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Energy present in a localized area during nodal interference

  1. Apr 6, 2012 #1
    When two waves interact producing a "cancelling" effect as seen by noise reducing headsets, what kinematic energy is associate with the effected medium immediately near the cancellation point(standing wave)? Furthermore, in an ideal setting, would it be possible to instantly reorient the surrounding local environment to release a high energy coherently combined and vectored event? Stated in better terms, a seemingly undisturbed point that is a neutralized(stabilized?) by extreme opposite and equal input energies releasing a combined impulse-like output shortly after an instantaneous reconfiguration of the local environment. For simplicity's sake waves on water can be used to answer the question.

    [Edit] for a little background i wanted to include what initiated my curiosity: could an effect like this be used in either a practical or ideal(allowing instant reconfiguration and perfect interactions) setting to produce a high energy ultra-fast pulse from things like laser-pumped crystals and/or solids(for a highly disruptive result)?
    Last edited: Apr 6, 2012
  2. jcsd
  3. Apr 6, 2012 #2


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    Whurtz, Welcome to Physics Forums! Here is a place where well-educated and experienced members all contribute towards increasing the scientific knowledge of others.

    All four questions in your post relate to a common process called “interference”. Here is an excerpt from a Wikipedia page:

    “In physics, interference is a phenomenon in which two waves superimpose to form a resultant wave of greater or lower amplitude. Interference usually refers to the interaction of waves that are correlated or coherent with each other, either because they come from the same source or because they have the same or nearly the same frequency. Interference effects can be observed with all types of waves, for example, light, radio, acoustic, and surface water waves.

    The principle of superposition of waves states that when two or more waves are incident on the same point, the total displacement at that point is equal to the vector sum of the displacements of the individual waves. If a crest of a wave meets a crest of another wave of the same frequency at the same point, then the magnitude of the displacement is the sum of the individual magnitudes – this is constructive interference. If a crest of one wave meets a trough of another wave then the magnitude of the displacements is equal to the difference in the individual magnitudes – this is known as destructive interference.”

    See: http://en.wikipedia.org/wiki/Interference_(wave_propagation [Broken])

    My suggestion is that you read and study this Wiki article. I think you will get answers to all four questions that you asked in your post. If you have any doubts or any further questions then, come right back here and post your questions.

    Last edited by a moderator: May 5, 2017
  4. Apr 6, 2012 #3
    thanks for the welcome and reply bobby. i am familiar with super-position and have completed a fair share of a bachelors in the physics discipline(years ago unfortunately and im rusty), i will read up on the link you suggested and if i have further inquiry ill re-post a more targeted question. i was being a little lazy asking the forum so i could skip the research, i just had the recollection that after the nullified area from super-position the waves continued to propagate in areas beyond, thus conserving their energy through what appeared to be a static area. as i said ill do the busy work myself and get back to the forum if im confused after.
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