Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Do magnetic feilds operate at a frequency?

  1. Jul 16, 2010 #1
    Do magnets and their Feilds have a frequency? If photons have a frequency, then does this apply to magnetic feilds?
     
  2. jcsd
  3. Jul 16, 2010 #2
    Frequency is not an observed characteristic of a photon; frequency IS a characteristic of the wavelike nature of light. A photon is a quanta of an electromagnetic wave.

    The magnetic field of a magnet is a stationary field. A changing electrical field produces a magnetic field and a changing magnetic field produces an electric field.

    So if you rapidly pass a magnet, you'll observe an electrical field; or if you rotate a magnet rapidly, you'll produce an electric field...that's the basis of alternators and generators.

    You can read about the physical properties ofphotons here:
    http://en.wikipedia.org/wiki/Photon#Physical_properties

    The electromagnetic wave nature of fields is described by Maxwell's classical equations; photons are described by quantum mechanics....both are mentioned in the above Wikipedia reference.
     
  4. Jul 16, 2010 #3
    If visible light operates in the Terahertz range then what range does magnetism operate in?
     
  5. Jul 16, 2010 #4

    Dale

    Staff: Mentor

    The whole range.
     
  6. Jul 16, 2010 #5
    okay, i am not gettng it. I need to read more. I am reading the Wiki page now
     
  7. Jul 16, 2010 #6

    Dale

    Staff: Mentor

    Visible light, like all EM radiation, is half electric field and half magnetic field. So magnetic fields operate at all frequencies from DC to gamma ray frequencies.
     
  8. Jul 16, 2010 #7
    If magnetism is a Exchange force. Dosnt it need to operate at a specific frequency?
    I dont see how it couldn't.
     
  9. Jul 16, 2010 #8

    Dale

    Staff: Mentor

    No exchange force "operates at a specific frequency" to the best of my knowledge. The force carriers in the standard model each have a specific mass, not a specific frequency.
     
  10. Jul 16, 2010 #9

    Pythagorean

    User Avatar
    Gold Member

    I guess you could argue that a constant field has a frequency of zero...
     
  11. Jul 16, 2010 #10
    The photons that exchange the magnetic force. Are they at operating at a frequency? Or is it posible that i am thinking about the magnetic force all wrong?
     
  12. Jul 16, 2010 #11

    Pythagorean

    User Avatar
    Gold Member

    well, it's somewhat confusing because your title asks about fields but you are asking about photons. I think your question was answered with regards to photons in post #2.
     
  13. Jul 16, 2010 #12
    yes to the extent your ideas do not match current mathematical descriptions.....but "right" and "wrong" in physics is relative.
    but the original post gets into a lot of complicated issues very quickly. You are inferring conclusions not based on observations....like watching two cars go down the road with the red car passing the white car...what can you infer from that about the relative top speed of the two cars? nothing.....it's simply a false conclusion to say the red car has the faster top speed. That would have to be tested.

    No one to my knowledge has been able the describe the magnetic field of a magnet in terms of photons; and electromagnetic fields have not been successful at describing the photoelectric effect.....Einstein got a Nobel prize for figuring out a quantum description....

    Classicial electromganetic "fields and waves" has not been theoretically combined with the photons of quantum mechanics; different theories and mathematics have been used to describe different phenomena....I think the best we can do currently is assert a photon is a quanta, a "particle", of the electromagnetic field....

    edit: a related way to think about the "meaning" of things is this: If you have two different sets of rules for different mathematical calculations, and follow those rules correctly in each case, you have two "right" answers. But what answers are subject to experimental verification and what they actually MEAN is subject to interpretation.

    Neither answer may match physical observations or both may, in which case some other prediction must be used to weed out the "right" from the "wrong" calculation. Then scientists may argue for 100 years, as in quantum mechanics, about about what the answer(s) mean. In other cases, scientists may get different answers, as in string theory, only to later discover (as Ed Witten did) that the answers are actually consistent!!!
     
    Last edited: Jul 17, 2010
  14. Jul 17, 2010 #13
    Maybe this is a better answer: (I also added an edit to post #12)...almost 100 years of experimental investigations and development of quantum theory has revealed that the most accurate way to think about a photon is (as a quanta of the electromagnetic wave as mentioned above but also) as a probability function. It is not so much a physical particle, as in the sense of a billiard ball, but the chance of finding electromagnetic characteristics at a given point in space. A probability wave typically exists throughout all of space, but increases in value like a mountain peak rising from a flat plane where a photon is most likely to be found. But even after 100 years scientisits do NOT have a universally upon way to envision what quantum mechanical probability waves really are.

    It is also useful to keep in mind other fundamental particles, such as electrons, also have both particle ( discrete quantum ) and wavelike (continuous) characteristics.

    You can find a variety of interpretations discussed in these forums, most likely under a "quantum" description.
     
    Last edited: Jul 17, 2010
  15. Jul 20, 2010 #14
    Thank you Naty1, The last two replys of yours really help me! They got me going it the right direction.

    John B
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook