Heisenberg uncertainty principle

[stephen_speicher]

I'd love to read an Objectivist resource.

I have defended what is right about about modern physics in many posts on forums like this one and others, as well as condemned what is wrong. If you want to get a layman's understanding of a proper approach to quantum mechanics, you can read my three-part article here. (The article is in need of updating and re-writing, but should still be of benefit.)

[stephen_speicher]

This is an assertion, not an argument. Why can it not be in the nature of matter to act in a non-deterministic manner?

You mean, why cannot existence be different from what it is?

[Dominique]

If you want to get a layman's understanding of a proper approach to quantum mechanics, you can read my three-part article here. (The article is in need of updating and re-writing, but should still be of benefit.)

Thank you! It is much appreciated.

[stephen_speicher]

A friend of mine recommended it (the book), so I began reading it to discuss with him. I had my doubts from the beginning but thought it was due to my inexperience with the subject matter and I should try at least to see where he was coming from. I suspected just exactly what you are saying (perhaps I should trust those little warnings more, but I still want the knowledge to discuss it properly). I mentioned I have since put Deutsch's book down and gone back to Ayn Rand, as he lost me when he started getting too far out. I do want to understand these things though, and if you have any specific reccomendations I would appreciate it, otherwise I will just take your advice and stick to philosophy for now.

I made such a suggestion in this post, which I guess you did not get to read before now.

[Hal]

You mean, why cannot existence be different from what it is?

No, I mean what basis do you have for asserting that this is not how existence is?

[stephen_speicher]

No, I mean what basis do you have for asserting that this is not how existence is?

You do not appear to realize that the indeterminism of your "metaphysical randomness" is a violation of both identity and causality. To exist is to be something specific, and an entity's identity is the sum total of all of its attributes and characteristics. When we say that an entity acts in accord with its nature, we mean that the entity's attributes and characteristics determine, in any given set of physical circumstances, what an entity can do. The action possible to an entity is caused and necessitated by what the entity is.

For an entity to act against its nature would be a contradiction of its identity; it would be saying that, in spite of the specific attributes and characteristics possessed by the entity, it would act otherwise. According to your notion of metaphysical randomness, an entity could act in two contrary ways under the exact same physical circumstances, and that would imply the existence of two contrary attributes being part of the entity's nature, and that would be a contradiction.

Identity is the totality of attributes and characteristics possessed by an entity, and such attributes and characteristics cannot be contradictory. If an entity were able to move left in some particular physical circumstances, and yet able to move right in the same physical circumstances, such contradictory actions would be derived from contradictory aspects of the entity's nature. But contradictions do not exist, A is A, and the only action possible to an entity, in any given physical circumstances, is that single action which is caused and necessitated by its nature. Choice is that single action possible to a volitional consciousness, and it is that attribute which permits freely selecting from among alternatives. And, unlike the notion of "metaphysical randomness," causality is operative throughout.

[danielshrugged]

If by "randomness" in this context you mean that the exact same non-volitional entity may act differently under the exact same physical circumstances, then that is a violation of the law of causality, and causality is a fundamental axiom of Objectivism.

The following is to be taken as my tentative thoughts on this subject:

This is a view expressed by many Objectivists, but I disagree with it--or, at the least, it is not the full truth (the full truth being that it is only after gaining some scientific knowledge that we can recognize metaphysical randomness as a violation of causality). The law of causality is a very general law: it applies the law of identity to action. Everything acts in accordance with its nature; it cannot act in contradiction to its nature. This law by itself does not refute a scientist who argues that something in the nature of an entity allows it the ability to move either left or right in the same physical circumstances, to go with your example. It might indeed be true that the entity would in fact require contradictory attributes for this to occur--but in that case this would have to be argued on scientific grounds. I think the best response to a scientist who argues for metaphysical randomness is to show him how he has misinterpreted the data and to invoke the principle of the burden of proof.

[stephen_speicher]

Everything acts in accordance with its nature; it cannot act in contradiction to its nature. This law by itself does not refute a scientist who argues that something in the nature of an entity allows it the ability to move either left or right in the same physical circumstances, to go with your example.

But we already know the nature of an entity that acts way -- a volitional consciousness. We do not need a scientist to tell us that, and volition is the general principle which accounts for that sort of behavior.

It might indeed be true that the entity would in fact require contradictory attributes for this to occur--but in that case this would have to be argued on scientific grounds.

Why? I made that argument in a philosophical context, in this post.

[EC]

Yes, the double-slit experiment is fundamental to quantum mechanics. But, regarding your assertion of  "the wave nature of all matter" you need to learn to make the distinction between experimental fact, and the inferences drawn from fact based on ones premises.

 

Which notion is exactly the problem. Instead, quantum mechanics needs to be induced from experiment.

You need to get  your theoretical and historical facts straight. You are confusing the Copenhagen interpretation with other theories for whom consciousness has a special significance. Here is a direct quote from Werner Heisenberg, one of the main founders of the Copenhagen interpretation.

"Therefore, the transition from the 'possible' to the 'actual' takes place during the act of observation. If we want to describe what happens in an atomic event, we have to realize that the word 'happens' can apply only to the observation, not to the state of affairs between two observations.  It applies to the physical, not the psychical act of observation, and we may say that the transition from the 'possible' to the 'actual' takes place as soon as the interaction of the object with the measuring device, and thereby with the rest of the world, has come into play; it is not connected with the act of registration of the result by the mind of the observer." 

--Werner Heisenberg, _Physics and Philosophy_, Prometheus Books, 1999.

Are you making the claim that the Copenhagen interpretation, or many of the standard theories, do not obliterate causality? If so, you are grossly mistaken.

The many-worlds interpretation is "determinsitic" only in the sense that it a obeys a deterministic wave equation. But mathematics does not a theory make, and the physical content of many-worlds is  fundamentally absurd. To believe that branches of the universal wavefunction actually exist is to believe in a fairy-tale world of science fiction. I mean, really, it is hard to keep a straight face and talk about worlds splitting in a quantum superposition decoherence.

Smart move. 

I am absolutely *not* making the assertion that the Copenhagen interpretation or other like theories do not obliterate causality.

The whole point of my post was that Objectivists have hostility to parts of modern physics precisely because they only hear incorrect interpretations such as these.

And by the way Mr. Expert how do "you" do calculations using a *wave*function and then deny that the *wave* exists? Do you "believe" it to be just a trick of mathematics? Is this not a contradiction? Sorry I so don't interpret data I take it at face value. That is why I "know" that the Many Worlds interpretation is valid and not "absurd".

You should check "your" premises, and while your at it quit criticizing others posts.

[punk]

I apologise if this gets too technical. I've given some thought to this philosophically and....

Isn't the issue here one of how momentum and position are defined in quantum mechanics? They are not defined the way they are in classical mechanics, but people keep trying to apply classical mechanical views to them in quantum.

Using q(*) and p(*) to be "position" and "momentum" functions:

In classical mechanics these are number-valued functions (that is for values of the variable(s) put into * they give values like 1.0, 2.5, etc. Also the relation:

q(*)p(*) - p(*)q(*) = 0 (i.e. q(*)p(*) = p(*)q(*) )

holds.

Now in quantum mechanics in the canonical formulation we do not want these to be number-valued functions, we want these to be operator-valued functions. Now an operator is something that maps a function into a different function, so for functions f(*) and g(*) and operator O we get:

g(*) = O(f(*))

So since q(*) and p(*) are operator-valued functions they do not have any single clear value, they have a set of values. To get this we assume (suppressing planck's constant):

q(*)p(*) - p(*)q(*) = i (i.e. q(*)p(*) does not equal p(*)q(*) )

(we are only dealing with boson quantum mechanics). Now this relation above is assumed at the outset to force q(*) and p(*) to be operators. Now the Uncertainty Principle is implied by this relation.

So the real issue is why we make q(*) and p(*) be operators. Once we make this assumption the Uncertainty Principle is required.

The consequence of making them operators is that there is no such thing as a single meaningful value of position or momentum, but rather a set of values. Moreover the physics is dependent upon all of this set of values and cannot be viewed as depending on any one of the values.

Anyway our intuitions from classical mechanics is that the physics is dependent upon a single value and that is not true in quantum mechanics at its very foundation.

[stephen_speicher]

I am absolutely *not* making the assertion that the Copenhagen interpretation or other like theories do not obliterate causality.

Okay, but I am a little perplexed by what you now claim as compared to what you wrote. I asked that question in response to this which you wrote:

"Or, for some time t, much, much quicker than the blink of an eye, a proton and anti-proton pop into existence, ex nihilo, cross paths and dissapear again. See why certain Objectivists are "hostile" to the theory? It 'seems' like is's not "deterministic". Like cause and effect is in some sense obliterated."

When you say "It 'seems like it is not ..." gave me the impression that you thought the theory just appears to be not determinsitic, but it actually is. This seems to be further supported by your claim, multiple times, that these theories are misunderstood by Objectivists because of bad interpretations.

The whole point of my post was that Objectivists have hostility to parts of modern physics precisely because they only hear incorrect interpretations such as these.

If that is truly the case then, I must say, you yourself have been guilty of just that, as I demonstrated in your misinterpretation of the Copenhagen intepretation.

And by the way Mr. Expert how do "you" do calculations using a *wave*function and then deny that the *wave* exists?

Leaving aside your somewhat disrespectful attitude, you really need to learn to read with greater care and precision, what others write. I challenged your "wave nature of all matter" as being just an inference from experiment, not a scientific fact as you made it appear. I never denied that any wave exists, as you now claim. It is easy enough to intepret the mathematical form of the Schroedinger equation as representing a set of waves that physically exist independent of any matter particles. As I said, your "wave nature of matter" is an inference (a very bad one), not an experimental fact.

Do you "believe" it to be just a trick of mathematics?  Is this not a contradiction?

No, to both. It just requires some understanding, understanding beyond the absurdities inherent in the theories you described.

Sorry I so don't interpret data I take it at face value.

Well, then, you must be unique. The rest of us in physics actually judge and evaluate data according to some set of ideas that we hold. Some ideas being better than others, means that some interpretations of experimental fact are better than others.

That is why I "know" that the Many Worlds interpretation is valid and not "absurd".

You are free to believe whatever you like and ignore the philosophical and scientific contradictions that the theory is based upon. But, in that case, it is a good thing that you put the scare quotes around "know." (By the way, what is it with you and these scare quotes you use all over the place? You use them so often, and so out of context, that they lose their meaning.)

You should check "your" premises, and while your at it quit criticizing others posts.

Well, thanks for the advice, but since I take my physics and philosophy seriously, I reserve the right on this public forum to reasonably criticize errors when I see them. You are free to do so too, but note that in doing so you need to back your criticism up with fact, not vague assertions and misrepresentations.

[stephen_speicher]

Anyway our intuitions from classical mechanics is that the physics is dependent upon a single value and that is not true in quantum mechanics at its very foundation.

That depends upon how you build your foundation. It is easy enough to use a single particle as the basis for the theory, along with position and momentum operators. So, for instance, we can take particle and momentum operators, X_m and P_n respectively, to describe the position and momentum vectors of a particle in some space. The canonical commutation relations are then expressed as

[ X_m, X_n] = 0 = [P_m, P_n],

[X_m, P_n] = i h <delta>_mn.

Define a simple particle as that which has observables x_m and p_n which satisfy the commutation relations, but there do not exist observables compatible with all x_m and p_n. These are equivalent to the operators acting on the wave function <psi>.

