The mystical Copenhagen Interpretation

@Bones-O,

Bones-O!;80507 wrote:

All the delayed choice experiment shows is that the first beam splitter is also in two states at once.

Something is in two states at once? Do you consider this logical by the way most philosophers think of logic?

This in itself is quite interesting and perplexing. In fact, the whole notion of delayed choice, i.e. the choice of measuring a particle or wave is made after the photon has already chosen what it is, is mind boggling for anyone who is attempting to understand the fundamental nature of nature.

After a Short Delay, Quantum Mechanics Becomes Even Weirder -- Cho 2007 (216): 4 -- ScienceNOW

The results, reported this week in Science, prove that the photon does not decide whether to behave like a particle or a wave when it hits the first beam splitter, Roch says. Rather, the experimenter decides only later, when he decides whether to put in the second beam splitter. In a sense, at that moment, he chooses his reality.

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The only thing mystical or magical is how the photon ends up in one detector and not the other, a mechanism not explained by QM, a purely probabilistic theory. Everything else is explained, and so is not magical.

Wheeler seems to have a different take on the significance of his Gendanken experiment which now is being verified in laboratory experiments - 30 years after Wheeler first proposed it:

Wheeler's delayed choice experiment - Wikipedia, the free encyclopedia

Wheeler:

The thing that causes people to argue about when and how the photon learns that the experimental apparatus is in a certain configuration and then changes from wave to particle to fit the demands of the experiment's configuration is the assumption that a photon had some physical form before the astronomers observed it. Either it was a wave or a particle; either it went both ways around the galaxy or only one way. Actually, quantum phenomena are neither waves nor particles but are intrinsically undefined until the moment they are measured. In a sense, the British philosopher Bishop Berkeley was right when he asserted two centuries ago 'to be is to be perceived'.[5]

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This isn't true at all. QM holds up very well in the macro world. For instance, Newton's laws of motion are derivable from QM.

What I find interesting, and well within the province of metaphysics, is why we have different sets of laws in science . e.g. Relativity for very high speeds, Quantum Mechanics for very small distances, and something called Classical (Newtoian) Mechanics for everything in between. While scientists may be blase about this, I find it incredibly fascinating. Some speculate there is some hidden variable. May I suggest that the hidden variable may be consciousness - something that cannot be measured or sensed by the physical senses but can certainly be sensed by the mind sense, as we do every day in our lives.

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You do just get 'comfortable' with it. Good choice of words. As for your question- that's the biggie! It may not be one thing, but complexity is key. The more complex the system, the less 'quantum' it behaves.

So the question for philosophers is why? And I would not sell philosophers short in this regards. Much can be intuited by the mind, way before it may be ever sensed by the five physical senses. The Daoists intuited much from their exploration about the nature of the universe and the nature of the human being. I use the results of their work throughout my daily life - e.g interaction with human beings, health maintenance, etc. For me, these intuited thoughts are far more helpful to my life than most technology discoveries, and for me far more interesting.

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This is most likely to be because certain behaviours of a quantum particle compatible with one part of the complex system are incompatible with other parts and so are suppressed (i.e. the particle can't evolve to exhibit these behaviours).

These are all reasonable speculations, but as in all cases of attempting understand the underlying description of nature that manifests in quantum effects, it is all speculation.

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This is a vague description of decoherence. Another might be chaos theory, again due to the complexity of the macroscopic system, which leads the particle down certain state paths. Resonance might effect things too: look at the single-electron transistor as an example.

Or, possibly, the mind?

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Judging by the myriad (and imo often ridiculous e.g. MWI) interpretations given by physicists, I'm inclined to agree. We need a new Einstein, someone both possessed of mathematical grounding in QM but able to provide a philosophically solid picture of what is actually going on.

d"Espagnat has both qualities and has suggested a Veiled Reality.

Bernard d'Espagnat - Wikipedia, the free encyclopedia

In Search of Reality, the Outlook of a Physicist), he encouraged physicists and philosophers to think afresh about questions long considered marginal but which today serve as the foundation for new fields of research into the nature of reality.[2

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The wave nature of matter is more fundamental than any understanding something made from matter has, yours or mine. At some point you either have to accept or reject the possibility that there are fundamental truths contrary to everyday experience, irrespective of how the theory is presented.

Both the Daoist and Heraclitus intuited the wave nature of Nature by observations - internal and external. Some philosophers may find that they might also intuit some interesting ideas about the fundamental nature of Nature by exploring the questions raised by their everyday experiences, as well as those raised by science when attempting to understand the very small and the very fast.

Thanks very much for your comments.

Rich

1 Reply

@Exebeche,

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Everything else is explained, and so is not magical.

Ah! But you only need a sprinkle:bigsmile:

1 Reply

@jeeprs,

jeeprs;80660 wrote:

Ah! But you only need a sprinkle:bigsmile:

I think it is more than just a little sprinkle. I think it is a torrential storm.

Physicists have no idea how to describe the fundamental character of the universe - but for show they pretend that all is OK.

And, since everything is comprised of fundamental stuff, whatever it is, then science has not idea what we are. So, we all just have to figure it out the best we can, if we would like to give it our best shot. For me, all these little sprinkles, which make up the greater part of the universe, is our mind at work. And what a job it is doing. :a-ok:

Rich

0 Replies

@richrf,

richrf;80542 wrote:

Something is in two states at once? Do you consider this logical by the way most philosophers think of logic?

