Does the world operate deterministically?

[moving finger]

I am amazed by the number of times I keep having the same debate, in various threads, about the true nature of determinism. Many people seem to conclude that the principles and experimental results of quantum mechanics, and in particular Heisenberg's uncertainty principle, prove that the world operates indeterministically, at least at a quantum level.

I wish to show this conclusion is incorrect.

First we must distinguish between the meanings of Determinability and Determinism (it is important to understand that these words have different meanings).

Definition of Determinism
The universe, or any self-contained part thereof, is said to be evolving deterministically if it has only one possible state at time t1 which is consistent with its state at some previous time t0 and with all the laws of nature.

Definition of Determinability
The universe, or any self-contained part thereof, is said to be determinable if it has only one possible state at time t1 which can in principle be predicted (determined) by an agent (observer) based on a knowledge of its state at some previous time t0 and with all the laws of nature.

Clearly, Determinism is an ontic property of a universe, and neither its definition nor existence is dependent on either observers or observation, ie a universe operates either deterministically or it does not, regardless of whether there are any observers around to know about it.

Determinability, on the other hand, is clearly an epistemic property of a universe, it is dependent on the presence of an (in principle) observer, because it is defined in terms of the knowledge such an observer can have about the universe.

The question posed in this thread is : Does the world operate according to the definition of determinism? (The question NOT posed here is "does the world operate according to the definition of determinability?")

Epistemic Determinability vs Ontic Determinism
The principles and experimental results of quantum mechanics, and in particular Heisenberg's uncertainty principle, show that there is an in-principle limit to our knowledge about the world - we have an "epistemic horizon" beyond which we are unable, in principle, to gain knowledge. This is characterised by Planck's consstant, and it places a lower limit on our ability to distinguish between determinism and indeterminism as true (ontic) properties of the world. In other words, we simply cannot know whether the quantum world is truly (ontically) deterministic or not.

In absence of any conclusive experiment or evidence either way, it follows that if one believes the world is either deterministic or indeterministic then this is simply a matter of faith, and not one of science.

The correct scientific answer to the question "Does the world operate deterministically?" is therefore "we simply do not know".

Niels Bohr brainwashed a whole generation of physicists into believing that the problem had been solved
Murray Gell-Mann

We might ask the additional question : "Why do so many people seem to believe the world is not operating deterministically, when there is in fact no scientific basis for such a belief?"

I believe there are several possible answers to this second question :

1 Amongst many humans, there is a intuitive feeling of "free will" which naively seems at odds with the idea of a deterministic world. This naive intuition over-rules rational thinking and causes a mis-placed emotional belief in indeterminism. There is not much I can say to this except - please try to look at the issues open-mindedly and rationally, rather than intuitively and emotionally.

2 Many humans confuse ontic determinism with epistemic determinability. I hope my clear definition and explanation above has cleared this up.

3 Many humans are influenced by the propaganda that continues to be promulgated by learned scientists who, for one irrational reason or another, believe that the world is somehow indeterministic. To these people I say : Be more open-minded and critical, and question the basis for such beliefs. If you follow my above argument you will see such beliefs are founded more on faith than on rational scientific thinking.

MF

 

[seratend]

May be you are confusing determinism with (temporal) causality.
You are free to use your own definitions and build logical conclusions based on these definitions. However it is dangerous to mix your own definitions (interpretations) with other ones that are not the same (except for the words) to make general conclusions/extrapolations.

Seratend.

 

[moving finger]

May be you are confusing determinism with (temporal) causality.
You are free to use your own definitions and build logical conclusions based on these definitions. However it is dangerous to mix your own definitions (interpretations) with other ones that are not the same (except for the words) to make general conclusions/extrapolations.

IMHO it is dangerous to enter into any debate with clearly defining the concepts being debated.

Would it be correct to interpret your comments above as meaning that you disagree with one or more of my definitions?

If so, would you care to explain which of my definitions you disagree with, and why?

MF

 

[Billy T]

May be you are confusing determinism with (temporal) causality.
You are free to use your own definitions and build logical conclusions based on these definitions. However it is dangerous to mix your own definitions (interpretations) with other ones that are not the same (except for the words) to make general conclusions/extrapolations.

Seratend.

MF is not currently loged on, but I can predict what he will ask. so I ask for him to save time (and because I want to know):

What is your definition of causality?

Until you explain the difference to me, I admit to some confusion. The only difference I see is that in a deterministic universe, causality certainly is always operating, but in a non deterministic universe, causality, as most people understand this work, may not always operate, especially if what I call genuine free will exists.

I would BTW add a fourth possible reason to MF's list of reasons why most people tend to rule out the possibility of a deterministic universe, which is related to his first (the free will belief bias). MF probably knows it, but is too modest to have included it.

(4) Most people either can't (or don't want to bother) to think as carefully (with well defined terms, etc.) as he does as simple assume that quantum uncertainty "proves" the universe is not deterministic.

 

[seratend]

IMHO it is dangerous to enter into any debate with clearly defining the concepts being debated.

Well, that's precisely the problem. In physics and math we like to define precisely the concepts before, without them we can almost always say what we want. In QM theory the postulates are self coherent, only interpretations of QM words almost always lead to false conclusions/incoherencies.

Would it be correct to interpret your comments above as meaning that you disagree with one or more of my definitions?

That's the problem: they are definitions: we can take them as true or false (it is a logical choice) and make logical conclusions based on these definitions. However, before that, we must prove that they are self consistent: this is the main difficulty. I.e. I do not know if your definitions are consistent or ill defined, it is you job to prove they are self consistent (i.e. you have to build demonstration).
Now one of the common dangers with the definitions is their labelling (e.g. determinism). 2 different definitions with the same label does not mean they are identical (i.e. yours and the other ones).
In your post, you are mixing different definitions using the same label to make certain (surely unlogical) conclusions. e.g. The correct scientific answer to the question "Does the world operate deterministically?" is therefore "we simply do not know".


Seratend.

 

[seratend]

What is your definition of causality?

There are many definitions of causality (one is to take an english dictionnary). I do not know all. The first one is the existence of a function, i.e. a=f(b), another one a partial ordering relation (like =>). In QM (and more precisely QFT) we have other possible definitions: the clustering principle (weinberg), etc ...
The definition of MF is what I call a naive one (in a non pejorative sense). He assumes we describe the universe properties by a single time parameter. This is almost the Newtonian/gallilean view (the absolute time). Now, we have dicovered, thanks to relativity and QM theories, that there are other forms of causality definitions.
Therefore, the danger comes from the mixing of these different definitions to build unlogical conclusions.

if what I call genuine free will exists.

Please try to give your self coherent definition of "genuine free will" in a non "determinsitc" universe. (based on the fact that your deterministic definition is false). Otherwise, we may developp all the conclusions we want.

he does as simple assume that quantum uncertainty "proves" the universe is not deterministic.

That's again a conclusion without self coherent definitions (universe, deterministic defs in the context of QM theory).

Seratend.

 

[ZapperZ]

So how did this thread escaped from the Philosophy section? Was the warden asleep at the guard tower? :)

Something like "... it is dangerous to enter into any debate with clearly defining the concepts being debated... " can only belong there.

Zz.

 

[moving finger]

So how did this thread escaped from the Philosophy section? Was the warden asleep at the guard tower? :)

Something like "... it is dangerous to enter into any debate with clearly defining the concepts being debated... " can only belong there.

Zz.

I hope you are not suggesting that true science proceeds on the basis of undefined concepts?

Clear definition of concepts forms the basis of all science (except of course for those of us who wish to obfuscate).

MF

 

[seratend]

So how did this thread escaped from the Philosophy section? Was the warden asleep at the guard tower? :)

Something like "... it is dangerous to enter into any debate with clearly defining the concepts being debated... " can only belong there.

Zz.

Yes, However, currently, as there is not much activity on PF, we may try to focus this thread into "How it is difficult to build self coherent definitions before making physical conclusions" ; )

Seratend.

 

[seratend]

I hope you are not suggesting that true science proceeds on the basis of undefined concepts?

Clear definition of concepts forms the basis of all science (except of course for those of us who wish to obfuscate).

MF

I am confused, I think there is a misundertanding of your sentence "it is dangerous to enter into any debate with clearly defining the concepts being debated". I interpret it as "defining clear concepts are dangerous to start a debate". This point of view is more related to phylosphie (definitively to politics ;) than sciences (or may be physics).

Seratend.

 

[moving finger]

Well, that's precisely the problem. In physics and math we like to define precisely the concepts before, without them we can almost always say what we want.

We agree then, that it is important to define concepts being debated.

In QM theory the postulates are self coherent, only interpretations of QM words almost always lead to false conclusions/incoherencies.

Can you explain what you mean by "QM word"?
"Determinism" is a word in the English language, I am not aware that it is a "QM word"?

Are you perhaps trying to say that "interpretations of QM almost always lead to false conclusions/incoherencies"?

That's the problem: they are definitions: we can take them as true or false (it is a logical choice) and make logical conclusions based on these definitions.

Agreed.

However, before that, we must prove that they are self consistent: this is the main difficulty. I.e. I do not know if your definitions are consistent or ill defined, it is you job to prove they are self consistent (i.e. you have to build demonstration).

Now one of the common dangers with the definitions is their labelling (e.g. determinism). 2 different definitions with the same label does not mean they are identical (i.e. yours and the other ones).

