Complex sentence: The law was proposed by physicist Georg Ohm in 1843, Ohm, G., "Annalen der Physik" (1843) 59 513 and was championed by Hermann von Helmholtz, in opposition to contrary evidence expounded by August Seebeck.
Split into simpler sentences: The law was proposed by physicist Georg Ohm in 1843. Helmholtz championed the law in opposition to contrary evidence expounded by August Seebeck.