They say light cannot exist without darkness, but in the space that is seething with energy, darkness cannot exist without light: Light is just waves of energy, and light sources interfere with each other, and even with themselves.
I saw this one day in my own bathroom: the PL light on the ceiling showed a pattern of sixteen bands of dark and light, and yet there was only one light source: a folded glass tube that had eight vertical tubes, whose interfering light drew eight light and eight dark bands on the ceiling. This happened because in some directions the waves amplified one another, and in the interleaved areas they dampened one another.