As a statement on its own, there's no basis to judge whether it is logical or not except everyday experience (or even any pre-1900 experience). On that basis, it is illogical since it is being included in a logical framework where it doesn't fit. But the conclusion that some property may be in a mixed state is logically derived within QM from more fundamental principles. If we accept those principles, the conclusion is logical, and when we compare predictions drawn from this conclusion with experiment (e.g. delayed choice), it is also logical to accept its validity. I think any logician would have no problem with QM. Metaphysicists on the other hand...

richrf;80542 wrote:

The thing that causes people to argue about when and how the photon learns that the experimental apparatus is in a certain configuration and then changes from wave to particle to fit the demands of the experiment's configuration is the assumption that a photon had some physical form before the astronomers observed it. Either it was a wave or a particle; either it went both ways around the galaxy or only one way. Actually, quantum phenomena are neither waves nor particles but are intrinsically undefined until the moment they are measured. In a sense, the British philosopher Bishop Berkeley was right when he asserted two centuries ago 'to be is to be perceived'.[5]

Yes, there is too much freedom to choose an ontology in QM which does give rise to frustrations in pinning down what it says beyond predicting results (which is, of course, nothing or at least very little). As I said before, we need a new Einstein here and I think this will come once the collapse mechanism is understood. For now my view is this: if it acts like a wave, call it a wave. Interference and defraction effects are not the results of a measurement: we see them over the course of many measurements. This suggests the particle is a wave before it is measured.

richrf;80542 wrote:

Thanks very much for your comments.

No problem, thanks for the discussion. I didn't comment on the consciousness stuff. I'm very interested in consciousness but it's well outside my expertise and I'm fairly inclined to believe that the link between consciouessness and QM is very long and weak. But that's just an inclination.

richrf;80542 wrote:

Physicists have no idea how to describe the fundamental character of the universe - but for show they pretend that all is OK.

This is a little harsh, but I understand where that view comes from. The job of the modern theoretical physicist is to model reality, not to describe it. Sometimes the model is so good it acts much like a description (e.g. relativity). But these days physicists are all too aware of the limitations of direct study. The quark model and QCD is a good example of this.

However, models aren't very exciting so in mags like SciAm and New Scientist the tendancy is not to say: "Model X predicts black holes in centre of atoms" but "There are black holes in the centre of atoms!!!!!!!!". Many books are written in this way too - if you think about it, if you're writing a QM-related pop sci book it's probably because you have an oh-so definite idea about reality (or else you'll be writing QM for Dummies or some such).

I'm not, as you can tell, a big fan of the way physics is communicated to wider audiences, and one bugbear is this idea that physicists discover positive truths about how reality really is. Some theories, QM included, are compelling, not least because of their astounding experimental success. But actual fundamental reality?!?!? I'll take anyone's idea on that with a huge helping of salt.

I believe QM is the best description of the dynamics of fundamental particles we've got, and maybe will ever get. I believe it's good enough to get a rough picture of how these particles behave. But I don't think it's fundamental, only as close as we may get.

Bones

1 Reply

@Bones-O,

Bones-O!;80836 wrote:

I think any logician would have no problem with QM. Metaphysicists on the other hand...

Einstein, and others, have had lots of problems with the logic of QM. It is one thing to be comfortable with the predictive nature of the equations (at least to with the degree of tolerance that is allowed), it is an entirely different animal to be comfortable with what ever the heck the equations are describing. I cannot find any room for logic in a world that is totally unknown and defies description. Yes, there are constants and variables, but what are they describing? That is the question for people of all backgrounds to inquire into. Each, is bringing their own knowledge intot he game.

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This suggests the particle is a wave before it is measured.

My understanding of Bohr's views are different. He no longer felt that one can think in terms of causality, which means that a wave preceding a particle no longer makes any sense. The delayed-choice experiment sort of puts an exclamation point on this notion. Further, Bohr seemed to feel that we were categorizing quanta stuff as waves or particles, because that is what experiments are attempting to measure. It may simply be a limitation of our technology. Given this, then whatever it is, it is not one or the other, but rather something that can be characterized mathematically as one or the other, depending on what is being measured. What it actually is is totally open to question. Rather than characterize QM as largely a settled situation, it becomes more and more crazy as experiments are performed that verify thought experiments - e.g. the Bell Theorem and Wheeler's delayed-choice.

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No problem, thanks for the discussion. I didn't comment on the consciousness stuff. I'm very interested in consciousness but it's well outside my expertise and I'm fairly inclined to believe that the link between consciouessness and QM is very long and weak. But that's just an inclination.

Bohm suggests that the variable in Schrodinger's equation can very well be a quantum force. That is, some body that is exerting some sort of intensity that creates the probability wave. Maybe it is what is being called black matter? Maybe it is the force of consciousness that is attempting to create order? Teller suggests that the difference between the quantum world and the classical world is not one of size but should be thought of as order. I would suggest that something is attempting to create order.

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This is a little harsh, but I understand where that view comes from. The job of the modern theoretical physicist is to model reality, not to describe it. Sometimes the model is so good it acts much like a description (e.g. relativity). But these days physicists are all too aware of the limitations of direct study. The quark model and QCD is a good example of this.

Yes, and I believe that only applied technology problems will force theoreticians back to the drawing board. Right now they are very comfortable with the notion they cannot know. Einstein did not receive much support for his attempts to try to understand a Theory of Everything. Why even go there?, is a question asked by the comfortable. However, there are always those who continue to explore.

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However, models aren't very exciting so in mags like SciAm and New Scientist the tendancy is not to say: "Model X predicts black holes in centre of atoms" but "There are black holes in the centre of atoms!!!!!!!!". Many books are written in this way too - if you think about it, if you're writing a QM-related pop sci book it's probably because you have an oh-so definite idea about reality (or else you'll be writing QM for Dummies or some such).

Very few physicists, or any scientists, are going to go out on the limb and suggest something that is much beyond what is acceptable in polite scientific circles. Those who try to are beaten up pretty bad. Someone has to push the envelope a bit. So let philosopher, biologists, mechanical engineers do their thing, and speculate. Technology is just one aspect of life. For many, understanding who they are and why they are here is of greater interest.

Thanks for your comments.

Rich

2 Replies

@Exebeche,

and from Heraclitus, to whom Rich has already referred, a quote which I think describes your attitude very nicely:

Quote:

'A dry soul is wisest and best'.

