what makes comprehension "intuitive" or not?

[lemur]

It is common to hear the claim that quantum physics or other forms of modern physics are not intuitive and that any attempt to understand them intuitively can only result in increasing misunderstanding. So what exactly does it mean to think about or understand something intuitively? What other kinds of thinking/understanding are there that are not intuitive? I would guess that everything that is understood is understood intuitively in some sense, but maybe others see the possibility of totally non-intuitive understanding and, if so, what does/would that mean?

[TonyMcC]

I think that when you are logically developing an idea step by step with complete understanding of each step you are not acting intuitively.

Intuition (IMO) comes into play when the logical process seems to come to an end. At this time another approach, or gap filler in the logical chain, might seem to come "out of nowhere" and allow further development of your idea. This (again IMO) would be intuition.

Edited April 2, 2011 by TonyMcC

[Marat]

It is interesting in the context of this question to consider the efforts of Frege and Peano to develop the foundations of mathematics in the late 19th and early 20th centuries. Frege tried to articulate our intuitive sense of number by partially formalizing it in terms of one to one correspondence, but this is still a highly intuitive concept and clearly appeals to intuition for its any power it has to clarify our understanding of number. Peano extended the formalization further by defining number in terms of a successor function, yet this still seems not to have completely filtered out some covert appeal to intuition.

 

For those parts of physics and mathematics which initially resist intuitive comprehension, like Riemannian or Lobachevskian geometry, it seems that once you have absorbed them by the brute force of an intellectual mastery of what they entail and imply even beyond their intuitive sense, they then come to constitute a background knowledge which subconsciously becomes so familiar over time that it eventually constitutes a kind of intuitive knowledge relative to new things learned beyond it.

[Cap'n Refsmmat]

In physics, at least, "intuitive" refers to everyday experience with everyday objects. We all have an "intuitive" understanding of how objects interact, based on past experiences, and so we know that gravity makes things fall, no two objects occupy the same space simultaneously, objects can't pass through walls, and so on. Shown a basic physics problem, we can make a guess as to the answer simply by intuition, making analogies to real-world experiences to determine the likely result.

 

Quantum physics is non-intuitive because it violates many of our everyday principles. In quantum physics, two objects sometimes do occupy the same space simultaneously; objects passing through "walls" is in fact essential; and gravity behaves in very strange ways. Any attempt to understand quantum physics by analogy to everyday experiences -- i.e. any attempt to understand it "intuitively" -- is bound to fail, because it is so different from ordinary experience.

 

Hence in quantum physics it's helpful to consider things mathematically. Making analogies to everyday experience is misleading.

[lemur]

In physics, at least, "intuitive" refers to everyday experience with everyday objects. We all have an "intuitive" understanding of how objects interact, based on past experiences, and so we know that gravity makes things fall, no two objects occupy the same space simultaneously, objects can't pass through walls, and so on. Shown a basic physics problem, we can make a guess as to the answer simply by intuition, making analogies to real-world experiences to determine the likely result.

 

Quantum physics is non-intuitive because it violates many of our everyday principles. In quantum physics, two objects sometimes do occupy the same space simultaneously; objects passing through "walls" is in fact essential; and gravity behaves in very strange ways. Any attempt to understand quantum physics by analogy to everyday experiences -- i.e. any attempt to understand it "intuitively" -- is bound to fail, because it is so different from ordinary experience.

 

Hence in quantum physics it's helpful to consider things mathematically. Making analogies to everyday experience is misleading.

To me it sounds like what you're saying is that observed physical behavior of everyday objects is subject to certain limitations that are removed in quantum behavior. On the other hand, there are other limitations in quantum behavior that do not correspond with those of observable everyday objects. So, for example, the fact that a partial photon can't be created by making an electron emit it in a certain way or sub-dividing an existing photon somehow is a limitation that doesn't make (intuitive) sense from a broad perspective on analog physical behavior in which things can usually be further subdivided and partial version of things are possible (although I can think of numerous other examples where you could say that, e.g. a partial plant can't be created - although it can be subdivided once growing, etc.)

 

However, once you understand that electrons emit whole quanta of energy and this corresponds to whole numbers of waves in their electrons, and that electrons spin either up or down but never at different speeds or not at all, these things can become someone intuitively referenced, imo. For example, I can imagine a perfectly frictionless sphere that must always spin because it cannot remain motionless, and that the direction of the spinning could change instantly if the sphere had no inertia. In fact, this concept becomes more intuitively logical if you understand that light has no mass and always travels at C or gets absorbed, with no in-between speed. It may not be intuitively plausible in terms of how observable objects with mass move, but how does that prevent you from imagining it in its own right?

 

What I would like to know is if there are totally anti-intuitive forms of math in quantum physics. The example I have in mind of this is a statistical T-test, which eliminates the use of subjectivity to analyze a research question by replacing intuitive analysis with a seemingly-arbitrary mathematical protocol which acts as a black box. i.e. you feed your data into the black box and it gives you back numerical output that can be interpreted as telling you that either your hypothesis is supported or it's not. E.g. it works sort of like those liquid-filled 8-balls except there's only two answer "hypothesis supported" or "hypothesis not supported."

 

To me, what "intuitive" really means is that you develop a deep understanding of how the parameters work and you are able to make further predictions and theorize from that understanding. So, for example, if you just understand mathematically that acceleration is change in speed and that force is acceleration of a mass, you could calculate the relationship between force and momentum at a given speed at a certain rate of acceleration. But if you deeply understand these concepts, you can intuitively conceptualize how a waterfall can run a turbine and do work that generates energy, etc. You may not be able to calculate the exact quantities without the equations, but you can even develop an intuitive sense of relationships between things. E.g. I watched a documentary about the first telephones recently and it seemed quite intuitive, according to Planck's comparison of electricity with gas-dynamics, that sound could be translated from air-waves to electron-waves through a conductor. Yet I can remember being amazed when I was young that Bell was able to transmit sound through a wire (i.e. because it wasn't intuitively logical at that time for me).

[Cap'n Refsmmat]

To me it sounds like what you're saying is that observed physical behavior of everyday objects is subject to certain limitations that are removed in quantum behavior. On the other hand, there are other limitations in quantum behavior that do not correspond with those of observable everyday objects. So, for example, the fact that a partial photon can't be created by making an electron emit it in a certain way or sub-dividing an existing photon somehow is a limitation that doesn't make (intuitive) sense from a broad perspective on analog physical behavior in which things can usually be further subdivided and partial version of things are possible (although I can think of numerous other examples where you could say that, e.g. a partial plant can't be created - although it can be subdivided once growing, etc.)

Indeed.

 

However, once you understand that electrons emit whole quanta of energy and this corresponds to whole numbers of waves in their electrons, and that electrons spin either up or down but never at different speeds or not at all, these things can become someone intuitively referenced, imo. For example, I can imagine a perfectly frictionless sphere that must always spin because it cannot remain motionless, and that the direction of the spinning could change instantly if the sphere had no inertia. In fact, this concept becomes more intuitively logical if you understand that light has no mass and always travels at C or gets absorbed, with no in-between speed. It may not be intuitively plausible in terms of how observable objects with mass move, but how does that prevent you from imagining it in its own right?

The trouble is that this physical analogy is highly misleading. It is, in fact, physically impossible for electron spin to be caused by physical spin, because the electrons would have to spin faster than the speed of light. It also fails to explain numerous aspects of spin, such as its relation to other quantum numbers or why spin-1/2 particles behave entirely differently from spin-1 particles. (Spin-1 particles do not follow the Pauli exclusion principle and can occupy the same space at the same time.) Certain composite particles also have more possible spin states than "up" and "down."

 

Hence intuition leads you astray.

 

What I would like to know is if there are totally anti-intuitive forms of math in quantum physics. The example I have in mind of this is a statistical T-test, which eliminates the use of subjectivity to analyze a research question by replacing intuitive analysis with a seemingly-arbitrary mathematical protocol which acts as a black box. i.e. you feed your data into the black box and it gives you back numerical output that can be interpreted as telling you that either your hypothesis is supported or it's not. E.g. it works sort of like those liquid-filled 8-balls except there's only two answer "hypothesis supported" or "hypothesis not supported."

The math that leads to quantum tunneling can be pretty freaky.

[lemur]

The trouble is that this physical analogy is highly misleading. It is, in fact, physically impossible for electron spin to be caused by physical spin, because the electrons would have to spin faster than the speed of light. It also fails to explain numerous aspects of spin, such as its relation to other quantum numbers or why spin-1/2 particles behave entirely differently from spin-1 particles. (Spin-1 particles do not follow the Pauli exclusion principle and can occupy the same space at the same time.) Certain composite particles also have more possible spin states than "up" and "down."

 

Hence intuition leads you astray.

Ok, but then you can attempt to critically reform your intuitive understanding with respect to the given parameters. For example, is there some underlying logic in the Pauli exclusion principle or is it just totally arbitrary rules? Also, I don't know why the electron would have to spin faster than C, but it does make intuitive sense that a rotating electron would generate a magnetic fields the same way a moving charge in a conductor does. In that case, you have an intuitive basis for exploring further questions like what the relationship might be between different forces at the sub-atomic level. Without any intuitive sense of anything, all you can really do is calculate outcomes according to different parameters, no?

 

 

The math that leads to quantum tunneling can be pretty freaky.

