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News: Paul Reiche and Fred Ford want to continue the story they started when they created Star Control II — The Ur-Quan Masters. «Happy days and jubilation!» «But wait!» «There is something wrong here... something which makes my sheath retract and my talons ooze.» «Please, Captain, we need your help!»

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Author Topic: Temporal information assymtery  (Read 482 times)
Zanthius
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Temporal information assymtery
« on: July 30, 2018, 09:18:21 am »

Since we have much more information about the past than about the future, our brains might have developed a bias which makes us assume a causal connection from the past to the future.  If we collected billions of data points between the first and second world war and fed the data points to a machine learning algorithm, would the machine learning algorithm believe that the data points from the first world war necessarily gave rise to the data points from the second world war, or could it perhaps also come to the conclusion that the data points from the second world war retro-caused the first world war?

I suspect that it might be an equally valid interpretation that the data points from the second world war retro-caused the first world war.  You might argue that according to the many-worlds interpretation of quantum physics, there isn't necessarily just one possible future, but rather an almost infinite number of possible futures. However, according to the multiple histories interpretation of quantum physics, there isn't necessarily just one past either.

Maybe our belief about the past causing the future is just a bias formed because our brains have much more information about the past than about the future.
« Last Edit: July 30, 2018, 09:29:55 am by Zanthius » Logged
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Re: Temporal information assymtery
« Reply #1 on: July 30, 2018, 01:57:37 pm »

That is not how MWI works. QM obeys forwards causality, and not retrocausality.

What they're seeing must have an 'also a consequence' relationship to the causes of more notable events. Or QM is actually wrong and the universe is even weirder. I'd put my money on the former.
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Zanthius
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Re: Temporal information assymtery
« Reply #2 on: July 30, 2018, 02:20:26 pm »

That is not how MWI works. QM obeys forwards causality, and not retrocausality.

What they're seeing must have an 'also a consequence' relationship to the causes of more notable events. Or QM is actually wrong and the universe is even weirder. I'd put my money on the former.

Maybe you are right. I just find it somewhat suspicious to assume forward causality since we have much more information about the past than about the future. If I had as much information about the future as I now have about the past, and as little information about the past as I now have about the future, I am convinced that I would assume the universe to follow retrocausality.

But I don't have as much information about the future as about the past, and maybe there is a reason for that. Maybe there is no retrocausality.
« Last Edit: July 30, 2018, 02:22:49 pm by Zanthius » Logged
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Re: Temporal information assymtery
« Reply #3 on: July 30, 2018, 09:15:16 pm »

That is not how MWI works. QM obeys forwards causality, and not retrocausality.

This article seems to disagree:

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The fundamental laws of physics work in the same way whether time moves forward or backward. Yet, while a glass can fall and scatter shards across the floor, glass shards never gather together and leap back onto the counter to form a complete glass. The source of this temporal asymmetry is one of the deepest mysteries in physics. We tackle this problem by combining two different disciplines, computational and quantum mechanics. Our results illustrate that the asymmetry could emerge from forcing classical causal explanations on observations in a fundamentally quantum world.

Computational mechanics asks the following question: Given a sequence of observations, how many past causes must we postulate to explain future behavior? This quantity is asymmetric when time is reversed. There is an unavoidable memory overhead cost for modeling a process in the “less-natural” temporal direction—one must pay a price to enforce explanations adhering to a less-favored order of events.

We show that quantum models always mitigate this overhead. Not only can we construct quantum models that need less past information than optimal classical counterparts, these models can always be reprogrammed to model the time-reversed process without additional memory cost. This remains true even for observational data where this classical overhead diverges, such that all classical models for the less-natural temporal direction require unbounded memory.

We illustrate scenarios where classical favoritism for particular causal orders vanishes when quantum models are permitted, thus highlighting a new mechanism for the origin of time’s arrow.

https://journals.aps.org/prx/abstract/10.1103/PhysRevX.8.031013
« Last Edit: July 30, 2018, 10:36:20 pm by Zanthius » Logged
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Re: Temporal information assymtery
« Reply #4 on: July 30, 2018, 11:34:37 pm »

They're talking about where the arrow of time comes from. They don't deny that there is one. And that's all I need for QM to obey causality and not retrocausality. Newton's mechanics are time-reversible too, but we don't say it has retrocausality.

Do you know about the idea of boundary conditions setting the solutions of differential equations? Particularly, partial differential equations?

The universe seems to have a simple boundary condition 13.5 billion years in the past. Things that are further from this boundary condition a timelike direction are later. The symmetry of the rules of QM say that on the other side of this boundary condition - if there is one - forwards in time would be pointed the other direction, what we'd call into the past. But on our side of that event, forwards in time is forwards.

