The Abraham–Minkowski controversy is a physics debate concerning electromagnetic momentum within dielectric media. Two equations were first suggested by Hermann Minkowski (1908) and Max Abraham (1909) for this momentum. They predict different values, from which the name of the controversy derives. Experimental support has been claimed for both. David J. Griffiths argues that, in the presence of matter, only the total stress–energy tensor carries unambiguous physical significance, and how one apportions it between an "electromagnetic" part and a "matter" part depends on context and convenience. Several papers have claimed to have resolved this controversy. References External links Physical Review Focus: Momentum From Nothing Physical Review Focus: Light Bends Glass Electric and magnetic fields in matter Hermann Minkowski 1908 introductions