I have not said that my definition is the only possible definition. I have asked whether you agree with it. You seem not to want to answer.

In your post, you are mixing different definitions using the same label to make certain (surely unlogical) conclusions.

What "different definitions using the same label" am I using? I do not believe this is a correct statement, can you elaborate please?

e.g. The correct scientific answer to the question "Does the world operate deterministically?" is therefore "we simply do not know".

In what sense is this a "mixing of different definitions using the same label"? I have defined very clearly what I mean by determinism.

Perhaps you are suggesting that I have not defined "deterministically"? I agree. The correct question, given my definitions, should have been "Does the world operate according to determinism?".

Determinism is clearly defined.

MF

 

[ZapperZ]

I hope you are not suggesting that true science proceeds on the basis of undefined concepts?

Clear definition of concepts forms the basis of all science (except of course for those of us who wish to obfuscate).

MF

Re-read the quote I attributed to you.

Zz.

 

[moving finger]

I am confused, I think there is a misundertanding of your sentence "it is dangerous to enter into any debate with clearly defining the concepts being debated". I interpret it as "defining clear concepts are dangerous to start a debate". This point of view is more related to phylosphie (definitively to politics ;) than sciences (or may be physics).

Seratend.

ooops, I must admit to a typo. My apologies.

I meant to type "it is dangerous to enter into any debate without clearly defining the concepts being debated".

Must learn to type more slowly and carefully.

Thanks for pointing out my error.

MF

 

[Billy T]

There are many definitions of causality (one is to take an english dictionnary). I do not know all. The first one is the existence of a function, i.e. a=f(b), another one a partial ordering relation (like =>). In QM (and more precisely QFT) we have other possible definitions: the clustering principle (weinberg), etc ...
The definition of MF is what I call a naive one (in a non pejorative sense). He assumes we describe the universe properties by a single time parameter. This is almost the Newtonian/gallilean view (the absolute time). Now, we have dicovered, thanks to relativity and QM theories, that there are other forms of causality definitions.
Therefore, the danger comes from the mixing of these different definitions to build unlogical conclusions.

I AGREE, but I asked for your definition so I would know what you are taking about.

Please try to give your self coherent definition of "genuine free will" in a non "determinsitc" universe. ... That's again a conclusion without self coherent definitions (universe, deterministic defs in the context of QM theory). Seratend.

I won't for two reasons, most important is that I can not give one that satisfied MF and other careful thinkers. I can tell many things it is not. (E.g. It is not based on the freedom of the uncertainty principle of QM - these probabilistic results do not provide me with any option for GFW that is better than tossing a coin does.)
Second reason is that ZapperZ has a good point. this thread must say focused on the quantum mechanics aspects of this. Thus only as Free Will relates to QM is it appropriate to discuss FW (or GFW) here.

 

[moving finger]

Re-read the quote I attributed to you.

Zz.

yep, sorry, my mistake. I made a typo in my original post.

Thanks

MF

 

[ZapperZ]

The correct scientific answer to the question "Does the world operate deterministically?" is therefore "we simply do not know".

Fine. Let's LEAVE it at that. No one can say the world is deterministic, and no one can say the world is indeterministic, FOR NOW. Now can we go on to something that actually is productive?

Zz.

 

[DrChinese]

So how did this thread escaped from the Philosophy section? Was the warden asleep at the guard tower? :)

Something like "... it is dangerous to enter into any debate with clearly defining the concepts being debated... " can only belong there.

Zz.

You got to love him.

 

[Billy T]

It seems to me also that it is appropriate here to focus on the need for clear definitions in QM. As i can not define a QM "observation" {other than by the nearly (if not completely) circular form: "Something that causes a mixed state wave function to collapse into a pure eigen state." }I would appreciate it if someone would try.

The main unhappiness I have with the fantastically successful QM (Its predictions, even one that seem to be impossible to me, like quantum entanglement, have turned out to be confirmed by experiments.) is that it seems to me to logically incomplete: It requires something ad hoc, outside of the QM theory, namely an "observation" to interrupt the smooth and deterministic evolution of the wave function that one can, at least in principle, compute with the Schrodinger equation.

 

[DrChinese]

Definition of Determinism
The universe, or any self-contained part thereof, is said to be evolving deterministically if it has only one possible state at time t1 which is consistent with its state at some previous time t0 and with all the laws of nature.

Definition of Determinability
The universe, or any self-contained part thereof, is said to be determinable if it has only one possible state at time t1 which can in principle be predicted (determined) by an agent (observer) based on a knowledge of its state at some previous time t0 and with all the laws of nature.

Clearly, Determinism is an ontic property of a universe, and neither its definition nor existence is dependent on either observers or observation, ie a universe operates either deterministically or it does not, regardless of whether there are any observers around to know about it.

Determinability, on the other hand, is clearly an epistemic property of a universe, it is dependent on the presence of an (in principle) observer, because it is defined in terms of the knowledge such an observer can have about the universe.

The question posed in this thread is : Does the world operate according to the definition of determinism? (The question NOT posed here is "does the world operate according to the definition of determinability?")

Epistemic Determinability vs Ontic Determinism
The principles and experimental results of quantum mechanics, and in particular Heisenberg's uncertainty principle, show that there is an in-principle limit to our knowledge about the world - we have an "epistemic horizon" beyond which we are unable, in principle, to gain knowledge. This is characterised by Planck's consstant, and it places a lower limit on our ability to distinguish between determinism and indeterminism as true (ontic) properties of the world. In other words, we simply cannot know whether the quantum world is truly (ontically) deterministic or not.

In absence of any conclusive experiment or evidence either way, it follows that if one believes the world is either deterministic or indeterministic then this is simply a matter of faith, and not one of science.

The correct scientific answer to the question "Does the world operate deterministically?" is therefore "we simply do not know".

OK, I am a sucker for these discussions anyway...

1. So I will counter: Perhaps there was not conclusive evidence either way 75 years ago. But EPR+Bell is very persuasive if you were previously on the fence. If there are no hidden variables, then time does not have the property you ascribe to it in your definition. The state of the system at T1 is dependent not only upon T0 in the past, but also T2 which is in the future.

2. In addition, there is plenty of evidence that the universe is not in a single state at T1 as you suppose. It is in a superposition. This can be seen in the double slit experiment, for one.

So the point is that your conclusion fails because there is counter-evidence to your hypothesis. Now, you may reject that evidence. But doing so ignores its scientific acceptance; its acceptance is why books talk about an indeterministic universe.

 

[Billy T]

...
1. So I will counter: Perhaps there was not conclusive evidence either way 75 years ago. But EPR+Bell is very persuasive if you were previously on the fence. If there are no hidden variables, then time does not have the property you ascribe to it in your definition. The state of the system at T1 is dependent not only upon T0 in the past, but also T2 which is in the future.

2. In addition, there is plenty of evidence that the universe is not in a single state at T1 as you suppose. It is in a superposition. This can be seen in the double slit experiment, for one.

So the point is that your conclusion fails because there is counter-evidence to your hypothesis. Now, you may reject that evidence. But doing so ignores its scientific acceptance; its acceptance is why books talk about an indeterministic universe.

I type both slowly and inaccurately and thread is currently so active that by time I am done, MF and others may have responded, but I want to put in my one penny:

On your (1) I think you are incorrect and MF is OK. If the universe is deterministic, then acts at T2 having influence at T1 is ok. Think of all history (including what you and I now call the future) as being a recorded movie - that we experience "now" by "now" or in the evolving time you say MF is misusing.

On your (2) I don't think MF has ever denyed the possibility that QM is indeterminate. I.e. He would accept that the UP of QM limits our knowledge to be as if there are mixed states existing. Your "superposition of states" is no problem for him. He only wants to keep open the possibility that this is not fundamental, but only epistemic, if the universe is deterministic. I'll stop on (2) as he can better defend his view than I can. - my only real contribution, if any, is on (1) above.

 

[seratend]

We agree then, that it is important to define concepts being debated.

I am not so sure, see my previous post (however my english is poor, so may be I have misinterpretd your sentence). However, I you agree that the concepts must be defined before (I agree) , you should be aware on how it is difficult to get self consistent concepts and to proove they are self consistent. Thereofre adding new concepts/definitions is not so easy (at least in a physical/mathematic theory).

Can you explain what you mean by "QM word"?
"Determinism" is a word in the English language, I am not aware that it is a "QM word"?

Welcome to the Quantum physics section of PF. If you do not known the context of the section of this forum we may have a lot of troubles. I am using (or at least trying to) the language of QM theory, you have therefore the need to use the same language.
Let's say that, in this forum, we deal, mainly, with the postulates of QM (Quantum Mechanics) to avoid any confusions.
In a physical theory, we have words (or if you prefer labels) to describe what occurs in reality. The meaning of these words is outside the theory scope (i.e. interpretation problem). Most of the problems with people who come into this forum come from mixing this. For example, most of the time, they assume (implicitely) that the QM momentum is the Newtonian momentum (education bias).

As I said before, it is your own righ to use other definitions for a given word (dictionary, etc ...), but first, to discuss in a physics forum, you need to make/translate them into logical consistent definitions in order to build logical conclusions (you have to map your external words in the words of QM theory).

I have not said that my definition is the only possible definition. I have asked whether you agree with it. You seem not to want to answer.

