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Old Feb 20th 2018, 05:49 AM   #1
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Widespread misinterpretation of quantum mechanics

In these past years I came to learn of a widespread misinterpretation of quantum mechanics. This misinterpretation is not merely by amateurs and students but by professional physicists as well.

The misinterpretation is that a particle, such as an electron or photon, can be in two places at once. To see how widespread it is just Google it and you'll see. I'm not the only one who knows this to be a gross error. I've spoken to several friends and acquaintances who teach the subject. One of them teaches it at MIT in fact. They too see the error in it.

It's due to a false grasp of the basic concepts of QM such as the notion of electron clouds and the false belief that a particle can interfere with itself in instances like a photon passing through a screen having a double slit.

I'll explain more when I see the responses to this thread. I'm almost certain that at least one person will attempt to correct what I've said. Wanna guess who that may be?
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Old Feb 20th 2018, 07:33 AM   #2
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Yep. QM is hard!
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Old Feb 20th 2018, 07:58 AM   #3
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Originally Posted by Pmb View Post
In these past years I came to learn of a widespread misinterpretation of quantum mechanics. This misinterpretation is not merely by amateurs and students but by professional physicists as well.

The misinterpretation is that a particle, such as an electron or photon, can be in two places at once. To see how widespread it is just Google it and you'll see. I'm not the only one who knows this to be a gross error. I've spoken to several friends and acquaintances who teach the subject. One of them teaches it at MIT in fact. They too see the error in it.

It's due to a false grasp of the basic concepts of QM such as the notion of electron clouds and the false belief that a particle can interfere with itself in instances like a photon passing through a screen having a double slit.

I'll explain more when I see the responses to this thread. I'm almost certain that at least one person will attempt to correct what I've said. Wanna guess who that may be?
Am I one of the ones that are going to try to correct you? From past experience you know far more about the philosophy behind QM so I'm not even going there!

However, in my estimation you are absolutely correct. And as I recall one of my QM texts actually has a description of single particle "interference" as a particle being at the two slots at the same time.

I suspect a large part of the problem is that the nature of the Quantum world can be so confusing to teach at an appropriate level and thus the students don't get what they need in most cases. Remember we are teaching students who generally are entirely unprepared to "get" how this all works so the teachers (sigh, myself included) try to "dumb it down" into more familiar concepts...an approach which really is an abysmal failure. A good try, perhaps, but a failure none the less.

It would be better that texts, Professors, etc. would simply start off the class by saying something like "We're going to teach you the rules. They have little to do with anything you have ever learned. But they are a logical system that has been proven to be consistent and experimentally valid. So buck it up kids! It's gonna be a wild ride!"

Of course the other problem, in which I have a problem with practically all Physics courses that I have taken, is that Physicists don't really teach the Math that their Physics students need to fully comprehend the material...particularly in the case of QM. I have a text that takes an axiomatic approach to undergrad QM. Practically everything develops from Linear Algebra, a class that is outside of any Physics curriculum I have seen. Really, a lousy 3 to 4 week long class in Linear Algebra would go a long way to help students.

Just my thoughts.

-Dan
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Old Feb 20th 2018, 08:01 AM   #4
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Originally Posted by benit13 View Post
Yep. QM is hard!
I find QM to be much easier to work with when I'm just a little drunk. (Really, it's true.)

-Dan
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Old Feb 20th 2018, 08:29 AM   #5
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Has anyone heard of Edward De Bono?

He introduced the concept of vertical v lateral thinking, amongst other ideas.

No disrespect, but Physicists tend to be vertical thinkers (Feynman apart) and that is what I see in the replies.
When presented with a scenario, they try to converge to an 'answer'.

This is what I try to do when helping questioners here, convergent thought.

But I see the need for some lateral thinking here.

I often preach the gospel that nature is stranger than any fiction that Man can devise, let alone rigourous thought.

All our best techniques fall into difficulties at the edges somewhere. QM, dimensional analysis, thermodynamics, infinite v finite, particle physics & the standard model........
And buried in all this is the conflict between pure maths and applied maths.

Which brings me to the OP scenario.

QM describes systems. If the systems includes particles then the system also includes the environment of those particles.

If you want to describe just the particles themselves, you need particle physics.

Incidentally there are umpteen equations, used everyday in Science, that are not dimensionally consistent.
Can anybody tell me what they are?

As a hint look at the tree thread everyone seems to have an angle on.
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Last edited by studiot; Feb 20th 2018 at 09:52 AM.
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Old Feb 20th 2018, 10:04 AM   #6
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Originally Posted by studiot View Post
Has anyone heard of Edward De Bono?

He introduced the concept of vertical v lateral thinking, amongst other ideas.
That's all fine and dandy but you neither provided a definition nor did you argue your case.

I looked those terms up and found that all physicists, at least the good ones, employ both methods. There are other terms used to describe those terms.

Vertical thinking == deductive logic
Lateral thinking == inductive logic
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Old Feb 20th 2018, 10:23 AM   #7
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Is it being suggested that the only way to describe QM interactions is via the mathematical equations?

Is it the case that the QM world is so dissimilar to everyday experience that any analogies that might be adopted are doomed to be inadequate?
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Old Feb 20th 2018, 10:43 AM   #8
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Originally Posted by Woody View Post
Is it being suggested that the only way to describe QM interactions is via the mathematical equations?

Is it the case that the QM world is so dissimilar to everyday experience that any analogies that might be adopted are doomed to be inadequate?
Not by me at any rate.

There is nothing you can say in Mathematics that you can't also say in English.

But there are things you can say in English that you can't say in Mathematics.


That's all fine and dandy but you neither provided a definition nor did you argue your case.
I think if you look closely at my comments you will find an answer here.

QM describes systems. If the systems includes particles then the system also includes the environment of those particles.

If you want to describe just the particles themselves, you need particle physics.
In QM you can't draw a free body diagram as you can in particle mechanics ( an indeed in other forms of mechanics.
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Old Feb 20th 2018, 10:45 AM   #9
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Originally Posted by Woody View Post
Is it being suggested that the only way to describe QM interactions is via the mathematical equations?
Close, but not exactly. However there is the old saying Shut up and calculate which is quite famous in QM circles.

Originally Posted by Woody View Post
Is it the case that the QM world is so dissimilar to everyday experience that any analogies that might be adopted are doomed to be inadequate?
Unfortunately when people try to relate it to everyday experience they almost always get the wrong idea. Oz appears to have rejected quantum mechanics because its so unlike everything he's used to.
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Old Feb 20th 2018, 11:00 AM   #10
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Microscopic Thermodynamics

If you have trouble sleeping, no booze needed. A few pages of

Microscopic Thermodynamics @ THERMO Spoken Here!

will do the trick. Check out Table IIIA-1 (Unit IIIA page 10). Exhaustive computer run
determines microstates among energy-levels, degeneracies to show "migration to equilibrium."
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