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About fields

  1. Oct 8, 2009 #1
    I wanted to know what is field anyway, Is it wave, particle or some different sort of physical entity.
  2. jcsd
  3. Oct 8, 2009 #2
    A field is a function of coordinates and time: f(r,t).

    A particle (point-like particle) has three coordinates depending on t: r(t). It is a line in the 3D space.

    A filed is normally defined in all points of space.

    Example of a scalar filed: pressure in the atmosphere p(r,t).

    Example of vector filed: wind velocity in the atmosphere V(r,t).
    Last edited: Oct 8, 2009
  4. Oct 8, 2009 #3
    Mr. Bob, I am very thankful to you about yours response. But sir I am not interested in the mathematical description but rather its physical description. e.g. whether em field really exist, or it is just a mathematical tool.
  5. Oct 8, 2009 #4
    Yes, the EM field exists: it can be received by a radio, TV, etc. Sound waves are also a good example: we hear them at any place of space.
  6. Oct 8, 2009 #5
    Thank You Mr. Bob
  7. Oct 8, 2009 #6


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    More correctly, it is waves in the EM-field that are "received" by a radio, not the field itself!
  8. Oct 8, 2009 #7
    Yes your are right. But question still remains there. What are exact physical phenomenons working behind these so called force fields?
    Last edited: Oct 8, 2009
  9. Oct 9, 2009 #8
    As for classical fields, one of my teachers, long ago, described them as an "influential domain of a source" (T.K.Ishii). I have always found this to be a satisfying non-mathematical description.

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