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Emission/Absorption and electron orbits

  1. Feb 17, 2008 #1
    Just a thought; if indeed electrons transit around the nucleus, shouldn't we see relativistic doppler shifting as their orbits will have them either receding away or moving towards us?
    Thus, shouldn't elemental spectral lines really exist as 'spectral bars' of measurable bandwidth using high resolution detectors?

    Finally, with some atoms this affect should be blatantly obvious - i.e Gold atoms possess electrons that move @ around half the speed of light + ..... therefore some of its Ab'/Emission lines should be particularly broad.

    What do you think?
     
    Last edited: Feb 17, 2008
  2. jcsd
  3. Feb 17, 2008 #2

    Mentz114

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    Yes, I believe the doppler shift is apparent when light reflects off shiny metallic surfaces. It makes mirrors look silvery. Unfortunately, I can't find any confirmation of this, so it could be inaccurate.
     
  4. Feb 17, 2008 #3
    It has another name: Compton Scattering. It's apparent only for high frequency em radiation, that is at least X-rays. In the more "common" interaction with atoms, instead, light doesn't interact with electrons as if they were "particle-like", but with the "wavelike" electronic cloud (or the "electronic gas" in a metal), so the mechanism is different, don't know how much Doppler effect (due to "moving electrons") there could be.
    There is a Doppler effect when light interacts with single atoms of a gas, due to the atoms' velocities (and this does indeed broaden the atomic spectrum lines).
     
    Last edited: Feb 17, 2008
  5. Feb 17, 2008 #4
    I disagree, the Compton Effect is based on conservation of energy in a 'recoil' type scenario and has nothing to do with the relativistic doppler mechanism I've postulated, however thanks for your input.


    Cheers.
     
  6. Feb 17, 2008 #5
    This sounds classical. The electron doesn't emit while orbiting, but rather when it changes orbitals. How does this affect your idea?
     
  7. Feb 18, 2008 #6
    Well it has be proved that relativistic electron velocities account for certain observable properties i.e the colour of Gold, therefore these quantum jumps do not raise any issues here.

    Cheers.
     
  8. Feb 19, 2008 #7
    If you didn't mean to refer to light interacting with the electrons, then, of which (possible) Doppler effect are you talking about?
     
  9. Feb 19, 2008 #8

    ZapperZ

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    I don't know about gold, but the color of a solid typically has very little to do with the property of the individual atoms that make up the solid. If not, then diamond would look very much like graphite. But they don't!

    Electrons in its atomic orbital emits no EM radiation. That's a given fact. Only when it makes a transition will there be an emission of a photon. There are relativistic corrections to various energy levels as one goes up to higher orbital states, such as d and f orbitals. This certainly would affect the nature of the energy spectra that one would obtain. However, I don't think this is what you're asking for.

    If you start confusing how "atoms" behave with what you notice from the bulk solid, then you'll get into trouble very quickly. Solid state physics is not identical to atomic/molecular physics. That's why they are two separate areas of study.

    Zz.
     
  10. Feb 19, 2008 #9
    I though I'd explained this ..... as electrons orbit the nucleus, photon emission will occur when they're either moving towards a detector or away (following so far) therefore, the wavelength of those moving towards a detector will shorten and lengthen correspondingly for those moving away, though my gedanken affect would only be obvious when said electrons are moving @ relativistic velocities, thus producing very short wavelengths i.e x-rays. This leads me to think the Compton Effect to be a mis-understood phenomenon and one which can more sensibly be explained with relativistic doppler shifting.

    Nobel prize on stand-by :rofl:
     
  11. Feb 19, 2008 #10

    http://www.fourmilab.ch/documents/golden_glow/

    <unfortunate commented deleted by pervect>
     
    Last edited by a moderator: Feb 19, 2008
  12. Feb 19, 2008 #11

    pervect

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  13. Feb 19, 2008 #12
  14. Feb 19, 2008 #13

    ZapperZ

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    But that article points to an atomic transition, no? The 4d to 5s, and the 5d to 6s are all transitions that in turn emits light. So it has nothing to do with the "orbit" itself that emits such light.

    Zz.
     
  15. Feb 19, 2008 #14
    Really!, I'm so, so totally impressed by your outstandingly rich comprehension of things .... and I'm not just saying that.


    :rofl:
     
  16. Feb 19, 2008 #15

    ZapperZ

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    If you're trying to be cute, then cut it out, because it isn't working.

    You will note that I was not the only one who read your original post and deduced that you were implying an electron in an orbital ("transiting" around the nucleus) was radiating. Now I'm not sure why you decided to suddenly turn this into this tone when I was trying to get a clarification out of that issue, but if you don't cut it out, this thread is done.

    Zz.
     
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