If you can proove it is logically consistent, yes. But do not forget, it is a simple definition, you may have call it instead "horse". At the end, based on this definition, we just deduce logical assertions such as "the universe is horse" ( or not) or sometimes the propostion is undecidable.
Now, my question, what usefull information do I get If I know if the universe is "horse" in the context of QM.?


I was trying to answer your questions, when finally I've noticed that this thread has been moved into the phylosophie section. Now, I have lost my QM theory context and you have recovered all you rights. Damned!
I appreciate phylosophie, but I prefer the rigor of mathematics and physics theories. Gambling with the concepts of words is interesting, but it is not my main scope.

Seratend.

PS.
you say:

What "different definitions using the same label" am I using? I do not believe this is a correct statement, can you elaborate please?
In what sense is this a "mixing of different definitions using the same label"? I have defined very clearly what I mean by determinism.

In this context, the label is the name of the definition, in your case "deterministic" label.
If you try to extrapolate your own definition to sentences used in other contextes, you are making dangerous extrapolations. Before, always ask: what does mean the word in this context (and do not implicitely assume the word is always defined by its dictionnary definition or your own definition)?
For example, The word "momentum" in QM has not the same signification as the word in Newtonian mechanics. Their logical signification (definition) are completely different. In other words, I do not know if the question "does the QM word momentum has a signification in Newtonian theory?" means something.

you say:
Perhaps you are suggesting that I have not defined "deterministically"? I agree. The correct question, given my definitions, should have been "Does the world operate according to determinism?".
Determinism is clearly defined.
MF

Just replace "determinism" by "horse" (just to avoid that your determinism label is the one of another people or the one used in a given physical theory: we can avoid false implicit assumptions).
You think that you have clearly defined your label "determinism". I am not sure. Making a consistent definition (at least in a mathematical or physical point of view) is far from being evident. And claiming that it is clearly defined without giving a demonstration is like writting a theorem without giving a demonstration: lack of logic, i.e. you accept to say what you want.

========

I have taken to much time to answer to this damned thread!

 

[seratend]

I AGREE, but I asked for your definition so I would know what you are taking about

.

Why do you think should I have a single definition? I have already said that there are many definitions (with surely different meanings). I try to use the one adapted to its context (it is why I do not like to speak of causality without specifying its context) when I have to.
In Newtonian mechanics, I will use an almost equivalent defintion to MF, In QFT, I think i wil use the clustering principle etc ...

Seratend.

 

[Billy T]

...I've noticed that this thread has been moved into the phylosophie section. Now, I have lost my QM theory context and you have recovered all you rights. Damned!
I appreciate phylosophie, but I prefer the rigor of mathematics and physics theories. Gambling with the concepts of words is interesting, but it is not my main scope. ...I have taken to much time to answer to this damned thread!

I join you (and hope we have not lost you) in protesting the move - for reasons stated in last sentence of post 14 and all of post 18, which asked a question I would much rather have physicists well versed in QM answer that philosophers. Please try to answer it or recruit someone else to try.

 

[seratend]

It seems to me also that it is appropriate here to focus on the need for clear definitions in QM.

This is the domain of interpretation. QM theory only gives labels ("measurement", collapse, observation, etc ...) used in its postulates like any other mathematical theory. They have no external signification (even if the same words have other significations in other contextes). The need to build external definitions is far from beeing evident, it is like fitting QM theory into the subset of a wider theory. If this new wider theory does not give additionnal testable information, assuming these external definitions are true is like assuming god exists. Very interresting but not very usefull.

Seratend.

 

[Billy T]

This is the domain of interpretation. QM theory only gives labels ("measurement", collapse, observation, etc ...) used in its postulates like any other mathematical theory. They have no external signification (even if the same words have other significations in other contextes). The need to build external definitions is far from beeing evident, it is like fitting QM theory into the subset of a wider theory. If this new wider theory does not give additionnal testable information, assuming these external definitions are true is like assuming god exists. Very interresting but not very usefull.

Seratend.

If you are saying, as I think your are, that QM is only a computational recipe that makes predictions, not any statement about what "exists" "reality" etc. then I agree with you, except for wanting to know how it can them be applied to experiments in the physical world.

I could develop an axiomatic theory of objects called "unicorns," "grass," " weight gain," etc. and it too (like QM) would not find any application in the real physical world I could justify by logic alone.

I think the safest answer to the basis for applying QM to real world experiments is to simply note that in certain experimental configurations / procedures we have learned (perhaps by trial and error, but intuition also, and certainly not by logic from our axioms.) that there is a one to one correlation (correctness) of these predictions with the experimental results.

The main problem I have with this is knowing what I must do in these experiments to make what the abstract QM theory terms an "observation."

This is why I would like that term, at least, defined and not just remain part of a mathematical /axiomatic structure. (I hope you can understand my concern, despite not expressing it too clearly.)

 

[seratend]

I could develop an axiomatic theory of objects called "unicorns," "grass," " weight gain," etc. and it too (like QM) would not find any application in the real physical world I could justify by logic alone.
I think the safest answer to the basis for applying QM to real world experiments is to simply note that in certain experimental configurations / procedures we have learned (perhaps by trial and error, but intuition also, and certainly not by logic from our axioms.) that there is a one to one correlation (correctness) of these predictions with the experimental results.

Exactly: this is the mapping to experiment trials problem of any physical theory. You can only verify it by experiments.
For example, take the geometry (Hilbert axiomatization): If I ask you to draw a circle, you will draw one. If after I ask you if it is a circle, we may use the mapping circle you draw <=> circle (mathematical object) to give the answer. However, we just have externally used a new element "the mapping circle you draw <=> circle" that does not belong to the mathematical theory geometry.

The main problem I have with this is knowing what I must do in these experiments to make what the abstract QM theory terms an "observation."
This is why I would like that term, at least, defined and not just remain part of a mathematical /axiomatic structure. (I hope you can understand my concern, despite not expressing it too clearly.)

This is the difficult part I agree (if I understand you). A measurement result of a given observable is a logical proposition on a given system (we note we get this value). The remaining problem is how we can say that a designed experimental trial (e.g. the analogue of the circle drawing) gives a result of a given observable rather than another (the mapping).
Well, currently I just know we have the working known experiments (a given mapping works: our current knowledge), the classical limit (~ classical mapping) and the decoherence. May be, what could solve better this mapping is the resolution of the preferred basis problem of QM large systems (or the human preferred basis: is it the position basis, the momentum etc ...).
However, this is far from being concrete and I am not sure that what I said here is completely consistent : ).

Seratend.

 

[moving finger]

Fine. Let's LEAVE it at that. No one can say the world is deterministic, and no one can say the world is indeterministic, FOR NOW. Now can we go on to something that actually is productive?

Zz.

Hey... that's fine by me!
That is all I am trying to say - but with respect Zz I think you will find that not everyone thinks the same as thee and me - there are some who believe QM shows the world is indeed indeterminsitic - these are the ones I am addressing here.

With respect - how do you define "something productive"? Please do not be so dismissive.

Thanks

MF

 

[moving finger]

1. So I will counter: Perhaps there was not conclusive evidence either way 75 years ago. But EPR+Bell is very persuasive if you were previously on the fence. If there are no hidden variables, then time does not have the property you ascribe to it in your definition. The state of the system at T1 is dependent not only upon T0 in the past, but also T2 which is in the future.

Two issues here :
EPR+Bell shows only that the world cannot be both "real" (ie deterministic) and local. In fact whatever interpretation we adopt, QM says the world must be non-local. But reality (determinism) is not ruled out by EPR+Bell+Aspect etc.
IMHO it follows from the definition of determinism that specifying the state of the universe at time t0 then fixes the state of the universe at all previous and at all subsequent times. So what is your point here?

2. In addition, there is plenty of evidence that the universe is not in a single state at T1 as you suppose. It is in a superposition. This can be seen in the double slit experiment, for one.

Any (QM) superposition of states can be expressed as a single (QM) state. QM wavefunctions are additive.
What is your point here?

So the point is that your conclusion fails because there is counter-evidence to your hypothesis.

The point is that you have not presented any evidence which stands up.

Now, you may reject that evidence. But doing so ignores its scientific acceptance; its acceptance is why books talk about an indeterministic universe.

I reject the evidence you present because it is in fact not evidence. You seem to accept this so-called evidence without questioning it at all. A "book talking about an indeterministic universe" does not mean the universe is in fact indeterministic.

If you are so sure you are right, I wonder why ZapperZ thinks you are wrong?

MF

 

[moving finger]

I you agree that the concepts must be defined before (I agree) , you should be aware on how it is difficult to get self consistent concepts and to proove they are self consistent. Thereofre adding new concepts/definitions is not so easy (at least in a physical/mathematic theory).

I agree completely with this, which is why I am keen to establish definitions of concepts in advance, and to invite constructive criticism of those definitions. I am not trying to add “new concepts” or “new definitions”, therefore if there is an existing definition of determinism that you would prefer me to use, please do tell me about it!

Welcome to the Quantum physics section of PF. If you do not known the context of the section of this forum we may have a lot of troubles.

I am familiar with QM.

I am using (or at least trying to) the language of QM theory, you have therefore the need to use the same language.

Agreed. As I said, if you have an existing definition of determinism that you prefer to use then please do tell me about it! Or is the language a “secret”?

Let's say that, in this forum, we deal, mainly, with the postulates of QM (Quantum Mechanics) to avoid any confusions.

Obviously. I will try to assume that you are not being patronising.

