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What can you talk about quantum mechanics?

  1. Apr 5, 2010 #1
    Hello, before I explain what I'm talking about, I just want you to know that isn't really a question about a homework.

    I'm in my last year at high-school and I decided to do a physics project in my class about quantum mechanics. Right now I'm at the point of trying to figure out everything I want to talk about, but I don't really know what subjects I should use.

    Right now I have a little list of things like Schrödinger's cat, Copenhagen interpretation and the Uncertainty principle. I'll be explaining the basics of quantum physics, but I'd like to go into detail, also.

    The problem is that I don't really know what are the more advanced subjects and theories. I was wondering if anyone had a list or something? Don't be shy if you think I don't know the mathematics to understand how it works, I might already know it, or I can simply learn it. I still have a while until I'm presenting. I'm gonna have to learn the math someday anyways, so might as well learn now. Anyways, thanks in advance!
  2. jcsd
  3. Apr 5, 2010 #2
    This definitely belongs in the Academic Guidence subforum. That said, and please don't take this badly, NO ONE could learn the math you describe in such a short interval, nor would it make any sense to the people you're talking to.

    Instead of trying to go 100mph, lets start at 50 for a second...

    Why not start, where Quantum Mechanics started? I know this isn't the list you want, but you could consider WHY we have QM in the first place.

    I would do a bit of research on a man named Paul Dirac, and Werner Heisenberg. You may have heard of "The Uncertainty Principle" or "Heisenberg Uncertainty Principle" (The HUP), but that alone is FAR more than one project's worth of info.

    You really have two good options here:

    1.) Make your project a historical (in brief) description of how we made it from Newton, to QM; what problems and observations led to this, etc. In other words, a synopsis.

    2.) Pick a single thought experiment (which is what Schrodinger's Cat is, and Wignger's Friend) and explore the ramifications of it, and how the physics community is still grappling with the implications of QM.

    You're essentially asking, "Stick all of physics from the last 100 years+ directly into my brain, please?". It's understandable, and even laudable, but you have to take these things step by step.
  4. Apr 5, 2010 #3
    You are lucky. When I was in high school, Physicsforums did not yet exist and I had to work my way through linear algebra books just to understand Dirac's book: "The Principles of Quantum Mechanics". :grumpy:
  5. Apr 5, 2010 #4
    Oh hell, I know. You might well enjoy 'The Strangest Man' by Graham Farmelo, a biography of Paul Dirac. Quite early he describes the incredible flurry around the emergence of Relativity, and the scarcity of people who even grasped it! Pamphlets and books to "teach" this new science cropped up much as you'd expect they would in these days, full of rubbish.

    No Polio or Smallpox, and an amazing new way of looking at the universe through theories and experiments and massive international projects with MEDIA coverage. All instnantly available.

    Pfft... I still remember trying to download document at 2400 baud. My head hurts just thinking about it.

    Then again, maybe you benefited more from your struggle than someone who has this ready access to information AND misinformation?
  6. Apr 5, 2010 #5
    Thank you very much Frame Dragger. But the thing is, I want to make my project long enough. I understand quite a lot of things already, too. You're right, though, I'm going for too much. I think I'm just gonna pick a few things and talk about those, but later on I'll study the other things (like during summer).

    Count Iblis, I've actually done quite a lot of work. I have plenty of books that I've read to understand the more advanced physics. I understand quite a lot of math from books I've gotten, also. I'm just not too familiar with quantum mechanics, yet, I haven't looked into it enough. Although, I do agree that it's helpful that people have the internet for information now.
  7. Apr 6, 2010 #6
    I think you should not aim to explain the precise mathematical details of QM in your presentation, that would be a recipe for disaster. Note that many professional physicists give a presentation with videos, pictures and just a few formulas when they give a presentation before their own collegues.

    Of course, you are free to study quantum mechanics in the way you like. I would suggest you study linear algebra and Dirac's book: The Principles of Quantum Mechanics, as that is still the best book on this subject every written. Contrary to some comments on that book, it is accessible to advanced high school students, it is just that this book is not suitable for people who want an easy, dumbed down explanation of the subject.
  8. Apr 6, 2010 #7
    Probably the biggest mistake when making a presentation is not making it SHORT enough.

    The more stuff you stick in your presentation, the less anyone will learn from it. If you stick to one topic and explain it slowly and clearly enough that your audience understands it, they'll enjoy your talk much more (and be much less likely to fall asleep) than if you try to cram lots of stuff in.
  9. Apr 6, 2010 #8
    This is a brutal question! You are going to get different ideas from all who respond.

    If I were to give a talk on quantum mechanics to high school students, I would first review the principles of classical physics, something the audience is familiar with. Then present the basic principles of quantum mechanics and compare it to classical theory. There are many experiments that can be used to do this. Then close with a couple of applications, emphasizing the need for quantum mechanics (since classical mechanics no longer works.) If this approach appeals to you, and since I have not seen this approach used elsewhere, I will help you to come up with a syllabus to get you started.

    A different approach might be to present the history of its development. There is much quantum physics learned in this approach also.

    A third approach is to discuss only one or two topics, such as the uncertainty principle or wave-particle duality, both of which are considered to be at the "heart" of quantum theory.

    If you want to shock everyone with the "weirdness" of it all, then go ahead and discuss Schrodinger's cat and the various interpretations.

    I would avoid the advanced stuff. Most of it is so esoteric that no one will understand you.
    Also, you can't do it all in one talk, so be selective and stick to those topics you choose to discuss.

    Best wishes
  10. Apr 6, 2010 #9
    Wow... I just mixed two threads I've been in... ok... time for FD to go to sleep!

    I edited the content out of this post, but I don't want to be dishonest and delete it. So... ignore this? heh... *groan*

    Last edited: Apr 6, 2010
  11. Apr 7, 2010 #10
    I think the first choice is what I will go with. I really don't want to talk about the history of things because I have little interest in such things. I'd rather learn about things that are more important and not have a bland presentation on history (it would be for me anyways). I think what should be explained is why is QM important and why classical mechanics can't be used for some things. However, I'd still like to speak about one topic having to do with QM. I might just mention other theories, or not.

    Oh, and I have to build something that matches my presentation. Not sure what I'll be doing yet, though.

    Thanks a lot for the help! (Sorry for my English, I'm French...)
  12. Apr 7, 2010 #11


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    Hmmm ... I'd say that it's pretty hard to engage an unknowledgeable audience about QM without using a historical context. That is the approach I generally take, and it seems to be well accepted by my audiences. I personally think it is fascinating how a few "minor" problems that were just considered "leftover details" at the end of the 19th century led to the development of a completely new branch of physics, and ultimately developed into "the most successful theory in physics". However, if that doesn't fascinate you personally (which is of course fine), then I agree that you probably shouldn't try to engage others by talking about it.

    Probably the easiest problem to explain that really requires QM to understand is spectroscopy. You can show them how a heated sample of metal shows a continuous shifting of its emission spectrum with temperature, but that a heated sample of a pure gas atoms (as in a neon lamp, or a sodium vapor streetlight) only emits light at certain well defined frequencies. You could then explain the Bohr model of the hydrogen atom, which although it is not correct in all of the details, gets a lot of important points correct, in particular the emission spectrum I mentioned above. Depending on how involved you want to get, you could then explain the modern, more correct QM description of atomic structure. There are lots of places in there where you could find something to build ... you could build a neon lamp for example, or a diffraction experiment, or just a mock-up of a Bohr atom, depending on how sophisticated you want to get.
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