(From The Aristos, by John Fowles).

Many thanks for your insights on this fascinating topic.

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@richrf,

richrf;80847 wrote:

Einstein, and others, have had lots of problems with the logic of QM.

Rich, you are confusing the word logic with what you or i consider reasonable.
Really, these are two completely different things.

1 Reply

@Exebeche,

Exebeche;80956 wrote:

Rich, you are confusing the word logic with what you or i consider reasonable.
Really, these are two completely different things.

I don't believe I am confused.

I do not see how one can make a proposition about the descriptive nature of quantum, if no one knows what it is.

What would your proposition be about the nature of quanta?

Rich

1 Reply

@richrf,

richrf;80961 wrote:

I don't believe I am confused.

Sorry, I didn't mean to say you were confused. I meant, you are confusing two things with different meanings.

richrf;80961 wrote:

What would your proposition be about the nature of quanta?

Are you kidding me? This is not a self-help group where everyone tells about his personal idea about what the nature of quanta could be.

1 Reply

@Exebeche,

Exebeche;80983 wrote:

Are you kidding me? This is not a self-help group where everyone tells about his personal idea about what the nature of quanta could be.

Nope, I am not kidding. There is no certainty in the realm of uncertainty. Einstein made many bold attempts to find certainty in the quantum world, and Bohr refuted them all.

There just isn't anything that can be descriptively said about the quantum world with certainty. One can only speculate and guess about quantum stuff using intuition and imaginative thoughts. I personally like what Bohm has to say and his speculations. It is the kind of world I thrive in but upset Einstein to know end. Different strokes for different folks.

Rich

0 Replies

@richrf,

richrf;80847 wrote:

Einstein, and others, have had lots of problems with the logic of QM.

I'm not aware of any such protests from Einstein. He was certainly at odds with the probabilistic nature of QM because he was a determinist. This is not a logical shortcoming of QM but an incompatibility between QM and something outside it that Einstein held as true (as do I for that matter). That said, the Born interpretation is, again, just an interpretation: probabilism is not a postulate of QM. Einstein also pointed out that wavefunctions would behave non-relativistically: all this means is that QM is incompatible with either localism or realism, again not a logical problem of QM, just an incompatibility with something outside of QM: local realism.

richrf;80847 wrote:

It is one thing to be comfortable with the predictive nature of the equations (at least to with the degree of tolerance that is allowed), it is an entirely different animal to be comfortable with what ever the heck the equations are describing. I cannot find any room for logic in a world that is totally unknown and defies description.

You appear to be using the words 'comfortable' and 'logical' interchangeably. They are not the same. One can be uncomfortable with what QM means and predicts, and perhaps reject it on those grounds as Einstein did, while still acknowledging that it is an entirely logical theory.

richrf;80847 wrote:

My understanding of Bohr's views are different. He no longer felt that one can think in terms of causality, which means that a wave preceding a particle no longer makes any sense. The delayed-choice experiment sort of puts an exclamation point on this notion. Further, Bohr seemed to feel that we were categorizing quanta stuff as waves or particles, because that is what experiments are attempting to measure. It may simply be a limitation of our technology.

This isn't what he meant. First, a fundamental particle is a wave. Wave-particle duality is very much overstated. When we measure that wave with experimental apparatus, the form the wave will be in depends very much on the type of apparatus we use: i.e. the variable we measure. If we measure position exactly, we will measure a delta function wave, one that has a magnitude of 1 at the measured position and zero everywhere else. If we measure momentum exactly we will measure a plane wave of fixed wavelength but infinite extent. If we measure a bit of both we get a wavepacket of some form. This is the extent to which experiments determine allowed (i.e. 'quantised') forms of waves. So there is no 'wave preceding a particle', merely a wave of one form that, after measurement, collapses into a different wave measurable by the apparatus. It's a particle all the way through this process.

richrf;80847 wrote:

What it actually is is totally open to question.

Like I said, my view is simple but logical: if it interferes and diffracts, it's a wave. In fact, these phenomena can act to define a wave since only waves do both.

richrf;80847 wrote:

Rather than characterize QM as largely a settled situation, it becomes more and more crazy as experiments are performed that verify thought experiments - e.g. the Bell Theorem and Wheeler's delayed-choice.

I don't get this. Are you saying the fact that experiments continue to verify QM is a reason to doubt that QM is settled? The opposite view seems the logical one.

richrf;80847 wrote:

Bohm suggests that the variable in Schrodinger's equation can very well be a quantum force. That is, some body that is exerting some sort of intensity that creates the probability wave. Maybe it is what is being called black matter? Maybe it is the force of consciousness that is attempting to create order?

But that doesn't actually mean anything does it? It sounds like 'life force' of 'spiritual energy' to me: something that sounds good but has no actual definition. Also, if the Bohm potential is 'the force of consciousness' that requires consciousness to precede matter in the Universe's chronology when everything we know about both tells us otherwise.

richrf;80847 wrote:

Yes, and I believe that only applied technology problems will force theoreticians back to the drawing board.

Experiment in general, that's how science works: theoreticians predict, experimenters provide results, theoreticians rethink... But, yes,technology is the largest research driver. Because it has the most funding...

richrf;80847 wrote:

Very few physicists, or any scientists, are going to go out on the limb and suggest something that is much beyond what is acceptable in polite scientific circles. Those who try to are beaten up pretty bad.

I can't agree with that. You can't 'beat up' someone if their paper gets through peer review and isn't later shown to be in error. We're actually a pretty social, amiable bunch when you get to know us, and we get off on new ideas and heated debate.

richrf;80847 wrote:

Someone has to push the envelope a bit. So let philosopher, biologists, mechanical engineers do their thing, and speculate. Technology is just one aspect of life. For many, understanding who they are and why they are here is of greater interest.

Indeed, let. It isn't a question of physicists OR philosophers, or physicists OR biologists, so there's no problem.

