1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Wave Optics: Electromagnetic Waves

  1. Oct 24, 2015 #1
    " Thus according to Maxwell, light waves are associated with changing electric and magnetic fields; changing electric field produces a time and space varying magnetic field and a changing magnetic field produces a time and space varying electric field. The changing electric and magnetic fields result in the propagation of electromagnetic waves even in vacuum" - NCERT Physics Grade XII.

    What does the term time and space varying electric field/magnetic field mean ?
  2. jcsd
  3. Oct 24, 2015 #2


    User Avatar
    2017 Award

    Staff: Mentor

    The fields vary both in space (they are not the same everywhere) and time (they are not the same forever).
  4. Oct 24, 2015 #3


    User Avatar
    Science Advisor
    Gold Member
    2017 Award

    That's a bit much for a single post, I think.
    The answer 42 springs to mind.

    What is your level of Science education? EM is a vast topic and best approached from some very basic ideas, based on well known phenomena. The presence of a force in the region of a charged object or a magnet can be conveniently 'explained' in terms of a Field (region of influence), in the same way that our weight can be explained in terms of the Earth's g 'Field'.
    A Field doesn't have to be looked upon as 'real'- just an aid to calculating and predicting effects. We are only aware of such a Field by its effect on objects and there are alternative ways of explaining such forces which don't necessarily involve the Field idea. But the Field approach has proved to be very powerful.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook