Perhaps quantum physics is elegant, but we lack an understanding?

[relativitydude]

Well, unlike other areas of physics where the rules are predictable 100% of the time and every aspect can be known with definite precision, quantum dynamics is not as elegant.

For example, we can know the position of a an electron, but not it's speed or so on, or something like that. Perhaps the quantum world is so hectic and not as elegant because our current equations and laws are not sufficient to let us view them correctly?

The current equations for quantum physics are genius, but could it be that they are no sufficient and that no brilliance could ever unlock an elegant view of quantum mechanics?

 

[ZapperZ]

Well, unlike other areas of physics where the rules are predictable 100% of the time and every aspect can be known with definite precision, quantum dynamics is not as elegant.

For example, we can know the position of a an electron, but not it's speed or so on, or something like that. Perhaps the quantum world is so hectic and not as elegant because our current equations and laws are not sufficient to let us view them correctly?

The current equations for quantum physics are genius, but could it be that they are no sufficient and that no brilliance could ever unlock an elegant view of quantum mechanics?

It isn't QM that is dictating this. A theory cannot dictate what Nature is. The "other areas of physics" only APPEARS to have rules that are "100%" predictable, because they do not deal with the scale and the conditions that QM has to deal with.

BTW, here's something to think about - if QM isn't "predictable", how come your electronics work predictably, or that you would trust your life in, for example, an MRI?

Zz.

 

[Mike2]

Well, unlike other areas of physics where the rules are predictable 100% of the time and every aspect can be known with definite precision, quantum dynamics is not as elegant.

For example, we can know the position of a an electron, but not it's speed or so on, or something like that. Perhaps the quantum world is so hectic and not as elegant because our current equations and laws are not sufficient to let us view them correctly?

The current equations for quantum physics are genius, but could it be that they are no sufficient and that no brilliance could ever unlock an elegant view of quantum mechanics?

I read an article once that complained a lot about how QM was just a device for fitting the known data to some equation, a curve fitting process. It seems that we don't yet have the fundamental principles from which QM is derived.

I have a suspicion that I think should be fully investigated by those more skilled in the art. I suspect that there is a conservation of information law at the heart of QM. In QM each alternative possibility has a probability of that alternative happening. Each alternative should have some entropy or information associated with that particular alternative. Paths that are far from the classical limit would have more entropy, etc. So there is information associated with the structure of each alternative, and there is information associated with the probability of that alternative happening. I suspect that these two sources of information would be equal and form some sort of conservation of information law.

 

[ZapperZ]

I read an article once that complained a lot about how QM was just a device for fitting the known data to some equation, a curve fitting process. It seems that we don't yet have the fundamental principles from which QM is derived.

You could say that with every physics principles. So why pick on QM alone?

Secondly, what exactly is meant by "the fundamental principles"? People throw this around as IF this is something that is obviously known.

Zz.

 

[Mike2]

You could say that with every physics principles. So why pick on QM alone?

Well, let's see. QM gives a classical limit, but we don't know why QM should be necessary other than it fits the data. Also, there is the search for Quantum Gravity, and there is a few approaches being tried: Loop Quantum Gravity, Dynamical Triangulation, String Theory, etc. So it would help if there were a principle that determined which QM approach is correct.

Secondly, what exactly is meant by "the fundamental principles"? People throw this around as IF this is something that is obviously known.

Zz.

Right. What I mean by fundamental is some principle which is undeniable because it comes from reasoning itself. For example: reality is a topology because it seems undeniable that unions and intersections of parts of reality are also parts of reality. Likewise, it seems undeniable that the universe as a whole cannot lose information... where can it go except somewhere that we also include as part of the universe.

 

[seratend]

Well, unlike other areas of physics where the rules are predictable 100% of the time and every aspect can be known with definite precision, quantum dynamics is not as elegant.

For example, we can know the position of a an electron, but not it's speed or so on, or something like that. Perhaps the quantum world is so hectic and not as elegant because our current equations and laws are not sufficient to let us view them correctly?

The current equations for quantum physics are genius, but could it be that they are no sufficient and that no brilliance could ever unlock an elegant view of quantum mechanics?

Have you ever seen a real experiment where the initial conditions are given with an infinite precision (e.g. classical mechanics)?

All the known experiments (at least, the ones I know) involve some uncertainty.

Therefore, what is the strangest? a theory allowing a possible system description with an infinite precision that has never seen in any experiment or QM theory postulating the uncertainty on the knowledge as a fundamental point?

If I take only the existing experimental results, I will be more confindent in QM theory than in any other theory allowing a deterministic (non statistical) description as a postulate.

Seratend.

 

[seratend]

BTW, here's something to think about - if QM isn't "predictable", how come your electronics work predictably, or that you would trust your life in, for example, an MRI?

Zz.

Well sometimes, even an electronic device commits some errors :tongue2: (for example a CMOS inverter, has a probability - very low - to give some errors as any detectors- it is sometimes basically modeled with a noise signal).
And when I take a software program like w...s on my computer, I really believe in QM or may be in gremlins

Seratend.

 

[ZapperZ]

Well, let's see. QM gives a classical limit, but we don't know why QM should be necessary other than it fits the data. Also, there is the search for Quantum Gravity, and there is a few approaches being tried: Loop Quantum Gravity, Dynamical Triangulation, String Theory, etc. So it would help if there were a principle that determined which QM approach is correct.

First of all, there seems to be this "trivialization" of the fact that "QM fits the data". Irregardless on whether this is really an accurate statement, the fact that something AGREES with an experimental measurement should be already an astounding observation.

Secondly, you seem to think that all of QM is nothing more than phenomenology. If this is so, then I question your understanding of what QM is. QM just doesn't FIT data. How did Dirac "fit" his data to came up with the existence of antiparticles? There were no "data" to fit! How did Luttinger "fit" his data to came up with the spin-charge fractionalization when it hasn't been discovered back then?

Right. What I mean by fundamental is some principle which is undeniable because it comes from reasoning itself. For example: reality is a topology because it seems undeniable that unions and intersections of parts of reality are also parts of reality. Likewise, it seems undeniable that the universe as a whole cannot lose information... where can it go except somewhere that we also include as part of the universe.

So where in physics do you get this? Nowhere! Again, why pick on QM only?

What you want is MATHEMATICS. Physics starts and ends with physical observation. It is why there are postulates that appear not out of First Principles, but out of numerous observations. There are no First Principle derivation for the constancy of the speed of light, nor the conservation of momentum. These cannot be arrived at simply by logic, because they are the physical principle of the universe we live in.

You should not confuse the fact that the physics (from the level you understand it) doesn't fit your world view with it being not having a "fundamental principle". Maybe the "lack of understanding" in the title of this thread should FIRST be directed inwardly to make sure none of what is being claimed is based on ignorance of the subject matter.

Zz.

 

[Mike2]

So where in physics do you get this? Nowhere! Again, why pick on QM only?

Are you trying to ask "what is so physical about information?"

What you want is MATHEMATICS. Physics starts and ends with physical observation. It is why there are postulates that appear not out of First Principles, but out of numerous observations. There are no First Principle derivation for the constancy of the speed of light, nor the conservation of momentum. These cannot be arrived at simply by logic, because they are the physical principle of the universe we live in.

Zz.

Basing postulates on nothing more than observation only begs the question as to why things are as they are. It is the same as giving up on the search for truth. It is an arbitrary choice to be content with a particular set of observations when more detailed observations require more detailed answers. It is not possible to finish with inquiry until the answer stem from the principles of reasoning itself. So physics will not be complete until it can be derived from logic. Anything less is just stopping for a moment to look at your accomplishment in order to be proud of yourself. :grumpy:

Even conservation law are based on invariance principles acording to Noether.