1 Reply

@Bones-O,

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This isn't what he meant. First, a fundamental particle is a wave.

This statement says it all. The fundamental particle is a wave. Say what?? Let's have that one more time. The particle is a wave.

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But that doesn't actually mean anything does it? It sounds like 'life force' of 'spiritual energy' to me: something that sounds good but has no actual definition. Also, if the Bohm potential is 'the force of consciousness' that requires consciousness to precede matter in the Universe's chronology when everything we know about both tells us otherwise

.

Exactly. It has no definition of what it is at this time. Just a set of predictive equations. e=mc**2. What is energy? What is mass? (particularly in light of quantum physics). What is light?? - that which illuminates all except itself. Same with quantum mechanics. What do each of the constants and variables mean. What is quanta? Time to go digging into imagination.

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I can't agree with that. You can't 'beat up' someone if their paper gets through peer review and isn't later shown to be in error. We're actually a pretty social, amiable bunch when you get to know us, and we get off on new ideas and heated debate.

Most of the great theories were initially ridiculed, including Einstein's. And it took quite some time for experimental proof to verify. In fact, the initially experiments invalidated Einstein's work and Einstein never received a Nobel prize award for relativity. The initial work on QM was likewise met with lots of skepticism. The vast majority of scientists are not looking to rock the boat. They are quite comfortable teaching the same old stuff year after year in school. Heck, I was taught the Rutherford atom in college, in 1972 - 40 years after quantum theory eradicated that model. Why?

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Indeed, let. It isn't a question of physicists OR philosophers, or physicists OR biologists, so there's no problem.

Yes, I agree. Everyone has a equal shot at trying to understand the nature of Nature. It is not difficult to understand Planck's energy quanta, Einstein's photoelectric effect and the quantum nature of light, Bohr's Aspect experiment and Wheeler's Delayed-Choice as well as the double slit. Once, one understands it, it is time to ponder, what the heck is going on. This is a nice link to get one started:

The Wave Nature of Matter

"Photons don't have mass, but they do have energy--and as Einstein famously proved, mass and energy are really the same thing. So photons have momentum--but what exactly is a photon? For centuries, a heated debate went on as to whether light is made up of particles or waves. In some experiments, like Young's double slit experiment, light clearly showed itself to be a wave, but other phenomena, such as the photoelectric effect, demonstrated equally clearly that light was a particle.

Well, it's both--or it's neither. Sometimes light displays particle-like behavior, and sometimes it acts like a wave; it all depends on what sort of experiment you're doing. This is known as wave/particle duality, and, like it or not, physicists have just been forced to accept it."

Schrdinger's Atom

"Isn't the electron in some definite place?So where is an electron when you're not looking? Doesn't it have to be somewhere? That's the bizarre part: an electron isn't in any particular place when you aren't looking."

Lots more on this site. It is worth while to read about the the bizarre nature of quantum.

What confuses me is that in this thread we have one person describing quanta as a billiard ball (a totally false and outmoded representation), and another describing it as a wave (equally false). It is neither. No one knows what it is. What we can say, is that under certain conditions there are mathematical formulas that can predict the behavior in a way that can be likened either to a particle or a wave, depending upon what is being measured. That is all.

To say, that quanta is either particle or a wave ignores the duality that it demonstrates in theory and experiments. It is something, but no one knows what. The site that I refer to provides a reasonably concise and easy to understand description of the history of quanta and quantum mechanics.

Here is an short article written by Bernard d'Espagnat:

Bernard d'Espagnat: What we call 'reality' is just a state of mind | Science | guardian.co.uk

And here is a nice blog posting on the double slit and delayed choice experiment:

wave-particle duality Morning Coffee Physics

Rich

1 Reply

@Exebeche,

Without being too adventurous or supposing anything very specific about 'nature' or 'consciousness', it would seem to me that the very least you can conclude from this discussion is something very close to one of these positions:

There is no absolute objectivity
No 'atom' in the sense proposed by philosophical atomism (where the atom is an indivisible particle or point) has been discovered
Therefore, we have yet to locate an ultimate constituent of material objects.

I would have thought that if this were true, physics, insofar as it is concerned with the nature of reality, has something of a problem on its hands. Isn't this why they are calling this 'Higgs Boson' the God particle? Because without it, we really don't have a model of sub-atomic matter (not to mention Dark Matter and String Theory and Multiple Universes and all of the other wildly speculative creatures of the scientific imagination....)

My take: we are on the verge of a complete revolution in understanding. Because the 'current model' can barely qualify as a 'model' any more.

---------- Post added 08-03-2009 at 04:09 PM ----------

Incidentally I am quite happy to adopt the position of 'agnostic' in all of this. The out look of an agnostic provides for many different possibilities or potential explanations without necessarily jumping to a conclusion about it.

1 Reply

@jeeprs,

jeeprs;81033 wrote:

Incidentally I am quite happy to adopt the position of 'agnostic' in all of this. The out look of an agnostic provides for many different possibilities or potential explanations without necessarily jumping to a conclusion about it.

I too am certainly agnostic, since I have absolutely no idea what it might be at the moment. However, I do like Bohm's point of view on this matter, and it is certainly an viewpoint that I will be investigating further.

http://www.math.rutgers.edu/~oldstein/quote.html And is it not clear, from the diffraction and interference patterns, that the motion of the particle is directed by a wave? De Broglie showed in detail how the motion of a particle, passing through just one of two holes in screen, could be influenced by waves propagating through both holes. And so influenced that the particle does not go where the waves cancel out, but is attracted to where they cooperate. This idea seems to me so natural and simple, to resolve the wave-particle dilemma in such a clear and ordinary way, that it is a great mystery to me that it was so generally ignored."[RIGHT] J.S. BELL
Speakable and Unspeakable in Quantum Mechanics [/RIGHT]

Rich

0 Replies

@Exebeche,

"What quantum mechanics tells us, I believe, is surprising to say the least. It tells us that the basic components of objects - the particles, electrons, quarks etc. - cannot be thought of as "self-existent". - Bernard D'espagnant

interesting use of words there - 'self existent'. Absence of self-existence =(or 'svabhava', 'own-being') is the hallmark of all existing particulars according to Mahayana Buddhism. This is why they are described as 'sunya', empty. It is not to say that they don't exist, which is nihilism, nor to say that they exist for ever, which is eternalism. Their existence is conditioned and contingent.

