I keep hearing the words quot;black lightquot;. But then in science class I remembered that my teacher said that black light means no light. Can someone explain this situation?
Ha. A black light is just a light a tad bid away from being ultraviolet. It's kind of in between violet and ultraviolet. It looks purple and white seems to glow under it. Many black lights aren't completely true ultraviolet, because true UV lights can be dangerous.
UV (ultraviolet) light makes certain pigments and chemicals (such as starch) glow with visible light yet UV light is not seen with the human eye. Sources of UV light for effects are fluorescent, incandescent, and spot lights with very heavy purplish black looking filtering which cuts out the visible light. Incandescent black light bulbs get very hot as the filter has to absorb a lot of visible, so fluorescent is used more often. Fluorescent actually comes in two forms - with and without the filter layer. UV bulbs without the filter look gray when off and actually give off some visible light but have no coating like a regular fluorescent light does to make it white. If you are in a room with dayglow posters and the more costly UV filtered bulbs are the only thing on, only the images in dayglow pigment (and men's starched white shirts) will glow. If the light source is the cheaper unfiltered UV bulbs, you can see the outline of the posters and items in the room as a faint ghost image at the limits of your vision.
By black lights people usually mean light bulbs that omit only UV rays and some purple visible light. We can't see UV rays, so in the dark, it looks as though it is completely dark even with the light on.
I made a black light that I used as a kid in the deserts of Arizona that would give me night shade. Soldier finding me in this total black shaw would laugh. I even made a black laser the beam was as black as oil. So yes there is a black light so as soon as I get some money I'm going remeber how I done it.
There is no such things as a black colored light. A black light is ultra violet. It is hard to see with the human eye. I think true ultra violet is impossible to see, but blacklights are UV lights with a purple coating. You see the light because it is reflected off of surfaces, so you are not seeing the UV itself but the light from the object reacting with the UV. So no, there are no true Black lights that take away light, it is simply a term based on the dark color of the bulb and the purple like light that comes out.