In a physical theory, we have words (or if you prefer labels) to describe what occurs in reality. The meaning of these words is outside the theory scope (i.e. interpretation problem). Most of the problems with people who come into this forum come from mixing this. For example, most of the time, they assume (implicitely) that the QM momentum is the Newtonian momentum (education bias).

As I said before, it is your own righ to use other definitions for a given word (dictionary, etc ...), but first, to discuss in a physics forum, you need to make/translate them into logical consistent definitions in order to build logical conclusions (you have to map your external words in the words of QM theory).

Once again – it seems that you perhaps have a problem with my definition of determinism. If so, then (a) please tell me what the problem is and/or (b) provide me with what you consider to be the “correct” “QM” definition of determinism.

I have not said that my definition is the only possible definition. I have asked whether you agree with it. You seem not to want to answer.

If you can proove it is logically consistent, yes. But do not forget, it is a simple definition, you may have call it instead "horse". At the end, based on this definition, we just deduce logical assertions such as "the universe is horse" ( or not) or sometimes the propostion is undecidable.
Now, my question, what usefull information do I get If I know if the universe is "horse" in the context of QM.?

It seems clear to me from the definition. If we know that the universe is deterministic then (as per the definition) this means that the state at any time t1 is uniquely determined by the state at time t0 plus the laws of nature – ie the future is not “open”.

I was trying to answer your questions, when finally I've noticed that this thread has been moved into the phylosophie section. Now, I have lost my QM theory context and you have recovered all you rights. Damned!

It is a poor reflection of this forum if the “context” and “rights” are dictated by a few individuals. I am interested only in truth, whether the thread appears in the QM section, or the philosophy section, or the section on pink fairies, matters not to me. The only thing that matters (and this should be your concern also) is what is being discussed.

I appreciate phylosophie, but I prefer the rigor of mathematics and physics theories. Gambling with the concepts of words is interesting, but it is not my main scope.

Perhaps (with respect) this is why so few quantum physicists can tell us anything useful about ontology.

In this context, the label is the name of the definition, in your case "deterministic" label.
If you try to extrapolate your own definition to sentences used in other contextes, you are making dangerous extrapolations. Before, always ask: what does mean the word in this context (and do not implicitely assume the word is always defined by its dictionnary definition or your own definition)?
For example, The word "momentum" in QM has not the same signification as the word in Newtonian mechanics. Their logical signification (definition) are completely different. In other words, I do not know if the question "does the QM word momentum has a signification in Newtonian theory?" means something.

Once again, you seem to be implying that I am introducing a new meaning for determinism, where an accepted “QM meaning” already exists. If this is the case, can you tell me what is the existing “QM meaning” of determinism? If there is no existing meaning, then I cannot see how you can object to me defining it as I wish.

I have asked many times what you consider to be unacceptable or wrong with my definition, you have not provided any reply. I have also asked now several times whether there is another definition of determinsim that you would prefer to use……

Just replace "determinism" by "horse" (just to avoid that your determinism label is the one of another people or the one used in a given physical theory: we can avoid false implicit assumptions).
You think that you have clearly defined your label "determinism". I am not sure. Making a consistent definition (at least in a mathematical or physical point of view) is far from being evident. And claiming that it is clearly defined without giving a demonstration is like writting a theorem without giving a demonstration: lack of logic, i.e. you accept to say what you want.

Simplistically : Determinism = There is only one state at time t1 which is consistent with a prior state at time t0 plus the laws of nature.

What could be more simple than this? Please explain where you think the problem is.

ZapperZ seems not to have a problem with this definition, in fact he seems to think the conclusion that the statement “we do not know whether the world is deterministic or indeterministic” is so obviously true that no further discussion is needed.

MF

 

[seratend]

I agree completely with this, which is why I am keen to establish definitions of concepts in advance, and to invite constructive criticism of those definitions. I am not trying to add “new concepts” or “new definitions”, therefore if there is an existing definition of determinism that you would prefer me to use, please do tell me about it!

Now, this thread is in the philosophy section, you have to first understand this unusual for me (I prefer the mathematics and physics "rigor"/constraints/reductions: bias choice), so forgive me for all my non-orthodox philosophical words.
However, I may try to answer to some of your questions with my own knowledge.
Note that this is a personal opinion, who tries, when I am able to, to make logical assertions based only with logical deductions. However, as a human being, I often make mistakes (i.e. what I can say may be false or the worse totally stupid :).

First, if you look at the physical theories (e.g. Newtonian mechanics, special/general relativity, Quantum physics), you will note that no one really defines the determinism. When this label is used within these theories, it is rather an ad hoc construction/deduction/choice. This is why I cannot say I have a determinism definition or may be causality definition.
In this post, I will mix “causality” with “determinism” as long as I (personal) think it is not important for the debate (I think I understand better “causality” rather than “determinism” “concepts” ;).
I have rather multiple definitions of causality (and may be determinism). I have given some examples, in a previous post of how these labels may are defined in given physical theories.

Now, if I have to give you what I think could be a common denominator between all these definitions (of causality: easier to defined than determinism for me ;), I would say:
Causality is when there exists of a partial ordering relation (represented by a symbol label “ -->”: A -->B) on the elements of a given ZFC set.

This is what I think, the more abstract and concrete definition of causality (i.e. I am assuming already restrictions: the domain of validity of definition: ZFC sets).
The only advantage of this definition is that I can always define such an ordering relation as long as I stay with the ZFC axiomatic sets: we can always construct logical causal structures (~local determinism).
In other words, with this type of definition, the existence of a causality property (or may be the determinism t.b.d.) in a system is a matter of [logical] choice rather than an a priori obligation (~ontology).

Now, If I look at your definition, the first problem I see is that you, implicitly (as I interpret it), assume that there should only be one definition for this label. How can you logically conclude that?

In addition, if you assume that there is a single definition, the main problem becomes its undefined domain of validity:

:
Definition of Determinism
The universe, or any self-contained part thereof, is said to be evolving deterministically if it has only one possible state at time t1 which is consistent with its state at some previous time t0 and with all the laws of nature.

Your are using many undefined (context dependant) words like: universe, self-contained part, evolution, states and time, “consistent”, previous (i.e. you are implicitly assuming an ordering relation: partial, total ? etc ...), “laws of nature”. As long as I have no logical ground to attach these words, it is rather difficult for me to understand your definition without making my own implicit assumptions.
Currently I only know one tool to make logical deductions: mathematics. Therefore, I need that you attach all your words to mathematics. For example, does a state is an element of a set (ZF axiomatics?)? If yes, what set? What do you mean by consistent, in this context? Etc ...

In your definition, I may decide to add a parameter to all the “true” states, we human can take as “true”, or “consitent” (the “past”, the “present” and the “future”). (up to you to adapt these words such they are consistent with your own implicit assumptions and definition). In addition, if I suppose that the collection of these parameters is a ZFC set (my freedom with you definition), I may define, a posteriori an ordering relation on these parameters (existence). Now if I assume that these parameters are what you call “time”, I have defined an ad hoc causality relation, i.e. the “universe” may be deterministic.
Therefore, assuming only the ZFC set, I conclude I know that the universe is deterministic. Great, isn’t it?
Well, now, the main question, what type of new “useful” information does this property bring?
I think it explains well the fact that I may choose the universe to be deterministic or non-deterministic, just by selecting my own definition (choice).

Seratend.

P.S.

Perhaps (with respect) this is why so few quantum physicists can tell us anything useful about ontology.

I think it is rather a choice (except for the interpretation lovers, in a non pejorative sense). Physics mainly focus on the explanation of the experimental results. What additionnal usefull information bring the ontology to such a choice?

 

[moving finger]

Now, this thread is in the philosophy section, you have to first understand this unusual for me (I prefer the mathematics and physics "rigor"/constraints/reductions: bias choice), so forgive me for all my non-orthodox philosophical words.

I apologise if I seem to be forcing the debate onto unfamiliar terrirory. Please understand that I am open-minded and rational, and my only objective is truth and understanding. If it helps to discuss these concepts and issues in mathematical terms then I shall do my best to cooperate within my abilities.

However, I may try to answer to some of your questions with my own knowledge.
Note that this is a personal opinion, who tries, when I am able to, to make logical assertions based only with logical deductions. However, as a human being, I often make mistakes (i.e. what I can say may be false or the worse totally stupid :).

Believe it or not, I am human too, and (as you know already) I do make mistakes. Mistakes are nothing to be ashamed of – only “refusing to admit a mistake” is something we should be ashamed of.

First, if you look at the physical theories (e.g. Newtonian mechanics, special/general relativity, Quantum physics), you will note that no one really defines the determinism. When this label is used within these theories, it is rather an ad hoc construction/deduction/choice. This is why I cannot say I have a determinism definition or may be causality definition.
In this post, I will mix “causality” with “determinism” as long as I (personal) think it is not important for the debate (I think I understand better “causality” rather than “determinism” “concepts” ;).

Hmmm. OK, but I have a problem with the concepts surrounding the word “causality”. As a scientist familiar with QM, you are obviously aware that there is little (if any) evidence for causality at the quantum level. Quantum events simply seem (experimentally) to “happen” without any prior “cause” being identifiable, whereas macroscopic events seem (intuitively) to always have some “cause”. It may be the case, therefore, that causality is not present at the quantum level and “emerges” as a possible epistemic “macroscopic illusion”. For this reason I am always very wary of arguments based on a concept of “causality”.

