Light waves oscillate far faster than most sensors can respond. A solar cell, or the infrared photodetector used to receive the signal from the remote in your DVR, can only sense the total energy delivered by the light — it can’t pick up the subtle details of the rapidly oscillating electric field the light consists of. Essentially all commercial light sensors suffer from this same problem: They act like a microphone that can tell that a crowd of people are yelling (or whispering), but can’t make out any of the…