"Entanglement-at-a-distance does physically exist, in the sense that it has physically verifiable (and verified) consequences. Which proves beyond a shadow of a doubt that some of our most engrained notions about space and causality should be reconsidered."

It all points towards the fact that material reality is not absolute.

I think this is the part that is upsetting to scientists. 'Cosmos is all there is' says Sagan.

'Not', says QM.

1 Reply

@jeeprs,

jeeprs;81057 wrote:

I think this is the part that is upsetting to scientists. 'Cosmos is all there is' says Sagan.

'Not', says QM.

Yes, there is plenty of mystery out there for everyone to explore.

Rich

0 Replies

@richrf,

richrf;81024 wrote:

This statement says it all. The fundamental particle is a wave. Say what?? Let's have that one more time. The particle is a wave.

One more for luck? The fundamental particle is a wave. Where's the problem?

richrf;81024 wrote:

Same with quantum mechanics. What do each of the constants and variables mean. What is quanta? Time to go digging into imagination.

I was refering to 'force of consciousness' not any actual science. 'Force of consciousness' is meaningless. Planck's constant isn't. The origin of its value is unknown, but the constant itself has a definition. 'Force of consciousness' has none.

richrf;81024 wrote:

Most of the great theories were initially ridiculed, including Einstein's. And it took quite some time for experimental proof to verify. In fact, the initially experiments invalidated Einstein's work and Einstein never received a Nobel prize award for relativity. The initial work on QM was likewise met with lots of skepticism.

What are we talking about here, skepticism or ridicule? Two different things. Skepticism is healthy: analysis of a new theory or result should be rigorous. Ridicule is something else. I'm not sure what you have in mind about relativity. There was an alternative theory, Lorentzian ether theory, which predicted the same results for certain dynamics. This couldn't hold up after the work of Minkowski and others demonstrated the far-reaching and experimentally testable foundation Einstein laid. Secondly, I was talking about physicists today; you're talking about physicists in and around world wars. Politics are different now - the physics community is global.

richrf;81024 wrote:

The vast majority of scientists are not looking to rock the boat.

Proof? Or is this just opinion stated as fact?

richrf;81024 wrote:

They are quite comfortable teaching the same old stuff year after year in school. Heck, I was taught the Rutherford atom in college, in 1972 - 40 years after quantum theory eradicated that model. Why?

Easy. The basics of electronics in atoms is crucial to understanding basic chemical procresses, and so teaching chemistry. To date, these processes are still difficult to compute even with supercomputers using QM for anything but the smallest of atoms. Even describing the electronics of hydrogen is way beyond the capabilities of a high school student. The Rutherford model acts a simple approximation for getting across some of the basic concepts such as valency.

richrf;81024 wrote:

What confuses me is that in this thread we have one person describing quanta as a billiard ball (a totally false and outmoded representation), and another describing it as a wave (equally false). It is neither.

No, it is a wave. It interferes, it diffracts and it is described by a function that is a solution to a wave equation. That's a wave. The 'particle-like' aspect is conditional on some apparatus that is looking for 'particle-like' behaviour, e.g. a measurement of position, but even then the particle has a wavefunction. It never ceases to be a wave. The mystery lies in how it collapses/evolves from one waveform to another that is compatible with single-valued measurement.

Wave-particle duality is overstated because it is easier to explain to mass audiences than the more complicated and ontologically-up-for-grabs but much more accurate theory.

Take the double slit experiment. In the absence of a scatterer betraying which slit the particle passed through, the question of which is irrelevant. The particle, a wave, passes through both slits just as, say, a water wave will pass through two arches. When it reaches the screen at the other end, some collapse mechanism (unknown) causes it to change from a wave occupying the whole apparatus to, say, a point on the screen (it needn't, in fact probably WOULDN'T, be a point but a wavepacket of some kind). Here the particle has been emitted and transmitted as something approaching a plane wave but has collapsed to a delta function (a spike) or a constricted wavepacket.

If you add the scatterer and ensure it is strong enough to always detect which path the particle took, then the scatterer will collapse the wavefunction first. This gives a new point of transmission from which the particle continues to the screen. Since there are no more slits to pass through, there is no interference and the particles arrive at the screen exactly as if they'd passed through one slit or the other, a very different statistical distrubution to that described above (which gives rise to the interference bands). This is what those who write pop sci books mean when they say 'particle-like', but in fact there's no difference: simply an additional event in the particle's evolution between transmission and detection on the screen. It never stopped being a wave.

All this highlights a problem I mentioned earlier. QM desperately needs a philosophy if it is to be anything other than a results-forecaster, but it requires years of mathematical physics study to get even basics like the double-slit experiment. Unfortunately good philosophers are a rarity in physics (bad philosophers are abound, as are anti-philosophers... the 'shut-up-and-calculate' posse), and good QM understanding rare in philosophers. Alas it's been around so long everyone's formed their own opinions.

---------- Post added 08-05-2009 at 04:13 PM ----------

jeeprs;81057 wrote:

"What quantum mechanics tells us, I believe, is surprising to say the least. It tells us that the basic components of objects - the particles, electrons, quarks etc. - cannot be thought of as "self-existent". - Bernard D'espagnant

interesting use of words there - 'self existent'. Absence of self-existence =(or 'svabhava', 'own-being') is the hallmark of all existing particulars according to Mahayana Buddhism. This is why they are described as 'sunya', empty. It is not to say that they don't exist, which is nihilism, nor to say that they exist for ever, which is eternalism. Their existence is conditioned and contingent.

