Search results
Results from the WOW.Com Content Network
In vacuum, the Lagrangian density for classical electrodynamics (in joules per cubic meter) is a scalar density = +, where =. The 4-current should be understood as an abbreviation of many terms expressing the electric currents of other charged fields in terms of their variables.
In electromagnetism, Jefimenko's equations (named after Oleg D. Jefimenko) give the electric field and magnetic field due to a distribution of electric charges and electric current in space, that takes into account the propagation delay (retarded time) of the fields due to the finite speed of light and relativistic effects.
Classical electromagnetism or classical electrodynamics is a branch of physics focused on the study of interactions between electric charges and currents using an extension of the classical Newtonian model. It is, therefore, a classical field theory.
In theoretical physics, the Born–Infeld model or the Dirac–Born–Infeld action is a particular example of what is usually known as a nonlinear electrodynamics.It was historically introduced in the 1930s to remove the divergence of the electron's self-energy in classical electrodynamics by introducing an upper bound of the electric field at the origin.
A 2006 report by a joint taskforce between the American Physical Society and the American Association of Physics Teachers found that 76 of the 80 physics departments surveyed require a first-year graduate course in John Jackson's Classical Electrodynamics. [4]
The physicist Richard Feynman predicted that, "From a long view of the history of mankind, seen from, say, ten thousand years from now, there can be little doubt that the most significant event of the 19th century will be judged as Maxwell's discovery of the laws of electrodynamics. The American Civil War will pale into provincial ...
Curvature of spacetime affects electrodynamics. An electromagnetic field having energy and momentum also generates curvature in spacetime. Maxwell's equations in curved spacetime can be obtained by replacing the derivatives in the equations in flat spacetime with covariant derivatives. (Whether this is the appropriate generalization requires ...
The first edition cover featured an iridescent soap bubble, an example of the phenomenon of interference.. In an acknowledgement Feynman wrote: [1] This book purports to be a record of the lectures on quantum electrodynamics I gave at UCLA, transcribed and edited by my good friend Ralph Leighton.