I have been wondering about quantum tunneling. Is that just what electrons do within the probability wave of their location or is it a completely different topic? If it at least describes actual behavior, that would be better, imo, than the statistical procedures that turn methodological questions like whether the data support or reject the hypothesis into a number. That's similar to me as when an election candidate wins with 51% and they call it a majority as if practically the exact same number of votes were cast for the opponent. I like math that directly represents/describes something empirical instead of abstracting something from empirical data and describing that, like a distribution of data points on various axes.

 

 

 

[Cap'n Refsmmat]

Ok, but then you can attempt to critically reform your intuitive understanding with respect to the given parameters. For example, is there some underlying logic in the Pauli exclusion principle or is it just totally arbitrary rules? Also, I don't know why the electron would have to spin faster than C, but it does make intuitive sense that a rotating electron would generate a magnetic fields the same way a moving charge in a conductor does. In that case, you have an intuitive basis for exploring further questions like what the relationship might be between different forces at the sub-atomic level. Without any intuitive sense of anything, all you can really do is calculate outcomes according to different parameters, no?

For a rotating electron to have the correct angular momentum as determined by experiment, it would have to spin so quickly that its surface would rotate faster than the speed of light. As for the Pauli exclusion principle, the underlying logic comes out of the mathematics.

 

Without an intuitive sense, you can still determine useful facts about a situation. Thinking in terms of mathematical features allows you to estimate how something will behave, but you think about it in terms of wavefunctions and exponentials rather than physical objects doing physical things.

 

I have been wondering about quantum tunneling. Is that just what electrons do within the probability wave of their location or is it a completely different topic? If it at least describes actual behavior, that would be better, imo, than the statistical procedures that turn methodological questions like whether the data support or reject the hypothesis into a number. That's similar to me as when an election candidate wins with 51% and they call it a majority as if practically the exact same number of votes were cast for the opponent. I like math that directly represents/describes something empirical instead of abstracting something from empirical data and describing that, like a distribution of data points on various axes.

The point of quantum mechanics is that there isn't something physical beyond the wavefunction, which describes the probability of the particle existing at various locations. When you work out the mathematics, it turns out that there is a nonzero probability of a particle making it past a boundary, simply because the boundary conditions on the wavefunction require this to be true for the equation to be solved. There is no known "actual behavior" beyond what the mathematics predicts will occur.

 

Drawing a physical analogy to explain the behavior intuitively will mislead you, because there is no known physical explanation, only mathematics. One might postulate that there are hidden processes occurring "underneath" to explain quantum behavior, and that such processes can be modeled intuitively, but Bell's theorem rules that out.

[lemur]

Drawing a physical analogy to explain the behavior intuitively will mislead you, because there is no known physical explanation, only mathematics. One might postulate that there are hidden processes occurring "underneath" to explain quantum behavior, and that such processes can be modeled intuitively, but Bell's theorem rules that out.

I just googled Bell's theorem and it was not very clear to me. The introduction of the wiki page says something about either having to violate the principle of locality or counterfactual definiteness. Why is the principle of locality a stumbling block for intuitive modeling? Doesn't gravitational relations between heavenly objects in classical mechanics require planets and stars to influence each other at a distance? And although you may not be able to define things without being able to empirically measure them, you can model them and test the implications of the model against knowable data as well as deduce further implications of the model and test those or evaluate them with respect to known parameters, no?

 

Anyway, this is getting off track. What it seems you're saying is that while it may be possible to develop mathematical intuition, the math doesn't describe anything visualizable. Nevertheless, I think you can develop an intuitive sense of quantification translated through subsequent contexts. E.g. EM emissions are quantized, which makes it logical that electrons are quantized, which may translate into some other aspects of physical behavior being explained by whatever it is the prevents energy from radiating in non-discreet amounts. That would still be intuitive logic, even if it wasn't the same intuitive logic as knowing why a ball decelerates as it goes up and accelerates on the way down.

 

 

[Cap'n Refsmmat]

I just googled Bell's theorem and it was not very clear to me. The introduction of the wiki page says something about either having to violate the principle of locality or counterfactual definiteness. Why is the principle of locality a stumbling block for intuitive modeling? Doesn't gravitational relations between heavenly objects in classical mechanics require planets and stars to influence each other at a distance? And although you may not be able to define things without being able to empirically measure them, you can model them and test the implications of the model against knowable data as well as deduce further implications of the model and test those or evaluate them with respect to known parameters, no?

Sure.

 

Locality isn't a problem. Locality is intuitive. Particles only influence their surroundings, or interact through forces which travel at the speed of light, like gravity. Gravity is intuitive.

 

However, if we allow locality, we have to throw out counterfactual definiteness, which says something like this: If I have not yet measured some property of a system, the system merely has a definite property but I do not know it. For example, the particle has a certain momentum, and I merely need to do an experiment to determine what it is.