"Entanglement-at-a-distance does physically exist, in the sense that it has physically verifiable (and verified) consequences. Which proves beyond a shadow of a doubt that some of our most engrained notions about space and causality should be reconsidered."

It all points towards the fact that material reality is not absolute.

I think this is the part that is upsetting to scientists. 'Cosmos is all there is' says Sagan.

'Not', says QM.

This is interesting. You should look into the 'Dirac sea'. It is an interesting illustration of this idea. We have defined electric charge to be positive or negative: e.g. positrons (+) and electrons (-). However, this is arbitrary. We could say electrons have + charge.

Now, when Dirac formulated relativistic QM, he found that there should be an infinite number of negative energy electron states. If there's a basic law of nature it is this: any system (inc. a single particle) will spontaneously decay to the lowest possible energy that there exists a means to reach. This means that any positive energy state (a normal electron state) should spiral down the negative energy ladder ad infinitum, releasing energy as it does so.

Why does this not happen? Dirac offered this explanation: all of the negative energy states are already filled, and a known law called the Pauli exclusion principle forbids two particles be in the same state. This continuum of filled states became known as the 'Dirac sea'.

It offers a nice explanation of matter-antimatter creation: a photon of light may excite a particle from the sea into the positive enegry spectrum, leaving a positive energy particle (electron, say) and a hole in the filled states (positron).

All well and good, yes? BUT... what can be said of electrons may equally be said of positrons (remember the charge assignment is arbitrary). So positrons may be positive energy excitations from the negative energy 'Dirac sea' leaving electron 'holes'. Which is it?

Mathematically it doesn't matter: the situation is completely symmetric. But philosophically it must be one or the other. We cannot say electrons are excitations from the sea, or positrons. Which we do say, and so our entire philosophy of particle creation, depends on an arbitrary choice of our own. Is anything more contingent than that?

Good addition to the topic. Thanks.

Bones

1 Reply

@Bones-O,

Bones-O!;81467 wrote:

One more for luck? The fundamental particle is a wave. Where's the problem?

Well, unlike myself and all of the physicists who developed quantum physics, who had a real issue coming to grips with the wave/particle duality of quanta, you seem to take it in casual stride. If it does not shock you, then I guess nothing will.

If quantum mechanics hasn't profoundly shocked you, you haven't understood it yet. [Neils Bohr]

Bones-O!;81467 wrote:

I was refering to 'force of consciousness' not any actual science. 'Force of consciousness' is meaningless.

Maybe for you. For me and for others who are considering the role of consciousness in organizing chaos, it is quite meaningful. And if science wants nothing to do with it, it is fine with me. I enjoy discussing the possibilities with other metaphysicists. There is nothing that precludes the notion and it is certainly something that I find interesting enough to investigate.

Bones-O!;81467 wrote:

Planck's constant isn't. The origin of its value is unknown, but the constant itself has a definition. 'Force of consciousness' has none.

OK. Call consciousness the organizing force, if that helps. I'm open to discussion, seeing how it is with use every where we go, even while we are asleep.

Bones-O!;81467 wrote:

What are we talking about here, skepticism or ridicule?

I guess I am talked about ridicule being masked as scientific skepticism. I see it all the time. And the hammer that enforces it is called job opportunities. Here is but one example:

Einstein's Special Theory of Relativity ? FREE Einstein's Special Theory of Relativity information | Encyclopedia.com: Find Einstein's Special Theory of Relativity research

Other American scientists, with considerably less understanding, ridiculed special relativity, attacking it as metaphysical and unrelated to observation.

History Asia - Einstein

Although Einstein's greatest work was accomplished in 1905 when he thought up his theories of relativity and special relativity, it was 14 years before his "outside the box" principles were proven. Until then, he was ridiculed, challenged and had difficulty getting a prestigious job.

I have read several books which provide a full discussion on this matter. Scientists are humans, and their first gut reaction is usually to ridicule anything that may upset the cart - and their sources of funding for their own pet research. They are not immune to basic human emotions and behavior - e.g. self preservation.

Bones-O!;81467 wrote:

Secondly, I was talking about physicists today; you're talking about physicists in and around world wars. Politics are different now - the physics community is global.

I realize every generation would like to believe that they are different - but the more things change the more they stay the same. I know it is a paradox, but one that seems to describe human nature very well.

Bones-O!;81467 wrote:

Proof? Or is this just opinion stated as fact?

Everything I state is always an opinion based upon my own experiences.

Bones-O!;81467 wrote:

The Rutherford model acts a simple approximation for getting across some of the basic concepts such as valency.

Unfortunately it perpetuates notions within other disciplines, e.g. philosophy, which are totally outdated.

Bones-O!;81467 wrote:

No, it is a wave.

Feynman, in his book Six Easy Pieces, explicitly says it is neither particle nor wave. However, he says, one may refer to it as a particle-wave if one wishes.

Bones-O!;81467 wrote:

It interferes, it diffracts and it is described by a function that is a solution to a wave equation. That's a wave.

The problem is that when it is observed, it also acts exactly like a particle.

Bones-O!;81467 wrote:

The mystery lies in how it collapses/evolves from one waveform to another that is compatible with single-valued measurement.

Yep, that is a mystery. No one knows whether it collapses, whether it discards, whether it goes off into many-universes. It is a total, complete unknown. Your choice to call it a wave is actually quite a outlying opinion, and is one of the reasons I don't take as given what a scientist says. You are in direct contradiction to Feynman on this point who considers it neither, and has no idea what it is - a stance taken by most physicists that I have read on this subject. However, there are many interpretations and speculations.

For a rather complete discussion on wave-particle duality. The article actually says that there is one scientist who proposes it is a wave. So you have one scientist who supports your view.

Wave?particle duality: Information from Answers.com

Quote:

If you add the scatterer and ensure it is strong enough to always detect which path the particle took, then the scatterer will collapse the wavefunction first.