This is a rather simple formulation, but if you study the history of the development of quantum mechanics -- a fascinating subject -- you can see the ebb and tide between conflicting interpretations, on a foundational level, repeat itself from generation to generation. An excellent place to start with this, for the technically minded, is Max Jammer's The Conceptual Development of Quantum Mechanics, McGraw-Hill Book Company, 1966.

[danielshrugged]

But we already know the nature of an entity that acts way -- a volitional consciousness. We do not need a scientist to tell us that, and volition is the general principle which accounts for that sort of behavior.

How does this tell us that there is not some other principle to account for this sort of behavior in some non-volitional entity?

Why? I made that argument in a philosophical context, in this post.

You argued:

Identity is the totality of attributes and characteristics possessed by an entity, and such attributes and characteristics cannot be contradictory. If an entity were able to move left in some particular physical circumstances, and yet able to move right in the same physical circumstances, such contradictory actions would be derived from contradictory aspects of the entity's nature

I see no argument that the two actions--moving left and moving right--are contradictory. They are certainly not contradictory in the case of volitional entities.

[Bowzer]

I see no argument that the two actions--moving left and moving right--are contradictory. They are certainly not contradictory in the case of volitional entities.

The argument would be that this represents a violation of the law of causality! The same entity under the same circumstances must act the same way. If it is absolutely random which direction the particle will swerve, then there is no necessity, no identity determining what will happen.

See "Causality as a Corollary of Identity" in OPAR, Chapter 1.

One cannot use the fact of volition to argue for non-deterministic behavior in nature. This is to steal the concept of "alternative" (which is only applicable to volitional actions).

[stephen_speicher]

How does this tell us that there is not some other principle to account for this sort of behavior in some non-volitional entity?

That would be a completely arbitrary assertion. The current argument is that there are two fundamental and mutually exclusive modes of actions possible to all entities that exist in the universe; they either act deterministically, or by choice.

Now, there is one sense in which I would actually agree with the spirit of your concern, if not the letter, and that is in regard to the ultimate constituents of reality. (Note that here I am at odds with some other Objectivists, noteably Harry Binswanger.) The "mutually exclusive modes of action" argument pertains to entities that we perceive in the three-dimensional world of our senses, and in my view we have to allow that the ultimate constituents, which may themselves give rise to these three-dimensional effects, might be as radically different in nature as volition is to deterministic entities. Until we identify the nature of the ultimate constituents we cannot say anything about their mode of action, other than that they act in accord with their nature.

I see no argument that the two actions--moving left and moving right--are contradictory. They are certainly not contradictory in the case of volitional entities.

I think you need to go back to that post and read my argument more carefully.

[danielshrugged]

That would be a completely arbitrary assertion.

Which is precisely what I said earlier:

I think the best response to a scientist who argues for metaphysical randomness is to show him how he has misinterpreted the data and to invoke the principle of the burden of proof.

The current argument is that there are two fundamental and mutually exclusive modes of actions possible to all entities that exist in the universe; they either act deterministically, or by choice

The only way in which I hold out agreeing with you is in my doubt over how much one has to know about the world before one can induce this alternative.

[Hal]

You do not appear to realize that the indeterminism of your "metaphysical randomness" is a violation of both identity and causality. To exist is to be something specific, and an entity's identity is the sum total of all of its attributes and characteristics. When we say that an entity acts in accord with its nature, we mean that the entity's attributes and characteristics determine, in any given set of  physical circumstances, what an entity can do. The action possible to an entity is caused and necessitated by what the entity is.

The attributes and characteristics of a particular human do not determine what it does in any given set of circumstances; if they did, volition not exist. A human can act in multiple ways under the same set of physical circumstances - I could continue writing this post, or I could stop and go to the toilet. This does not constitute a violation of identity, since it is the nature of a human to make choices. By the exact same logic, one could suppose that it is the nature of a particle to act in a random fashion, hence again leading to different actions under the same set of circumstances. We know there are some mechanisms in nature which lead to indeterminism (namely volition), so there are no grounds on which to declare in advance that others are fundamentally impossible, due to identity.

