time loop…

SF worldbuilding at
http://www.orionsarm.com/main.html

28

Was that
this thread, by any chance?
I already linked to that thread earlier in this one;
I feel like I am stuck in some kind of time loop…

SF worldbuilding at
http://www.orionsarm.com/main.html

29

Oh, what a pleasant surprise.

I’ve been making that claim for quite some time now.

It’s nice to see that someone else came up with it independently. :slight_smile:

30

So for every decision you’ve ever made, a myriad copies of you have been spawned into the multiverse living out all possible consequences of every action you could have taken?

I hope your an atheist, cause God may not like the copies of you that did the bad stuff when you all get to heaven.

Even as an atheist, the inherent lack of free will in the many worlds theory turns me off.

31

But you never have “free will” in any theory.

In deterministic models, your actions proceed from your nature, which in turn proceeds from the states of the universe.

In non-deterministic models, your actions are fundamentally random and cannot be attributed to any cause or principle.

Either way, you lose.