Is time travel possible in the many-worlds interpretation of quantum mechanics?

In summary, the many-worlds interpretation of quantum mechanics suggests that the grandfather paradox can be avoided by traveling back in time and ending up in a different universe. It is unclear if this is true or how it works, but there may be a website that explains it well. However, there are also concerns about consistency constraints and a potential global version of the grandfather paradox across all alternative universes. Furthermore, the possibility of infinite alternative universes raises questions about the effectiveness of using FTL send-messages-to-the-past devices in an Everett universe, as it could result in multiple branches and potential interference.
  • #1
Ontoplankton
152
0
A common claim is that in the many-worlds interpretation of quantum mechanics, grandfather paradoxes are avoided because you end up in a different universe when you travel back in time. Does anyone here know whether this is true, and how it works? Is there a website that explains it well?

I'm suspicious because it seems to me it would give you a way to test which interpretation of quantum mechanics is true.

Also, aren't there just as strong consistency constraints on a "wave function of the universe" as on a classical, single universe? Does this lead to a global version of the grandfather paradox across all Everett-worlds?
 
Physics news on Phys.org
  • #2
Considering an infinite number of alternative universes, all possiblities of all outcomes are possible. It would essentially be childsplay to avoid the grandfather paradox in such a situation.
 
  • #3
Suppose you had one of those FTL send-messages-to-the-past devices that works by sending an instantaneous message to a remote frame moving away at a high sublight speed, converting the message to that frame (e.g. by reflection) and sending it back, still instantaneous but now in the remote frame's spacelike slice which intersects the past of your worldline. What would you get back in an Everett universe? White noise? For in interacting with the remote frame certainly many branches could be created and they would all be relected back.
 

1. What is the Everett interpretation of time travel?

The Everett interpretation, also known as the Many-Worlds interpretation, is a theory in quantum mechanics that suggests every possible outcome of a quantum event actually occurs in a different universe. This means that when a person travels back in time and makes changes, they are creating a new parallel universe rather than altering the existing one.

2. How does the Everett interpretation affect the concept of causality in time travel?

The Everett interpretation challenges the traditional concept of causality, which states that every event has a cause and effect. In this theory, the idea of cause and effect becomes blurred as every possible outcome is considered to have already happened in a different universe. Therefore, the concept of causality is not as straightforward in the context of time travel in the Everett interpretation.

3. Can the Everett interpretation of time travel be tested or proven?

At this time, there is no way to test or prove the Everett interpretation of time travel. It is a theoretical concept that is still being explored and debated by scientists and philosophers. However, some theories in quantum mechanics, such as the double-slit experiment, provide evidence that supports the idea of parallel universes and the existence of multiple outcomes.

4. Is the Everett interpretation of time travel the only theory in quantum mechanics?

No, the Everett interpretation is just one of many theories in quantum mechanics. Other theories include the Copenhagen interpretation, the Transactional interpretation, and the Many Minds interpretation. Each theory offers a different perspective on the nature of reality and the concept of time travel.

5. How does the Everett interpretation of time travel impact our understanding of the past, present, and future?

The Everett interpretation suggests that there are infinite parallel universes, each with their own version of events and outcomes. This means that the past, present, and future are constantly changing and evolving in different universes. It challenges the traditional linear concept of time and suggests that all possible timelines exist simultaneously.

Similar threads

B Need help with understanding time travel
    • Other Physics Topics
Replies
8
Views
1K
B Is Time Emerging? Physicists' Experiments & Many-Worlds Interpretation
    • Other Physics Topics
Replies
4
Views
1K
I Many-Worlds and Testable Claims
    • Quantum Interpretations and Foundations
Replies
1
Views
338
B Time travel in the quantum world
    • Quantum Physics
Replies
10
Views
1K
I Are there any accepted relativistic interpretations of quantum mechanics?
    • Quantum Interpretations and Foundations
Replies
30
Views
1K
I Nima Arkani-Hamed's opinion on Many Worlds?
    • Quantum Interpretations and Foundations
Replies
5
Views
2K
I Many Worlds, EPR and ER=EPR
    • Quantum Interpretations and Foundations
Replies
3
Views
2K
I Many Worlds as Many Histories?
    • Quantum Interpretations and Foundations
Replies
1
Views
2K
B Trying to understand what "time" is (layperson)
    • Special and General Relativity
Replies
21
Views
1K
I Could many worlds be a solution to time travel paradoxes?
    • Quantum Interpretations and Foundations
Replies
3
Views
720

Hot Threads

Recent Insights

Back
Top