Electron Orbits and Nuclei 2- Rotation vs Orbital Motion

[sokrates]

Debunking? I'm not debunking anything. I'm taking issue with unsupported claims.

And I'm talking about editing posts that have already been in the discussion stream.

That's the definition of debunking, considering that you are trying to take the issues with humor.

You just edited your post as well. But that's OK... There's a reason why the edit button is there, and I don't sit here all day to instantly reply to posts ,this is not instant messaging.
You should wait a while before you take the post into the stream (your reply rate averages on seconds) if you don't want to see edited replies.

My claims are not unsupported. You just don't understand them. Because you don't read them carefully. Because you post too fast. Then you complain about the whole process.

 

[DaveC426913]

My claims are not unsupported. You just don't understand them. Because you don't read them carefully. Because you post too fast. Then you complain about the whole process.

Nonsense. I read everything. I got what you were saying. I got that you were attacking the earlier argument. That does not change my objection.

 

[humanino]

Understanding and calculating are two different things.

QM has never been falsified, so discussing your emotions belongs to the philosophy forum, please.

 

[Phrak]

If this were universally enforced, all discussion of multiple world theories, and the Copenhagen interpretations, and notions concerning elements of physical reality would be moved from the quantum mechanics folder to philosophy, where they would die in the sesquipedalian world where conculsions are never meant to be found.

 

[DaveC426913]

If this were universally enforced, all discussion of multiple world theories, and the Copenhagen interpretations, and notions concerning elements of physical reality would be moved from the quantum mechanics folder to philosophy, where they would die in the sesquipedalian world where conculsions are never meant to be found.

humanino didn't post the full quote. His rebuke makes more sense with it:

Understanding and calculating are two different things. But I have a feeling that you feel better when you think you understand QM...

 

[sokrates]

humanino didn't post the full quote. His rebuke makes more sense with it:

1) His rebuke doesn't make sense at all (but I can see why otherwise you'd be happy) - because he's simply proposing to put all the interpretational discussions to philosophy board (as pointed out) which, with all due respect, is not up to anyone who dislikes the course of a debate.

Despite the resistance, the research on the interpretation of QM is still evolving, slowly but surely.

2) Adding that second line, made *so much more* sense... Thank you for the clarification.

 

[Phrak]

Yeah, well, I did read the post by sokrates.

I do appreciate an escalating argument between the two of you as well as the next guy, but if anyone isn't uncomfortable with the structure of quantum mechanics they've either gained immunity through repetition, or don't understand it.

 

[humanino]

he's simply proposing to put all the interpretational discussions to philosophy board

I really think discussions of the interpretation of QM have nothing to do here. If you apply the same well-defined set of rules, you'll obtain the same results. It is a matter of philosophy to decide whether you want to go for this or that interpretation. I did not say I was not interested in interpretation. I claim that you should be able to do the calculations first, and you can discuss that here. Once you are able to do decent calculations, you may discuss interpretations. There is enough technical material in QM to keep this part of the forum quiet and rigorous. I suggest you read serious books about the interpretation of QM if you want to attract people who really understand the issues.

 

[DaveC426913]

His rebuke doesn't make sense at all...

Adding that second line, made *so much more* sense... Thank you for the clarification.

It pointed out that you were talking about your (and other people's) feelings.

 

[sokrates]

I really think discussions of the interpretation of QM have nothing to do here. If you apply the same well-defined set of rules, you'll obtain the same results. It is a matter of philosophy to decide whether you want to go for this or that interpretation. I did not say I was not interested in interpretation. I claim that you should be able to do the calculations first, and you can discuss that here. Once you are able to do decent calculations, you may discuss interpretations. There is enough technical material in QM to keep this part of the forum quiet and rigorous. I suggest you read serious books about the interpretation of QM if you want to attract people who really understand the issues.

I don't agree. "Being able to do the calculations" cannot be a measure at all. I like this requirement a lot... So how do I know whether I am "allowed" to discuss the interpretations? Maybe you could upload some qualification tests and we could try to solve the exercises...

I am a Ph.D student, I am able to do the calculations , but I cannot at all condone the snobbish physicist view: Only people good at math can discuss the interpretations.

Really?

You are right on the spot. BECAUSE we don't know the answers yet,, we don't want laymen to come here and ask : "OK what is the electron doing inside the atom?" That's annoying. But sending people (no, thanks I have read enough on the subject) to books because we don't know simple answers is just hypocrisy... As if they would REALLY find the answers in the books... The answers are NOT in the books, if they were in the books, we'd be able to tell them the answers - rather than bash them due to their lack of mathematical knowledge when they come up with innocent questions.

We could say, we don't know the answer to that. And people in this thread did that. That's perfectly okay! And that's arguably the answer. It's much more exciting and fascinating than pointing out some graduate level theorem.

-----------------
@DaveC: I'm really not interested about getting into a discussion about your "feelings" - since this is Physics Forums (rather than Loveshack) so I'll leave it here, I proved my points.

Whenever you want to follow up intellectually, I'll be here.

 

[StandardsGuy]

This is what distinguishes mediocre physicists from the precious few... Physics is about INTUITION and IDEAS, not just some extremely complicated mathematical construct.

I applaud this sentence. There is too much math with too little logic and common sense.

 

[humanino]

If you think you have studied the maths enough, I do not question it. I point out that before asking the physical meaning, the physical content of an equation, one should be able to define and manipulate the concepts at the very least. If you need help with an equation, how to define or manipulate the terms, the place is here. Yet my ultimate stance on the interpretation, once we have discussed something, I suspect will remain that it does not belong here anymore, unless you have a proposal to distinguish interpretations (but that does not qualify for merely "interpretation" anymore it seems to me...)

Note that I do not want the discussion to close either. If you start adding material making it interesting, it will survive for sure, with or without me BTW. Please feel free to add beef to it. Define a situation, give us a matrix element, construct a complete orthonormal basis, tell us how you think your operator is represented, question the role of gravity in the reduction/collapse/measurement... something. There are very interesting technical papers published for decades.

 

[DaveC426913]

@DaveC: I'm really not interested about getting into a discussion about your "feelings"

What is with you??

You said "I have a feeling that you feel better when you think you understand QM..." You are talking about feelings. Your own and those of an ambiguous "you". You have been asked to take this kind of talk somewhere else.



Now that that's straightened out, I'm still interested in what "buzzwords" you think QM is filled with. That post never did emerge.

 

[humanino]

If you think you have studied the maths enough, I do not question it.

Please note that angular momentum is kindergarden still. It does not present any serious difficulty in terms of interpretation at all.

 

[jtbell]

Physics is about INTUITION and IDEAS,

...which lead to quantifiable predictions that can be tested through experiment...

not just some extremely complicated mathematical construct.

 

[sokrates]

Please note that angular momentum is kindergarden still. It does not present any serious difficulty in terms of interpretation at all.

Read my posts in their context (not in their deliberately distorted form quoted by DaveC), I was talking about electron inside an atom, how do we think about the rotation of an electron, how does it relate to angular momentum and so forth...

 

[sokrates]

What is with you??
Now that that's straightened out, I'm still interested in what "buzzwords" you think QM is filled with. That post never did emerge.

Sigh... I really don't have time for this. It did emerge really well. My point is delivered to the people who read my posts. Go back and read them a few more times before "contributing" another dozen posts and you'll get it. Thanks

 

[humanino]

I was talking about electron inside an atom, how do we think about the rotation of an electron, how does it relate to angular momentum and so forth...

Do you realize that there is absolutely no difficulty with that ? Have you ever read any serious book saying there is a fundamental problem with that ? There is a tower of wavefunctions for the electrons which we can calculate to daunting accuracy. The only theoretical issue with the angular momentum of the constituents was remaining 10 years ago with the partons inside hadrons, in a highly relativistic fully quantum situation. Today we understand this in terms of Wigner functions, we can define the energy momentum tensor for those states, and this is merely an experimental problem with model-dependent (but consistent) results already.