 

[seratend]

Right. What I mean by fundamental is some principle which is undeniable because it comes from reasoning itself.

Well, you should look at godel incompletness theorem (1931) and even with mathematics a consistent theory may be taken as wright or wrong (you cannot demonstrate it is wright or wrong).

For example: reality is a topology because it seems undeniable that unions and intersections of parts of reality are also parts of reality.

Your own reality seems to be a little bit too restrictive comparatively with the current physical models: in this case, Reality is more a sigma-algebra than a topology.
And if you look further on, you will discover that all the currently used physical models are based on the set theory, say zermello-frankel axiomatic set theory (unions, intersections, etc...). It is a consistent theory: you can take the axioms as true, what we impliciteley do with the current physical theories or you may assume them false.
Even the mathematical logic is not able to say if reality is true or not!

So physics will not be complete until it can be derived from logic. Anything less is just stopping for a moment to look at your accomplishment in order to be proud of yourself.

You are asking for the completeness of physics based on mathematical tools that are "incomplete" by principle.

Mathematics have discovered the modesty with persons like Godel during the first half of the 20th century like classical physics with the advent of quantum physics.

Sometimes, it is good to know the limits of our current logic and structures. One of the most simple examples is: the set of all the possible sets is not a set.

Seratend.

 

[ZapperZ]

Even conservation law are based on invariance principles acording to Noether.

I could play your game too. I could ask, so why is there "invariance principles"? Such symmetries are NEVER derived logically. They are only realized after all the observations that are made. Just look at the history of discoveries that led to Noether to arrive at that conclusion. It was based, FIRST, on the discoveries of all those conservation laws based entirely on observations. Thus, those invariance principles are NOT derived out of some "fundamental derivations".

I still question your understanding of QM to be able to question it. This, you have never addressed in this and all your postings.

Zz.

 

[jackle]

Right. What I mean by fundamental is some principle which is undeniable because it comes from reasoning itself..

Nobody has ever started with mathematics and derived the universe. I think it can be proved that this is always impossible. Mathematics and reasoning without observation clearly alllow for an infinite spectrum of 'possible' universes. Most of these would be nothing like the observed one we live in.

Basically, the whole thing doesn't work like that and never has. When you introduce observation you then can make predictions based on experience. This is reasoning isn't it?

 

[Mike2]

Well, you should look at godel incompletness theorem (1931) and even with mathematics a consistent theory may be taken as wright or wrong (you cannot demonstrate it is wright or wrong).

The effort to complete physics is not the same as the effort to complete mathematics. We are not trying to find every single mathematical expression which is true or provable within mathematics. That's not what physics is trying to do. In fact, we are looking for only one equation, not all of them, that describes our reality. Therefore, Godel's Incompleteness Theorem is irrelevant.

Nobody has ever started with mathematics and derived the universe. I think it can be proved that this is always impossible. Mathematics and reasoning without observation clearly alllow for an infinite spectrum of 'possible' universes. Most of these would be nothing like the observed one we live in.

Basically, I think we are getting quite close. When we start to think that spacetime itself may be a quantum mechanical superposition of various geometries, all we need is a more fundamental reason for accepting QM superpositions to begin with, and we may be done. I am of the opinion (though not proven yet) that some sort of conservation of information law is at the heart of QM.

Basically, the whole thing doesn't work like that and never has. When you introduce observation you then can make predictions based on experience. This is reasoning isn't it?

The problem is that if you do not have a physics based on principles of logic itself, and instead have one based on curve fitting of prior observation, then you can never really say that things could not be any other way. As far as you know, something fundamental could change and physics could start operating differently than it did in the past. You can't say that it won't. But if physics were derived from logic (reasoning) alone, then everyone would have to conclude that physics could not change.