I enjoy your simplified treatment of the subject, just as I enjoyed the billiard ball example. However, unfortunately, it is neither this simple nor that simple. And while other physicists grope with what might be going on (or simply ignore it as being inconsequential), you seem to have found a very comfortable spot in life. Congratulations.

From the above article:

Treatment in modern quantum mechanics

Wave-particle duality is deeply embedded into the foundations of quantum mechanics, so well that modern practitioners rarely discuss it as such. In the formalism of the theory, all the information about a particle is encoded in its wave function, a complex valued function roughly analogous to the amplitude of a wave at each point in space. This function evolves according to a differential equation (generically called the ), and this equation gives rise to wave-like phenomena such as interference and diffraction.
The particle-like behavior is most evident due to phenomena associated with measurement in quantum mechanics. Upon measuring the location of the particle, the wave-function will randomly "collapse" to a sharply peaked function at some location, with the likelihood of any particular location equal to the squared amplitude of the wave-function there. The measurement will return a well-defined position, a property traditionally associated with particles.
Although this picture is somewhat simplified (to the non-relativistic case), it is adequate to capture the essence of current thinking on the phenomena historically called "wave-particle duality".

Quote:

simply an additional event in the particle's evolution between transmission and detection on the screen. It never stopped being a wave.

It probably never was one either.

Quote:

Alas it's been around so long everyone's formed their own opinions.

I think that most philosophers and physicists, and anyone else who has investigated quantum phenomenon, as well as Relativity, have probably formed no opinion at all, but are rather agnostic as they try to grapple with he meaning of the mathematical formulas and what they are observing experimentally.

"I think I can safely say that nobody understands quantum mechanics." --R.P. Feynman

Rich

2 Replies

@richrf,

richrf;81473 wrote:

Well, unlike myself and all of the physicists who developed quantum physics, who had a real issue coming to grips with the wave/particle duality of quanta, you seem to take it in casual stride. If it does not shock you, then I guess nothing will.

If quantum mechanics hasn't profoundly shocked you, you haven't understood it yet. [Neils Bohr]

Luckily I didn't have the baggage Bohr had. QM was new to him, and much less understood. I only became interested in physics via QM. The velocities of balls rolling down inclines and the electric field energy of a charged capacitor just don't do it for me. Yeah, I see no problem with particles being described by waves. Of all the aspects of QM, I find that the least shocking.

richrf;81473 wrote:

Maybe for you. For me and for others who are considering the role of consciousness in organizing chaos, it is quite meaningful. And if science wants nothing to do with it, it is fine with me. I enjoy discussing the possibilities with other metaphysicists. There is nothing that precludes the notion and it is certainly something that I find interesting enough to investigate.

Okay if it has meaning for you, groovy. Lay it out for me. The wording itself screams pseudoscience. If you have a self-consistent idea of what this force is, I'd be interested to read it.

richrf;81473 wrote:

OK. Call consciousness the organizing force, if that helps. I'm open to discussion, seeing how it is with use every where we go, even while we are asleep.

Yes we do. But unless we're more than a tiny part of this Universe, that doesn't suggest consciousness is fundamental to nature in any way.

richrf;81473 wrote:

I guess I am talked about ridicule being masked as scientific skepticism. I see it all the time. And the hammer that enforces it is called job opportunities. Here is but one example:

Einstein's Special Theory of Relativity ? FREE Einstein's Special Theory of Relativity information | Encyclopedia.com: Find Einstein's Special Theory of Relativity research

Other American scientists, with considerably less understanding, ridiculed special relativity, attacking it as metaphysical and unrelated to observation.

History Asia - Einstein

Although Einstein's greatest work was accomplished in 1905 when he thought up his theories of relativity and special relativity, it was 14 years before his "outside the box" principles were proven. Until then, he was ridiculed, challenged and had difficulty getting a prestigious job.

I have read several books which provide a full discussion on this matter. Scientists are humans, and their first gut reaction is usually to ridicule anything that may upset the cart - and their sources of funding for their own pet research. They are not immune to basic human emotions and behavior - e.g. self preservation.

Oh sure. On the first point, this takes us back to politics. On both, neither quote gives us the nature of the ridicule. I'd be interested to see what constitutes ridicule. Scientific skepticism isn't it.

richrf;81473 wrote:

I realize every generation would like to believe that they are different - but the more things change the more they stay the same. I know it is a paradox, but one that seems to describe human nature very well.

Well... no. We were actually at war with the Germans twice around that era. We had political reasons for not endorsing a German theory. If an Iraqi and an Afghan got together and solved, say, the origin of mass I don't think we'd react in anything like that manner. Irrespective of generations, the scientific community has changed. It used to be isolationist. Now networking and sharing is everything. Technology has driven this to a large extent. Saying 'the more things stay the same' suggests... what? Conferences weren't rarer, Skype has always existed, travel abroad wasn't harder..?

richrf;81473 wrote:

Everything I state is always an opinion based upon my own experiences.

You don't have the necessary experience to make gross generalisations like that. You're not in that field, yet you'll swear blind you know enough to tell someone in that field what it's like.

richrf;81473 wrote:

Unfortunately it perpetuates notions within other disciplines, e.g. philosophy, which are totally outdated.

Well that comes down to teachers. Ours made it clear that the Rutherford model was an approximation and outdated. Again, the communication of science leaves much to be desired.

richrf;81473 wrote:

Feynman, in his book Six Easy Pieces, explicitly says it is neither particle nor wave. However, he says, one may refer to it as a particle-wave if one wishes.

Again, a layman's book.

richrf;81473 wrote:

The problem is that when it is observed, it also acts exactly like a particle.