Greater proximity to this simple boundary condition is what we mean by 'earlier', and being further from it is what we mean by 'later'. This continues to apply in QM theories without parameter time ('timeless physics'), which you may have heard of. Most importantly, events closer to this boundary condition are logically prior to things further from it, and not vice versa.
« Last Edit: July 31, 2018, 01:07:22 pm by Death 999 » Logged
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Re: Temporal information assymtery
« Reply #5 on: July 31, 2018, 08:58:43 am »

Greater proximity to this simple boundary condition is what we mean by 'earlier', and being further from it is what we mean by 'later'.


Interesting. So you believe that we have memories from the past since the particles in our region of the universe move away from a boundary condition? I assume this would be somewhat similar to a particle moving away from a black hole, or a particle decelerating from light speed.

Then, if particles moved towards a boundary condition, you think brains formed by such particles would have memories from the future? I assume this would be somewhat similar to a particle falling into a black hole, or a particle accelerating towards light speed.

Also. Do you think it could be possible for particles to move both away from a boundary condition and towards a different boundary condition at the same time? In that case, could perhaps the particles have memories both from the past and the future? Like this:

« Last Edit: July 31, 2018, 01:11:58 pm by Zanthius » Logged
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Re: Temporal information assymtery
« Reply #6 on: July 31, 2018, 01:18:35 pm »

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So you believe that we have memories from the past since the particles in our region of the universe move away from a boundary condition? I assume this would be somewhat similar to a particle moving away from a black hole, or a particle decelerating from light speed.

Not exactly. It's more like if you have a guitar string, and you pluck on it, and release it. You have the boundary conditions at the ends of the string, they persist in time (because it's finite), and you have what is called the initial condition - what the state is when you release the string. But that's just a boundary condition along the past end of the string's history.

When you're calculating out the string's history future, for each section of the string, you look at the past neighborhood - the position and velocity of itself and the neighboring parts of the string. You look at that side because it's closer to the initial condition. Looking at the future neighborhood doesn't help because there isn't a constraint there. The future uses you; you do not use the future.

If you are doing it backwards in time, then it's nominally the future end, but really effectively it's the past end because it's what was fixed. You knew about that part before you knew about the things further backwards, if you're solving the equation numerically. And the second law of thermodynamics is acting in that direction, with more order towards that fixed point and less further away. It brings the vibrations up to a plucked string just in time for you to release it, if you run it 'forwards', but if you run it backwards, it looks normal.

So in no event do you get memories - or any consequences - from the future.

Unless, that is, there happens to be a boundary condition at both ends. But you'd immediately know about that because of massive violations of the second law of thermodynamics. Specifically, it wouldn't be like your having memories from the future. On your graph, we'd be around t = 5 or t = 95, and everything between 30 and 70 is what we'd think of as 'heat death of the universe' kinds of conditions. Another way of looking at it is that there are two universes there, and they have the same endpoint, but under time-reversal symmetry.
« Last Edit: July 31, 2018, 01:34:23 pm by Death 999 » Logged
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Re: Temporal information assymtery
« Reply #7 on: July 31, 2018, 01:34:01 pm »

So in no event do you get memories - or any consequences - from the future.

Hmm... to me it seems like the big bang boundary condition gives "energy" to keep the particles alive, and that is why we get memories from the past, which is closer to the big bang boundary condition. But this energy declines over time, and that is why radioactive elements have a half-life. Maybe all particles have a half-life, but the half-life of a proton is so long that we haven't really observed any proton decaying.  However, if a proton starts to get "energy" from a future boundary condition before that, it might never decay, but rather become increasingly retrocausal.
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Re: Temporal information assymtery
« Reply #8 on: July 31, 2018, 01:36:46 pm »

A) I've modified my post; I suggest rereading the second and last paragraphs

B) the 'energy' you've put in quotes is a lot like thermodynamic free energy, but I wouldn't want to guarantee that it's exactly the same.

C) in the retrocausal regime, you'd see an exponential un-decaying as decay products seemingly randomly flew in and combined. It would be exactly like normal events going backwards.

The only time when physics would make sense in both directions is when everything is at maximum entropy already - heat death of the universe conditions. When you have as much organization as a person, only one direction makes sense.
« Last Edit: July 31, 2018, 01:43:42 pm by Death 999 » Logged
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Re: Temporal information assymtery
« Reply #9 on: July 31, 2018, 03:45:01 pm »

C) in the retrocausal regime, you'd see an exponential un-decaying as decay products seemingly randomly flew in and combined. It would be exactly like normal events going backwards.