 

[ZapperZ]

The problem is that if you do not have a physics based on principles of logic itself, and instead have one based on curve fitting of prior observation, then you can never really say that things could not be any other way. As far as you know, something fundamental could change and physics could start operating differently than it did in the past. You can't say that it won't. But if physics were derived from logic (reasoning) alone, then everyone would have to conclude that physics could not change.

CURVE FITTING. So then I was right. You have an erroneous impression that QM (and physics, in fact) is nothing more than phenomenology.

I have shown why this is incorrect (refer to Dirac and Luttinger examples). The whole area of phase transitions IS the study of things that simply will not "fit" into any smooth "curve fitting".

Have you ever considered the possibility that it is your knowledge of QM that is faulty here? "Imagination without knowledge is ignorance waiting to happen".

Zz.

 

[russ_watters]

Well, unlike other areas of physics where the rules are predictable 100% of the time and every aspect can be known with definite precision, quantum dynamics is not as elegant.

For example, we can know the position of a an electron, but not it's speed or so on, or something like that. Perhaps the quantum world is so hectic and not as elegant because our current equations and laws are not sufficient to let us view them correctly?

It may surprise you to learn that QM has produced the most precise and accurate predictions of any theory, ever. Strange, that this would come from a theory that says some things can't even be known, huh?

The problem is that if you do not have a physics based on principles of logic itself, and instead have one based on curve fitting of prior observation, then you can never really say that things could not be any other way. As far as you know, something fundamental could change and physics could start operating differently than it did in the past. You can't say that it won't. But if physics were derived from logic (reasoning) alone, then everyone would have to conclude that physics could not change.

That's Aristotle's view - everything can be figured out via logic alone. Its quite obviously an invalid approach to science: it has been used in the past and gives wrong answers about how things work.

 

[ZapperZ]

the TERMINAL PROBLEM with physics are the Physicists that pretentiously practice it.

At www.unifiedtheory.org.uk there is an unanswerable proof of this. $500,000,000,000 to $1 says that I am right.

I'm sorry, but you are pointing to a site that claims some work to be "irreverant", and you're accusing me of being pretentious? Hello?

The "terminal problem" here is that we have the ignorant who are claiming to know everything, when in reality, they don't know when something new comes along even when it bites them on their rear end.

http://insti.physics.sunysb.edu/~siegel/quack.html

Zz.

 

[Mike2]

That's Aristotle's view - everything can be figured out via logic alone. Its quite obviously an invalid approach to science: it has been used in the past and gives wrong answers about how things work.

See:
http://arxiv.org/abs/quant-ph/0205039

 

[ZapperZ]

See:
http://arxiv.org/abs/quant-ph/0205039

Good grief! THIS is what you have been trying to champion?!

Again, it appears that you are confusing between the formalism of QM and the interpretation of QM. Read carefully the very text you are referring to. ALL the formalism of QM are INTACT, whether you believe him or not! The equation for an entangled state is still IDENTICAL! Of course, you would have known that had you learned QM.

This is a paper on how to look at the SAME formalism differently. It would be nice to know if it has been published anywhere (or do you not care?). This belongs more in the philosophy section than on here.

Zz.

 

[Mike2]

Good grief! THIS is what you have been trying to champion?!

Again, it appears that you are confusing between the formalism of QM and the interpretation of QM. Read carefully the very text you are referring to. ALL the formalism of QM are INTACT, whether you believe him or not! The equation for an entangled state is still IDENTICAL! Of course, you would have known that had you learned QM.

This is a paper on how to look at the SAME formalism differently. It would be nice to know if it has been published anywhere (or do you not care?). This belongs more in the philosophy section than on here.

Zz.

What formalism am I trying to change? I did not even write an equation yet. I am merely suggesting a reason for QM the way it is today. I wasn't trying to change anything. Your criticism is presumptuous at best, it is a strawman at worst.

 

[ZapperZ]

What formalism am I trying to change? I did not even write an equation yet. I am merely suggesting a reason for QM the way it is today. I wasn't trying to change anything. Your criticism is presumptuous at best, it is a strawman at worst.