 

But if we allow locality, Bell's theorem requires us to throw out counterfactual definiteness. Now, if I have not yet measured the momentum of a particle, it has no definite momentum. It's as if reality hasn't yet decided what to do with the particle until I force its hand by trying to measure it.

 

So you could try thinking of quantum mechanics in terms of particles moving around and being observed by experiment, but that'd be wrong, because the particles don't decide how to move around until I look at them.

 

Alternately, we could throw out locality and allow particles to instantaneously affect other particles a great distance away, which our sensibilities as well. Even Einstein whined about "spooky action at a distance."

 

Anyway, this is getting off track. What it seems you're saying is that while it may be possible to develop mathematical intuition, the math doesn't describe anything visualizable. Nevertheless, I think you can develop an intuitive sense of quantification translated through subsequent contexts. E.g. EM emissions are quantized, which makes it logical that electrons are quantized, which may translate into some other aspects of physical behavior being explained by whatever it is the prevents energy from radiating in non-discreet amounts. That would still be intuitive logic, even if it wasn't the same intuitive logic as knowing why a ball decelerates as it goes up and accelerates on the way down.

Intuitive logic as I defined it comes from everyday experience, in which case this is not true, because QM cannot be related to everyday experience.

 

It is true, however, that working from some physical principles not present in everyday experience but nevertheless essential to physics, we can build an understanding of modern physics using these basic building blocks. However, it is necessary to introduce new building blocks, rather than relying on the material concepts we already know.

 

We must also remember Richard Feynman's words: "I think I can safely say that nobody understands quantum mechanics."

[lemur]

However, if we allow locality, we have to throw out counterfactual definiteness, which says something like this: If I have not yet measured some property of a system, the system merely has a definite property but I do not know it. For example, the particle has a certain momentum, and I merely need to do an experiment to determine what it is.

Even if you can't directly measure momentum, couldn't you recognize its consequences in observable phenomena?

 

But if we allow locality, Bell's theorem requires us to throw out counterfactual definiteness. Now, if I have not yet measured the momentum of a particle, it has no definite momentum. It's as if reality hasn't yet decided what to do with the particle until I force its hand by trying to measure it.

This I don't get, like the dead/alive cat in the box. It sounded like a philosophical issue to me until someone posted that it could be due to the EM effects of the body of the observer. I don't see what's so hard about modeling a system with all possible parameters, including observer effects. Ok, I do see what's hard about it, but I don't see why it should impede progress to the point of giving up on logical (intuitive) modeling. Otherwise, what would physics become except for trial and error in fitting mathematical models to experimental data?

 

Alternately, we could throw out locality and allow particles to instantaneously affect other particles a great distance away, which our sensibilities as well. Even Einstein whined about "spooky action at a distance."

I'm at the point where I'm questioning how anything can occur at a distance if all force-fields extend indefinitely with decreasing intensity - but that is because I view a field as a type of object/entity. Does the sun attract the Earth via contact between the two gravitational fields or does the sun's gravitation act directly on the matter that constitutes the Earth? If so, what does "matter" ultimately refer to, the nuclei of atoms and to a less extent because of their small mass, the electrons?

 

Intuitive logic as I defined it comes from everyday experience, in which case this is not true, because QM cannot be related to everyday experience.

This is why I posted this thread. What basis do humans have to make sense of anything except multiple layers of abstraction based on foundations in their everyday experiences?

 

It is true, however, that working from some physical principles not present in everyday experience but nevertheless essential to physics, we can build an understanding of modern physics using these basic building blocks. However, it is necessary to introduce new building blocks, rather than relying on the material concepts we already know.

Exactly, so how are people supposed to understand the new building blocks except in comparison/contrast/analogy with familiar concepts in one form or another (or perhaps by hybridizing known forms).

 

We must also remember Richard Feynman's words: "I think I can safely say that nobody understands quantum mechanics."

I dislike that quote because it always seems to remind me of the link between atomic physics and atomic bombs, which is a political issue, imo, not one of physics.

 

 

[Cap'n Refsmmat]

Even if you can't directly measure momentum, couldn't you recognize its consequences in observable phenomena?

That's the same thing.

 

This I don't get, like the dead/alive cat in the box. It sounded like a philosophical issue to me until someone posted that it could be due to the EM effects of the body of the observer. I don't see what's so hard about modeling a system with all possible parameters, including observer effects. Ok, I do see what's hard about it, but I don't see why it should impede progress to the point of giving up on logical (intuitive) modeling. Otherwise, what would physics become except for trial and error in fitting mathematical models to experimental data?

It's not a matter of modeling systems more carefully. The particle has no definite momentum until it is observed. That's not to say we can't figure out the momentum -- that means it has no definite momentum. It has nothing to do with the accuracy of our models or how many parameters we can account for.

