Consistent Histories solipsism?

[Morbert]

Then after all this why was CH accused of being solipsistic?
From the sounds of things it definitely isn't...

I think what I'll do is reread Dowker and Kent's paper and specifically address their charge of solipsism.

 

[JamieSalaor]

I think what I'll do is reread Dowker and Kent's paper and specifically address their charge of solipsism.

That would be amazing thank you!
The thing is its a very old paper. So I imagine their opinions must have changed since then.
Furthermore they specify that they think solipsism is daft..
I would love hear your opinions on it all.
Again thank you for everything!

 

[Anixx]

Well. First of all, besides solipsism, there is another, less radical possibility: an ego-asymmetric theory.
In solipsism the objective reality does not exist. In ego-asymmetric theory the objective reality exists, but one observer is distinguished and follows different physical laws than the rest.

One can notice that even the Anthropic principle somehow implies ego-asymmetry.
There is also a big problem of self-reference. Thomas Breuer in his papers showed that from the point of view of any observer, a system in which he is properly included follows different physical laws compared to an external system, due to self-reference. And his proof is purely mathematical. Particularly, such system is less predictable (has indistinguishable states or uncertain probabilities).

 

[JamieSalaor]

Well. First of all, besides solipsism, there is another, less radical possibility: an ego-asymmetric theory.
In solipsism the objective reality does not exist. In ego-asymmetric theory the objective reality exists, but one observer is distinguished and follows different physical laws than the rest.

One can notice that even the Anthropic principle somehow implies ego-asymmetry.
There is also a big problem of self-reference. Thomas Breuer in his papers showed that from the point of view of any observer, a system in which he is properly included follows different physical laws compared to an external system, due to self-reference. And his proof is purely mathematical. Particularly, such system is less predictable (has indistinguishable states or uncertain probabilities).

Why would one observer be distinguished?
I had a little look and found very little information in this idea.
Just saw a few threads on forums..

 

[JamieSalaor]

Well. First of all, besides solipsism, there is another, less radical possibility: an ego-asymmetric theory.
In solipsism the objective reality does not exist. In ego-asymmetric theory the objective reality exists, but one observer is distinguished and follows different physical laws than the rest.

One can notice that even the Anthropic principle somehow implies ego-asymmetry.
There is also a big problem of self-reference. Thomas Breuer in his papers showed that from the point of view of any observer, a system in which he is properly included follows different physical laws compared to an external system, due to self-reference. And his proof is purely mathematical. Particularly, such system is less predictable (has indistinguishable states or uncertain probabilities).

From what I have read this idea posits that consciousness is important in QM?
Is that correct?

 

[Anixx]

this idea posits that consciousness is important in QM?

No. It does not imply consciousness at all. The theorem is similar the the Goedel's incompleteness theorem or Cantor's diagonalization argument. Put is simply, a computer, however powerful it is, cannot predict its own future state (or have a model of itself). Since the usual physical laws allow to predict a future state of any closed system, the conclusion is, from the point of view of the computer it does not follow the usual (bayesian) physical laws. In other words, you cannot predict a system from within that system, only from the outside of it.
So, there are true statements about physical reality that do not follow from any physical laws (compare Goedel here). Or unpredictable events.
The relevant papers by Breuer:
https://homepages.fhv.at/tb/tb/cms/index.html?download=tbDISS.pdf
https://homepages.fhv.at/tb/tb/cms/index.html?download=tbPHILSC.pdf
https://homepages.fhv.at/tb/tb/cms/index.html?download=QuantumTuring-v2b.pdf

 

[Anixx]

This leads to one of the following conclusions:
* The most complete physical description of reality is non-Bayesian. It includes uncertain probabilities (such as Knightian uncertainty).
or
* The universe constantly experiences influence from the outside of physical (measurable) world (God's intervention, free will, input ports etc)
or
* The universe includes an oracle or a hyper-turing computing device (hypercomputer)
or
* The universe has infinitely many in principle immesurable initial conditions that yet did not affect any events in the past but will affect events in the future, however distant that future is.

 

[Anixx]

Yes, in quantum mechanics one should sacrifice some basic philosophical principles that otherwise are looking obvious. In some interpretations you sacrifice equivalence of all observers, in others you sacrifice indivisibility of mind, etc.

 

[JamieSalaor]

Idk what to make of all that (I'm not a physicist, but a philosopher)
But talk of God and free will or the oracle idea throws me off...

Maybe I am getting the wrong idea.. But I couldn't find anyone else talking about these ideas except you on forums.
Please correct me if I'm confused..

 

[EPR]

Objections to a purported theory of everything are mainstream science. From Goedels theorem to emergent properties.

 

[JamieSalaor]

Objections to a purported theory of everything are mainstream science. From Goedels theorem to emergent properties.

Yes I thought that was broadly the case. Theories of everything tend to be extremely problematic and controversial to say the least.
Though I'm by no means against them

 

[Anixx]

Look, there are some mathematical theories that generalize the probability theory. Such as Generalized Information Theory or Dempster-Shafer theory, and others.
The main point of these theories is that they deal with uncertain probabilities.