It acted like a particle before. It had discrete quantities (mass, charge, angular momentum) and was indivisible. It just didn't act like a point particle, or a rigid extended body (like a billiard ball). Nor does it when it is measured. A point represents a limit of some kinds of measurement, but not all. For instance, in measuring the particle's momentum it remains an extended wave.

richrf;81473 wrote:

I enjoy your simplified treatment of the subject, just as I enjoyed the billiard ball example. However, unfortunately, it is neither this simple nor that simple. And while other physicists grope with what might be going on (or simply ignore it as being inconsequential), you seem to have found a very comfortable spot in life. Congratulations.

Glad you enjoyed it. Yes, it was simplified, but much less so than the usual manner it is presented to general audiences. In fact, I hope I've demonstrated that it isn't too hard to describe QM without misleading the reader. To say that, when we try to measure which slit the particle passes through it will pass through one or the other (point particle, or billiard ball model) is misleading, yet it is omnipresent in pop sci literature. The particle evolves as a wave exactly as in the absence of the scatterer... up until the scatterer collapses it. We infer a particular slit from the side of the scatterer that collapse occurred. But the particle passed through both slits regardless (it had to to reach the scatterer). Simplified, yes, but there's nothing there that's untrue. No other theoretical physicist has a problem with this. There are many other problems in QM... this isn't one. It used to be, of course...

richrf;81473 wrote:

I think that most philosophers and physicists, and anyone else who has investigated quantum phenomenon, as well as Relativity, have probably formed no opinion at all, but are rather agnostic as they try to grapple with he meaning of the mathematical formulas and what they are observing experimentally.

Sure, about some things. In fact, about many things. I'm not sure there are many who would disagree that particles are waves tho. I've certainly never met one, or read one of late.

Your reference to Bohm earlier is an example of someone who clung to classical ideas of point particles. His theory is mathematically equivilent to QM - it was designed to be. Bohmian mechanics isn't highly regarded in physical circles. I initially took this to be because physicists tend to be a bit religious about their interpretations (string theorists, MWI-ers, shut-up-and-calculate, etc) and that Bohm's theory was perfectly plausible. But it undermines itself. It presents an attractive theory of point particles guided by a single potential wave. However, the ground state electron charge density of hydrogen is spherically symmetric about the nucleus: the atom has no electric dipole moment. This cannot be the case for a point particle electron. It was suggested that the charge is actually held in the space of the potential wave rather than the particle, thus destroying the reason for a point-particle model such as Bohm's.

I'm actually fine with hidden variables. I'm happy to talk about things that we can't measure since I don't think everything in reality is measurable. But Bohmian mechanics is not a good theory.

1 Reply

@Bones-O,

Bones-O!;81476 wrote:

Okay if it has meaning for you, groovy. Lay it out for me. The wording itself screams pseudoscience.

Everything we are talking about is opinion, speculation, and creative imagination.

Bones-O!;81476 wrote:

You don't have the necessary experience to make gross generalisations like that. You're not in that field, yet you'll swear blind you know enough to tell someone in that field what it's like.

Everyone, every statement, every reference that you disagree with you dismiss. Of course, you have your own opinions and speculations just like everyone else. However, I prefer those authors who offer it up as such.

Bones-O!;81476 wrote:

I'm not sure there [re many who would disagree that particles are waves tho. I've certainly never met one, or read one of late.

If you want to read someone who disagrees, may I refer you to d'Espagnat or Bell. Bell seems to support Bohm and de Broglie:

While the founding fathers agonized over the question 'particle' or 'wave', de Broglie in 1925 proposed the obvious answer 'particle' and 'wave'. Is it not clear from the smallness of the scintillation on the screen that we have to do with a particle? And is it not clear, from the diffraction and interference patterns, that the motion of the particle is directed by a wave? De Broglie showed in detail how the motion of a particle, passing through just one of two holes in screen, could be influenced by waves propagating through both holes. And so influenced that the particle does not go where the waves cancel out, but is attracted to where they cooperate. This idea seems to me so natural and simple, to resolve the wave-particle dilemma in such a clear and ordinary way, that it is a great mystery to me that it was so generally ignored.

"Six Possible Worlds of Quantum Mechanics" (1986), included in Speakable and Unspeakable in Quantum Mechanics (1987), p. 191

Thanks for sharing your opinions with me. I enjoy reading and hearing all points of view. I do prefer those presentations that present all viewpoints in an unbiased manner, e.g.

Interpretation of quantum mechanics - Wikipedia, the free encyclopedia

The most common interpretations are summarized in the table below. The values shown in the cells of the table are not without controversy, for the precise meanings of some of the concepts involved are unclear and, in fact, are themselves at the center of the controversy surrounding the given interpretation.

No experimental evidence exists that distinguishes among these interpretations. To that extent, the physical theory stands, and is consistent with itself and with reality; difficulties arise only when one attempts to "interpret" the theory. Nevertheless, designing experiments which would test the various interpretations is the subject of active research.

Most of these interpretations have variants. For example, it is difficult to get a precise definition of the Copenhagen interpretation. The table below gives two variants: one that regards the waveform as being a tool for calculating probabilities only, and the other regards the waveform as an "element of reality."

http://i801.photobucket.com/albums/yy293/richrf/quantumtable.png

1 If wavefunction is real then this becomes the many-worlds interpretation. If wavefunction less than real, but more than just information, then Zurek calls this the "existential interpretation".
2 Quantum mechanics is regarded as a way of predicting observations, or a theory of measurement..
3 But quantum logic is more limited in applicability than Coherent Histories.
4 Observers separate the universal wavefunction into orthogonal sets of experiences.
5 Both particle AND guiding wavefunction are real.
6 Unique particle history, but multiple wave histories.
7 In the TI the collapse of the state vector is interpreted as the completion of the transaction between emitter and absorber.
8 Comparing histories between systems in this interpretation has no well-defined meaning.
9 Any physical interaction is treated as a collapse event relative to the systems involved, not just macroscopic or conscious observers.
10 The nature and collapse of the wavefunction are derived, not axiomatic.

Rich

1 Reply

The mystical Copenhagen Interpretation

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