It's also called a darkon. When you turn on a lamp, what really happens is that it starts to attract and absorb darkons. A bright room is really a darkon-depleted room. A more powerful lamp can really suck the darkons in big league. Of course, the sun is the most powerful darkon absorber in the neighborhood.
I’ll look them up.
Listening to Vince Guaraldi Trio and missing my city of five generations. (SF)