This talk has two goals. The first is the derivation of a time-dependent KPZ equation (TDKPZ) from a time-inhomogeneous Ginzburg-Landau model, which describes, among many other things, stochastic dynamics of ferromagnets whose physics have been known to be time-dependent (due to Eddy currents) since the 1800s. The TDKPZ has a nonlinear twist that is not seen in the usual KPZ equation, making it a...