I think that sunlight is highly desirable, to an extent!<p>A building&#x27;s function is to block unpleasant sun, but a window&#x27;s function is to let it in and to control it. Artificial sunlight could enable more control over the sunlight factor.<p>Regarding circadian rhythm, it is not fully understood and blue light may not be the only important factor. Perhaps the visual sense that there is sunlight is also an important cue. But yes, blue light is clearly important. I would hope that any public lighting system would strongly take it into account.<p>For example, the color and feel should reflect what happens in the natural world! The LED lights being installed on city streets right now might cause problems for us (not to mention the blue light in our screens).<p>Unpleasant surroundings take a huge toll on people in cities. I am dismayed by the noise, pollution, lack of overhead cover, and threatening cars when I walk around SOMA and so many other places. A single tech like artificial sunlight won&#x27;t cure all ills, but it is a tool that will help cities become larger and more livable.<p>Construction robotics, new materials, methods to better maintain plants and trees, and obviously transportation are also important tools in this fight.