I have rather multiple definitions of causality (and may be determinism). I have given some examples, in a previous post of how these labels may are defined in given physical theories.

Now, if I have to give you what I think could be a common denominator between all these definitions (of causality: easier to defined than determinism for me ;), I would say:
Causality is when there exists of a partial ordering relation (represented by a symbol label “ -->”: A -->B) on the elements of a given ZFC set.

Hmmm. Can you translate this into plain English please?
In plain English, does “ A-->B” mean something like “if A then necessarily B”?
(This to me could indeed represent a causal relation. It could also represent a deterministic relation, in the sense that B is determined by A.)

This is what I think, the more abstract and concrete definition of causality (i.e. I am assuming already restrictions: the domain of validity of definition: ZFC sets).
The only advantage of this definition is that I can always define such an ordering relation as long as I stay with the ZFC axiomatic sets: we can always construct logical causal structures (~local determinism).
In other words, with this type of definition, the existence of a causality property (or may be the determinism t.b.d.) in a system is a matter of [logical] choice rather than an a priori obligation (~ontology).

I do not understand this. Are you saying that the relation “ A-->B” is an epistemic property of the given set (it somehow depends on our knowledge), and not an ontic property (is independent of our knowledge)? Can you elaborate please?

Now, If I look at your definition, the first problem I see is that you, implicitly (as I interpret it), assume that there should only be one definition for this label. How can you logically conclude that?

What “label” are you referring to please?
By “label” do you mean the word “determinism”?
If your answer is yes, then (with respect) surely the whole concept of a definition (the “definition of a definition” if you like) is that a label should have a unique definition. Are you suggesting one should allow multiple, possibly conflicting, definitions for the same label?

Take your symbolic labelling “A-->B” for example. Is it legitimate for me to also suggest (as you do) that you implicitly (as I interpret it), assume that there should only be one definition for this label? To use your logic : How can you logically conclude that?

The answer to this is : One must “define” in advance the symbolic labelling to “mean”, insofar as possible, something unique and unambiguous. If one does not define this in advance then the symbolic notation “ A-->B” means nothing. Going back to the word “determinism” we must do the same thing, we must choose (define) a meaning for the word before we can usefully use it in a logical argument.

In addition, if you assume that there is a single definition, the main problem becomes its undefined domain of validity:

Again, the entire concept of a “definition” is to have, insofar as possible, a unique and unambiguous semantic meaning for a particular word. Or, if the meaning is context-dependent, to specify the nature of that dependency.

Definition of Determinism
The universe, or any self-contained part thereof, is said to be evolving deterministically if it has only one possible state at time t1 which is consistent with its state at some previous time t0 and with all the laws of nature.

Your are using many undefined (context dependant) words like: universe, self-contained part, evolution, states and time, “consistent”, previous (i.e. you are implicitly assuming an ordering relation: partial, total ? etc ...), “laws of nature”. As long as I have no logical ground to attach these words, it is rather difficult for me to understand your definition without making my own implicit assumptions.

I agree, and that is why my definition does not translate easily to a rigorous mathematical definition. But with respect, this is true of the definitions of most words.

Currently I only know one tool to make logical deductions: mathematics.

Perhaps I could introduce you to “logic”? Mathematical logic is a particular subset of logic, but not all logic is necessarily expressed in mathematical terms.

Therefore, I need that you attach all your words to mathematics. For example, does a state is an element of a set (ZF axiomatics?)? If yes, what set? What do you mean by consistent, in this context? Etc ...

I understand the problem. But just as you have problems debating issues in logic outside of mathematics, so I have problems translating everything into mathematics. I will study this and get back to you.

In your definition, I may decide to add a parameter to all the “true” states, we human can take as “true”, or “consitent” (the “past”, the “present” and the “future”). (up to you to adapt these words such they are consistent with your own implicit assumptions and definition). In addition, if I suppose that the collection of these parameters is a ZFC set (my freedom with you definition), I may define, a posteriori an ordering relation on these parameters (existence). Now if I assume that these parameters are what you call “time”, I have defined an ad hoc causality relation, i.e. the “universe” may be deterministic.
Therefore, assuming only the ZFC set, I conclude I know that the universe is deterministic. Great, isn’t it?

I fail to see above how you get from the assumption “the ‘universe’ may be deterministic” to your conclusion “the universe is deterministic”.? Can you explain please?

Well, now, the main question, what type of new “useful” information does this property bring?
I think it explains well the fact that I may choose the universe to be deterministic or non-deterministic, just by selecting my own definition (choice).

I think you and I have a problem communicating, which is deeper than the “English language/mathematical” barrier.
The purpose of my post is NOT to show by logic alone that the universe is either determinisitic or indeterministic depending upon one’s choice of definition. I do not personally believe that this can be proven (by logic alone) one way or another (and I suppose that this is what you have been trying to show)
.
The purpose of my post is instead to show that “given an agreed definition of determinism, the experimental evidence of QM does not allow us to conclude whether the universe is deterministic or indeterministic”.

Physics mainly focus on the explanation of the experimental results. What additionnal usefull information bring the ontology to such a choice?

I would be very happy if you agree that physics provides only an epistemic view of the world, and tells us nothing of ontic value – this would in effect accord with my ideas in this thread – that QM allows us to make conclusions about epistemic properties of determinism, but does not allow us to make any conclusions about the ontic properties of determinism. Is this in effect what you are trying to say here?

MF

 

[seratend]

Hmmm. OK, but I have a problem with the concepts surrounding the word “causality”. As a scientist familiar with QM, you are obviously aware that there is little (if any) evidence for causality at the quantum level. Quantum events simply seem (experimentally) to “happen” without any prior “cause” being identifiable, whereas macroscopic events seem (intuitively) to always have some “cause”. It may be the case, therefore, that causality is not present at the quantum level and “emerges” as a possible epistemic “macroscopic illusion”. For this reason I am always very wary of arguments based on a concept of “causality”.

Well, we are now in the world of interpretation of physics where we can say almost all what we want if it does not change the theory predictions (otherwise we must construct a new theory).
I think you are making implicit assumptions (/interpretations) concerning the use of the word “causality” in QM. In my modest opinion, this is the source of much confusion with QM.
In QM, we may simply notice the words we need to use in this theory are very different from their usual definition (dictionary). Most of the words of QM are first introduced by an analogy with the words definitions at the classical limit of the QM theory (position, momentum, etc ...): they are only labels that reflect the experimental results. Many interpretations are based on this classical limit. However, we are now with interpretations: as long as they do not change the theory predictions (taking the words as simple labels of the theory definition), we are free to choose the one we prefer (choice): we have many possible interpretations (orthodox view, CI, MWI, Bohmian, MMI, etc ...).
Now, let’s say that we decide that causality applies to the states of quantum systems: given an initial state, an observable, a value we know surely the new state (collapse postulate). Therefore, I may define a causality function in QM (and a deterministic evolution), if I want.
Now, you can say this is not the “real” causality definition (your choice). However, for me it is one possible abstract causality definition of QM (my choice). However, I accept both possibilities as long as they do not change the theory.

Hmmm. Can you translate this into plain English please?
In plain English, does “ A-->B” mean something like “if A then necessarily B”?
(This to me could indeed represent a causal relation. It could also represent a deterministic relation, in the sense that B is determined by A.)

Your answer is surprising and underlines may be some mutual understanding problem (your intrinsic need to associate the adequate English words to labels, while I do not reall care). It is unusual for me to discuss with philosophers, but interesting to understand the communication problems when the common knowledge ground is somewhat different ; ).
“-->” is the label of a partial ordering relation (I could have used R or f or whatever you want).
If the relation has the additional property to be a functional relation (i.e. A-->B, A-->C => B=C), then you have what I think you implicitly (for me) call a deterministic relation.
You can say A then necessarily B, even if I am not sure of the implicit definition (and conclusions you may attach to “necessarily”. For me it is just a simple mathematic formal definition.

I do not understand this. Are you saying that the relation “ A-->B” is an epistemic property of the given set (it somehow depends on our knowledge), and not an ontic property (is independent of our knowledge)? Can you elaborate please?

Well, if your knowledge can be mapped (at least a representation) into a ZFC set, then we can define (choice) what I think you call an epistemic property on this representation.
However, we may have other choices. For example in bohmian mechanics formulation of QM, we define an external new property (ontic property): the path of a particle (where the path word is chosen with the classical mechanics analogy). Based on this new property, we may define a new causality relation definition (another choice) and this time, I think this is what you call an ontic property (we choose to explain the theory with the path of particle and the causality we define on it).

What “label” are you referring to please?
By “label” do you mean the word “determinism”?

Sorry, Yes I mean “determinisn”

If your answer is yes, then (with respect) surely the whole concept of a definition (the “definition of a definition” if you like) is that a label should have a unique definition. Are you suggesting one should allow multiple, possibly conflicting, definitions for the same label?

Yes, but one is true at time: I have chosen the word label (the identifier of the concept if you want) to try to remove implicit assumptions (may be it is not the better “word” ; ). In mathematics, we define objects and attach a label to these objects.
For example the label “ssezrzer” may represent a function relation (a mapping), a relation, a set, a property, etc ...
However, “at a time”, it only represents one definition (required by my basic logic) otherwise we will have to accept the definition of a new objects that are something more complicated than the usual ones I am currently able to use. In other words to use 2 incompatible definitions at time in my basic logic, I must attach a different label (e.g. determinism1, determinism2, etc ...) to solve the possible logic conflicts.

