Destructive Interference

  1. I do not understand the full theory behind destructive interference. Hence I need helps:

    1. The topic on destructive (and constructive) interference was always discussed on light and sound wave. Will this theory applicable on other radiation such as gamma?

    2. During two wavelenghts met at a point with completely opposite phase, does the cancellation occur at that point with loss of energy? If so, how does the energy balance? does it still obey the energy conversation? if so, can provide some explanation on this?

    Thank you.

    Looking forward for some good discussion and explanation.

  2. jcsd
  3. Danger

    Danger 9,878
    Gold Member

    Hi. I can't really help you, but I do want to point out one thing: gamma is light. It's just an unpleasant form of it. Although we tend to think of light as being just the visible and near-visible (IR and UV) components, they're all part of the electromagnetic spectrum.
  4. For question 2, in free space, whenever you have destructive interference in one location you have constructive interference somewhere else. Energy is not created nor destroyed, it is simply moved away from regions of destructive interference towards regions of constructive interference.
  5. Hi DaleSpam,

    I agreed with you. But if I induce destructive interference to a single photon (gamma radiation, and to reduce complexity of gamma radiation so let's simplify the example) would I still be able to observe constructive interference together with destructive interference?

    btw, have you come across mathematical models on destructive and constructive interference especially on energy and mass conversative?

    Thank you.
  6. Light is EM radiation, Gamma is EM radiation of high energy.

    If you were to induce interference with a single photon i.e. youngs slit experiment you will have constructive and destructive interference and a situations such as dale explained.
    Displacement is additive when talking about superposition therefore if one wave with amplitude/displacement of +2 meets another 180 degrees to it with the same amplitude (displacement -2) the resultant will be 0.
  7. jtbell

    Staff: Mentor

    If you "fire" a single photon through an apparatus that produces interference (two slits or something else), and is "ideal" in the sense that it doesn't absorb or lose the photon through some other process, the photon always ends up somewhere. You can't really "observe" the interference using a single photon.

    If you "fire" many photons through the apparatus, more of them will arrive at locations of constructive interference, and fewer of them will arrive at locations of destructive interference, but again none of them are destroyed. The interference process simply distributes them according to a certain pattern.
  8. Yes. For a single photon, destructive interference simply means a location where the probability it is there is low. Since the probability that it is somewhere is 1, if the probability goes down in one location (destructive interference) then it must go up in another (constructive interference).

    I am not sure what you mean. Maxwells equations is the mathematical model. Both interference and energy conservation can be derived from Maxwells equations.
Know someone interested in this topic? Share this thead via email, Google+, Twitter, or Facebook

Have something to add?

Draft saved Draft deleted