In other words, if bayesian (usual) probabilistic theory has less predictive power than a deterministic theory, a non-bayesian theory (for instance, possibilistic) has even less predictive power than a probability theory.

Standard quantum mechanics is bayesian: given the state of a system at one point, one can predict (probabilistically) the state of the system at another point.

Breuer, however, showed that this is only true if the system to predict does not include the observer themself.
An universally-valid bayesian theory is impossible.

One can put it in other words: the observer's own wavefunction is uncertain (in a more fundamental way than the wave function of any other system, external to the observer).

Thus, a system that includes the observer either has undistinguishable states or somehow "channels" information from the outside of the physical world. In other words, it includes variables which are neither deterministic, not probabilistic in nature, but affect the future of the system. It can be from-the-outside intervention or "free will" or initial conditions of the universe (as in Bohmian mechanics).

One can think of it as of a computer game where no in-game computer can predict the future behavior of a player-controlled character, whose behavior from the in-game point of view is neither deterministic, not probabilistic.

 

[Anixx]

In short, one can summarize it this way: "There are unpredictable (probabilistically) events." Or events with no physical cause.

 

[Halc]

In the paper it appears as if they believe this interpretation implies solipsism (which may be why it is so unpopular).

However, I'm not entirely sure what they mean by this.
There seems to be two definitions of solipsism; epistemological and metaphysical.
With epistemological saying that we cannot be sure about the true nature of reality, but not outright denying other minds, and with metaphysical straight up denying other minds and external reality.

I am no expert on CH, but that interpretation, like almost all (*) the others, does not acknowledge the existence of an entity of 'mind', nor even mention any arrangement of quantum particles (life forms say) that has quantum properties absent in other arrangements.
In other words, the positing of the special status of 'mind' goes against the principle methodological naturalism. That principle is what got science out of the dark ages.

* The only exception is the Wigner interpretation which suggests such a special status, thus being in violation of said principle methodological naturalism. Wigner himself withdrew support of it since it was logically driven to philosophical solipsism. No other interpretation implies it.
No, there is no way to actually falsify such solipsism.

 

[Morbert]

Then after all this why was CH accused of being solipsistic?
From the sounds of things it definitely isn't...

Dowker and Kent bring up solipsism in a few contexts. I'll start with the first:

In section 5.1 they discuss the notion of an "actual history", the history containing all actual facts. They remark that the notion of an actual history is ambiguous and we could define the actual history in various solipsistic ways. E.g. "Solipsism of the moment" would only ascribe factive status to propositions about the present. Darwin's records are factive. Dinosaurs are not.

Codifying the "actual history" is an interesting challenge, but CH is an interpretation of the language of quantum theories, not a theory in itself. It offers us an interpretation of operators, state spaces and subspaces, projectors, decompositions etc. What is and is not a fact would depend on the theory we subscribe to. If we want to postulate the factive existence of dinosaurs to explain the observed fossil record, CH will let us employ a logic to evaluate this theory, but CH itself is neutral about what the correct theory for explaining the fossil record is.

 

[JamieSalaor]

Dowker and Kent bring up solipsism in a few contexts. I'll start with the first:

In section 5.1 they discuss the notion of an "actual history", the history containing all actual facts. They remark that the notion of an actual history is ambiguous and we could define the actual history in various solipsistic ways. E.g. "Solipsism of the moment" would only ascribe factive status to propositions about the present. Darwin's records are factive. Dinosaurs are not.

Codifying the "actual history" is an interesting challenge, but CH is an interpretation of the language of quantum theories, not a theory in itself. It offers us an interpretation of operators, state spaces and subspaces, projectors, decompositions etc. What is and is not a fact would depend on the theory we subscribe to. If we want to postulate the factive existence of dinosaurs to explain the observed fossil record, CH will let us employ a logic to evaluate this theory, but CH itself is neutral about what the correct theory for explaining the fossil record is.

So, would solipsism of the moment be if we ascribe the only reality to be now? As in presentism. So the solipsism here refers to time? Only one time exists at once.

As you say CH is neutral. It doesn't at all imply solipsism. But if you were to say solipsism was true you could produce a framework that correlated with that?

So, obviously no body is a solipsist (as they say in the paper its unreasonable and has no scientific reasoning behind it).
So though you can construct such a framework if you desire, but it's realistically wrong.

Surely we could construct another where just me and you exist and nobody else?

Am I getting the right idea?

 

[Morbert]

So, would solipsism of the moment be if we ascribe the only reality to be now? As in presentism. So the solipsism here refers to time? Only one time exists at once.

As you say CH is neutral. It doesn't at all imply solipsism. But if you were to say solipsism was true you could produce a framework that correlated with that?

So, obviously no body is a solipsist (as they say in the paper its unreasonable and has no scientific reasoning behind it).
So though you can construct such a framework if you desire, but it's realistically wrong.

Surely we could construct another where just me and you exist and nobody else?

Am I getting the right idea?

