When faced with two objectives to maximize, engineers expect a trade-off. In the lighting industry, for example, one wishes to maximize the efficiency of a light source, and also the uniformity of its illumination. Almost all engineers will tell you, without any further thought, that there will be a trade-off between the two. Light source designers have come to live with this trade-off, and write many papers on how to measure and co-optimize these, and other measures of light sources. Enter, a new theorem. We will show that (under certain conditions) this trade-off vanishes: both uniformity and efficiency can be fully optimized. In other words, there is a light source which is as efficient as a light source can be, and as uniform as a light source can be. We will also describe our attempts at creating actual light sources using the new theory, and certain "exotic" side-effects.