- Lorentz–Heaviside units
Lorentz–Heaviside units (or Heaviside–Lorentz units) for
Maxwell's equationsare often used in relativistic calculations. They differ from the equations in CGSunits by a factor of in the definitions of the fields and electric charge. The units are particularly convenient when performing calculations in spatial dimensions greater than three such as is done in string theory.
Maxwell's equations with sources
The equations with sources take the following form:
where "c" is the speed of light in a vacuum. Here E is the electric field, B is the magnetic field, is the charge density, and J is the current density.
The charge and fields in Lorentz–Heaviside units are related to the quantities in cgs units by
The force exerted upon a charged particle by the
electric fieldand magnetic fieldis given in both cgs and Lorentz–Heaviside units by the Lorentz forceequation:
where q is the charge on the particle and v is the particle velocity. The magnetic field B has the same units as the electric field E.
* [http://www.du.edu/~jcalvert/phys/hlu.htm Heaviside–Lorentz units]
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