You are correct. It was presumptuous of me to assume that you have very little formal knowledge of QM based simply of what you have written. I AM wrong in making this assumption, aren't I?

Let's see what you have written:

I read an article once that complained a lot about how QM was just a device for fitting the known data to some equation, a curve fitting process. It seems that we don't yet have the fundamental principles from which QM is derived.

You shouldn't be talking about making a "strawman", when you REPEATEDLY make the claim that QM is nothing more than a glorified curve fitting. If it is, then keeping the formulation, but changing its interpretation changes NOTHING. That's the same irrational act as changing NMR into MRI so that it sounds more "safe". If you truly believe that QM is nothing more than curve fitting, you should also be weary of that website you proudly cited, since he did nothing more than change the color of the stripe on the tiger. The formulation is still identical! Nothing has changed, except your "feelings" towards it.

Zz.

 

[Mike2]

You shouldn't be talking about making a "strawman", when you REPEATEDLY make the claim that QM is nothing more than a glorified curve fitting. If it is, then keeping the formulation, but changing its interpretation changes NOTHING. That's the same irrational act as changing NMR into MRI so that it sounds more "safe". If you truly believe that QM is nothing more than curve fitting, you should also be weary of that website you proudly cited, since he did nothing more than change the color of the stripe on the tiger. The formulation is still identical! Nothing has changed, except your "feelings" towards it.

Zz.

Are you saying there is no value in discovering some fundamental principle from which QM is derived?

 

[ZapperZ]

Are you saying there is no value in discovering some fundamental principle from which QM is derived?

No, I am saying that there's no value in discovering some fundamental principle from which QM is "derived" when you have no clue what QM is in the first place. How can you derive something when you have no idea what it is in the first place? This is an irrational act.

Zz.

 

[Mike2]

No, I am saying that there's no value in discovering some fundamental principle from which QM is "derived" when you have no clue what QM is in the first place. How can you derive something when you have no idea what it is in the first place? This is an irrational act.

Zz.

According the the experts I've read, nobody really knows what QM is all about. That's the point. We can never know what QM is about until we discover some underlying principle that we do understand from which QM is derived. Until then it cannot be anything more than a "curve fitting device".

 

[ZapperZ]

According the the experts I've read, nobody really knows what QM is all about. That's the point. We can never know what QM is about until we discover some underlying principle that we do understand from which QM is derived. Until then it cannot be anything more than a "curve fitting device".

Maybe what these "experts" are trying to convey a different meaning than what you interpret. It is always risky when you rely on 2nd hand information. Have you ever consider that?

Furthermore, if you rely on experts to tell you about QM, why aren't you paying any attention to what *I* have to say, or even a few others on here who are certainly knowledgeable about the content of QM? And secondly, if you really are serious about "reinterpreting" QM, isn't it prudent that you yourself learn it, rather than rely on "experts" to tell you what it is and it isn't? This is the part that I find rather irrational. All you have is a superficial knowledge of QM. I don't understand how you can feel comfortable with what you know and do not feel foolish about about your ability to talk about it. To say what you are claiming based simply on what you "read" from "experts" is like having sex through an interpreter - you'll never feel what it is like no matter how accurately it is described.

Zz.

 

[Mike2]

And secondly, if you really are serious about "reinterpreting" QM, isn't it prudent that you yourself learn it, rather than rely on "experts" to tell you what it is and it isn't? This is the part that I find rather irrational. All you have is a superficial knowledge of QM. I don't understand how you can feel comfortable with what you know and do not feel foolish about about your ability to talk about it. To say what you are claiming based simply on what you "read" from "experts" is like having sex through an interpreter - you'll never feel what it is like no matter how accurately it is described.

Zz.

