Freethought & Rationalism Archive

show_no_mercy · 10-28-2004, 04:34 PM

n/m

Blueskyboris · 10-28-2004, 05:58 PM

Tetlepanquetzatzin:

That is just a point of departure and not an interpretation of QM. We expect of an informed and sophisticated interpretation of QM that it lets us understand the measurement process, the lack of simultaneous eigenstates of non-commuting observables, the EPR-correlations, etc.

Are you ever going to explain how the Uncertainty Principle proves randomness as a fundamental characteristic of the universe, or are your going to continue to travel the character-assination path?

I would argue that because you refuse to answer my question, you have no idea what you are talking about.

Tracey Hamilton:

Here would have been a place to mention that alternative, you know.
I certainly don't assume things are fundamentally random either - that is the
best explanation of the facts.

Excellent, since the other examples you bring are just interpretations and you assume the universe is not random in essence, we have nothing else to debate. That said, I do want to ask a question: The Heisenberg Principle is a well-accepted principle of modern physics, right? Why doesnt anyone want to talk about it?

Jesse · 10-28-2004, 06:35 PM

Quote:

Originally Posted by Blueskyboris

Tetlepanquetzatzin:

That is just a point of departure and not an interpretation of QM. We expect of an informed and sophisticated interpretation of QM that it lets us understand the measurement process, the lack of simultaneous eigenstates of non-commuting observables, the EPR-correlations, etc.

Are you ever going to explain how the Uncertainty Principle proves randomness as a fundamental characteristic of the universe, or are your going to continue to travel the character-assination path?

Since Tet. said earlier that "There are interpretations of QM according to which the world is deterministic (e.g. Bohm's and Everett's)", I think it's a safe bet that he does not believe quantum mechanics proves that the universe is non-deterministic. And since when does pointing out problems with someone's arguments qualify as a form of "character assassination"?

Blueskyboris · 10-28-2004, 06:44 PM

Jesse:

And since when does pointing out problems with someone's arguments qualify as a form of "character assassination"?

Can you point to my argument is in this thread? I did not make an argument. I challenged those interested to explain how the Uncertainty Principle proves randomness as a fundamental characteristic of the universe.

Jesse · 10-28-2004, 07:09 PM

Quote:

Originally Posted by Blueskyboris

Jesse:

And since when does pointing out problems with someone's arguments qualify as a form of "character assassination"?

Can you point to my argument is in this thread? I did not make an argument. I challenged those interested to explain how the Uncertainty Principle proves randomness as a fundamental characteristic of the universe.

This looks like an argument, or at least a statement of personal belief:

Quote:

I prefer A., because all laws and their effects to date are predictable. Therefore, I infer from this data that subatomic systems are also, most-likely, predictable.

Interpretation is just that, interpretation. I can argue all night long that God created the universe, but in the end, if i have not convinced enough people by good argument and demonstration, I am only interpreting the universe around me and talking past my audience.

The second paragraph suggests you don't understand how the word "interpretation" is used in the context of quantum mechanics, interpretations aren't just expressions of belief akin to the belief that God created the universe, they are detailed explanations for the observed rules of quantum mechanics. If you don't have any idea about the explanation for the various aspects of QM that Tet. asked about, like why there are no simultaneous eigenstates of position and momentum, then what you have is just a hunch that somehow everything is deterministic, not an actual deterministic "interpretation" of QM as physicists use the term.

In any case, even if someone wrongly assumes you are making an argument when you are really just expressing a hunch, attacking that supposed argument still wouldn't qualify as "character assassination", would it?

nukular · 10-28-2004, 08:53 PM

I think one should interject that the Bohm model, while considered a workable solution in "standard" quantum mechanics, has never been harmonized with the concept of a quantum field as opposed to the Schrodinger and Heisenberg pictures. Some effort has been put forth looking for accomodating quantum fields (e.g. using functional formulations) but with no workable results (at least known to me). In my opinion this is a serious defect of the Bohmian hypothesis and should be taken into account before enlisting it ones argumentation.

On a separate note, I think Jesse is correct that the sematics needs to be flushed out here, especially when dealing with quantum mechanics because "interpretation", "randomness", and "predictability" are used in stricter sense than in everyday language (akin to the bastardization of "momentum", "inertia", and "force").