Take your symbolic labelling “A-->B” for example. Is it legitimate for me to also suggest (as you do) that you implicitly (as I interpret it), assume that there should only be one definition for this label? To use your logic : How can you logically conclude that?

The answer to this is : One must “define” in advance the symbolic labelling to “mean”, insofar as possible, something unique and unambiguous. If one does not define this in advance then the symbolic notation “ A-->B” means nothing. Going back to the word “determinism” we must do the same thing, we must choose (define) a meaning for the word before we can usefully use it in a logical argument.

Well, we may proceed differently (another point of view, I am playing within the possibility of words): we may define a single property “determinism” and call determinist any object that has this property. Therefore, in this aspect we have many determinist definitions (the definitions where the determinism property is true).
For example, in my common denominator function of causality, I just define such a property: any ordering relation is a causality relation. If I define, for example, now “determinism” as an additional property (let’s say the relation is a functional relation), any ordering functional relation is determinist.
However, our problem is that I am using words as labels: they are only defined relatively to a context while you seem to want an absolute definition that holds for different contexts. This is, I think a personal choice and not a fundamental need. My choice tries only to reflect what I see (In a dictionary for one word, most of the time I have several definitions: e.g. the word Earth is such an example, it is what I call a label to different meanings/definitions). However, we can create a new labelling such that we have a simple one to one correspondence (once again it is a choice).

Again, the entire concept of a “definition” is to have, insofar as possible, a unique and unambiguous semantic meaning for a particular word. Or, if the meaning is context-dependent, to specify the nature of that dependency.

I agree, therefore I think you need to specify the context of your definition to avoid the implicit interpretations. In other words, I have specified the context of my causality definition: the ZFC axiomatic set theory. With you definition, I do not know what I can assume for granted and not (consistence pb)

I agree, and that is why my definition does not translate easily to a rigorous mathematical definition. But with respect, this is true of the definitions of most words.

Well, if the context of this thread is really words significations (without a given logic ground selection, nor a context), I am completely lost. In addition if the context is a not science theory, how can you apply conclusions to science
I currently see no practical need for a determinism definition/conclusions that are independent of physical theories (using the word determinism in conversations in pubs is not current nowadays ; ). However, for philosophers (pubs ; ), I may understand this can be important. However for me, it is difficult to understand why (may be I am too short minded?).
You must understand me; I voluntarily [try to] reduce the words to labels in the context of a theory (physical or mathematical) in order to make logical deductions (basic binary logic). I admit that I do not know all the theories (personal knowledge restriction and brain capacity :) and I try to take into account these restrictions when I try to answer. Without that, I am in a terra incognita.
Therefore, if you want to create an “ontic” definition of determinism, I will say great, that’s all (and surely I will use it and adapt it to the context of physical theories).
Note, that I still have not find a usefull application of the word “god” to a physical theory.

Perhaps I could introduce you to “logic”? Mathematical logic is a particular subset of logic, but not all logic is necessarily expressed in mathematical terms.

Yes I will appreciate it (i have always been reluctant/frightened to extend my logical knowledge). Currently, I only understand my binary logic within the usual classical mathematical context (mainly the ZF axiomatic basis) that can be extended somewhat to multivalued logic.
Can you explain what you intend by “not all logic is necessarily expressed in mathematical terms”? (or may be give a simple example in order to understand better what you assume in this sentence).

I fail to see above how you get from the assumption “the ‘universe’ may be deterministic” to your conclusion “the universe is deterministic”.? Can you explain please?

Well I thought I was clear (even if my English is poor ;):
In the beginning of the sentence I have used “I may define ... an ordering relation”. Therefore, I ended with the “universe may be deterministic”. In the last sentence, I assume (true) the ZFC set, this assumption implies the existence of an ordering relation (with some properties), therefore, this time (true), I conclude the universe is deterministic. This is only deductions.

I think you and I have a problem communicating, which is deeper than the “English language/mathematical” barrier.
The purpose of my post is NOT to show by logic alone that the universe is either determinisitic or indeterministic depending upon one’s choice of definition. I do not personally believe that this can be proven (by logic alone) one way or another (and I suppose that this is what you have been trying to show)
.
The purpose of my post is instead to show that “given an agreed definition of determinism, the experimental evidence of QM does not allow us to conclude whether the universe is deterministic or indeterministic”.

This is the general problem of communication. Due to the multiple word meanings and without a common context and ground (to solve the implicit assumptions), most of the time one do not understand the other one. This is why I implicitly choose the mathematical/physics bias/constraint (to define a common ground). However now we are in the philosophy domain and I am lost.
However, if you choose to allow all the possibilities to get an agreed definition (e.g. by the context by the definition update), just say that at the beginning: I think we have already your conclusion. No need to develop to conclude “given an agreed definition of determinism, the experimental evidence of QM does not allow us to conclude whether the universe is deterministic or indeterministic”, because I am not even sure that we can have an agreed definition (by a universal mutual agreement ; ).

I would be very happy if you agree that physics provides only an epistemic view of the world, and tells us nothing of ontic value – this would in effect accord with my ideas in this thread – that QM allows us to make conclusions about epistemic properties of determinism, but does not allow us to make any conclusions about the ontic properties of determinism. Is this in effect what you are trying to say here?

As long as I choose the epistemic view of physics, yes (the shut up and calculate choice). However, I may choose to define on ontic point view (this is what I call the interpretation of physics). This is another choice that is in general well separated from the “epistemic” part. However, it may lead to paradoxes (e.g. if the ontic part is not completely independent from the epistemic part: e.g. the reality problem of the path of a bohmian particle in QM associated with the formal collapse postulate)

Seratend.

 

[moving finger]

Well, we are now in the world of interpretation of physics where we can say almost all what we want if it does not change the theory predictions (otherwise we must construct a new theory).

Would you perhaps prefer that we make no “interpretation of physics”?
Why are “theory predictions” sacrosanct? Surely the only important issue is whether the “interpretation” agrees with the “experimental results”.

I think you are making implicit assumptions (/interpretations) concerning the use of the word “causality” in QM. In my modest opinion, this is the source of much confusion with QM.

My apologies. You introduced the word “causality” into this thread – rather than me make implicit assumptions perhaps you can define exactly what you mean by causality, so that the “confusion” can be removed?

In QM, we may simply notice the words we need to use in this theory are very different from their usual definition (dictionary). Most of the words of QM are first introduced by an analogy with the words definitions at the classical limit of the QM theory (position, momentum, etc ...): they are only labels that reflect the experimental results.

Yes, you have mentioned this before – that “words in QM may have different meanings” – and I have asked you to clarify by defining for example “determinism”, but (with respect) you seem to wish to prevaricate.

Many interpretations are based on this classical limit. However, we are now with interpretations: as long as they do not change the theory predictions (taking the words as simple labels of the theory definition), we are free to choose the one we prefer (choice): we have many possible interpretations (orthodox view, CI, MWI, Bohmian, MMI, etc ...).

Now you are talking about “interpretations of QM”. Are you suggesting that each of these interpretations has a different “meaning” for concepts such as “causality” and “determinism”?

Now, let’s say that we decide that causality applies to the states of quantum systems: given an initial state, an observable, a value we know surely the new state (collapse postulate).

Sorry, what is the “collapse postulate”?

Therefore, I may define a causality function in QM (and a deterministic evolution), if I want.
Now, you can say this is not the “real” causality definition (your choice). However, for me it is one possible abstract causality definition of QM (my choice). However, I accept both possibilities as long as they do not change the theory.

I disagree. I would say one could accept both possibilities as long as they do not conflict with experimental results. Surely it is the result of experiment, and not the prediction of theory, which determines the validity of a possible definition?

In plain English, does “ A-->B” mean something like “if A then necessarily B”?
(This to me could indeed represent a causal relation. It could also represent a deterministic relation, in the sense that B is determined by A.)

Your answer is surprising and underlines may be some mutual understanding problem (your intrinsic need to associate the adequate English words to labels, while I do not reall care).

With respect, I did not “answer”, I asked you a question. You introduced a new expression “ A-->B” into our discussion, why should it be surprising to you that I ask you to define what it means?

My ”intrinsic need”, as you call it, is an attempt to reach a common understanding, rather than to continue with obfuscation. With respect, I might also say that you have an “intrinsic need” to reduce everything to mathematics, or that “I do not really care what mathematical symbols you use”, but that would not really help us very much in communicating would it?

It is unusual for me to discuss with philosophers, but interesting to understand the communication problems when the common knowledge ground is somewhat different ; ).

What makes you think I am a philosopher? Maybe it is unusual for me to discuss with someone who finds it hard to communicate in anything but mathematics, but so what?

“-->” is the label of a partial ordering relation (I could have used R or f or whatever you want).
If the relation has the additional property to be a functional relation (i.e. A-->B, A-->C => B=C), then you have what I think you implicitly (for me) call a deterministic relation.
You can say A then necessarily B, even if I am not sure of the implicit definition (and conclusions you may attach to “necessarily”. For me it is just a simple mathematic formal definition.

I believe the symbolism that you suggest “A-->B”, based on your (with respect, reluctant) explanation, is probably accurately expressed in English as “if A then necessarily B”.

I do not understand this. Are you saying that the relation “ A-->B” is an epistemic property of the given set (it somehow depends on our knowledge), and not an ontic property (is independent of our knowledge)? Can you elaborate please?

