nice , If we try to relate this to the pound-rebka experiment , when they tried to measure the gravitational shift of light , If we wanted to expand this to light traveling from a stronger magnetic field to a weaker one , I don’t think we would measure a shift in the light because photons do not interact with magnetic fields at least i think , But would we measure a shift because the magnetic field has an energy density therefore it would have a gravitational field , so would we then measure a shift in the light .