Well... I don't intend to get into a bragging contest with you about how much I know about QM. Obviously no one knows enough about QM to tell us where the postulates come from yet. How would you know how much I know about QM? Suppose you state the extent of my knowledge (what classed I took), or appologize for you presumption, again.

 

[russ_watters]

Well... I don't intend to get into a bragging contest with you about how much I know about QM. Obviously no one knows enough about QM to tell us where the postulates come from yet. How would you know how much I know about QM? Suppose you state the extent of my knowledge (what classed I took), or appologize for you presumption, again.

All ZZ is saying is that from your posts here, it appears you don't know a whole lot about QM. Your posts certainly imply that.

In your first post, for example, you said the math was insufficient - now you're saying that the math is fine the way it is and only the physical interpretation of the math is lacking. It seems like you don't even know your own opinion.

 

[ZapperZ]

Well... I don't intend to get into a bragging contest with you about how much I know about QM. Obviously no one knows enough about QM to tell us where the postulates come from yet. How would you know how much I know about QM? Suppose you state the extent of my knowledge (what classed I took), or appologize for you presumption, again.

I had to presume because each time I asked, you refused to answer. If I were to base it entirely on what you posted, then I say you exhibit the same symptoms that quacks have, where you only learn some superficial ideas about QM. How else would you dare to make the claim that QM is nothing more than "curve fitting" even AFTER I asked you where is the "curve fitting" when Dirac came up with antiparticles, and Luttinger made his "spin-charge" separation, and the study of phase transition, etc. etc...

While no one is claiming to know everything about QM, one can certainly learn MORE about it by carefully studying it, and certainly more than what you have appeared to show. There is a difference in learning about QM simply for "cultural fulfilment" and learning it in order to be able to question it. The latter requires that you understand it beyond just the level of "oh, I read it from a bunch of experts".

Zz.

 

[quantumdude]

Mike2:

If you think that QM is just a curve fitting program, then can you please cite an example of a theory that in your opinion isn't just a curve fitting program, and explain why it isn't?

 

[Mike2]

I had to presume because each time I asked, you refused to answer. If I were to base it entirely on what you posted, then I say you exhibit the same symptoms that quacks have, where you only learn some superficial ideas about QM. How else would you dare to make the claim that QM is nothing more than "curve fitting" even AFTER I asked you where is the "curve fitting" when Dirac came up with antiparticles, and Luttinger made his "spin-charge" separation, and the study of phase transition, etc. etc...

While no one is claiming to know everything about QM, one can certainly learn MORE about it by carefully studying it, and certainly more than what you have appeared to show. There is a difference in learning about QM simply for "cultural fulfilment" and learning it in order to be able to question it. The latter requires that you understand it beyond just the level of "oh, I read it from a bunch of experts".

Zz.

We all only just "read it from the experts" unless you do the experiments yourself. Even that can be read from the experts. In fact, I got the complaint against QM for no basis in principle, even that I got from the experts. And I don't understand your complaint. If some procedure for predicting experiment does not stem from principle, then by definition it is curve fitting. If your postulates are only just generalizations from observation, then again they are only curve fitting. Why can't you accept that? Yes those postulates may lead to predictions we haven't already seen, but still the postulates themselves beg the questions of what deeper principle gives rise the them.

If you think that QM is just a curve fitting program, then can you please cite an example of a theory that in your opinion isn't just a curve fitting program, and explain why it isn't?

I don't know that I have a complete theory yet. I was simply trying to point out that in the process of the search for the basis of QM, it seems that it might be worth a try to see if some conservation of information law might be what we are looking for.