 

[Phrak]

Please note that angular momentum is kindergarden still. It does not present any serious difficulty in terms of interpretation at all.

Does a particle have absolute angular momentum or angular momentum in relation to another particle?

 

[Civilized]

Sokrates, I read your posts, and I disagree with your statements about mathematical understanding. First of all, mathematical understanding is not to be confused with calculations. Anyone can "shut up and calculate" without understanding QM mathematically. The working knowledge of QM that they teach in grad school (e.g. Sakurai, Shrednicki, etc) shows you how to calculate, but does not show you much of the mathematial understanding behind QM. The mathematical understanding explains why QM is the way it is, why it works, by developing Classical Mechanics and Classical Statistical Mechanics in a sufficiently abstract setting so that QM is seen as a natural generalization. Physics books describe quantization in terms of poissoin brackets - > i*hbar*commutators. Mathematical understanding shows us why this is the case.

Classical intuition is not that mathematically appealing to me. Quantum intuition is much more mathematically rich I think.

 

[humanino]

Does a particle have absolute angular momentum or angular momentum in relation to another particle?

I am not sure what "absolute" angular momentum may be, and I don't know what a particle is without any other particle in principle. But a particle has intrinsic angular momentum, which is related to the representation of the Lorentz group it belongs to, and it can also have "orbital" angular momentum.

 

[StandardsGuy]

Today we understand this in terms of Wigner functions

This is some of those mathematical constructs socrates was talking about. A "quasi-probability distribution" is not much of an enlightenment. It doesn't answer the question of what the electron is up to. Just admit it, you have no idea. You also don't know if the electron is a point particle, a cloud, a smaller diameter particle that a proton, or even a particle at all. This is NOT understanding. So when they get higher energy they go into 'higher' "orbitals" but they don't orbit? jtbell had a much better answer in #17.

-S

P.S. I'm not a physicist, so don't be too hard on me.

 

[sokrates]

This is some of those mathematical constructs socrates was talking about. A "quasi-probability distribution" is not much of an enlightenment. It doesn't answer the question of what the electron is up to. Just admit it, you have no idea. You also don't know if the electron is a point particle, a cloud, a smaller diameter particle that a proton, or even a particle at all. This is NOT understanding. So when they get higher energy they go into 'higher' "orbitals" but they don't orbit? jtbell had a much better answer in #17.

-S
P.S. I'm not a physicist, so don't be too hard on me.

They'll never admit it, don't waste your time, resistance is futile... Let them cherish the illusion that they really understand...
JTBell #17 was a jewel in this thread. We must read it over and over again.

 

[sokrates]

Classical intuition is not that mathematically appealing to me. Quantum intuition is much more mathematically rich I think.

Quantum intuition? I hope you really know what you are talking about (considering the fact that all the fuss is really because quantum is utterly non-intuitive).

 

[Phrak]

I am not sure what "absolute" angular momentum may be, and I don't know what a particle is without any other particle in principle. But a particle has intrinsic angular momentum, which is related to the representation of the Lorentz group it belongs to, and it can also have "orbital" angular momentum.

Intrinsic was the word I was searching for, thank you. I don't think any dynamical variables of a particle are provably intrinsic within the scope of quantum mechanics.

As a particle cannot be prepared or measured in isolation, this begs the question: is the state of a particle, or a system of particles, intrinsic or relative?

I've had a tendency to consider--unlike everybody else, it seems--that particle states are not about particles but about what is between particles. Your thoughts?

 

[humanino]

Let them cherish the illusion that they really understand...

I mentioned the fact that you need to write down at least one mathematical symbol before we can discuss the interpretation of anything. You replied "but I'm a PhD student, I am certified to understand so I am allowed to come around with my claims". And then "for instance, I don't understand angular momentum". And then

Just admit it, you have no idea.

