1. The problem statement, all variables and given/known data Question 1: Is Ohm's Law (V = IR) invariant under Galilean transformations? Question 2: Model the earth as an ellipsoid or a spheroid, and find the lowest order correction to the inverse square law at points inside and outside the earth's surface. 2. Relevant equations -- 3. The attempt at a solution Question 1: Using the low velocity regime of the Lorentz transformations, we see that j = j', E = E' and so [tex]j = \sigma E[/itex] is invariant in both reference frames. As lengths are invariant under a Galilean transformation, this is equivalent to V = IR in all inertial frames. Is this correct? Can this be argued without using the Lorentz transformations, i.e. without treating Galilean transformations as a special case of the Lorentz transformation for [itex]v << c[/itex]? (Also, can resistivity or conductivity be regarded as a Lorentz invariant scalar?) Question 2: This has me stumped right now....I don't understand what has to be done here. I would appreciate if someone could point me in the right direction.