Monday, May 10, 2010

Why are vampire movies so popular?

It’s well known that LEDs produce a single color of light, like green, blue, red and amber. Mixtures of colors like purple (red and blue) or even white (full color spectrum) are possible only when the LED is used in conjunction with a phosphor. A phosphor is a material that emits light when it is excited by light. So a phosphor takes in one color of light, say blue, and reemits another color or typically a variety of colors. Sort of like the game you used to play in elementary school called “telephone”. Remember, you give your neighbor a message and then it gets translated into an entire spectrum of messages by the time it makes it around the circle. Phosphors do the same sort of thing with light so they are useful at converting a blue LED into a white LED for example.

The phosphors that are typically used in LEDs are similar to those found in fluorescent light tubes. In fact, if you’ve ever seen a broken fluorescent tube there is a white powder on the inside of the glass. That powder is the phosphor that converts the inherent UV light of the fluorescent tube into white-ish looking light. A fluorescent light tube without this phosphor layer is the ever-popular “black light”. Anyway, the light produced using phosphors is not really “white” light. In fact, the light is largely void of any red light component. Hence, you look like a vampire when you see yourself illuminated with a fluorescent light or white LED light. Without a red component, your skin looks like it is without blood since there is no reflected red light to show your true rosy color. Researchers around the world are looking for better phosphors to improve the color of LED light but it is a difficult challenge because current phosphor technologies are inexpensive, long-lasting and efficient. For now, we have to be content with white-ish light from these efficient light sources but someday LEDs and fluorescent lights will have better color quality because of a new phosphor technology or other discovery.

I’m not really into that whole vampire phenomenon that has swept the nation and I don’t understand the wild popularity of pasty-white teens biting each other. Sure some feel it is because Edward is so handsome. From a scientific standpoint, the popularity may be driven by the fact that people are replacing incandescent (full-spectrum white) bulbs with LEDs and fluorescent bulbs that make you look like a vampire. Under the white-ish glow of today’s light sources, perhaps today’s teens see a bit of themselves in the characters on screen. Just a thought.