Perhaps a better question to address is whether predictability is a "fundamental property of the universe" before discussing randomness. The Heisenberg uncertainity principle concerns the predictability for measurement of various properties of quantum objects and states that states that various complimentary quantities can only be measured with certain limits, handicapping any notion of determinism. This handicap is well demonstrated in the tests of Bell's theorem.

Of course being the creatures that we are we attribute deeper ideas to the mathematical relations -- in the case of the uncertainity principle, we can attribute it as approximate property of "physical" waves in Fourier space or as vector products in a Hilbert space. As it stands the Copenhagen interpretation has led a more successful existence as a scientific theory than the Bohmian interpretation (which Bell himself has spent considerable time working to improve) and in the world of science it is the successful theories that rules the roost and it seems to be doing a pretty good job of it too.

Blueskyboris -- Are there any physical reasons why you question the constancy of the light in vacuum? There is little controversy regarding this idea, although there have been those who have recently questioned this idea regarding supernovae spectra but various people (see John Bahcall's page here ) have roundly criticized the priors used to arrive at this conclusion. As it stands there seems to be little evidence for your assertion as far as I know, but feel free to enlighten me with any new experimental results which might cause us to question the constancy of light.

Answerer · 10-29-2004, 09:13 AM

Guys, I will advise you all to reduce the amount of time on blue as he hadn't provided any single convincing evidences or arguments to support his beliefs while kept on accusing and demanding answers from others who tend to disagree with him. Furthermore, so far his statements here (and in another thread at e & c) like to go something like that:

I don't like that theory, therefore it must be wrong or correct for now

This is not the first time we meet someone like that, its time (I believe) for us to develop some kind of "immune system".

Blueskyboris · 10-29-2004, 12:36 PM

Jesse:

There are interpretations of QM according to which the world is deterministic (e.g. Bohm's and Everett's) or where the QM formalism is interpreted epistemologically, rather than ontologically, so that the question is left undecided or meaningless (e.g. the Copenhagen interpretation and the new informational interpretation).

That is just a point of departure and not an interpretation of QM.

The compound concept "point of departure" is exactly the same as the concept "interpretation". Since the phenomena studied by QM is still unexplained, interpretation, or the theoretical points of depature like "determinism" and "non-determinism" become important. When the phenomena is finally considered "explained", interpretation becomes a nullgame, because there is only one interpretation: the correct one, which has been discovered and proved. Moreover, interpretation in QM is exactly the same concept employed in chemistry, political science, fairy dance techiques, etcetera, etcetera. A definition of the word is as follows: To give or provide meaning of X. There are only two types of meaning: Objective and Subjective.

The second paragraph suggests you don't understand how the word "interpretation" is used in the context of quantum mechanics, interpretations aren't just expressions of belief akin to the belief that God created the universe, they are detailed explanations for the observed rules of quantum mechanics. If you don't have any idea about the explanation for the various aspects of QM that Tet. asked about, like why there are no simultaneous eigenstates of position and momentum, then what you have is just a hunch that somehow everything is deterministic, not an actual deterministic "interpretation" of QM as physicists use the term.

And this paragraph suggests that you do not want to discuss the Uncertainty Principle directly.

Guys, I will advise you all to reduce the amount of time on blue as he hadn't provided any single convincing evidences or arguments to support his beliefs while kept on accusing and demanding answers from others who tend to disagree with him. Furthermore, so far his statements here (and in another thread at e & c) like to go something like that:

Guys, I would advise you not to heed these unwise words. Each individual posting arguments on these boards has a rational faculty called "the mind." Therefore, if what I am saying is in fact gibberish, you will pick up on it quite easily. Please confront what is at issue directly, the Uncertainty Principle.

:down:

Tracy P. Hamilton · 10-29-2004, 01:04 PM

Quote:

Originally Posted by Blueskyboris

Tracy Hamilton:

Here would have been a place to mention that alternative, you know.
I certainly don't assume things are fundamentally random either - that is the
best explanation of the facts.

Excellent, since the other examples you bring are just interpretations and you assume the universe is not random in essence, we have nothing else to debate.

"Not assuming" is not the same thing as "assuming not". The phrase
"not random in essence" is meaningless. Please don't put words in my
mouth, when you can't even put them into your own in a sensible manner.

