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Topic: Temporal information assymtery (Read 25150 times)
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Death 999
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Because the math is identically the same whether you have one kind of stuff going forward and backward in time or two kinds of stuff only moving forwards in time.
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Death 999
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… what?
the consequences of Feynman diagrams being valid are far-reaching and affect waaaay more than the exact value of the g-factor. Moreover, I am not disputing their accuracy! Just, interpreting them does not require introducing backwards-propagation in time. There is a very good - preferred, even - physical interpretation of Feynman diagrams which does not change the predictions even one tiny bit from what you're talking about, yet also does not have any particles going back in time at all. You can include backwards-traveling particles if you want, and if you're only looking at the microscopic level. But when you zoom out to the point where entropy gets to be a consideration, you lose that option. That's just not compatible with what time means to us in our world.
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Zanthius
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But if we have multiple possible futures, I don't quite understand why we don't have alternate histories:
Couldn't it be that we come from different configurations of the universes, that for some reason converged into the configuration of the universe we have today?
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« Last Edit: August 27, 2018, 02:38:00 pm by Zanthius »
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Death 999
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1) Whether we have multiple pasts is one of those cases where it's not entirely clear. We definitely have multiple intermediary pasts (in a similar way to how we have multiple futures) in simple cases like a two-slit experiment, but the distant past looks so much like a low-entropy initial condition that in order for us to have multiple terminal pasts, its being low-entropy would have to be an illusion.
2) You've zoomed out to the level where backwards time travel makes less sense. Like, how would the universe fill in those dots? Would it start in the past and work its way forward, except when it has antimatter it puts… just… that backwards? But each of these is a total configuration of all particles in the universe. How would you send just part of it back? How do you even get 'ahead' of antimatter? Does there need to be a path to the future that doesn't involve any antimatter and then you get to fill it in from the other end? But due to the whole thing with the anomalous dipole moment as you've seen and the renormalization group in general, every regular particle carries a very small amount of antimatter around with it (and vice versa).
If you don't take the 'flow of time is flow of information' route and everything is moving forwards, then you end up in contradictions and not knowing where information comes from. It ends up worse than IRS forms where they tell you to put numbers down on lines you've already filled out, because in that case it means you misread the instructions; if antimatter travels back in time, that's actually baked into the rules.
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Zanthius
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If space is 3 dimensional, and spacetime is 4 dimensional, couldn't we regard scale as a 5th dimension?
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Death 999
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No. Scale is firmly on the 'map' side of the 'map vs territory' distinction.
Even if there were a physical effect, it would be a property of the contents, not an independent dimension. ''Dimension' has a specific meaning, and scale doesn't fit it any better than temperature or magnetic field, neither of which are dimensions (if you are making a model, there is a specific way you can use a different kind of dimension to handle those quantities, but it's not what is meant by 'dimension' in the sense of physical dimensions).
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« Last Edit: August 30, 2019, 07:26:03 pm by Death 999 »
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Zanthius
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Ok. What about this?
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Death 999
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A) Bosons don't stack. You're thinking of Fermions.
We might not see any stacking of bosons in our 4 dimensional perspective of spacetime. But can't bosons be stacked in another 5th dimension that is hidden to us, and still appear to have the same location in our 4-dimensional perspective?
This is a very interesting question. The answer is, we can tell.
Suppose you have two identical bosons trapped in an infinitely deep square well; we'll label the two dimensions of this system X and Y. The state can be summarized by two quantum numbers - the number of half-wavelengths in the X direction, and the number of half-wavelengths in the Y direction. Suppose we can only actually see the first of these - we can only measure the number of half-wavelengths in the X direction.
The interesting bit is, even if we can't tell how many half-wavelengths the two bosons have in the Y direction, if they have the same number of half-wavelengths in the X direction, we can tell if they also have the same number of half-wavelengths in the Y direction - if they're in the exact same state in every dimension, that changes the statistics of any interactions.
So, adding a new dimension doesn't let you hide stacking where we can't see it. You might be able to go out of your way to create a janky theory which reproduces the effect at the cost of being much more complicated and not explaining anything new.
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« Last Edit: September 03, 2019, 07:07:28 pm by Death 999 »
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Zanthius
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« Last Edit: December 08, 2019, 01:29:11 pm by Zanthius »
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Zanthius
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