High intensity discharge (HID) is a general term for mercury, metal halide, and high-pressure sodium lamps. Mercury lamps operate at a relatively high pressure and temperature. Most of the light is ...

After switching out about 1,100 of its more than 2,000 streetlight fixtures in Santa Fe this year from sodium vapor to LEDs, Public Service Company of New Mexico will switch out its remaining lights ...

All urban stargazers know this and have done since the switch from orange sodium vapor lamps to white LEDs, which emit much more blue light. Now we have a mass of observational evidence.

After switching out about 1,100 of its more than 2,000 streetlight fixtures in Santa Fe this year from sodium vapor to LEDs, Public Service Company of New Mexico will switch out its remaining lights ...