What causes some of the lights on campus to flicker at times?
The lights which flicker are the high pressure sodium lamps. This type of lamp has a vapor of sodium inside, which in the presence of a sufficient voltage, will emit energy seen as light. This light has a yellowish color indicative of the sodium vapor inside. As the lamp approaches the end of life (insufficient vapors remaining for continuous operation), the lamp cycles from off to on to off, appearing to flicker. It’s a normal phenomenon which tells us it is time to replace the lamp.