Are you arguing that there is no evidence of metaphysical randomness and hence that it is a purely arbitrary assertion, or are you saying that metaphysical randomness is impossible as a result of identity, hence no evidence could possible exist? The 2 positions are very different.

[stephen_speicher]

We know there are some mechanisms in nature which lead to indeterminism (namely volition)

False. Indeterminism is acausal, which does not describe volitional action.

(I have snipped the rest since it is just repetitive misunderstanding.)

[stephen_speicher]

The only way in which I hold out agreeing with you is in my doubt over how much one has to know about the world before one can induce this alternative.

Your statement assumes that we induce this from large-scale observation of action, rather than recognizing what matter is, i.e., non-volitional. Note that this is why I exclude the ultimate constituents from this determination.

[Hal]

False. Indeterminism is acausal

Not necessarily. Indeterminism just implies that future states are not fully determined by present ones. Do you believe that the future states of a human are fully goverened by their state at any particular time (ie that full and complete knowledge of everything about a human, from their complete belief structure, to precise physical information about every atom composing their body) is sufficient to allow one to predict with 100% accuracy every future choice they will make? If not, you're an indeterminist.

[stephen_speicher]

Not necessarily.

Yes, necessarily, since that is the historical root and proper philosophical meaning of the term. Indeterminism is acausal and implies randomness, which fact highlights the essence of the entire discussion, attempts to obliterate the proper philosophical distinctions notwithstanding. The historical roots of indeterminism lie in Ancient Greece where Epicurus first introduced random 'swerves' to Democritus' atoms in an attempt to explain why there were atomic collisions. Then, in an apparent response to the Stoic view of determinism in man, Epicurus' indeterminism meant a choice between possibilities for man which paralleled the actions of atoms -- it was causeless. Indeterminism is acausal, and that certainly implies randomness

Here are a few words from a most authoritative classic source.

"Epicurus went still further. He found the Stoic determinism so irreconcilable with the wise man's self-determination which formed the essential feature of his ethical ideal, that he would rather still assume the illusory ideas of religion than believe in such a slavery of the soul. Therefore he, too, denied the universal validity of the causal law and subsumed freedom together with chance under the conception of uncaused occurrence. Thus, in opposition to Stoic determinism, the metaphysical conception of freedom arose, by means of which Epicurus put the uncaused function of the will in man upon a parallel with the causeless deviation of the atoms from their line of fall. The freedom of indeterminism means, accordingly, a choice between different possibilities that is determined by no causes ..."

--Wilhelm Windelband, "A History of Philosophy," p. 194, _The Paper Tiger, Inc._, 2001.

[Hal]

Yes, necessarily, since that is the historical root and proper philosophical meaning of the term. Indeterminism is acausal and implies randomness, which fact highlights the essence of the entire discussion, attempts to obliterate the proper philosophical distinctions notwithstanding.  The historical roots of indeterminism lie in Ancient Greece where Epicurus first introduced random 'swerves' to Democritus' atoms in an attempt to explain why there were atomic collisions. Then, in an apparent response to the Stoic view of determinism in man, Epicurus' indeterminism meant a choice between possibilities for man which paralleled the actions of atoms -- it was causeless. Indeterminism is acausal, and that certainly implies randomness

I dislike arguing over the origins of terms, since meanings tend to change over time. However, the swerves of Epicurus represent his belief that the indeterminacy of mental events requires the indeterminacy of physical events. Traditionally, the causation of mental processes has been seperated from the causation of physical processes. As far as I know, Objectivism adheres to this distinction - all physical events are both caused and determined, whereas mental processes are caused and non-determined (feel free to correct me). Your claim that physical indeterminism implies randomness is question begging and seems to miss the point that most (libertarian) incompatibalists are getting at - they would hold that physical indeterminism is not random; it is caused by mental processes (which are themselves uncaused and non-determined). This is fundamental to the classic argument for free-will.