For in the path integral formulation each "path" is given a certain amplitude and phase and these are integrated over all possible paths. Now it occurs to me that each path in and of itself should have some entropy associated with it. Paths that are as straight as possible would have the least entropy, whereas paths that wind their way all over the place, through all sorts of loop-tee-loop configurations would have the greater entropy. And if given that, then one might wish to compare that to the information associated with choosing that path over the other possible paths. Choosing one improbable option over many others always increases information, lowers entropy. It's my suspicion at this time that somehow the entropy of these two (the path and the choice of the path) will cancel. My intuition comes from considering the universe when it was at the smallest of all possible scales, when the first quantum mechanical situation arose. There some simpler form of extreme symmetry broke by giving us a quantum mechanical superposition of alternatives. Each alternative has some entropy, and each choice of that path decrease entropy. I suspect that the two cancel because the prior condition of extreme symmetry would seem to have no entropy associated with it. And it would seem that there can be no information/entropy outside the universe which starts from zero with nothing at the beginning that can have entorpy.

It seems however, that information in the literature is only applied to distributions, and not to geometrical object. It is mostly applied to probability distributions, but I have seen it applied to mass distributions. However, since information is applied to signals and geometric shapes might be regarded as signals, it seems to me that there should be information associated with geometrical shapes as well. What I don't understand yet is how you would calculate the entropy/information of a geometric shape. It seems easy to calculate a function that mimics the behavior of distributions, one y-value for each x-value. But how to calculate the entropy of a space curves that do loop-tee-loops in multiple dimensions. I suppose you add entropy for each little twist and turn you make, perhaps multiplying by the number of possible dimensions there are to twist and turn in.

Any help is appreciated.

 

[jackle]

I think you are curve fitting.

 

[Mike2]

I think you are curve fitting.

How do you figure?

Entropy can be calculated of any signal, physical or not. If entropy/information can be calculated of any geometric object, physical or not, and if some sort of conservation of information law is only logical, then since we describe physics in geometrical terms, it would seem that QM is perfectly logical in abstract terms as well as in physical terms.

Just to continue the thought process (whether anyone helps or not), I think that entropy would have to be invariant with respect to coordinate changes. It would have to be an intrinsic property of the geometry. Are there any studies or thoughts on how that would be calculated? I wonder if entropy would be connected to the curvature of a given geometry. Certainly straight lines and flat surfaces would have less entropy than wildly curved lines or surfaces, right? (actually, I'm not sure at this point whether the more wildly curved line would not have more information involved. It seems it would take more bits to describe a curve than a straight line, right?). Anyway, more or less, one might suspect that entropy is connected to how curved a geometry is and how often that curvature changes, etc. That would probably be how curved it is per length or per surface area. Are there any math procedures out there that I may wish to consider?

 

[ZapperZ]

How do you figure?

Entropy can be calculated of any signal, physical or not. If entropy/information can be calculated of any geometric object, physical or not, and if some sort of conservation of information law is only logical, then since we describe physics in geometrical terms, it would seem that QM is perfectly logical in abstract terms as well as in physical terms.

This is gooblygook! Entropy of a "geometric object"?! You can calculate the entropy of a cube? Please show this.

I take back what I said about you having only a superficial knowledge of QM. I think you have a superficial knowledge of physics. Period.

Zz.

 

[masudr]

Postulates as fundamental aspects of physical theories

In the 19th century, mechanics was based on "postulates" of varying kinds. For example, Newton used his (now) famous three laws and derived a complete mechanics based on those (and other expressions for force).

This was later reformulated by assuming the postulate that a trajectory that any particle takes is such that it's action is stationary with respect to extremal variations of the path (this is Lagrangian mechanics, look it up if you're interested). This postulate has been proven to be exactly the same as Newton's three laws. (There has also been a similar reformulation called Hamiltonian mechanics [this is related but indirectly to quantum mechanics, so just assume that it is a completely different thing; the argument is still the same]).

The point I am trying to make is that ALL physics is based on postulates of some kind. Even those that dream of a final theory which is self-evident still requires various postulates, one of them being the invariance of physical laws over spacetime. Or that reality is real and we are experiencing that through our senses; if not the theory wouldn't really describe reality and would be demoted into metaphysics.

