Backward Causation in Quantum Mechanics: A Refreshing Discussion

In summary, the conversation discusses a proposal to allow backward causation in quantum mechanics and the idea that time asymmetry in QM violates our expectations of a fundamental theory. The concept of past, present, and future co-existing in a four-dimensional spacetime is also explored, as well as the possibility of a superluminal particle connecting photons. The idea of the future affecting the past is seen as impossible by some, while others argue for its possibility.
  • #1
selfAdjoint
Staff Emeritus
Gold Member
Dearly Missed
6,894
11
http://realityconditions.blogspot.com/2006/09/on-price-and-penrose-on-time-asymmetry_18.html" is a very interesting discussion of a proposal to allow backward causation in quantum mechanics. The basic idea is that the time asymmetry of QM ("collapse of the wave function") violates our expectations of a fundamental theory; all previous candidates from Newton on have been time symmetric and time asymmetry then arises from statistical probabilities. The ideas are discussed back and forth in a refreshing way, and I strongly recommend it.
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
selfAdjoint said:
http://realityconditions.blogspot.com/2006/09/on-price-and-penrose-on-time-asymmetry_18.html" is a very interesting discussion of a proposal to allow backward causation in quantum mechanics. The basic idea is that the time asymmetry of QM ("collapse of the wave function") violates our expectations of a fundamental theory; all previous candidates from Newton on have been time symmetric and time asymmetry then arises from statistical probabilities. The ideas are discussed back and forth in a refreshing way, and I strongly recommend it.
Shoot, I've had Price's book for a couple of years, read it a while ago, and must have skipped over this bit. Will have to go back and read it again.

Certainly fits very well with my current philosophy (time-symmetric, realistic, deterministic, "free-will skeptical" physicalist that I am)

Thanks for this.
 
Last edited by a moderator:
  • #3
Wonderful, thanks.
 
  • #4
http://electrodynamics-of-special-relativity.com/" is a site that gives an explanation of backward causation from an analysis of the consequences of the Minkowski metric.
 
Last edited by a moderator:
  • #5
Also there are several essays related to this on "www.mathpages.com"[/URL]
 
Last edited by a moderator:
  • #6
It seems to me that the very concept that the future can affect the past is incredibley absurd. It is in the same category as saying 0=1. The only way that 0=1 is to change one or both of their definitions. IF you assert that the future has affected the past, you have changed one or both of their definitions.

Why do we not accept the proposition that there is a particle that is superluminal (probably a form of a graviton) that is connecting the photons. If this particle had less mass than the photon, it would be possible for it to be much faster than the photon, but it's combination of less mass and greater speed would together equal that of the the photon. Only particles of less mass than the photon can exceed the speed of the photon.

This is speculation but it is at least possible. The future affecting the past is semantically, logically and conceptually impossible.
 
  • #7
sd01g said:
It seems to me that the very concept that the future can affect the past is incredibley absurd. It is in the same category as saying 0=1. The only way that 0=1 is to change one or both of their definitions. IF you assert that the future has affected the past, you have changed one or both of their definitions.
Not necessarily. Think of time as the fourth dimension, and think of spacetime being laid out in a 4-dimensional spacetime - then past, present and future "co-exist" in this four-dimensional spacetime. The only constraint on the configuration at any position on the time axis is that it must be consistent (according to the "laws of nature") with all points both past and future from that position. In this sense, past determines future just as much as future determines past - all co-exist as a single 4-dimensional self-consistent solution to the "laws of nature"

sd01g said:
Why do we not accept the proposition that there is a particle that is superluminal (probably a form of a graviton) that is connecting the photons. If this particle had less mass than the photon, it would be possible for it to be much faster than the photon, but it's combination of less mass and greater speed would together equal that of the the photon. Only particles of less mass than the photon can exceed the speed of the photon.
A photon has zero rest-mass. Are you postulating the existence of a particle with negative rest-mass?

sd01g said:
This is speculation but it is at least possible. The future affecting the past is semantically, logically and conceptually impossible.
Not at all, as I have shown above. You just need to get your head around it :smile:

MF
 
  • #8
moving finger said:
Not necessarily. Think of time as the fourth dimension, and think of spacetime being laid out in a 4-dimensional spacetime - then past, present and future "co-exist" in this four-dimensional spacetime. The only constraint on the configuration at any position on the time axis is that it must be consistent (according to the "laws of nature") with all points both past and future from that position. In this sense, past determines future just as much as future determines past - all co-exist as a single 4-dimensional self-consistent solution to the "laws of nature"


A photon has zero rest-mass. Are you postulating the existence of a particle with negative rest-mass?


