I woke at three in the morning to answer a call of nature. I'm one of those people who has to have moving air on me at all times when I sleep. So, in a pitch black room I open my eyes and I see a halo of light in front of me. I quickly blink to see if I'm hallucinating, but nope, it's still there.

Because I'm me, I alternately close one eye and then the next. The halo disappears when my right eye is closed. Hmm, says I. What fresh Hell is this? I lay there while my sleep-addled brain turns this problem over.

Finally, I realize that my right eye has the perfect paralax to see past the spinner of the fan and be able to observe the faint spark from the brushes in the fan motor glowing in the dark room.

Cool.