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Randomly emit of photon

  1. Feb 29, 2008 #1
    hi, as we know, lamp emits light not continuously but in 'burst', which we may call wave packet or photon. my question is,
    1. Is it emitted one photon by one photon with random time delay ?
    2. it is said that the duration time of the photon from white light is about 10^-9 sec(nanosecond), does it mean that each photon lasts for 10^-9 sec ?
    3. if the above two questions are both correct, then does it mean that 10^-9 sec late after the emission of the first photon, wait an unpredictable time later, another photon emitted ? then how about the first one ? where does it go ? die out ?

    can anyone help ? thank you so much !
  2. jcsd
  3. Feb 29, 2008 #2


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    Gold Member

    Photons don't 'die out'. They continue until they are absorbed, at which time they no longer exist as photons.

    Surely you can see this must be so ? If each photon lasted only for a short time, we would be in a dark universe. When you look at starlight, some of it could have been travelling for hundreds of millions of years to get to your eye and be absorbed.
  4. Mar 1, 2008 #3


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    Staff: Mentor

    Where does it say that?
  5. Mar 1, 2008 #4
    I don't get this. Care to elaborate, please ? What's this "burst" you are talking about ?

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