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!

Is the Maxwell stress tensor a true stress?

  1. Nov 28, 2013 #1
    Should it be added to the Cauchy stress to calculate a "total stress", or it doesn't have such a physical interpretation as a surface force(EM field force is usually considered more of a "body force")?
    Certainly when the MST was first derived before aether theories were made superfluous by Einstein, it might make sense to think of the MST as a physical true stress, I think now it is rather considered a mathematical device to ease calculations of EM forces at a point.
    There seems to be situations in wich the magnetization of the material is not strictly linear(i. e. ferrofluids) and demand the use of an non-symmetric MST where it leads to incorrect results.
    Maybe this is an issue more related with the different view of engineers and field theoretic physicists on EM problems(fluid and solid mechanics versus classical EM field in vacuum).
  2. jcsd
  3. Nov 28, 2013 #2

    Jano L.

    User Avatar
    Gold Member

    Your question is hard to answer. It seems too general to me - could you could formulate definite situation (liquid, solid?) and what is your definition of "total stress" ?

    Feynman's remark from his lectures (vol. II, sec. 10-5):

  4. Dec 2, 2013 #3

    Andy Resnick

    User Avatar
    Science Advisor
    Education Advisor

    Electromechanical systems (piezoelectricity, acousto-optics, magnetohydrodynamics, etc.) incorporate both electromagnetic and "mechanical" stress terms.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook