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Thread: please criticize my QM paper

  1. #1 please criticize my QM paper 
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    Hello QM experts,

    I've just written a paper on quantum mechanics, and I need some expert criticism. Basically, I want to know if I've got it right. Keep in mind it's written by a non-expert for non-experts.

    The paper is written in three parts. The first part covers the basic facts of quantum mechanics, the second part covers the major interpretations in the field, and the third is my own personal take on these interpretations. Mostly, I need criticism on the first two parts. You can criticize the third part as well, but I'd appreciate if you kept your criticisms to an assessment of my understanding of the subject - not whether or not you agree with the positions I take (you can criticize my positions if you want, but that's not what I'm centrally concerned with).

    I guess I should also say that this paper is part of a larger collection of papers that makes up my website. Right now, the QM paper is the only one up there, which means that a lot of the links don't work. This also means there might be some confusion over references to "my theory", so just FYI, the theme of the website is a philosophy of mine concerning the problem of consciousness (i.e. it's a theory of what consciousness is). Also note that I haven't tested it out in Mozilla (let me know if anything doesn't work in Mozilla).

    Lastly, I hope it's acceptable posting a link to my website and asking people to visit it. I know this is sometimes taken as spamming or advertizing, but I hope this can be taken as a special case since I'm asking for an evaluation on my understanding of quantum mechanics (consider it one enormous question that I had to create a whole new website in order to post it).

    Anyway, here's the link: http://www.shahspace.com/mm-theory/qm/qm.htm

    EDIT: I almost forgot to mention - I hope no one gets offended if I ask for sources in response to your comments. I know it seems contradictory to ask for criticism and then ask for proof once it's delivered, but on the internet, one never knows who the other person is. Anyone could post a criticism claiming to be an expert even though he/she is just some dilettante crackpot who thinks they know it all. I wouldn't know them from the real experts, so if I don't know who you are or if your comments seem suspicious, I might ask for sources. So don't take it as confrontational, it's just that I want to be sure I'm getting the goods.


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  3. #2  
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    Excellent. Magnificent work. Thorough and understandable. I also checked the website on Netscape 9.0 (Mozilla 5.0) and everything looks the same.

    Now take my advice and delete the first three sentences in the introduction. Everything from "There are two papers..." to "...to procede with these papers" must go. I offer you no explanation -- it should be self-evident.

    Again, well done.

    ¬*


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  4. #3  
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    Quote Originally Posted by SteveF
    Excellent. Magnificent work. Thorough and understandable. I also checked the website on Netscape 9.0 (Mozilla 5.0) and everything looks the same.

    Now take my advice and delete the first three sentences in the introduction. Everything from "There are two papers..." to "...to procede with these papers" must go. I offer you no explanation -- it should be self-evident.

    Again, well done.

    ¬*
    Wow, that was quick. Thanks for the positive comments.
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  5. #4  
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    Editorial comment: "procede" = "proceed"

    Editorial comment: "Indeed, quantum mechanics does need interpretation. But so does every other science. However, quantum mechanics is unique in this respect because in no other field of science..."
    These sentences are contradictory. If it is like every other science it is not unique. Find a different word than "unique."

    Technical comment: "relinquishing their energy, which readily occurs when the element is burnt..." The element does not need to be burnt. It might be heated or excited with an electrical current for example.

    Editorial comment: "the baseball doesn't end up defusing itself in the form of a wave" I think the word you are looking for is "diffusing."

    Editorial comment: "did it, in becoming a wave, take a different form, like an actually wave, " I didn't understand this sentence. What's an actually wave?

    Editorial comment: "The most frequently sited of Schrödinger's equations is the 'wavefunction,..'" The word you want is "cited."

    Editorial comment: "Now that we have elucidated on the roll superposition and randomness play" The word "roll" should be "role."
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  6. #5  
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    Quote Originally Posted by Harold14370
    Editorial comment: "procede" = "proceed"

    Editorial comment: "Indeed, quantum mechanics does need interpretation. But so does every other science. However, quantum mechanics is unique in this respect because in no other field of science..."
    These sentences are contradictory. If it is like every other science it is not unique. Find a different word than "unique."

    Technical comment: "relinquishing their energy, which readily occurs when the element is burnt..." The element does not need to be burnt. It might be heated or excited with an electrical current for example.

    Editorial comment: "the baseball doesn't end up defusing itself in the form of a wave" I think the word you are looking for is "diffusing."

    Editorial comment: "did it, in becoming a wave, take a different form, like an actually wave, " I didn't understand this sentence. What's an actually wave?

    Editorial comment: "The most frequently sited of Schrödinger's equations is the 'wavefunction,..'" The word you want is "cited."

    Editorial comment: "Now that we have elucidated on the roll superposition and randomness play" The word "roll" should be "role."
    Thanks for the comments. Gotta watch those subtle spelling mistakes :-D
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  7. #6  
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    I find I prefer to read things offline, so I've printed it and get back to you with what I can. Please note that my first print is now in the bin due to truncation, though I did print it adequately in landscape orientation.

    For now:

    It's important to ensure that your opening has a good impact, with no flaws or issues that might put people off.

    It looks like your abstract has a "for" missing before "further consideration".

    The opening paragraph of your introduction needs reworking as per SteveF's comment, and to avoid repetition of the abstract.

    I very nearly abandoned this immediately upon reading your second sentence. I'm sorry, but I find "God" something of a turn-off when it comes to physics.

    Lose the smiley.

    You might consider dropping paragraph 1 altogether and starting with your paragraph 2.

    Quantum physics isn't a science. Physics is a science. So you need to look at paragraph 2 some more. The sort of thing I might write is this:

    Quantum mechanics stands unique amongst scientific theories in that it does not offer a "common sense" interpretation that people can intuitively understand..."

    Spellcheck it ASAP. I striped it into Word and did a spellcheck seeing the "procede" then "is is" and "methemetical" before halting. People will be less inclined to assist if they perceive that you can't be bothered to spellcheck it.

    With the sort of feedback you're asking for, you will not get perfect feedback from any one person, including me. Only you can honestly judge what feedback to action or reject.
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  8. #7  
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    Quote Originally Posted by Farsight
    I find I prefer to read things offline, so I've printed it and get back to you with what I can. Please note that my first print is now in the bin due to truncation, though I did print it adequately in landscape orientation.

    For now:

    It's important to ensure that your opening has a good impact, with no flaws or issues that might put people off.

    It looks like your abstract has a "for" missing before "further consideration".

    The opening paragraph of your introduction needs reworking as per SteveF's comment, and to avoid repetition of the abstract.

    I very nearly abandoned this immediately upon reading your second sentence. I'm sorry, but I find "God" something of a turn-off when it comes to physics.

    Lose the smiley.

    You might consider dropping paragraph 1 altogether and starting with your paragraph 2.

    Quantum physics isn't a science. Physics is a science. So you need to look at paragraph 2 some more. The sort of thing I might write is this:

    Quantum mechanics stands unique amongst scientific theories in that it does not offer a "common sense" interpretation that people can intuitively understand..."

    Spellcheck it ASAP. I striped it into Word and did a spellcheck seeing the "procede" then "is is" and "methemetical" before halting. People will be less inclined to assist if they perceive that you can't be bothered to spellcheck it.

    With the sort of feedback you're asking for, you will not get perfect feedback from any one person, including me. Only you can honestly judge what feedback to action or reject.
    Thanks for the comments, Farsight
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  9. #8  
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    More editorial comments

    Heisenber's= Heisenberg's
    Gleen = glean
    Spoky =spooky
    Sophisticate= sophisticated
    Aught=ought several places
    Crackpotery = ?
    Lead = led in a bunch of places where you meant the past tense.
    never the twine shall meet= never the twain shall meet
    Orchistrated= Orchestrated
    compliment each other.= complement each other.
    didn't fair so well= didn't fare so well
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  10. #9  
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    Quote Originally Posted by Harold14370
    More editorial comments

    Heisenber's= Heisenberg's
    Gleen = glean
    Spoky =spooky
    Sophisticate= sophisticated
    Aught=ought several places
    Crackpotery = ?
    Lead = led in a bunch of places where you meant the past tense.
    never the twine shall meet= never the twain shall meet
    Orchistrated= Orchestrated
    compliment each other.= complement each other.
    didn't fair so well= didn't fare so well
    Well, I'll be damned if "aught" doesn't mean what I thought it meant. Thanks for your very observant eye, Harold.
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  11. #10  
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    And I just love "orchistrated"! No, I'm not being sarcastic, as anyone with a classical education or a passing familiarity with medical terminology will see.

    I will use it frequently, it's great, thanks for inventing it.
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  12. #11  
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    gib65:

    Once I got into it I found it nice and easy reading, useful, frienfly, and informative. Here are my comments:

    In the introduction paragraph 3 you talk about interpretations, and talk about an essential lesson. I rather felt that you were introducing an interpretation here.

    You should lose the smiley and the comment "because I don't understand it myself".

    In "The Basics" paragraph 1 you give an overview before starting the history with "Energy Quanta". I think you need to prune "The Basics" because there overall effect is that there's too much beating about the bush with the Introduction before getting down to telling the story.

    Once we get into the history it starts working nicely.

    You've got a mistake when you're talking about the photoelectric effect. You use the word "amplitude" when you should use the word "intensity". This is of utmost importance. Turn back one page to the diagram of Electromagnetic Radiation. Look at the waveform. See the wave height? That's the amplitude. It's the same for all wavelengths.

    Lose the "his was better" Schrodinger smiley.

    I think you spend too long talking about the HUP.

    You say "Heisenberg insisted that this principle was unconditionally valid.." and then talk about "making contact" and "bumping into each other". There's an inherent problem with this wherein mystery is being created because of a concept that says particles are like tiny billiard balls. I think you need to bring this out instead of taking it for granted.

    The paragraph before "Entanglement, Cats, and Other Paradoxes" sounds a little mystic. You are perhaps injecting your interpretation again here.

    As you might expect, I think you should lose "Don't worry it has eight more lives ".

    The cat is not "in a state of superposition". Some people think it is, but it isn't a fact like your phraseology suggests.

    Its "breed" of scientists, you've got "bread" of scientists.

    You say "gleen" instead of "glean".

    You say "spoky" instead of "spooky".

    You say "sophisticate" instead of "sophisiticated".

    I'm generally with Einstein on my view of QM, and think you come over as a little antagonistic towards him.

    Bell's proof is of paramount importance. You shouldn't skip over it.

    There's something else that's crucial here: "The effect was that the great majority of physicists took it as proof that some things can have instantaneous effects on other things despite the fact that they may be separated from each other by vast amounts of space". This is an interpretation. It isn't proven.

    That's all I've got time for for now. I'll try to look at the "Interpretations" tomorrow. Do note however that I have my own interpretation of QM which does not rely on many worlds or the act of observation, but instead gets rid of billiard-ball particles and says what the essence of those waves are. This colours my attitude towards the official interpretations, so I may not be able to offer you much that you find useful.
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  13. #12  
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    Thanks again for your comments, Farsight.

    There's one comment you made that I'm going to ask for sources on:

    Quote Originally Posted by Farsight
    You've got a mistake when you're talking about the photoelectric effect. You use the word "amplitude" when you should use the word "intensity". This is of utmost importance. Turn back one page to the diagram of Electromagnetic Radiation. Look at the waveform. See the wave height? That's the amplitude. It's the same for all wavelengths.
    You might be right, but I'm pretty sure intensity=amplitude in this context. I'll research this myself, but if you have a source readily available, I'd appreciate a reference to it.
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  14. #13  
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    In the description of waves of any type, light or water, there is a difference between amplitude and intensity.

    Waves transport energy, and the amount of it that flows across the unit area perpendicular to the direction of travel is called the intensity of the wave. The intensity is proportional to the square of the amplitude.

    I can offer the proof starting with the wave equation y = a sin (wt-alpha) if you wish. Otherwise accept my word for it that the intensity, or energy density, is proportional to the square of a, the amplitude, as well as to the square of w, the frequency.

    I will leave it up to you to decide whether you intended to use intensity or amplitude.
    ¬*
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  15. #14  
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    Wikipedia has this but does not cite any sources:
    http://en.wikipedia.org/wiki/Amplitude
    For electromagnetic radiation, the amplitude corresponds to the electric field of the wave. The square of the amplitude is proportional to the intensity of the wave.
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  16. #15  
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    Quote Originally Posted by SteveF
    In the description of waves of any type, light or water, there is a difference between amplitude and intensity.

    Waves transport energy, and the amount of it that flows across the unit area perpendicular to the direction of travel is called the intensity of the wave. The intensity is proportional to the square of the amplitude.

