Back to Muller's 'Now and the Flow of Time'

In summary, Muller postulates that time is expanding similar the way space is expanding, and that this asymmetry in the creation of new space and new time is explained by a principle of causality. However, this same principle of causality is also relevant to quantum mechanics, and can lead to inconsistencies if the past is changed.
  • #1
asimov42
377
4
Folks, I'm back to reading Muller's paper (https://arxiv.org/pdf/1606.07975.pdf) about the flow of time. He postulates that time is expanding similar the way space is expanding (ok... so if you can swallow that). He asks: "why are the new nows created at the end of time, rather than uniformly throughout time, in the same way that new space is uniformly created throughout the universe?"

One answer is he gives is "that a physics principle of causality accounts for the apparent asymmetry in the creation of new space and new time. In this view, we postulate that new time can be created only at the end of previous time, since its creation earlier would disrupt the causal connection of past events."

The above is fine from a relativistic perspective, but I'm wondering if it also extends to a quantum mechanical perspective? That is, can someone give an example of an inconsistency in that would result in QM (QFT) through the creation of new time throughout the past? (e.g., what would change - measurements, observers, etc.?)

I'm less familiar with causality in a quantum setting...
 
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  • #2
Ok, how about this - can two quantum systems in different states ever produce identical measurement results?
 
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  • #3
Of course. If I have a hydrogen atom in the 1S state and one in the 2S state, I can in both cases find an electron at a given r.
 
  • #4
Ok, going back to the original question, is there any reason why 'expanding time' would necessarily lead to inconsistencies with a quantum framework? Does the same problem Muller mentions with the "causal connection of past events" still occurs in QFT, where there is some probability of any measurement result?

That's is, does the causal nature of relativity carry over to QFT?

Or could someone point me to a place to look? (odd question I know - but I haven't seen it discussed anywhere)
 
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  • #5
asimov42 said:
can someone give an example of an inconsistency in that would result in QM (QFT) through the creation of new time throughout the past?
You don't need quantum mechanics to see a problem with this. "Changing the past" always contains seeds of paradox. If this "new time" actually has physical consequences, e.g. by changing how long it took light to travel from A to B, then the retrospective insertion of new moments of time is going to change what happened in the past.
 
  • #6
Thanks @mitchell porter - here's one QM-specific question:

Take the light ray example - where the time required for a photon to travel from A to B has increased slightly. Is it possible that an observer at B would (could) measure the photon to arrive at the original time? That is, due to uncertainty in the position of the photon, is there not some probability that you would obtain the same measurement, even though time has expanded?
 
  • #7
asimov42 said:
due to uncertainty in the position of the photon, is there not some probability that you would obtain the same measurement, even though time has expanded?
If the "expansion of time" in the past has any physical meaning, it has to change something. For example, if there is a probability distribution of possible durations of some event, then the distribution might shift to favor longer durations, even if the range of possibilities itself has not changed... The moment that your theory of reality allows the past to change, it faces the risk of self-contradiction through paradox and will require special features to avoid that.
 
  • #8
mitchell porter said:
The moment that your theory of reality allows the past to change, it faces the risk of self-contradiction through paradox and will require special features to avoid that.

Is there a simple toy QM example that would illustrate such a paradox?
 
  • #9
asimov42 said:
Is there a simple toy QM example that would illustrate such a paradox?
I suppose it's not a paradox - like traveling back in time and killing yourself before you make the time machine - because there's nothing in Muller's writing about controlling the "expansion of the past". But even having the past change spontaneously is akin to a contradiction, because what happens in the past has causal consequences for the present.

Suppose that extra proper time makes it take longer for something to happen. At the quantum level, it means that de Broglie waves or wavefunctions would experience a greater amount of phase rotation. At a more macroscopic level, if the change is big enough, it could mean that whether two objects collide is different. Either way, there are causal consequences downstream. If the past is different, then something about the present must be different, indeed history must always have been different, starting from the moment that changed.

The idea that the past can change, in any sense, is the real core of the problem. It's simply impossible unless you have some peculiar concept of time, like branching universes, or you suppose that for some reason the consequences of the change die out completely before the present. Since Muller seems to be pushing a concept of time like the "evolving block universe", where space-time is growing a new layer all the time, and the current top layer is "now", you might think that the past could change because you'd just be changing something deep inside the block, leaving "now" unaffected. But this is a peculiar concept of time, because time has actually been doubled - there's historical time, frozen in the block, and then there's evolving time, how the block changes.

In the context of general relativity, and really any gravity theory based on Einsteinian space-time, the concept of expansion of the past is incoherent, because it implies this doubling of time. So Muller is right to want to make "expansion of time" a phenomenon of the present. But there's actually no need to have "expansion of time" at all, as John Rennie explains here. General relativity makes sense without it. It's really up to Muller and Maguire to come up with a new theory of gravity in which their desired effect occurs.
 
  • #10
Did you read Rovelli's book: "The order of time"? (Amazon, Penguin, etc.) It perhaps contains elements concerning your quest (I just started it now and had until now no time to explore it until the end). Within Einstein's theory, the time is a very local and personal (eigentime) concept.
Otherwise I find the arXiv reference interesting because it is opening an unconventional door at the boarder between metaphysics and physics. Are there other/more authors defending this idea (time as a fourth vectoral dimension)? I would be interesting to know.
 
  • #11
Just an FYI...Muller did a presentation at a Time in Cosmology conference at Perimiter in the same month as the paper in the OP came out. He is the 3rd speaker on this presentation:-
http://pirsa.org/16060111/

Not sure if he is addressing the specific question on the OP but worth a look.
 
  • #12
maybe this is obviuos but:
If space is expanding all the time and everywhere ( except maybe in a black hole-like mass?) , couldn't space be said to flow also, like time "flows"?
There is no constant "here", its only an approximation but the change is of course extremely small on a human scale.
 
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1. What is Muller's "Now and the Flow of Time" theory?

Muller's "Now and the Flow of Time" theory is a scientific concept that proposes that time is a continuous flow and that the present moment, or "now", is constantly moving forward. This theory challenges the traditional view of time as a series of distinct moments or snapshots.

2. How does Muller's theory differ from the traditional view of time?

Muller's theory differs from the traditional view of time in that it sees time as a continuous flow rather than a series of distinct moments. This means that the present moment is constantly changing and moving forward, rather than being fixed and unchanging.

3. What evidence supports Muller's theory?

There is evidence from various fields of science, such as physics and neuroscience, that supports Muller's theory. For example, the theory of relativity suggests that time is relative and can be affected by factors such as gravity. Additionally, studies on the brain have shown that our perception of time is not always accurate and can be influenced by external factors.

4. How does Muller's theory impact our understanding of time?

Muller's theory challenges our traditional understanding of time and suggests that it is a more complex and dynamic concept than we previously thought. It also raises questions about the nature of reality and our perception of the world around us.

5. What are the implications of Muller's theory for the future of science?

Muller's theory has the potential to change the way we approach and study time in various scientific fields. It may also lead to new discoveries and advancements in our understanding of the universe and our place in it. However, further research and experimentation are needed to fully explore the implications of this theory.

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