Just admit it, YOU do not understand the least beginning of it, so by deduction nobody understand, obviously because you are so smart.

Well bite it, that's flat wrong. There are difficulties with QM, I mentioned at least one (measurement and collapse, the role of unitarity... here is another, possibly related : the links between time and thermodynamics...), but that is not with angular momentum and that is not with Wigner functions. Both of those mathematical objects make perfect sense, they do not suffer from inconsistencies, they are pretty elementary and if they confuse you, just study harder, or do something else. Maybe the reason you do not understand QM is because you insist to apply Newton's laws of billiard collisions. Another news : if QM came first, maybe you would say that Newton does not make sense.

Once again, I admit that there are fundamental difficulties with QM, but not with what you mention. If you want to discuss something, please feel free to bring this discussion to a decent level. Please feel free to not post claims that nobody understand nothing since you do not understand elementary mathematics.

 

[humanino]

Intrinsic was the word I was searching for, thank you. I don't think any dynamical variables of a particle are provably intrinsic within the scope of quantum mechanics.

Intrinsic in the same sense as mass or electric charge of an elementary particle. Not dynamical indeed.

As a particle cannot be prepared or measured in isolation, this begs the question: is the state of a particle, or a system of particles, intrinsic or relative?

We define particles as representations of the Lorentz group because we want to be able to apply the symmetry to them. I do agree that the state of knowledge is always relative (Rovelli brought that to a new interpretation), but independently of the observer, all of them will make use of some representation of the Lorentz group since we assume relativity. You can not continuously deform one representation into another, but you can continuously go from one observer to the other, so you have quantum numbers for your particle.

 

[Phrak]

Thanks for responding. I hope you don't think I am combative as others here. I would really like to know your thoughts on this.

Intrinsic in the same sense as mass or electric charge of an elementary particle. Not dynamical indeed.

I know this is the usual understanding, but is it provable--or disprovable for that matter--again, within any given set of premises of quantum mechanic?

We define particles as representations of the Lorentz group because we want to be able to apply the symmetry to them. I do agree that the state of knowledge is always relative (Rovelli brought that to a new interpretation), but independently of the observer, all of them will make use of some representation of the Lorentz group since we assume relativity. You can not continuously deform one representation into another, but you can continuously go from one observer to the other, so you have quantum numbers for your particle.[/QUOTE]

This is a convenient image I found searching on trees_discrete_algebra.

Or this one, with thanks to lisab,

that I hijacked from a comoving thread. ()

Everyone talks about the nodes (particles). What can be said of the Lorentz representation of the lines?

 

[sokrates]

Just admit it, YOU do not understand the least beginning of it, so by deduction nobody understand, obviously because you are so smart.
Please feel free to not post claims that nobody understand nothing since you do not understand elementary mathematics.

Calm down. It’s alright. If this is going to chill you, I admit it, I don’t understand elementary mathematics. Please don’t go crazy. Let's try to keep it at the intellectual level, shall we? I don’t write “at least one mathematical symbol”, although it's really an idiotic way to judge knowledge because I can’t write it…! I have kept this as a secret for so many years… But amusingly, just because you probably have skimmed a few elementary books, you think you are an authority. I revealed my 'real life' profession. Could you enlighten us as to why we should take 'your deep understanding' more seriously?
We are not claiming we are smart. You know nothing about us because this is internet (so you shouldn't be so fierce to prove a point - this is not APS March Meeting, seriously it looks funny), and what we claim has nothing to do with your unwarranted attacks (on the lack of our mathematical knowledge which you know nothing about). That said, I am more than sure I’d beat your seemingly half-baked introductory understanding in any platform, but I am content and I don’t care at all.

I can see how your obsession with mathematics gets in the way, maybe you are a mathematician and you feel bad about it because you seem to have no idea what physics is really about. I suggest you start reading ‘lay’ books of Feynman, Gell-Mann instead of learning new tricks on ‘linear algebra’. That’ll do you more good.

