I'm writing a Science Fiction story which has one place where time runs at normal speed, and another place next to it, where time runs at a much slower speed. If you stand in the normal place and look into the slow place, you will see people moving around as if in slow motion. But what would happen to light? Would photons in the slow zone actually slow down? When photons leave the slow time zone and enter the normal time zone, would the wavelength of the light expand? Would it then seem that things inside the slow zone are reddish, as if looking through a red filter? Or would it seem normal? Thanks in advance for any help.