I do not assume randomness, I conclude it is the best explanation.
You offer no counterargument. I also realize that statistical
behavior gives well defined expectation values.

Quote:

Originally Posted by Blueskyboris

That said, I do want to ask a question: The Heisenberg Principle is a well-accepted principle of modern physics, right? Why doesnt anyone want to talk about it?

I tried to, but you wouldn't discuss what the meaning of delta x was.
If delta x is an *inherent* distribution about an average, then
such a thing IS randomness by any definition.

The Heisenberg Uncertainty Principle is derived from the mathematics of
operators in QM. I find it quite unlikely that the mathematical machinery
of QM would works so well, yet a mathematical consequence (that
does not rely on recourse to measurement theory) should depend on
OUR limitations on knowing things that should deep down be knowable.

[Do you understand the words that are coming out of my mouth?]

Now if they are deep down unknowable, then there is a reason for our
limitation on knowing things - it is a QM property that only so much can
be known about physical systems.

Another great example is the x,y and z components of angular momentum,
and the Stern-Gerlach experiment.

Jesse · 10-29-2004, 01:19 PM

Quote:

Originally Posted by Blueskyboris

Jesse:

There are interpretations of QM according to which the world is deterministic (e.g. Bohm's and Everett's) or where the QM formalism is interpreted epistemologically, rather than ontologically, so that the question is left undecided or meaningless (e.g. the Copenhagen interpretation and the new informational interpretation).

That is just a point of departure and not an interpretation of QM.

The compound concept "point of departure" is exactly the same as the concept "interpretation". Since the phenomena studied by QM is still unexplained, interpretation, or the theoretical points of depature like "determinism" and "non-determinism" become important. When the phenomena is finally considered "explained", interpretation becomes a nullgame, because there is only one interpretation: the correct one, which has been discovered and proved. Moreover, interpretation in QM is exactly the same concept employed in chemistry, political science, fairy dance techiques, etcetera, etcetera. A definition of the word is as follows: To give or provide meaning of X. There are only two types of meaning: Objective and Subjective.

First of all, the words you quote were written by Tet., not me. But I agree with what he says, and you are wrong that the word "interpretation" has the same meaning in quantum physics that it does in ordinary english. Scientists often take ordinary english words and assign them more narrow technical meanings, like how writing a letter to my congressman would be "taking action" in ordinary english while the meaning of action in physics is an integral of the Lagrangian L over a certain path x(t), as explained here. Similarly, when physicists talk about "interpretations" of quantum mechanics they don't just mean hunches about whether it is non-deterministic or deterministic, they mean a detailed proposal about how we can interpret the mathematical formalism of quantum mechanics in terms of some physical model. More on what an interpretation of QM needs to do is given in this discussion of the Copenhagen Interpretation:

Quote:

Two distinct functions are performed by the CI (or for that matter, by any physical interpretation of a mathematical formalism). First, as many authors have emphasized, the interpretation must provide a connection between the mathematics of the formalism and the physical world. This connection makes it possible to test the formalism by confronting its predictions with experimental results. Without some interpretation of the symbols of the formalism in terms which can be related to experimental observables the formalism remains abstract mathematics without a physical context. It is perhaps in this sense that Bohr maintained (Popper, 1967) that the Copenhagen interpretation had been "proven by experiment".

However, there is another function of the interpretation which is sometimes overlooked. This function relates to the question of how the theory deals with unobserved objects (Reichenbach, 1944). While participating in a colloquium at Cambridge, von Weizsäcker (1971) denied that the CI asserted: "What cannot be observed does not exist". He suggested instead that the CI follows the principle: "What is observed certainly exists; about what is not observed we are still free to make suitable assumptions. We use that freedom to avoid paradoxes." This principle does not, of course, uniquely define the CI, but it does give an important criterion for developing a consistent interpretation of a formalism. The interpretation must not only relate the formalism to physical observables. It must also define the domain of applicability of the formalism and must interpret the non-observables in such a way as to avoid paradoxes and contradictions.

It may seem surprising that the interpretation of a physical theory can perform the function of avoiding "paradoxes", i.e., internal contradictions and conflicts with other established theories. It is therefore useful to consider some examples. Newton's second law, F=ma, is of no physical significance until the symbol F is identified as a vector representing force, a as a vector representing acceleration, and m as a scalar representing mass. Further, while F and a can have any (real) magnitude and direction, the formalism is interpreted as meaningful only when m>0. This is because zero and negative masses lead to unphysical (or paradoxical) results, e.g., infinite acceleration or acceleration in a direction opposite that of the force vector.