 

I'm at the point where I'm questioning how anything can occur at a distance if all force-fields extend indefinitely with decreasing intensity - but that is because I view a field as a type of object/entity. Does the sun attract the Earth via contact between the two gravitational fields or does the sun's gravitation act directly on the matter that constitutes the Earth? If so, what does "matter" ultimately refer to, the nuclei of atoms and to a less extent because of their small mass, the electrons?

You might consider learning how general relativity treats gravity; it should answer your question. Nevertheless, this is irrelevant to the topic at hand.

 

(You have a tendency to ask 400 questions in each post, only a few of which relate to the topic. I know you're just curious, but you should filter your posts, or we quickly diverge from the intended subject.)

 

Exactly, so how are people supposed to understand the new building blocks except in comparison/contrast/analogy with familiar concepts in one form or another (or perhaps by hybridizing known forms).

I don't think it's absurd to suggest it's possible to introduce new familiar concepts. Mathematics, for example, becomes familiar and intuitive when you work with it for a long time, and physics expressed in mathematics becomes much easier to understand. Many physicists prefer reading equations to qualitative descriptions, because qualitative descriptions can be vague or confusing when mathematics cannot be.

 

I dislike that quote because it always seems to remind me of the link between atomic physics and atomic bombs, which is a political issue, imo, not one of physics.

It has nothing to do with atomic bombs.

[lemur]

That's the same thing.

How so? If I have a pot of boiling water, I might not be able to measure the momentum of any of the molecules directly, but I can model the phase change in a way that explains how momentum results in liberation from a liquid-state and I could thus deduce predictions that would falsify my model if they failed.

 

It's not a matter of modeling systems more carefully. The particle has no definite momentum until it is observed. That's not to say we can't figure out the momentum -- that means it has no definite momentum. It has nothing to do with the accuracy of our models or how many parameters we can account for.

How do you KNOW for certain it has no definite momentum? How can you control for the possibility that it does have definite momentum but you just can't measure it?

 

(You have a tendency to ask 400 questions in each post, only a few of which relate to the topic. I know you're just curious, but you should filter your posts, or we quickly diverge from the intended subject.)

Usually my questions are meant to illustrate a certain line of thinking in hopes of stimulating further discussion. It's not my intent to fragment the thread, just to stimulate people's best contribution to the potentially emergent discussion.

 

I don't think it's absurd to suggest it's possible to introduce new familiar concepts. Mathematics, for example, becomes familiar and intuitive when you work with it for a long time, and physics expressed in mathematics becomes much easier to understand. Many physicists prefer reading equations to qualitative descriptions, because qualitative descriptions can be vague or confusing when mathematics cannot be.

I understand why people like equations, diagrams, and other non-linguistic representations. They are a breath of fresh air in contrast to all those dusty pages of prosaic writing that seem to get to the point as gradually as possible. But, as someone who has gone from despising classical texts to enjoying at least some immensely, I can tell you that there is value in doing physics in descriptive language. I was particularly surprised when I read a book by Max Planck that it was not that different from reading other political/philosophical texts from before WWII. I thought it would be like reading a textbook or a lot of technical jargon but it was clear and concise to someone with even just a cursory understanding of the subject matter from online discussions and web pages (i.e. me).

 

It has nothing to do with atomic bombs.

I suppose it is me reading the word "safely" out of context and the fact that he worked on the Manhattan project. Also, people blame Einstein for nuclear weaponry, as if a conceptual connection between energy and mass is sufficient to develop a nuclear weapon. And they also dislike Einstein because he began with intuition and only subsequently moved to doing rigorous equation-work. Saying that one can "safely assume that no one understand quantum physics" otherwise makes no sense to me. Why would you value a paradigm that impedes understanding? I understand the argument that QP produces tangible results, but it is still a shortcoming that it fails to stimulate at least one avenue of potential scientific progress by engaging human imaginations in theorizing.

 

 

[Cap'n Refsmmat]

How so? If I have a pot of boiling water, I might not be able to measure the momentum of any of the molecules directly, but I can model the phase change in a way that explains how momentum results in liberation from a liquid-state and I could thus deduce predictions that would falsify my model if they failed.

In quantum physics, it doesn't matter if you measure it directly or if you find some indirect method of determining it.

 

How do you KNOW for certain it has no definite momentum? How can you control for the possibility that it does have definite momentum but you just can't measure it?

Because under Bell's theorem, that is physically impossible, unless you want to abandon locality and let particles interact with each other instantaneously over long distances.

 

Bell's theorem prohibits local hidden variables, which would be hidden properties, like momentum you can't measure. Local hidden variables cannot adequately explain how quantum physics works. It's as simple as that.

 

Usually my questions are meant to illustrate a certain line of thinking in hopes of stimulating further discussion. It's not my intent to fragment the thread, just to stimulate people's best contribution to the potentially emergent discussion.

Many of your questions are utterly irrelevant. It would be in your best interests to focus your posts carefully.