The debate is not spinning around specific functions (Wigner) or concepts (momentum), so please don't desperately hold on to those to deliver a message, the point is whether we can really say we understand Quantum Mechanics as well as we understand billiard balls. Being able to write down the mathematical formalism is not enough! And don't make sharp remarks on things you don't know (billiard balls) - Boltzmann equation solves a lot of applied problems. The semiconductor CAD industry (i,e the laptop you are using) is based on 'billiard balls'.

A prime example on how interpretation changes the WAY we think about is non-locality. To explain EPR - MWI does not require the dubious spooky action at a distance. Can you see how much of a difference a MERE interpretation ( no math difference ) can cause? You are welcome to fool yourself that you already know the answer, but physicists BOTHER about PHYSICAL implications a theory suggests. We are not satistified when we fit an experimental curve with some fancy function. You HAVE to explain why it works. We NEED to know the machinery, and it must MAKE SENSE. The ramifications of different interpretations are HUGE. And the theory is not over yet. And no matter how much you elaborate on the subject, NO, you HAVE NO IDEA what the electron is up to inside an atom. Get over it!

Edit: Nobody didn't complain about angular momentum, I am just clarifying this for others who haven't followed the discussion, you are frantically trying to bring the argument down to the so-called elementary level, but it's not about that.Follow the discussion and read #17.

Edit:

Another news : if QM came first, maybe you would say that Newton does not make sense.

Sweet dreams...

 

[Phrak]

Calm down. It’s alright. If this is going to chill you, I admit it, I don’t understand elementary mathematics. Please don’t go crazy. Let's try to keep it at the intellectual level, shall we? I don’t write “at least one mathematical symbol”, although it's really an idiotic way to judge knowledge because I can’t write it…! I have kept this as a secret for so many years… But amusingly, just because you probably have skimmed a few elementary books, you think you are an authority. I revealed my 'real life' profession. Could you enlighten us as to why we should take 'your deep understanding' more seriously?
We are not claiming we are smart. You know nothing about us because this is internet (so you shouldn't be so fierce to prove a point - this is not APS March Meeting, seriously it looks funny), and what we claim has nothing to do with your unwarranted attacks (on the lack of our mathematical knowledge which you know nothing about). That said, I am more than sure I’d beat your seemingly half-baked introductory understanding in any platform, but I am content and I don’t care at all.

I can see how your obsession with mathematics gets in the way, maybe you are a mathematician and you feel bad about it because you seem to have no idea what physics is really about. I suggest you start reading ‘lay’ books of Feynman, Gell-Mann instead of learning new tricks on ‘linear algebra’. That’ll do you more good.

The debate is not spinning around specific functions (Wigner) or concepts (momentum), so please don't desperately hold on to those to deliver a message, the point is whether we can really say we understand Quantum Mechanics as well as we understand billiard balls. Being able to write down the mathematical formalism is not enough! And don't make sharp remarks on things you don't know (billiard balls) - Boltzmann equation solves a lot of applied problems. The semiconductor CAD industry (i,e the laptop you are using) is based on 'billiard balls'.

A prime example on how interpretation changes the WAY we think about is non-locality. To explain EPR - MWI does not require the dubious spooky action at a distance. Can you see how much of a difference a MERE interpretation ( no math difference ) can cause? You are welcome to fool yourself that you already know the answer, but physicists BOTHER about PHYSICAL implications a theory suggests. We are not satistified when we fit an experimental curve with some fancy function. You HAVE to explain why it works. We NEED to know the machinery, and it must MAKE SENSE. The ramifications of different interpretations are HUGE. And the theory is not over yet. And no matter how much you elaborate on the subject, NO, you HAVE NO IDEA what the electron is up to inside an atom. Get over it!

Edit: Nobody didn't complain about angular momentum, I am just clarifying this for others who haven't followed the discussion, you are frantically trying to bring the argument down to the so-called elementary level, but it's not about that.


Follow the discussion and read #17.

Edit:

Sweet dreams...

You can use this opportunity to learn or teach or rant or in a combination of your choice.