OK guys, help me out on this.
Let's take a bubble where time is sped up inside, maybe to 10x, maybe to 100x. I'm thinking that if there is no light source inside the bubble, but all light comes from the area outside the bubble, to an observer outside the bubble all light that goes inside and gets redshifted will get blueshifted back the same amount when it exits the bubble. So the outside observer won't see a color change at all. (I'm ignoring refraction for the purposes of this post, but someone else may elucidate.)
The person inside the bubble will see a redshift of all light coming into the bubble--but will also see far fewer photons per second, so the world will go dim or even black.
At low time-speedups, the person in the bubble will see UV light shifted into the visible range, so will start effectively seeing in UV. At very fast speeds he can see X rays or even gamma rays. (I don't know from Brandon what the max speedup is.)
If the person inside the bubble turns on a flashlight, this will be shifted into the UV or X-ray range when it leaves the bubble. You can fry everyone around you with deadly radiation this way.
When you have a bubble that slows time, the opposite happens. People inside can see in infrared or radio waves. And if they go slow enough, visible light from the outside is shifted into the X-ray or gamma-ray range and the person inside gets fried by radiation. If they turn on a flashlight, people outside get cooked.
Can anyone point out flaws in this analysis? Does anyone have magical suggestions for why any of these things wouldn't happen?
For practical reasons it looks like there will need to be a lot of handwavium burned.