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Why we can say electron emit radiation when it is accelerating?

  1. Mar 23, 2013 #1
    Everything radiates. Then when we accelerate an electron (in the experiment of diffraction of electron to prove wave-particle duality), we say electron behaves as a wave, why cant we say its kinetic energy makes it radiates wave with higher frequency?
    When we say the electron behaves like a wave , then the mass of that electron becomes ...energy?

    Thank you
     
  2. jcsd
  3. Mar 23, 2013 #2

    Drakkith

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    Not true. Certain particles, such as neutrinos, do not radiate that we know of. There's also the case of dark matter, which also does not radiate.

    Because it isn't radiating. When something "radiates" it releases either EM radiation or other particles that 'radiate' out from it. Hence the name "radiation". During the acceleration of the electron it can emit EM radiation, but once it is moving with a steady velocity it no longer radiates. The wave-like properties of an electron, and of all matter, do NOT mean that it is radiating. It only means that it behaves similar to a wave in certain situations.

    No, the mass is still plain old mass.
     
  4. Mar 23, 2013 #3
    Thank you.
    So is that the radiation emitted when it is accelerated that makes us said electron behaves like a wave?
    To an electron, What is the difference between accelerating and no because one will emit EM ,one will not. I mean how acceleration can emit radiation?
     
  5. Mar 23, 2013 #4

    Drakkith

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    No. It intrinsically has wavelike properties at all times. See the following.
    http://en.wikipedia.org/wiki/Particle-wave_duality

    That I don't know.
     
  6. Mar 23, 2013 #5
    One more , is the accelration that emit EM that make the wave property more obvious to us?
     
  7. Mar 23, 2013 #6

    Drakkith

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    No. The acceleration has nothing to do with it. Nor does the EM radiation emitted during acceleration.
     
  8. Mar 24, 2013 #7
    Is the speed matter.
    ^^ really thank you
     
  9. Mar 24, 2013 #8

    Drakkith

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    What?
     
  10. Mar 24, 2013 #9
    Wrong ?
    λ= h/(mv)
    So only the v ( I don't know here is speed or velocity) that makes the wave property more obvious to us.
     
  11. Mar 24, 2013 #10

    Drakkith

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    No, I just had no idea what you were asking. Please try to use correct English.

    Actually no, increasing the velocity makes the wavelength shorter and makes it more difficult to see the effects. The same thing happens when you increase the mass of the particle. Electrons, being lighter in mass than protons, are easier to use for experiments such as the double slit.
     
  12. Mar 24, 2013 #11
    I am sorry.

    Do you mean that the shorter the wavelength , the smaller the deflection angle , and then it will not form rings ( in the electron deflection experiment) instead it will form continuous spectrum there?
     
  13. Mar 24, 2013 #12

    sophiecentaur

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    You may be confusing the De Broglie wavelength associated with the momentum of a Quantum particle and Electromagnetic Wavelength. I don't know your level of knowledge about these topics but there isn't a reliable 'quick way in' to understanding this stuff. Start somewhere nearer the beginning, I'd suggest.
     
  14. Mar 24, 2013 #13
    Can you please guide me? Any books recommend ?
    I only know that the electron diffraction experiment prove λ=h/p is correct.
    But if want to derive the formula suppose the electron should be in light speed, yet the experiment prove that this formula is correct even it is not light speed.
    Do you mean I should learn to understand how to derive Planck constant out first or relativistic momentum? Haisenberg uncertainty?
    Where should I start?
     
  15. Mar 24, 2013 #14

    sophiecentaur

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    You should start at the beginning of a University level Physics text book (take your choice) and work through to where you want to go. You cannot expect to get much sense out of this if you want to start half way through. You are asking such an open ended set of questions that a satisfactory answer seems impossible, imo.
     
  16. Mar 24, 2013 #15
    I am now first year taking modern physics, any good book recommend ?
     
  17. Mar 24, 2013 #16
    You have confused electromagnetic wave with electron wave. Any accelerating charge radiates electromagnetic waves. As electron is charged, it also emits EM wave when accelerated (and also when changing energy levels inside atom). This however has nothing to do with electron being a wave per De Brogli's particle-wave duality.
    According to De Brogli, every particle is also a wave, not only electron.
    As sophiecentaur suggested, you should start with some good entry level physics textbook. Here on this site you have excellent forum for good textbooks recomenbations:
    https://www.physicsforums.com/forumdisplay.php?f=151
     
  18. Mar 24, 2013 #17
    Thank you ^^
     
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