Not at all, as I have shown above. You just need to get your head around it :smile:

MF

In the interest of not having this thread locked, I will not respond and retract my prior post. Thanks.
 
  • #9
sd01g said:
It seems to me that the very concept that the future can affect the past is incredibley absurd. It is in the same category as saying 0=1. The only way that 0=1 is to change one or both of their definitions. IF you assert that the future has affected the past, you have changed one or both of their definitions.

Why do we not accept the proposition that there is a particle that is superluminal (probably a form of a graviton) that is connecting the photons. If this particle had less mass than the photon, it would be possible for it to be much faster than the photon, but it's combination of less mass and greater speed would together equal that of the the photon. Only particles of less mass than the photon can exceed the speed of the photon.

This is speculation but it is at least possible. The future affecting the past is semantically, logically and conceptually impossible.

I had no idea that either the future or the past existed in Quantum Mechanics. My initial impression was that conditions effect other conditions synergistically and that's it. Do the terms future and past actually apply in QM?
 
  • #10
sd01g said:
It seems to me that the very concept that the future can affect the past is incredibley absurd. It is in the same category as saying 0=1. The only way that 0=1 is to change one or both of their definitions. IF you assert that the future has affected the past, you have changed one or both of their definitions.
That is not what happens with the notion that lightlike paths may not just be future directed.

The distance between the emission and absorbtion of a photon in space-time is exactly zero, even if that space-time is curved.

How do we know for sure that absorbtion is not causally connected to the emission as is the emission to the absorbtion?
 
  • #11
MeJennifer said:
How do we know for sure that absorbtion is not causally connected to the emission as is the emission to the absorbtion?
sounds like Cramer's transactional interpretation to me - I like it :smile:
 
  • #12
Maybe both are just one.
 

1. What is backward causation in quantum mechanics?

Backward causation in quantum mechanics is a theoretical concept that suggests that events in the present can be influenced by events in the future. This is in contrast to our everyday experience, where cause and effect are seen as occurring in a linear and forward manner.

2. How does backward causation challenge traditional notions of causality?

Backward causation challenges traditional notions of causality by suggesting that the cause of an event can come after the effect. This goes against the common understanding that causes must precede their effects in a chronological order.

3. What evidence is there for backward causation in quantum mechanics?

There is currently no direct evidence for backward causation in quantum mechanics. It is a theoretical concept that has been proposed to explain certain phenomena observed in quantum systems, such as delayed choice experiments and quantum entanglement.

4. How does backward causation relate to the uncertainty principle?

Backward causation is often used to explain the uncertainty principle in quantum mechanics. It suggests that the uncertainty in the position or momentum of a particle may be due to its future interactions, rather than just its initial conditions.

5. What are the implications of backward causation for our understanding of time?

The concept of backward causation challenges our traditional understanding of time as a linear progression. It suggests that the future can influence the present, and raises questions about the nature of free will and determinism. However, the exact implications are still a topic of debate and further research is needed to fully understand the concept.

Similar threads

I Energy Non-Conservation in Quantum Mechanics
    • Quantum Physics
Replies
22
Views
1K
I QFT made Bohmian mechanics a non-starter: missed opportunities?
    • Quantum Interpretations and Foundations
11
Replies
371
Views
10K
I To rejuvenate the plausibility of stochastic mechanics
    • Quantum Interpretations and Foundations
Replies
1
Views
482
I Quantum Mechanics as a Probabilistic forecast of reality
    • Quantum Physics
Replies
21
Views
968
A Game theory, quantum physics and the Bell inequality (paper)
    • Quantum Interpretations and Foundations
Replies
2
Views
736
I A Bold New Take on Quantum Theory
    • Quantum Interpretations and Foundations
Replies
25
Views
978
I Modern Assesment of Grete Hermann's Philosophy on Quantum Mechanics
    • Quantum Interpretations and Foundations
Replies
2
Views
1K
What is the role of local realism in quantum mechanics?
    • New Member Introductions
Replies
1
Views
54
B Matter-antimatter asymmetry - a simple explanation?
    • Cosmology
Replies
12
Views
1K
I Relativistic hidden variable quantum mechanics?
    • Quantum Physics
4
Replies
122
Views
8K

Hot Threads

Recent Insights

Back
Top