Now onto quantum mechanics. QM was the result of about 26 years of research. The phrase "curve fitting" has now become slightly ambiguous since it has been used so many times. But of course there is curve fitting going on. And it always has been. Newton formulated his law of gravitation plus his three laws of motion by fitting his equations to the curves described by objects in gravitational attraction (his genius was to notice that all objects are falling).

Einstein fitted his special theory by noticing that no objects could discern motion when in an inertial frame and also on the invariance of light. There is no fundamental explanations for this. They have to be accepted.

So the same goes for QM, and Schrodinger's equation, and the canonical commutation relation and so on and on. These are based on thousands of experimental observations and hence we hold them to be "true". Based on the assumptions of QM we can build one of the most elegant theories so far, which has succeeded in describing the largest range of phenomena by any physical theory.

Some of the fruits of QM have been that based on these assumptions, theorists have been able to generate "new curves" and experimentalists have found that their experimental data fits these new curves (e.g. the existence of the positron etc.) This is a growing body of evidence that those initial assumptions are indeed correct or are the result of some other set of assumptions (this set could be of cardinality 1).

So, in conclusion, QM is a curve fitting process, but so are all physical theories. We cannot, however, discredit QM on the basis of its assumptions. The whole point of assumptions/postulates are that they are unquestionable and must be accepted on an ad hoc basis (or a priori as Einstein was fond of saying).

Even the greatest physical theory will be a curve fitting process. Any theory will have at least one degree of freedom. One constant to choose. A proportionality constant, for example. We then have to determine that constant (or whatever the variable may be) by adjusting it so the theory's curve fits the experimental curve.

As you can see from reading the above, the point of this discussion is highly non-physical and more philosophical. But I feel that without a true grasp of the ideas involved (e.g. Hilbert spaces, linear operators etc) one cannot truly appreciate quantum mechanics. Just to make things clear from the outset, I am an undergraduate in my first year of studying physics (i.e. I just started my "college" [as Americans would usually call it; I am from the UK] course); and most of my knowledge on these topics have come from extra reading beyond the scope of my course (at this stage anyway). So there may be errors in my understanding.

Finally, as a message to Mike2; you seem to have some very interesting (although unoriginal) ideas regarding information as a fundamental part of mechanics, and attempting to base a theory on this and some other related principles. I would be very interested to see a full list of postulates that your mechanics requires, and how you would perform calculations on your new mechanics. At least von Neumann et. al showed us how their systems worked. Until you do that, your ideas are just incoherent jumble of English words, not precise mathematical statements. This isn't bad or wrong in itself, but it just doesn't allow others to subject it to careful scrutiny and thus support it or disprove it.

 

[keebs]

I suspect that the two cancel because the prior condition of extreme symmetry would seem to have no entropy associated with it.

You obviously don't understand path integrals: http://www.princeton.edu/~jhunt/qft_path.pdf [Broken]

 

[Mike2]

This is gooblygook! Entropy of a "geometric object"?! You can calculate the entropy of a cube? Please show this.

Zz.

The entropy of continuous probability distributions is calculated all the time. Yet, this same probability distribution function is also a line on a graph of the distribution, a geometric object, as are all functions described by y=f(x). There are also probability distribution functions of many variables w=f(x,y,z), and these have the appearance of surfaces and volumes when plotted out. If the entropy of these distributions are the same when one rotates the coordinates so they are no longer single valued in the new coord system, then this will prove that entropy of such functions (whether viewed as distributions or geometric objects) is intrinsic. And if so, then entropy can be calculated of any geometric object. If the entropy of a probability distribution function (which appears as a geometric object when graphed) can be reformulated so that it is calculated along the line or along the surface, etc, then we could calculate the entropy of functions that loop-tee-loop (a technical term :-) all over the place so that they are not single valued functions. It could then apply to each path used in path integral formulations of QM.

My purpose is to stimulate study in this area in the hope that it has some intuitive appeal.