Well, if your knowledge can be mapped (at least a representation) into a ZFC set, then we can define (choice) what I think you call an epistemic property on this representation.
However, we may have other choices. For example in bohmian mechanics formulation of QM, we define an external new property (ontic property): the path of a particle (where the path word is chosen with the classical mechanics analogy). Based on this new property, we may define a new causality relation definition (another choice) and this time, I think this is what you call an ontic property (we choose to explain the theory with the path of particle and the causality we define on it).

Sorry, this still makes no sense to me.
It seems that you are saying the truth of the statement “A-->B” depends on the QM interpretation that we choose to use? Is that correct?
If yes, does this mean that the truth of the statement “A-->B” is subjective?

surely the whole concept of a definition (the “definition of a definition” if you like) is that a label should have a unique definition. Are you suggesting one should allow multiple, possibly conflicting, definitions for the same label?

Yes, but one is true at time: I have chosen the word label (the identifier of the concept if you want) to try to remove implicit assumptions (may be it is not the better “word” ; ). In mathematics, we define objects and attach a label to these objects.

Well that’s good, because in common language we do the same – we define a word (object) and attach labels (definitions) to these words (objects). Sometimes it may not be as rigorous as in mathematics, but we find that it tends to be much more flexible and useful for communication.

For example the label “ssezrzer” may represent a function relation (a mapping), a relation, a set, a property, etc ...
However, “at a time”, it only represents one definition (required by my basic logic) otherwise we will have to accept the definition of a new objects that are something more complicated than the usual ones I am currently able to use. In other words to use 2 incompatible definitions at time in my basic logic, I must attach a different label (e.g. determinism1, determinism2, etc ...) to solve the possible logic conflicts.

OK. I can accept that there are multiple definitions of “determinism”, differentiated by “determinism1”, “determinism2” etc. Now, can we define “determinism1” as I suggested in my first post, and proceed from there? Or do you still have a problem with this?

Take your symbolic labelling “A-->B” for example. Is it legitimate for me to also suggest (as you do) that you implicitly (as I interpret it), assume that there should only be one definition for this label? To use your logic : How can you logically conclude that?

The answer to this is : One must “define” in advance the symbolic labelling to “mean”, insofar as possible, something unique and unambiguous. If one does not define this in advance then the symbolic notation “ A-->B” means nothing.

Agreed, which is why I asked you “what does it mean”, which you then seemed “surprised” that I should ask, and reluctant to answer. We now seem to “agree” that any symbols (bet they mathematical symbols or words) need clear definition. Wow.

Going back to the word “determinism” we must do the same thing, we must choose (define) a meaning for the word before we can usefully use it in a logical argument.
That is exactly why I offered definitions in my first post in this thread. Those definitions may not have been “mathematical” definitions, they were in fact English language definitions, but that is hardly the point.

Well, we may proceed differently (another point of view, I am playing within the possibility of words): we may define a single property “determinism” and call determinist any object that has this property.

That is your choice.

Therefore, in this aspect we have many determinist definitions (the definitions where the determinism property is true).

No. From what you have said, it follows only that we may possibly have many objects which have determinist properties, but it does not follow that we would have many determinist “definitions”. The only “definitions” we have allowed in this context are (1) the definition of “determinism” and (2) the definition of “determinist”. It does not follow from this that this leads to many determinist definitions.

For example, in my common denominator function of causality,

What is a “common denominator function of causality”?

If I define, for example, now “determinism” as an additional property (let’s say the relation is a functional relation), any ordering functional relation is determinist.
However, our problem is that I am using words as labels: they are only defined relatively to a context while you seem to want an absolute definition that holds for different contexts.

I agree some definitions can be contextual.
This is why the definition needs to take account of the context in which the word is used.
Can you explain how you think the meaning of determinism as defined in my first post could be contextual?

Again, the entire concept of a “definition” is to have, insofar as possible, a unique and unambiguous semantic meaning for a particular word. Or, if the meaning is context-dependent, to specify the nature of that dependency.

I agree, therefore I think you need to specify the context of your definition to avoid the implicit interpretations. In other words, I have specified the context of my causality definition: the ZFC axiomatic set theory. With you definition, I do not know what I can assume for granted and not (consistence pb)

I believe this gets back to making the definition meaningful in mathematical terms. We may have to agree to disagree here.

I agree, and that is why my definition does not translate easily to a rigorous mathematical definition. But with respect, this is true of the definitions of most words.

Well, if the context of this thread is really words significations (without a given logic ground selection, nor a context), I am completely lost. In addition if the context is a not science theory, how can you apply conclusions to science

The context of this thread, and the entire forum, is an attempt at understanding. Most participants in the forum communicate in the English language rather than in mathematics. If you are saying that you can only accept a mathematical discussion, and not an English language discussion, then with respect I think we are wasting our time continuing.

I currently see no practical need for a determinism definition/conclusions that are independent of physical theories (using the word determinism in conversations in pubs is not current nowadays ; ). However, for philosophers (pubs ; ), I may understand this can be important. However for me, it is difficult to understand why (may be I am too short minded?).

I did not suggest that a definition of determinism needs to be independent of physical theories. For most of us, an English language definition of concepts is important, but perhaps not for all of us.

You must understand me; I voluntarily [try to] reduce the words to labels in the context of a theory (physical or mathematical) in order to make logical deductions (basic binary logic). I admit that I do not know all the theories (personal knowledge restriction and brain capacity :) and I try to take into account these restrictions when I try to answer. Without that, I am in a terra incognita.

And with respect, you must understand me, I try to interpret symbols in terms of meanings, and conveying meaning requires communication, and it seems we have trouble communicating. Sorry.

Therefore, if you want to create an “ontic” definition of determinism, I will say great, that’s all (and surely I will use it and adapt it to the context of physical theories).
Note, that I still have not find a usefull application of the word “god” to a physical theory.

You have no need of that hypothesis?

I fail to see above how you get from the assumption “the ‘universe’ may be deterministic” to your conclusion “the universe is deterministic”.? Can you explain please?

Well I thought I was clear (even if my English is poor ;):
In the beginning of the sentence I have used “I may define ... an ordering relation”. Therefore, I ended with the “universe may be deterministic”. In the last sentence, I assume (true) the ZFC set, this assumption implies the existence of an ordering relation (with some properties), therefore, this time (true), I conclude the universe is deterministic. This is only deductions.

You conclude determinism logically from the prior assumption of an ordering relation? OK, but this is (with respect) not the idea I was trying to convey. As explained, the purpose of my original post was instead to show that “given an agreed definition of determinism, the experimental evidence of QM does not allow us to conclude whether the universe is deterministic or indeterministic”.

I think you and I have a problem communicating, which is deeper than the “English language/mathematical” barrier.
The purpose of my post is NOT to show by logic alone that the universe is either determinisitic or indeterministic depending upon one’s choice of definition. I do not personally believe that this can be proven (by logic alone) one way or another (and I suppose that this is what you have been trying to show)
.
The purpose of my post is instead to show that “given an agreed definition of determinism, the experimental evidence of QM does not allow us to conclude whether the universe is deterministic or indeterministic”.

This is the general problem of communication. Due to the multiple word meanings and without a common context and ground (to solve the implicit assumptions), most of the time one do not understand the other one. This is why I implicitly choose the mathematical/physics bias/constraint (to define a common ground). However now we are in the philosophy domain and I am lost.

I think we will not resolve this. It seems to me that you are insisting I must translate my argument into mathematics for it to have any relevance to you, and I am saying that I do not have the mathematical skills to do that. Perhaps we must simply agree to disagree.

However, if you choose to allow all the possibilities to get an agreed definition (e.g. by the context by the definition update), just say that at the beginning: I think we have already your conclusion. No need to develop to conclude “given an agreed definition of determinism, the experimental evidence of QM does not allow us to conclude whether the universe is deterministic or indeterministic”, because I am not even sure that we can have an agreed definition (by a universal mutual agreement ; ).

An “agreed definition” need not be universal – in the context of a debate it needs to be agreed only between the debating parties. Why are you not sure that we can have an agreed definition?

As long as I choose the epistemic view of physics, yes (the shut up and calculate choice). However, I may choose to define on ontic point view (this is what I call the interpretation of physics). This is another choice that is in general well separated from the “epistemic” part. However, it may lead to paradoxes (e.g. if the ontic part is not completely independent from the epistemic part: e.g. the reality problem of the path of a bohmian particle in QM associated with the formal collapse postulate)

Can you explain this paradox in more detail please? My understanding is that there is no “collapse postulate” in Bohmian mechanics?

MF

 

[seratend]

Originally Posted by seratend
Your answer is surprising and underlines may be some mutual understanding problem (your intrinsic need to associate the adequate English words to labels, while I do not reall care).

With respect, I did not “answer”, I asked you a question. You introduced a new expression “ A-->B” into our discussion, why should it be surprising to you that I ask you to define what it means?

I am sorry, but I am very disappointed by your post, I have found it unconstructive (too many questions, very few answers) and very difficult to understand the place where you want to go. [However, I see this is no more true in the second part of your post].

I have selected the above section of your post, just to underline our current problem: the word meanings in a discussion between 2 persons without a common ground.
I think (or may be I understand, may be it’s wrong) that you need to get some truth behind every words you use while I do not (my labelling preference). I do not mean that your choice (whatever it could be) is true or false, I just say that we have many possibilities (our choices) and we should take them into account in such a discussion. In other words, both parts need to build a common ground, and it is very difficult when we get misunderstandings and almost only questions from one side.