You could be a presentist while still believing that at some stage dinosaurs existed in the past even if they don't exist now. A solipsist of the moment would deny even this and deny any inference about what might have been the case in the past based on what is now. Kind of like someone who believe we all came into existence today, with preformed fictitious memories. If an interpretation entails solipsism of the moment it is a mark against it.

 

[JamieSalaor]

Right I see...
So, what Dowker and Kent are saying that if an interpretation starts to imply solipsism then there's something wrong with the interpretation?
They aren't saying quantum mechanics implies solipsism. They are saying that some interpretations can imply solipsism and that they should be discredited.
CH is a tool that can be used by solipsist interpretations.
But CH is not solipsistic?

 

[Morbert]

They ultimately go on to argue that CH implies solipsism an I will get to that but I have so far only addressed their first charge, which is that since CH does not sharply define the notion of an "actual history" it accommodates all sorts of notions of an actual history, including solipsism of the moment. They see this as a negative point.

 

[JamieSalaor]

As a supporter of CH do you think implies solipsism of the moment?

 

[Morbert]

As a supporter of CH do you think implies solipsism of the moment?

definitely not

 

[JamieSalaor]

Do you think that, since 25 years has passed since the publishing of this paper. The CH interpretation has changed a lot?
Dowker and Kent's opinions are obviously very old now...

 

[Morbert]

Do you think that, since 25 years has passed since the publishing of this paper. The CH interpretation has changed a lot?
Dowker and Kent's opinions are obviously very old now...

It has not changed dramatically. Details have been filled in, and Omnes's notion of truth across multiple history sets has been refuted, but the broad structure is the same.

 

[JamieSalaor]

Have these details been vital in showing that CH is not solipsistic?

 

[Morbert]

Have these details been vital in showing that CH is not solipsistic?

Not vital, but probably helpful in clarifying.

 

[JamieSalaor]

So, would you say even with the 1995 formulation of CH they were mistaken to accuse it?

 

[Morbert]

yes

 

[JamieSalaor]

I was looking at more recent work by them and they don't seem to have accused CH since.
Nor have any other authors...
So maybe more people are coming to realize that it isn't solipsism
Thanks for this by the way, you've been loads of help!

 

[JamieSalaor]

Does Solipsism of the moment link to the idea put forward in that other forum about us not being able to determine the age/existence of dinosaurs?
I assume you believe this isn't the case and that dinosaurs obviously did exist 66mya?

 

[AlexCaledin]

- I believe dinosaurs were briefly simulated in the Great Computer)

(our unruly brains - that's the only physical thing which is real hard to compute)

 

[JamieSalaor]

I think you've cracked it mate

 

[Morbert]

Does Solipsism of the moment link to the idea put forward in that other forum about us not being able to determine the age/existence of dinosaurs?
I assume you believe this isn't the case and that dinosaurs obviously did exist 66mya?

Yes

As soon as we decide to believe in dinosaurs, we have left the solipsist position. I.e. We have decided to interpret some propositions about the past as factive.

Dowker and Kent argue that we are forced back to the solipsis position if we accept CH.

"If one accepts the formalism as it stands, and introduces no historical actual facts, one seems to be led toward solipsism of the present, since it is unlikely that any past event can be described in every consistent set, and each consistent set gives an equally valid description of the past."

Basically, they are arguing we can always eliminate a fact about the past by selecting a consistent set incompatible with the fact we want to eliminate. But the selection of a consistent set is not a selection of facts that exists. It is instead the selection of a set we wish to use to reason about some facts.

 

[JamieSalaor]

I don't understand how it's actually solipsist.
It seems as if you have a choice in the development of frameworks whether or not you want to deny the existence of dinosaurs or anything else.
But since that's a really backwards thing to do you won't do it...

Do you think they've misunderstood CH. Or are unnecessarily making it seems bad..

Would you say CH even at all disregards real historical facts? I don't think that's reasonable..

 

[JamieSalaor]

It doesn't seem as if the CH interpretation requires you to deny historical facts at all.
It just says you could, but that would obviously be wrong. So you don't

 

[PeterDonis]

Would you say CH even at all disregards real historical facts? I don't think that's reasonable..

What are "real historical facts"? Remember that we only directly experience our present, not our past; we directly experience having memories of a past, or looking at records that we interpret as evidence of something having happened in the past, but that's not the same as directly experiencing, now, an event in the past.

From a CH point of view (or at least the CH point of view being taken by Dowker and Kent), however, interpreting our present experience of memories or looking at records as evidence of particular past events is only a valid inference, strictly speaking, if all consistent histories that contain those present experiences also contain the past events being inferred from those experiences. But that's not the case. There will be consistent histories containing the same present experiences, but which don't contain the past events we infer from those experiences, because the present experiences are due to some kind of astronomically unlikely quantum fluctuation that basically rewrote all of our memories and records to indicate a past event that didn't actually happen.

I don't think one is required to adopt such a point of view if one adopts the CH interpretation, but one cannot rule it out by any logical argument, since such astronomically unlikely quantum fluctuations are present in the math of QM.