Question about Sci Fi Time Travel

AI Thread Summary
The discussion centers on the concept of time travel, particularly the idea of time loops as depicted in films like "Groundhog Day." Participants explore the notion that future events cannot affect past events and question the feasibility of time travel scenarios. They reference the Novikov self-consistency principle, which suggests that time travel would be impossible in a block universe where events cannot vary. However, they also consider multiverse theories, where each time loop could exist in a different universe, potentially allowing for such scenarios without violating physical laws. The conversation acknowledges the limitations of applying real-world physics to fictional narratives, emphasizing that time travel in movies often operates under its own set of rules, making it a fascinating but ultimately fantastical concept.
TheQuestionGuy14
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Hey. I know I asked questions about time travel before, but I'm just really interested in it.

So, you know the phrase 'Future events cannot effect past events'. Well, in certain movies (eg. Groundhog Day) time keeps resetting, so future events don't effect past events in this scenario. So, what makes this type of do-over time travel impossible? I'm just confused at how it is. Thanks.

Sorry this is the last post I'll make about time travel.
 
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A script makes this possible.
 
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You lied. You posted again regarding Time Travel next Thursday!
Laws of Transtempodynamics:
1) Speculation about Time Travel is a waste of Time.
2) Speculation about Perpetual Motion is a waste of Energy.
3) The previous Laws hold true, even though Entropy is not what it used to be.
Although impossible, Time Travel would be more possible if people didn't frivolously use up the medium, and the impossibility should not prevent you from further research. I thoroughly recommend Flann O'Brien's "The Third Policeman". There lies all the logic an Irishman needs.
Now this question is released from being doomed to reside for eternity (if it exists) in the temporal stasis of Unanswered Questions.
I sent it back in time to the early Royal Society so they can discuss it when they are finished with the powdered Unicorn horn debate.
 
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TheQuestionGuy14 said:
So, you know the phrase 'Future events cannot effect past events'. Well, in certain movies (eg. Groundhog Day) time keeps resetting, so future events don't effect past events in this scenario. So, what makes this type of do-over time travel impossible?

I'm not sure what exactly you are talking about. Do you mean any form of violations of causality or just just cases with contradicting results? In the first case there is no time travel at all. The second case would be impossible in a block universe (due to the Novikov self-consistency principle) but possible in a multiverse scenario.
 
DrStupid said:
I'm not sure what exactly you are talking about. Do you mean any form of violations of causality or just just cases with contradicting results? In the first case there is no time travel at all. The second case would be impossible in a block universe (due to the Novikov self-consistency principle) but possible in a multiverse scenario.

I mean any violations of any laws. I don't see how a time loop breaks the laws of physics. Here's what kind of time loop I'm talking about:

http://tvtropes.org/pmwiki/pmwiki.php/Main/GroundhogDayLoop
 
TheQuestionGuy14 said:
I mean any violations of any laws. I don't see how a time loop breaks the laws of physics. Here's what kind of time loop I'm talking about:

http://tvtropes.org/pmwiki/pmwiki.php/Main/GroundhogDayLoop

Such time-loops are impossible in a block universe. There can't be different versions of the same events.
 
DrStupid said:
Such time-loops are impossible in a block universe. There can't be different versions of the same events.

I noticed you said that it would be possible in a multiverse. What do you mean by this?
 
TheQuestionGuy14 said:
I noticed you said that it would be possible in a multiverse. What do you mean by this?

In a multiverse each loop can be in a different universe.
 
DrStupid said:
In a multiverse each loop can be in a different universe.
But does that make it possible, or is there still laws not allowing it?
 
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TheQuestionGuy14 said:
But does that make it possible, or is there still laws not allowing it?

At least it doesn't make it impossible. In order to check if it would violate any laws in a multiverse we first need to know these laws. In reality we don't even know if there is a multiverse at all. In science fiction you can define the laws accordingly.
 
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DrStupid said:
At least it doesn't make it impossible. In order to check if it would violate any laws in a multiverse we first need to know these laws. In reality we don't even know if there is a multiverse at all. In science fiction you can define the laws accordingly.
There's still a lot that doesn't make sense though,

1. Why would all the other universes he creates start a day behind the previous, what's causing this?

2. Why does he keep his memory, how does it leek into the other universes?

3. Wouldn't still be time travel, as he's still going back a day either way?
 
  • #12
Seriously it’s just the script. You’re not going to ever make it make sense with real world physics anymore than you’re going to explain Harry Potter. Fiction exists in a world of its own where things are often different. In some cases it’s worth trying to explain how things could work or if they would (e.g if the science in The Martian is solid) but for time travel in films you just aren’t.

Take it for what it is: a fascinating story that works because it invokes the fantastical.
 
  • #13
Ryan_m_b said:
Seriously it’s just the script. You’re not going to ever make it make sense with real world physics anymore than you’re going to explain Harry Potter. Fiction exists in a world of its own where things are often different. In some cases it’s worth trying to explain how things could work or if they would (e.g if the science in The Martian is solid) but for time travel in films you just aren’t.

Take it for what it is: a fascinating story that works because it invokes the fantastical.

Ok sorry.
 
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