Your reply (now I try to avoid the word answer ; ) and the subsequent questions in this section perfectly highlights this problem. You have interpreted the word “your answer” in my reply as an answer to a question while it was simply meaning “your reply” in this context (my context).
You may argue that, in good English the answer word must be applied to a question, however, I think you are also able to understand the context of the post to make some basic deductions. If it is not the case, we are just playing with words and it is not very constructive (at least for me).

I understand you better now, you are in the mode “I write” (a definition always selects one word) and I am in the mode “I read” (from a word, and a partly known context, I have to recover a single definition: not always possible). This is why, generally, I prefer the mathematics and physics restrictions: we loose less time in communicating and defining a common context/ground.
Now, as long as you cannot understand both modes of communication, we are in troubles: I understand that you cannot understand my words. However, do you understand the same thing applies to your words?

I believe the symbolism that you suggest “A-->B”, based on your (with respect, reluctant) explanation, is probably accurately expressed in English as “if A then necessarily B”.

Well, even with symbols, we may have the problem of implicit associations! I should have used instead of “A-->B”, P(A,B) where P is a proposition that depends on 2 parameters A and B. This proposition is only defined by the following properties:

P(A,A) is true
If P(A,B) true and P(B,A) true then necessarily A=B
If P(A,B) true and P(B,C) true then necessarily A=C

Seratend edit: big mistake, I hope everyone has corrected it:we should not read:
If P(A,B) true and P(B,C) true then necessarily A=C
but rather:
If P(A,B) true and P(B,C) true then necessarily P(A,C)
(this is the well known transitivity relation on the partial ordering relation)
(shame on me ! errare humanum est : )
end of edit

Therefore, I think the interpretation of the sentence “if A then necessarily B” may be adequate and sometimes inadequate: we may have several possibilities (to be choosen before the use of the property P(A,B)):
* P(A,B) is A equivalent to B or
* P(A,B) is A equals B
* P(A,B) is A included in B
* P(A,B) is A => B
* P(A,B) is B => A
etc ...
Therefore, If you decide to use the English words “if A then necessarily B” instead of “P(A,B)” or “A -->B”, please do not try to attach any other intrinsic meaning. The only true definition that applies to the word you select for conveniance is the properties cited above (and not its definition in a dictionary).

Originally Posted by seratend
Yes, but one is true at time: I have chosen the word label (the identifier of the concept if you want) to try to remove implicit assumptions (may be it is not the better “word” ; ). In mathematics, we define objects and attach a label to these objects.

Well that’s good, because in common language we do the same – we define a word (object) and attach labels (definitions) to these words (objects). Sometimes it may not be as rigorous as in mathematics, but we find that it tends to be much more flexible and useful for communication.

Thanks a lot: we may get our first common ground in this discussion and explain some of the problems we have encountered:

(me) objects <--~--> labels (you)

If we understand that the definition meaning is common for us. Otherwise we still have some problems (and I think there may be)

(me) label <--~--> word (you)

and the understanding problems:

(me) object is equivalent to a definition [versus] (you) word is equivalent to an object

(you) label is equivalent to a definition [versus] (me) object is equivalent to a definition

We are thus using inverse procedures (and I think I remember a long time ago a course on that):
You are using a definition to identify a single word, the object (what a brain normally does to speak) and I use a word to identify a single definition (what a brain normally does to understand)!

This explains well the confusion on the word “label”, “word” and, definitively, I am lost in this country.

In your language, can we say that 2 different definitions may call the same word?
Can you confirm that (at least for what I have expressed as your part)?

Note: to avoid non-useful comments, what I have written above does not mean that your language choice is worse or better, just they are different.

Therefore, to use your words, I need a context and effectively we may use the word determinism1 to choose unambiguously your definition of determinism (I have a headache now).

Originally Posted by seratend
The answer to this is : One must “define” in advance the symbolic labelling to “mean”, insofar as possible, something unique and unambiguous. If one does not define this in advance then the symbolic notation “ A-->B” means nothing.

Agreed, which is why I asked you “what does it mean”, which you then seemed “surprised” that I should ask, and reluctant to answer. We now seem to “agree” that any symbols (bet they mathematical symbols or words) need clear definition. Wow.

It was not originally posted by seratend but by yourself. It is a pleasure for me to check that you are self-consistent with yourself! : ).
Now, in the context of what I understand you may say, I am not sure I understand at all this post section.

I give up, for the moment, for your comments in definitions (as I am afraid we may have again some mutual comprehension problem).

Can you explain how you think the meaning of determinism as defined in my first post could be contextual?

Just by the words used in the definition of determism1 (you write, I read therefore I interpret if I have not a sufficient context/ground/reference).
In order to be able to understand your definition of determinism1, one must know what single definition applies to each word (note: this just an extreme view). However, if, in your definition of determinism1, you allow one to choose its own definition for each word, we have not one determinsm1 definition, but a collection of determinsm1, 2 etc ... definitions that may be use for determinism1.

For example: I may choose for the word t1 a real number, a vector space, a set, a state of a hilbert space etc...
I may choose as the definition of the universe, a collection of sets, a separable hilbert space, a Lorentzian manifold etc ... (I also may choose other definitions where I cannot apply my logic).

I believe this gets back to making the definition meaningful in mathematical terms. We may have to agree to disagree here.

Not necessarily: i am flexible (or i try to). The advantage of mathematics is mainly on the definition of the context: it is very concise. My example: the ZFC axiomatic set theory.
Now, if you do not want to use mathematics, I think it is your job (the writer), to explain all the words you use such that you are sure the reader only gets one possible meaning: the meaning you use when writing your definition at the beginning of this thread. This can be very short (e.g. something like: I do not care of the meaning the reader has of my definition) or very long or impossible as it depends on what you really mean with your definition.

An “agreed definition” need not be universal – in the context of a debate it needs to be agreed only between the debating parties.

Always interesting, how you seem to take, usually, the extreme definition of words (in this case “universal”).
If I was saying the universe (my universe) is made of our 2 persons (or the debate group), what do you think of the meaning of “universal agreement” in this context?

Why are you not sure that we can have an agreed definition?

Simply by a formal choice. If I decide not to agree with your definition, can we say we have an agreed definition? I think no. (However, my answer remains context dependant : ).

Sorry, what is the “collapse postulate”?
...
Can you explain this paradox in more detail please? My understanding is that there is no “collapse postulate” in Bohmian mechanics?

Well, It is very difficult for me to understand what you may understand if you do not know the collapse postulate (the resulting state of the system "after" a measure has given a certain result is the projection of the initial state "before" the measure: it is important to note that "after" and "before" are only a logic order not a time ordering).
In the “genuine” bohmian mechanics, probably there is not the full collapse postulate (however, I am not sure it is 100% consistent), but the adapted one of the q representation of QM in Bohmian mechanics.
In my statement, I just take the formal part (the mathematical part) of bohmian mechanics that is compatible with QM (i.e. I have the abstract usual QM theory with the collapse postulate + an abstract “bohmian particle”, the ontic part, that respects this collapse postulate).

Seratend.

 

[Billy T]

To Seratend - I don't want to interfere in your and MF's efforts to find a common language, so I won't, but may have a little fun with it.

I have asked MF if he had any ideas as to how a Non deterministic, Non random "agent" could be logically implemented (or something essentially like that) and he "answered" (that word should be OK with both of you as it was a question): "beats me." and I replied: "me too" (could not answer him as it was not a question - just trying to have some fun, no offense to either of you.) But inspite of this fun?, please read my request for help below your quoted text.

...Well, even with symbols, we may have the problem of implicit associations! I should have used instead of “A-->B”, P(A,B) where P is a proposition that depends on 2 parameters A and B. This proposition is only defined by the following properties:

P(A,A) is true
If P(A,B) true and P(B,A) true then necessarily A=B
If P(A,B) true and P(B,C) true then necessarily A=C

Therefore, I think the interpretation of the sentence “if A then necessarily B” may be adequate and sometimes inadequate: we may have several possibilities (to be choosen before the use of the property P(A,B)):
* P(A,B) is A equivalent to B or
* P(A,B) is A equals B
* P(A,B) is A included in B
* P(A,B) is A => B
* P(A,B) is B => A
etc ...
Therefore,...Seratend.

From above and your reply to me about mappings between axiomatic structures and real world procedures (especially as we agreed) I am now impressed by your precise nature also. So I want to ask you also for help: Do you have any ideas as to how a Non deterministic, Non random "agent" could be logically implemented in a simulations?

I don't know to what extent you are aware of my strange views. MF and I have had several long exchages and some understanding of them although he has never commented directly on my ideas about perception, our essential nature as only information in a real time simulation of the physical world, etc.
You are a "reader" needing context. You can get a quick idea about the context of my request for help above from my response to MF in post 48 of thread "Has determinism ever bothered you?" but if interested in seeing ideas and context more fully, the attachment to first post of thread "what price free will" is where to look (It prints as about four pages if margins not wide.) It is mainly about why the standard view of perception held by cognitive scientists is wrong (three independent proofs given -if not "proofs" at least quite persuasive arguments - I recognize I'm dealing with two very strick guys here ) but concludes with idea that my alternative view of perception may open a crack that genuine free will can slip thru and exists. I never claim GFW is demonstrated, only that it may not be impossible as I believed for at least three decades.)