I don't think it would look like that at a macroscopical scale. Only at a microscopical scale. It wouldn't necessarily make all the variety of macroscopical structures we have today, but rather just assimilate particles into a super highly organized microscopical structure, which expands until it has incorporated all the particles at the boundary condition.

I wonder if this super highly organized microscopical structure could have some kind of consciousness. If so, it might remember only its future, and nothing from its past.... far into the future would be vague memories, while its near future would be more clear memories. This super highly organized microscopical structure sounds a bit like Juffo-Wup:

Quote
Juffo-Wup is All... omni-existent, spreading and changing the Non into Juffo-Wup.
It flows through all things, binding them together, making them one.

When Juffo-Wup is complete
when at last there is no Void or Non
when the boundary condition returns
then we can finally rest.

« Last Edit: July 31, 2018, 05:53:32 pm by Zanthius » Logged
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Re: Temporal information assymtery
« Reply #10 on: July 31, 2018, 06:20:31 pm »

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I don't think it would look like that at a macroscopical scale. Only at a microscopical scale

I'd ask why you would think so, except that the rest of the paragraph is word salad. You have left the realm of physics and entered word games that aren't even philosophy.

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Re: Temporal information assymtery
« Reply #11 on: July 31, 2018, 07:02:22 pm »

I'd ask why you would think so

If you made a simulation where you made the conditions so that the second law of thermodynamics was reversed, I think you would see that things started to organize themselves at a microscopical scale, and it wouldn't necessarily look much like a video of the universe in reverse.

except that the rest of the paragraph is word salad. You have left the realm of physics and entered word games that aren't even philosophy.

I thought this was a Star Control 2 forum, not a physics forum....

I also think Jordan Peterson is right in that we need some kind of deeply rooted narrative. But when Jordan Peterson quotes from the Bible, I probably feel a bit like you do now, since I haven't been raised a Christian. However, his quotes from the Bible appeal to large segments of his fan base, since they have been raised as Christians and identify with the Christian narrative. To me, however, it seems like word salad.

Anyhow, there is plenty of research showing that humans learn better from stories:

Quote
Use of cognitive capacity was measured during reading of text in six experiments. Content features of the texts were varied. A secondary task technique was used to measure use of capacity. In all experiments, capacity was filled more completely while reading narrative text than while reading expository text. The finding was generalized over two pools of passages, over two modalities of secondary task probes— auditory and tactile—and over two secondary tasks—simple reaction time and choice reaction time. Three hypotheses for the narrativity effect were investigated. Not supported were an hypothesis based on the interest value of the passages and the hypothesis that difficult to comprehend passages induced problem solving cognitive operations that filled capacity. The results were consistent with a comprehensibility hypothesis, which states that when more meaning is produced in the reader's cognitive system while reading a text, more cognitive capacity is filled by reading it. Narrative passages produce more meaning because schemata for narrative texts are more familiar, more frequently encountered, and easier to comprehend than schemata for expository texts.

https://www.tandfonline.com/doi/abs/10.1080/01638538309544553

And, as far as stories go, I don't think stories from Star Control 2 is a particularly bad choice, although I also like some of the stories by Greg Egan.
« Last Edit: July 31, 2018, 11:40:49 pm by Zanthius » Logged
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Hyperorganization
« Reply #12 on: August 01, 2018, 11:02:51 pm »

I bought a new domain in regards to this:

https://www.hyperorganization.org/
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Re: Temporal information assymtery
« Reply #13 on: August 14, 2018, 01:10:18 am »

Maybe the universe is inside of a machine going like this:



Also, if the universe is expanding, aren't we getting longer and longer away from the heat death, since there are more possible configurations in a larger universe? Is entropy a measure of our distance from the big bang, or a measure of our distance from the heat death? It is not necessarily obvious that not both of these distances could increase if we count the number of steps.

« Last Edit: August 14, 2018, 01:25:12 am by Zanthius » Logged
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Re: Temporal information assymtery
« Reply #14 on: August 20, 2018, 10:40:08 am »

Found this comment which claims that antimatter is going back in timet:

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Antimatter is in every precise meaningful sense matter moving backward in time. The notion of "moving backward in time" is nonsensical in a Hamiltonian formulation, because the whole description can only go forward in time. That's the definition of what the Hamiltonian does--- it takes you forward in time a little bit. So if you formulate quantum mechanics the Hamiltonian way, this idea is difficult to understand (still it can be done--- Stueckelberg discovered this connection before the path integral, when field Hamiltonians were the only tool).