Do you hold that mental events (ie choices) are determined?

[stephen_speicher]

I dislike arguing over the origins of terms, since meanings tend to change over time. However, the swerves of Epicurus represent his belief that the indeterminacy of mental events requires the indeterminacy of physical events. Traditionally, the causation of mental processes has been seperated from the causation of physical processes. As far as I know, Objectivism adheres to this distinction - all physical events are both caused and determined, whereas mental processes are caused and non-determined (feel free to correct me). Your claim that physical indeterminism implies randomness is question begging and seems to miss the point that most (libertarian) incompatibalists are getting at - they would hold that physical indeterminism is not random; it is caused by mental processes (which are themselves uncaused and non-determined). This is fundamental to the classic argument for free-will.

Your protestations notwithstanding, if you study the history of ideas it is clear that indeterminism as acausal is both historically and technically correct, from earliest use to the fundamentals that underlie today's adherents. Your same confusion extends to your grasp of the libertarian incompatibilist position. The soft determinism of the compatibilists is not properly offset by the standard libertarian's view of free will and determinism. (Note for clarity of reading: By the "libertarian" here we do not mean the political "libertarian" we know today, but rather an historical view towards free will.)

The libertarian "classic argument for free-will" is most certainly not the perspective of Objectivism. One will search in vain through the traditional classic literature for the Objectivist arguments and perspective, and instead will find a mishmash of commonsensical and pseudo-philosophical half-truths. As Raphael notes (Causation and Free Will, D. Daiches Raphael, The Philosophical Quarterly, Vol. 2, No. 6, pp. 13-20, Jan. 1952):

"... libertarianism means that acts, or some acts, are uncaused, and that the view denies the universality of the causal axiom: 'Every change has a cause'."

One will not find the Objectivist view of free will anywhere in P.H. Nowell Smith's classic tome Determinists and Libertarians, Mind, New Series, Vol. 62, No. 251, pp. 317-337, July 1954. What one will find in the literature, however, are notions of the sort advanced by thinkers such as C. A. Campbell, of whom Edward Walter (Is Libertarianism Logically Coherent?, Philosophy and Phenomenological Research, Vol. 38, No. 4, pp. 505-513, June 1978) notes that he "has made what is considered to be the most powerful defense of libertarianism."

And this "powerful defense" of free will consists of elements such as "Campbell alleges that the self is the cause of behavior -- that self through creative energy overcomes the pulls of the formed character." This "formed character" is a pattern of behavior that a person tends towards as a result of experience or genetic factors, and "certain actions are more or less probable." The self can then intervene and perhaps override what would otherwise be destined to occur.

Indeterminism is not the answer to determinism, whether in the realm of consciousness or smuggled into the physical realm. Indeterminism is acausal, and it implies randomness.

[Marc K.]

Stephen,

While I consider myself scientifically adept, I must admit that I am not well read on the HUP. I was trying to follow your argument on a philosophical level and I completely agree with this statement:

The current argument is that there are two fundamental and mutually exclusive modes of actions possible to all entities that exist in the universe; they either act deterministically, or by choice.

but you lost me here:

Until we identify the nature of the ultimate constituents we cannot say anything about their mode of action, other than that they act in accord with their nature.

Are you saying that you hold open the possibility that inanimate matter could act volitionally?

Isn't it true that as long as current theory (the first quote above) doesn't contradict the fundamental axioms that no matter what we discover about the nature of the ultimate constituents their actions will not contradict that theory either?

Your assertion that the ultimate constituents could act indeterministically seems arbitrary to me. And since everything I've ever read from you negates this possibility it must be my interpretation that is faulty. Help.

Marc

[stephen_speicher]

Stephen, ...

Marc brings up an interesting question, deserving of its own thread. The issue is really philosophical, not scientific, so I started a new thread in the "Metaphysics and Epistemology" forum.