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EM wave from electrons V protons

  1. Apr 16, 2015 #1
    this is theoretical (and possibly stupid) question;

    accelerating protons would create an EM wave equivalent to an EM wave generated by electrons at same frequency but the amplitude would be opposite, is that possible.

    has anyone made a communication circuit from accelerating protons?

    are there any natural "radio" emissions that are made from protons (kind of like a pulsar) and are the same circuits used to detect them as electron generated waves of same frequency?
     
  2. jcsd
  3. Apr 17, 2015 #2

    Simon Bridge

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    1. yes
    2. yes
    3. yes and no and kinda.

    It is lots easier to generate radio waves for communication by accelerating electrons in a wire.
    A radio receiver only cares about the EM wave, it does not care or even know how the EM wave is generated.
     
  4. Apr 17, 2015 #3
    not sure which comments the yes and no's match with :smile:

    I thought there may be a detectable difference between a + source and a - source which could tell something about what particle is doing the accelerating.
     
  5. Apr 17, 2015 #4
    my question really relates to if a radio telescope could be made to detect and discriminate anti-matter/positron source.
     
  6. Apr 17, 2015 #5

    Simon Bridge

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    yes

    technically, the amplitude cannot be "opposite" - I took your meaning to be that the phase will be 180deg different from an electron undergoing the same exact acceleration.

    yes
    ... this should be "kinda" it's not like a radio broadcast but experiments have been done where protons are accelerated and their radiation is observed ... this communicates stuff about the protons and the equipment.

    yes

    no. astronomical objects are usually more complicated.

    kinda
    again - the circuit only cares about the EM wave, not the source. It's "kinda" because the natural radiation is usually detected by specialist equipment but it normally works by the same principles as, say, your phone.

    No. Not just from looking at the EM radiation coming from it. There are zillions of ways to get a particular EM wave.
     
  7. Apr 17, 2015 #6

    Simon Bridge

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    A radio telescope cannot tell the difference between radio waves from normal matter or from anti-matter... so you have to get clever.

    You need to find something characteristic about the radio that can only come from antimatter ... i.e. the electron-positron annihilation produces a characteristic frequency radiation so a lot of that going on somewhere would show as a curious source of this frequency. It could be made by something else, but that would be even more curious and Occam's razor... So 1.022MeV photons from a spot in the sky would be an indication that there is a LOT of antimatter off thataways.

    This is just like how we know that particular light was generated by electron transitions in hydrogen... in this case it's the characteristic pattern that the radiation has that gives it away, along with the assumption that the source is naturally occurring.

    See what I mean - radio-astronomy uses a bunch of physical models as well as the incoming light to figure stuff out about what probably caused the light.
     
  8. Apr 17, 2015 #7
    great explanation thanks
     
  9. Apr 17, 2015 #8

    Simon Bridge

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