2007-05-16 02:29:18 · 10 answers · asked by Anonymous in Science & Mathematics ➔ Other - Science
They are sodium lights.
(No magnesium)
I hope this explanation is correct. Basically they are a neon lamp (which glows red ). These 'yellow' lamps also have a small amount of sodium inside. Initially on switch on, the lamp glows red from the neon, but the sodium begins to vapourise, the sodium atoms excited by the electrical field glow a yellow colour.
This lamps are highly efficient, giving good luminance for the electrical power used.
2007-05-16 02:44:43 · answer #1 · answered by efes_haze 5 · 1⤊ 0⤋
Are most streetlights a rusty orange colour in the UK?
Because more cities in the US are changing from low-pressure sodium lights that give off a more yellowish/orange tint to high-pressure sodium lights, which provide a more traditional white lighting.
2007-05-16 02:46:33 · answer #2 · answered by Robert S 2 · 0⤊ 0⤋
Most use ionized sodium vapor. Nearly all the light comes from the primary line in the emission spectrum of 590nm, so the light is almost pure monochromatic. You thus don't get color vision, but that's a small price to pay for the efficiency and long bulb life.
Lick Observatory lies atop the Diablo Range above the San Francisco Bay area. It's extremely important to them that the area governments cooperate by using sodium vapor street lighting. That single wavelength is easy to filter out. White light greatly reduces the effectiveness of their world-class telescopes.
2007-05-16 06:03:41 · answer #3 · answered by Frank N 7 · 0⤊ 0⤋
Its the type of metal and gas used in the lamp
These are sodium Vapour Lamps the orange comes from the sodium vaporizing once they have warmed up
2007-05-16 02:46:28 · answer #4 · answered by maka 4 · 1⤊ 0⤋
It is the chemical inside used to illuminate the light. Magnesium I think is correct. It's one of those minerals. However, the rusty orange lights use less energy to burn compared to the bright ones we used to see all the time. I know this to be true as I attended one of our local council meetings one evening when they were discussing this subject.
2007-05-16 02:39:10 · answer #5 · answered by Anonymous · 0⤊ 1⤋
It's to do with the chemical in them....magnesium, if I remember righlty...
2007-05-16 02:33:44 · answer #6 · answered by swelwynemma 7 · 0⤊ 1⤋
to give enough light to see but not contribute too much to light pollution
2007-05-16 02:32:19 · answer #7 · answered by L 7 · 1⤊ 1⤋
because you don't want bright white nights for you street lamps
2007-05-16 02:33:39 · answer #8 · answered by retro 2 · 0⤊ 1⤋
Because they are dam it. (ahhh frustration)
Do apologise not in a very good mood.
2007-05-16 02:32:37 · answer #9 · answered by Pandora 5 · 0⤊ 2⤋
to stop glare
2007-05-16 02:32:45 · answer #10 · answered by lilian c 5 · 0⤊ 2⤋