> ... evolved with a 4100K light source at night As others have noted, we sleep poorly under strong moonlight. I live in a very rural wooded area, and I can l

> ... evolved with a 4100K light source at night As others have noted, we sleep poorly under strong moonlight. I live in a very rural wooded area, and I can leave my blinds open except when the moon is at its brightest -- I sleep very poorly if I don't use blackout curtains. Perhaps the fittest humans were the ones who stayed the most awake and aware of nocturnal predators during the brightest nights of the month?