But in Feynman's particle path-integral picture, when you parametrize particles by their worldline proper time, and you renounce a global causal picture in favor of particles splitting and joining, the particle trajectories are consistent with relativity, but only if the trajectories include back-in-time trajectories, where coordinate time ticks in the opposite sense to proper time.

Looked at in the Hamiltonian formalism, the coordinate time is the only notion of time. So those paths where the proper time ticks in the reverse direction look like a different type of particle, and these are the antiparticles.

Sometimes there is an idenification, so that a particle is its own antiparticle.

Precise consequence: CPT theorem

The "C" operator changes all particles to antiparticles, the P operator reflects all spatial directions, and the T operator reflects all motions (and does so by doing complex conjugation). It is important to understand that T is an operator on physical states, it does not abstractly flip time, it concretely flips all momenta and angular momenta (a spinning disk is spinning the other way), so that things are going backwards. The parity operator flips all directions, but not angular momenta.

The CPT theorem says that any process involving matter happens exactly the same when done in reverse motion, in a mirror, to antimatter.

The CPT operator is never the identity, aside from the case of a real scalar field. CPT acting on an electron produces a positron state, for example. CPT acting on a photon produces a photon going in the same direction with opposite polarization (if P is chosen to reflect all spatial coordinate axes, this is a bad convention outside of 3+1 dimensions).

This theorem is proved by noting that a CPT operator corresponds to a rotation by 180 degrees in the Euclidean theory, as described on Wikipedia.

Precise consequence: crossing

Any amplitude involving particles A(k_1,k_2,...,k_n) is analytic in the incoming and outgoing momenta, aside from pole and cut singularities caused by producing intermediate states. In tree-level perturbation theory, these amplitudes are analytic except when creating physical particles, where you find poles. So the scattering amplitudes make sense for any complex value of the momenta, since going around poles is not a problem.

In terms of mandelstam variables for 2-2 scattering, s,t,u (s is the CM energy, t is the momentum transfer and u the other momentum transfer, to the other created particle), the amplitude is an analytic function of s and t. The regions where the particles are on the mass shell are given by mandelstam plot, and there are three different regions, corresponding to A+B goes to C+D , Cbar + B goes to Abar+ D, and A + Dbar goes to C+Bbar. These three regimes are described by the exact same function of s,t,u, in three disconnected regions.

In starker terms, if you start with pure particle scattering, and analyticaly continue the amplitudes with particles with incoming momentum k's (with positive energy) to negative k's, you find the amplitude for the antiparticle process. The antiparticle amplitude is uniquely determined by the analytic contination of the particle amplitude for the energy-momentum reversed.

This corresponds to taking the outgoing particle with positive energy and momentum, and flipping the energy and momentum to negative values, so that it goes out the other way with negative energy. If you identify the lines in Feynman diagrams with particle trajectories, this region of the amplitude gives the contribution of paths that go back in time.

So crossing is the other precise statement of "Antimatter is matter going back in time".

Causal pictures

The notion of going back in time is acausal, meaning it is excluded automatically in a Hamiltonian formulation. For this reason, it took a long time for this approach to be appreciated and accepted. Stueckelberg proposed this interpretation of antiparticles in the late 1930s, but Feynman's presentation made it stick.

In Feynman diagrams, the future is not determined from the past by stepping forward timestep by timestep, it is determined by tracing particle paths proper-time by proper-time. The diagram formalism therefore is philosophically very different from the Hamiltonian field theory formalism, so much so Feynman was somewhat disappointed that they were equivalent.

They are not as easily equivalent when you go to string theory, because string theory is an S-matrix theory formulated entirely in Feynman language, not in Hamiltonian language. The Hamiltonian formulation of strings requires a special slicing of space time, and even then, it is less clear and elegant than the Feynman formulation, which is just as acausal and strange. The strings backtrack in time just like particles do, since they reproduce point particles at infinite tension.

If you philosophically dislike acausal formalisms, you can say (in field theory) that the Hamiltonian formalism is fundamental, and that you believe in crossing and CPT, and then you don't have to talk about going back in time. Since crossing and CPT are the precise manifestations of the statement that antimatter is matter going back in time, you really aren't saying anything different, except philosophically. But the philosophy motivates crossing and CPT.

https://physics.stackexchange.com/q/17781

And these two videos about Feynman diagrams by PBS spacetime on youtube:

https://www.youtube.com/watch?v=fG52mXN-uWI

https://www.youtube.com/watch?v=vSFRN-ymfgE

If it is the case that antimatter is going back in time, couldn't it be that more and more matter changes into antimatter as the universe progresses forwards in time, while more and more antimatter changes into matter as the universe progresses backwards in time.
« Last Edit: August 20, 2018, 10:46:01 am by Zanthius » Logged
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