 

Why would you value a paradigm that impedes understanding? I understand the argument that QP produces tangible results, but it is still a shortcoming that it fails to stimulate at least one avenue of potential scientific progress by engaging human imaginations in theorizing.

It accurately models experimental results. If anyone comes up with an intuitive formulation that still accurately models experimental results, it will be major news.

[lemur]

Because under Bell's theorem, that is physically impossible, unless you want to abandon locality and let particles interact with each other instantaneously over long distances.

Locality of what? What does it mean for force-fields to be distanced from each other?

 

Bell's theorem prohibits local hidden variables, which would be hidden properties, like momentum you can't measure. Local hidden variables cannot adequately explain how quantum physics works. It's as simple as that.

I guess I need a specific example to process this point.

 

Many of your questions are utterly irrelevant. It would be in your best interests to focus your posts carefully.

Well, if I learned what was irrelevant in responses, I would be able to focus on avoiding irrelevance in future posts, wouldn't I?

 

It accurately models experimental results. If anyone comes up with an intuitive formulation that still accurately models experimental results, it will be major news.

That seems to me to be part of the problem. If there is a culture of conformity that promises anyone who deviates from anti-intuitivism critical scrutiny and comparison with Einstein, of course people are going to avoid stepping into a spotlight that intense.

 

 

[Cap'n Refsmmat]

Locality of what? What does it mean for force-fields to be distanced from each other?

Interactions between particles happen at the speed of light. Violating locality would imply that if I moved an object here, an object light-years away would notice the difference in gravitational field instantaneously. Alternately, it'd imply that in quantum entanglement, some kind of information is instantaneously transmitted from one entangled particle to the other when one is observed. Or any number of other things.

 

I guess I need a specific example to process this point.

Put a particle in a sealed box. Leave it for a few hours and let it bounce around a bit. Return and stare at the box.

 

"Gee, I wonder where in the box the particle is," you think. "It'll be in there somewhere, I just don't know where exactly it is yet."

 

Suddenly, you are beaten over the head with a large physics textbook by the Quantum Physics Fairy, because it is not the case that the particle has one definite location inside the box that you just don't know. There is merely a wavefunction that can describe the probability of it being in any particular place. The particle will decide where it is once you open the box and take a look.

 

There is a fundamental difference between "I don't know where the particle is, but I shall find it shortly," and "The particle is not actually in a specific location until I look for it, at which point it decides where it is, based on the probability distribution given by the square of the wavefunction". The latter is experimentally correct, and the former is impossible.

 

Well, if I learned what was irrelevant in responses, I would be able to focus on avoiding irrelevance in future posts, wouldn't I?

Presumably a digression about quotes reminding you of nukes could be predicted in advance.

 

That seems to me to be part of the problem. If there is a culture of conformity that promises anyone who deviates from anti-intuitivism critical scrutiny and comparison with Einstein, of course people are going to avoid stepping into a spotlight that intense.

There is not a "culture of conformity." It is merely practicality. Experimental results are extremely hard to reconcile with intuitive models. Mathematics succeeds where intuition cannot, so physicists went with intuition. Should someone devise an intuitive model that can adequately explain quantum mechanics, physicists would be very happy, but they are not expecting that to ever happen, because quantum mechanics is very confusing and counterintuitive.

[lemur]

Interactions between particles happen at the speed of light. Violating locality would imply that if I moved an object here, an object light-years away would notice the difference in gravitational field instantaneously. Alternately, it'd imply that in quantum entanglement, some kind of information is instantaneously transmitted from one entangled particle to the other when one is observed. Or any number of other things.

In what situation would locality then be violated?

 

Put a particle in a sealed box. Leave it for a few hours and let it bounce around a bit. Return and stare at the box.

 

"Gee, I wonder where in the box the particle is," you think. "It'll be in there somewhere, I just don't know where exactly it is yet."

 

Suddenly, you are beaten over the head with a large physics textbook by the Quantum Physics Fairy, because it is not the case that the particle has one definite location inside the box that you just don't know. There is merely a wavefunction that can describe the probability of it being in any particular place. The particle will decide where it is once you open the box and take a look.

But why should this stop you from formulating ideas about how it got out of the box?

 

There is a fundamental difference between "I don't know where the particle is, but I shall find it shortly," and "The particle is not actually in a specific location until I look for it, at which point it decides where it is, based on the probability distribution given by the square of the wavefunction". The latter is experimentally correct, and the former is impossible.

Ok, what is then causal about looking for it?

 

Presumably a digression about quotes reminding you of nukes could be predicted in advance.

How do you know that Feynman wasn't playing with words to convey covert meanings? Regardless, the point is what value there is in quantum physics being incomprehensible and why Feynman would regard himself as "safely" being able to say so.