    I can offer the proof starting with the wave equation y = a sin (wt-alpha) if you wish. Otherwise accept my word for it that the intensity, or energy density, is proportional to the square of a, the amplitude, as well as to the square of w, the frequency.

    I will leave it up to you to decide whether you intended to use intensity or amplitude.
    ¬*
    Ooooh, I see. But still, amplitude and intensity are positively correlated, no? (unless you can have "negative" amplitude). So it wouldn't be wrong to say that increasing the amplitude causes more electron ejects, would it? I'll probably bite the bullet and use the word "intensity" anyway (just to be inline with the traditional way of explaining the photoelectric effect), but I still want to be sure I understand what you're saying.

    EDIT: I'm a little confused by your statement: "intensity, or energy density, is proportional to... the square of w, the frequency". In the photoelectric effect, the frequency is supposed to be the key variable that determines the energy with which the electrons are eject. So then why is that, in all the renditions of the photoelectric effects I've read, they say that the intensity only has effects on the number of electrons ejected, not the energy with which they are ejected? If intensity is proportional to frequency, intensity should (sometimes) have an effect on the energy with which electrons are ejected.
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  17. #16  
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    Yes, in your context you may use either amplitude or intensity. As you correctly point out, the two are positively correlated. Since we do not apply mathematics in your context, we can agree with your statement that the energy is increased by increasing the amplitude of the wave. This description also matches your illustration. Leave it be.
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  18. #17  
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    Quote Originally Posted by gib65
    Thanks again for your comments, Farsight.

    There's one comment you made that I'm going to ask for sources on:

    Quote Originally Posted by Farsight
    You've got a mistake when you're talking about the photoelectric effect. You use the word "amplitude" when you should use the word "intensity". This is of utmost importance. Turn back one page to the diagram of Electromagnetic Radiation. Look at the waveform. See the wave height? That's the amplitude. It's the same for all wavelengths.
    You might be right, but I'm pretty sure intensity=amplitude in this context. I'll research this myself, but if you have a source readily available, I'd appreciate a reference to it.
    No, you should definitely say intensity. Google on "photoelectric effect" and "intensity": http://www.google.co.uk/search?hl=en...t%22+intensity . You'll see lots of articles like this:

    http://www2.slac.stanford.edu/VVC/th...oelectric.html

    I'm emphatic about this because my own work tells me that the amplitude of all photons is 3.86 x 10¬Į¬Ļ¬≥ metres. You won't find that by searching google, and I don't want to hijack your thread by dwelling on it.

    Sorry Steve, it's not good to give conflicting feedback, but this minor-sounding point is more important than you perhaps appreciate.
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  19. #18  
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    Thanks for your comments, Farsight, and you get no argument from me.

    Once again we see the problem that occurs when folks try to deal with the particle nature of light (photons) in classical terms (waves). Amplitude is strictly a wave characteristic and Gib65's paper indeed shows an illustration of incoming waves. In that respect he is correct to deal with amplitude, at least initially.

    It was the landmark work of Einstein that showed us we need to think of the photoelectric effect in terms of particles of light -- quanta, or photons. Their numbers are characterized by the term intensity, as you have correctly noted.

    We might say (and Gib65 might add to his opus) that Einstein's explanation was crucial in changing the way we understood the nature of light -- henceforth it must be considered not exclusively as a wave but alternately as a stream of particles.
    ¬*
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  20. #19  
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    I think I will replace all references to "amplitude" with "intensity", and maybe make one mention of amplitude at the beginning. Something like this:

    "One could shorten this time by increasing the intensity, which is proportional to the amplitude (or brightness in the case of light), of the radiation."
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  21. #20  
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    I'm going to bow out at this juncture, gib. I'm a little off-message when it comes to interpretations of QM, and cannot give you acceptable advice on it.
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  22. #21  
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    Quote Originally Posted by gib65
    I think I will replace all references to "amplitude" with "intensity", and maybe make one mention of amplitude at the beginning. Something like this:

    "One could shorten this time by increasing the intensity, which is proportional to the amplitude (or brightness in the case of light), of the radiation."
    No, actually it's proportional to the square of the amplitude. Brightness is a subjective perception, and I don't think it's the same as amplitude.
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