Or consider the Lorentz transformations of special relativity for the case v>c. Until fairly recently physicists had always applied to this case Interpretation A: "The transformations with v>c produce unphysical imaginary values for the transformed variables and are therefore meaningless." But recently an alternative has been suggested by Feinberg (1967, 1978) as Interpretation B: "The transformations in the v>c domain describe a new kind of particle called the tachyon which has the characteristic of imaginary mass, which always travels at velocity v>c, and which approaches the v=c limit asymptotically from above when it is given additional kinetic energy."

While the tachyons of Interpretation B are by no means an established physical phenomenon, this example illustrates how a change in interpretation can alter the meaning of a formalism, can extend the range of its application, and can deal with "paradoxical" or unphysical results", e.g., v>c and imaginary mass. A study of the debate over interpretation in the early history of quantum mechanics (Jammer, 1966) will show a similar process at work in early attempts to interpret the QM formalism. It is this process which produced the Copenhagen interpretation.

Some interpretations of quantum mechanics are The Copenhagen Interpretation, The Transactional Interpretation, The Many-Worlds Interpretation, and Bohm's Causal Interpretation.

Quote:

The second paragraph suggests you don't understand how the word "interpretation" is used in the context of quantum mechanics, interpretations aren't just expressions of belief akin to the belief that God created the universe, they are detailed explanations for the observed rules of quantum mechanics. If you don't have any idea about the explanation for the various aspects of QM that Tet. asked about, like why there are no simultaneous eigenstates of position and momentum, then what you have is just a hunch that somehow everything is deterministic, not an actual deterministic "interpretation" of QM as physicists use the term.

And this paragraph suggests that you do not want to discuss the Uncertainty Principle directly.

I'd be happy to discuss the uncertainty principle, although it seems like a non sequitor for you to accuse me of "not wanting to discuss" something that wasn't even mentioned in the quote I was responding to. What do you want to ask me about it? I have already made clear that I do not claim the uncertainty principle proves that the universe is non-deterministic, if that's what you're asking about.

10-29-2004, 12:36 PM	#28
Blueskyboris Banned Join Date: Oct 2004 Location: Inside a Cheeseburger Posts: 5,374	Interpretation and Point of Departure Jesse: There are interpretations of QM according to which the world is deterministic (e.g. Bohm's and Everett's) or where the QM formalism is interpreted epistemologically, rather than ontologically, so that the question is left undecided or meaningless (e.g. the Copenhagen interpretation and the new informational interpretation). That is just a point of departure and not an interpretation of QM. The compound concept "point of departure" is exactly the same as the concept "interpretation". Since the phenomena studied by QM is still unexplained, interpretation, or the theoretical points of depature like "determinism" and "non-determinism" become important. When the phenomena is finally considered "explained", interpretation becomes a nullgame, because there is only one interpretation: the correct one, which has been discovered and proved. Moreover, interpretation in QM is exactly the same concept employed in chemistry, political science, fairy dance techiques, etcetera, etcetera. A definition of the word is as follows: To give or provide meaning of X. There are only two types of meaning: Objective and Subjective. The second paragraph suggests you don't understand how the word "interpretation" is used in the context of quantum mechanics, interpretations aren't just expressions of belief akin to the belief that God created the universe, they are detailed explanations for the observed rules of quantum mechanics. If you don't have any idea about the explanation for the various aspects of QM that Tet. asked about, like why there are no simultaneous eigenstates of position and momentum, then what you have is just a hunch that somehow everything is deterministic, not an actual deterministic "interpretation" of QM as physicists use the term. And this paragraph suggests that you do not want to discuss the Uncertainty Principle directly. Guys, I will advise you all to reduce the amount of time on blue as he hadn't provided any single convincing evidences or arguments to support his beliefs while kept on accusing and demanding answers from others who tend to disagree with him. Furthermore, so far his statements here (and in another thread at e & c) like to go something like that: Guys, I would advise you not to heed these unwise words. Each individual posting arguments on these boards has a rational faculty called "the mind." Therefore, if what I am saying is in fact gibberish, you will pick up on it quite easily. Please confront what is at issue directly, the Uncertainty Principle. :down:

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10-28-2004, 04:34 PM	#21
show_no_mercy Veteran Member Join Date: Jul 2004 Location: Dancing Posts: 9,940	n/m

10-28-2004, 05:58 PM	#22
Blueskyboris Banned Join Date: Oct 2004 Location: Inside a Cheeseburger Posts: 5,374	Tetlepanquetzatzin: That is just a point of departure and not an interpretation of QM. We expect of an informed and sophisticated interpretation of QM that it lets us understand the measurement process, the lack of simultaneous eigenstates of non-commuting observables, the EPR-correlations, etc. Are you ever going to explain how the Uncertainty Principle proves randomness as a fundamental characteristic of the universe, or are your going to continue to travel the character-assination path? I would argue that because you refuse to answer my question, you have no idea what you are talking about. Tracey Hamilton: Here would have been a place to mention that alternative, you know. I certainly don't assume things are fundamentally random either - that is the best explanation of the facts. Excellent, since the other examples you bring are just interpretations and you assume the universe is not random in essence, we have nothing else to debate. That said, I do want to ask a question: The Heisenberg Principle is a well-accepted principle of modern physics, right? Why doesnt anyone want to talk about it?

10-28-2004, 06:44 PM	#24
Blueskyboris Banned Join Date: Oct 2004 Location: Inside a Cheeseburger Posts: 5,374	Jesse: And since when does pointing out problems with someone's arguments qualify as a form of "character assassination"? Can you point to my argument is in this thread? I did not make an argument. I challenged those interested to explain how the Uncertainty Principle proves randomness as a fundamental characteristic of the universe.

10-28-2004, 08:53 PM	#26
nukular Junior Member Join Date: Dec 2003 Location: USA Posts: 42	I think one should interject that the Bohm model, while considered a workable solution in "standard" quantum mechanics, has never been harmonized with the concept of a quantum field as opposed to the Schrodinger and Heisenberg pictures. Some effort has been put forth looking for accomodating quantum fields (e.g. using functional formulations) but with no workable results (at least known to me). In my opinion this is a serious defect of the Bohmian hypothesis and should be taken into account before enlisting it ones argumentation. On a separate note, I think Jesse is correct that the sematics needs to be flushed out here, especially when dealing with quantum mechanics because "interpretation", "randomness", and "predictability" are used in stricter sense than in everyday language (akin to the bastardization of "momentum", "inertia", and "force"). Perhaps a better question to address is whether predictability is a "fundamental property of the universe" before discussing randomness. The Heisenberg uncertainity principle concerns the predictability for measurement of various properties of quantum objects and states that states that various complimentary quantities can only be measured with certain limits, handicapping any notion of determinism. This handicap is well demonstrated in the tests of Bell's theorem. Of course being the creatures that we are we attribute deeper ideas to the mathematical relations -- in the case of the uncertainity principle, we can attribute it as approximate property of "physical" waves in Fourier space or as vector products in a Hilbert space. As it stands the Copenhagen interpretation has led a more successful existence as a scientific theory than the Bohmian interpretation (which Bell himself has spent considerable time working to improve) and in the world of science it is the successful theories that rules the roost and it seems to be doing a pretty good job of it too. Blueskyboris -- Are there any physical reasons why you question the constancy of the light in vacuum? There is little controversy regarding this idea, although there have been those who have recently questioned this idea regarding supernovae spectra but various people (see John Bahcall's page here ) have roundly criticized the priors used to arrive at this conclusion. As it stands there seems to be little evidence for your assertion as far as I know, but feel free to enlighten me with any new experimental results which might cause us to question the constancy of light.

10-29-2004, 09:13 AM	#27
Answerer Veteran Member Join Date: Feb 2002 Location: Singapore Posts: 3,956	Guys, I will advise you all to reduce the amount of time on blue as he hadn't provided any single convincing evidences or arguments to support his beliefs while kept on accusing and demanding answers from others who tend to disagree with him. Furthermore, so far his statements here (and in another thread at e & c) like to go something like that: I don't like that theory, therefore it must be wrong or correct for now This is not the first time we meet someone like that, its time (I believe) for us to develop some kind of "immune system".

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