 

There is not a "culture of conformity." It is merely practicality. Experimental results are extremely hard to reconcile with intuitive models. Mathematics succeeds where intuition cannot, so physicists went with intuition. Should someone devise an intuitive model that can adequately explain quantum mechanics, physicists would be very happy, but they are not expecting that to ever happen, because quantum mechanics is very confusing and counterintuitive.

So do you mean to tell me that people who understand physics at this level are just as eager to spark an intuitive revolution as they are to take conservative steps forward that don't "rock the boat?" In every field, there is a "culture of conformity" so what makes you think quantum physics would be any different?

 

 

[swansont]

Because under Bell's theorem, that is physically impossible, unless you want to abandon locality and let particles interact with each other instantaneously over long distances.

 

Bell's theorem prohibits local hidden variables, which would be hidden properties, like momentum you can't measure. Local hidden variables cannot adequately explain how quantum physics works. It's as simple as that.

 

One should note that a number of experiments have been done which confirm this.

[lemur]

One should note that a number of experiments have been done which confirm this.

more nails in the coffin of hope for intuitive quantum physics?

[imatfaal]

How do you know that Feynman wasn't playing with words to convey covert meanings? Regardless, the point is what value there is in quantum physics being incomprehensible and why Feynman would regard himself as "safely" being able to say so.

 

We don't know he wasn't playing with words - but, in general, the simplest explanation is the best, until and unless it is shown to be deficient. There is no quest for 'value' - the quest is for models and theory that prediction and explain. A fuller version of the Feynman quote is as follows

 

There was a time when the newspapers said that only twelve men understood the theory of relativity. I do not believe there ever was such a time. There might have been a time when only one man did, because he was the only guy who caught on, before he wrote his paper. But after people read the paper a lot of people understood the theory of relativity in some way or other, certainly more than twelve. On the other hand, I think I can safely say that nobody understands quantum mechanics.

Again, the simplest explanation for the use of the word safely is that Feynman was contradicting one idea and replacing it with his own and he was sure that his new idea was unlikely to proven wrong ie "I can safely say this without fear of contradiction". If you are to impute non-standard usage and covert meanings then the burden of proof is on you - everything can be questioned and subtextualised (I am pretty sure I just made that word up) but some form of argument is needed to give foundation to that questioning.

The quote is taken from the Messenger Lecture series - it's all on-line, I will dig out a link

The next line from the lecture expands on the theme of this thread

So do not take the lecture too seriously, feeling that you really have to understand in terms of some model what I am going to describe, but just relax and enjoy it. I am going to tell you what nature behaves like. If you will simply admit that maybe she does behave like this, you will find her a delightful, entrancing thing. Do not keep saying to yourself, if you can possible avoid it, "But how can it be like that?" because you will get 'down the drain', into a blind alley from which nobody has escaped. Nobody knows how it can be like that.

Edited April 5, 2011 by imatfaal

[lemur]

There was a time when the newspapers said that only twelve men understood the theory of relativity. I do not believe there ever was such a time. There might have been a time when only one man did, because he was the only guy who caught on, before he wrote his paper. But after people read the paper a lot of people understood the theory of relativity in some way or other, certainly more than twelve. On the other hand, I think I can safely say that nobody understands quantum mechanics.

Again, the simplest explanation for the use of the word safely is that Feynman was contradicting one idea and replacing it with his own and he was sure that his new idea was unlikely to proven wrong ie "I can safely say this without fear of contradiction". If you are to impute non-standard usage and covert meanings then the burden of proof is on you - everything can be questioned and subtextualised (I am pretty sure I just made that word up) but some form of argument is needed to give foundation to that questioning.

There's no way of proving implicit meanings. That's one of the reason people use them to communicate; i.e. it shift responsibility for the meaning to the receiver. That's why you hear loads of public hearings and statements where people claim never to have said something that someone accused them of saying. People know how to be careful with words yet still convey the meanings they want to.

 

Generally that's true but in light of the context you posted for the Feynman quote, I can see how it refers to avoiding misinterpretation. Maybe I misinterpret it just because I can't stand the defeatism of giving up linguistic description and reasoning altogether to avoid the risk of misinterpretation. That would be as bad, imo, as giving up progress in science and technology altogether because some people use them to make deadly weapons and destructive and oppressive technologies of control. Oh wait, did I just tie it back into the nuclear weaponry issue?

 

 

[imatfaal]

There's no way of proving implicit meanings. That's one of the reason people use them to communicate; i.e. it shift responsibility for the meaning to the receiver. That's why you hear loads of public hearings and statements where people claim never to have said something that someone accused them of saying. People know how to be careful with words yet still convey the meanings they want to.

I agree - but when you posit an alternative reading/understanding with no indication of what the alternative intended meaning was or evidence to back up this claim then substantively you have said nothing. The questioning of motives only provides further information when it is accompanied by a logical argument (could be very short and implicit - "cui bono?") otherwise it is merely the automatic undermining of all comment through innuendo

 

Generally that's true but in light of the context you posted for the Feynman quote, I can see how it refers to avoiding misinterpretation. Maybe I misinterpret it just because I can't stand the defeatism of giving up linguistic description and reasoning altogether to avoid the risk of misinterpretation. That would be as bad, imo, as giving up progress in science and technology altogether because some people use them to make deadly weapons and destructive and oppressive technologies of control. Oh wait, did I just tie it back into the nuclear weaponry issue?

 

Watch the lecture - apologies for the larger than necessary mugshot of billy g http://research.microsoft.com/apps/tools/tuva/

 

 

 

 

 

[lemur]

I agree - but when you posit an alternative reading/understanding with no indication of what the alternative intended meaning was or evidence to back up this claim then substantively you have said nothing. The questioning of motives only provides further information when it is accompanied by a logical argument (could be very short and implicit - "cui bono?") otherwise it is merely the automatic undermining of all comment through innuendo

I watched the lecture, thanks for posting. It is ironic that he expresses the philosophical conclusion at the end that it is universally incorrect to assume that any knowable preconditions in nature determine experimental outcomes; since that itself would then be a known precondition, and thus undermine its own validity. To my credit, he does talk a lot about bullets and ultimately the possibility of WWIII in the lecture. He also worked on the Manhattan project and I read a book where he describes various aspects of information-security (secret keeping) of the project. I wouldn't, therefore, completely discount the possibility that part of his task as public physicist would be to promote nuclear security. Nevertheless, you're going to continue to tell me that without proof I shouldn't even mention the suggestion; plus I really don't like innuendo games. I just have to leave it at the fact that I find it hard to believe that following the enormous nuclear scare that existed subsequently to WWII and atomic weaponry, that no effort would have been made to systematically obfuscate knowledge that could potentially lead to nuclear developments. I don't see anything wrong with saying this because it is pretty obvious considering that some people have the notion that Einstein's work was foundational for inventing atomic weapons. Since I personally believe that humans have the power to resist destroying each other, I think the only way for them to exercise that power is to have it; plus I just don't like the idea of any knowledge being obfuscated because I find it anti-scientific. That said, there's no objective basis for knowing if Feynman's work (and Heisenberg's) helps clarify or obfuscate the possibility of attempting to theorize physics beyond quantum mechanics. Maybe he's right and there's no possible analogy in anything familiar, even though he goes on to use "analogy and contrast" to describe things in terms of familiar comparisons.

[imatfaal]

But there is objective proof - the ability of people (on this forum with whom you correspond) to make predictions based on non-classical physics that would have been impossible without their learned knowledge and the progress in the last 50 years or so based upon the work of people like Feynman and Heisenberg. There are people on this forum whose livelihoods depend on the results of experiment being as predicted and derived techniques behaving as expected - they will provide more physically accurate answers than those who base their reasoning upon intuitive feeling or even upon the mainstream physics of the mid-20C. This could be experimentally proven. If there is a deliberate obfuscation it has failed miserably - we are able to predict with greater precision and depth than we were before the "false-education" through bewilderment that you allege took place.

[lemur]

But there is objective proof - the ability of people (on this forum with whom you correspond) to make predictions based on non-classical physics that would have been impossible without their learned knowledge and the progress in the last 50 years or so based upon the work of people like Feynman and Heisenberg. There are people on this forum whose livelihoods depend on the results of experiment being as predicted and derived techniques behaving as expected - they will provide more physically accurate answers than those who base their reasoning upon intuitive feeling or even upon the mainstream physics of the mid-20C. This could be experimentally proven. If there is a deliberate obfuscation it has failed miserably - we are able to predict with greater precision and depth than we were before the "false-education" through bewilderment that you allege took place.

I'm completely familiar with the pragmatic validation of quantum physics. I'm not saying that it doesn't work or that people who do it are all engaged in some conspiracy to make sure another Einstein never surfaces. If anything, I'm just saying that the nature of anti-intuitive physics is such that it discourages create intuitive reasoning, partly because of its success, and that it would be nice if people wouldn't fear intuitive scientific thought as being a cause of nuclear weapons or something like that. What it really comes down to, imo, is a sense that number-crunching mathematics is more like other forms of bureaucratic work than the kind of intuitive theorizing associated with Einstein, so intuition tends to get demonized for this reason as well. Yes, I know you're going to tell me that is tangential to the facts about QP Feynman discusses, but I just have to point out that there are underlying "intuitive" reasons people favor one approach to science or another. People who are good at math LIKE science that highlights their math skills and downplay their uncertainty where creative intuitive reasoning is concerned. On the other hand, people who are good at intuitive reasoning like science that involves coming up with clever ways to explain and study things. There's no reason that physics should be a dead end where only one type of thought is able to go further.