Yes. White light LEDs use the same principle as fluorescent tubes; all fluorescent tubes are UV emitters inside and white phosphor outside.
The white light phosphor for LEDs can vary in emitted wavelengths by using slightly different compounds plus dye filters, but all the phosphors put out narrow bands unlike tungsten incandescents; hot tungsten puts out a broad spectrum somewhat like nature sunlight which our eyes like. LEDs suck due to the narrow wavelength range output.
UV LEDs are bad for eye health and they will damage the cornea and lens. Anyone working where these are used will get cataracts earlier in life. Beware.
Probably Best Buy has to teach employees how to count above ten without taking their shoes off.
I know that HR departments these days are phenomenally incompetent and themselves have very stupid employees. Likely BB gets only joggers and immigrants, and elevating them above a starting clerk probably requires a brain transplant. So they need remedial education for any manager candidates.
California state senator Democrat Scott Weiner, who marches in SF gay parades, promotes pedo rights, and school indoctrination of kids with gay sex methods, claims he gets thousands of death threats.
You would think he'd get a clue that people reject a pervert as their representative. Instead, he's trying to justify getting extra money to protect him from outraged citizens.
I'd hate to see him get monkeypox or AIDs.
"no evidence of private citizens being able to test this out."
No, all you need is a modified telescope. You align your laser source with the optical axis you are viewing with, place a photon detector in the return path, modulate the laser with a simple AM modulator, use the detector to pick up the same AM frequency. Then you aim the telescope at the moon and turn things on. The use of a modulated laser ensures you know it's your output beam you are receiving. A high school science fair kid could in theory build one of these setups.
I agree totally with you about the nature of the NYT though. I did not downvote you. We know what tribe does that of course.
Yes. It's been years since I read the details but they can be tracked down. A retroreflector has mirrors arranged in a cube corner shape so they bounce any focused beam right back to the location of the source. This reflection is many many times stronger than a simple single surface reflector and highly localized. So this means that anyone with a telescope and a laser could in theory aim at the moon landing site and instantly (well speed of light delay) see a reflection from there and only there. A merely shiny rock wouldn't work the same way.
Furthermore, the nature of the way the rr works is that no matter where in the moon's orbit the moon is and no matter what the angle is, as long as you can see the moon, the rr will bounce the laser back to you; a flat mirror or a shiny rock wouldn't, it would have to be at exactly the right angle (180 degrees to you) to work that way. So anyone at the equator or the north pole or China could do this test as long as the moon was in their sky at the time.
Here's an article that talks about all the tests: https://www.nytimes.com/2020/08/15/science/moon-lasers-dust.html
On the laser ranging - we put a retroreflector on the moon. If we shine a laser from earth to the moon and look for a reflection from the rr, that will be different from a return from a shiny rock, it will have many times higher luminance. Also the return will come from the exact spot where we placed the reflector. Since anyone on earth (any nation) can perform that test, it separates any chance of a fake US claim from ground truth data anyone can validate.
I'm okay with your inquisitive perspective, so ask away if you have questions. I do not lie nor bullshit, so it's okay to ask for documentation or verification. I am real.
I do contract engineering and have consulted at about 100 companies in a wide range of fields. This gives me an unusually broad perspective and knowledge background. I work for many companies and apply my background in physics, chemistry, electrical engineering, and computer design. I worked for NASA and aerospace companies. I'm kind of a black swan.
One company was Exclara, an LED lighting company. They made power supplies for LED street lighting. Since then I've consulted at a company that does quantum mechanics modeling for semiconductors (such as LEDs) and for chip manufacturers. So that's where I get my knowledge of factors in the purple street lights.
Humans can't see UV but your eyes can be damaged by it.
For LEDs putting out UV, we can also see nearby wavelengths which get pumped out too, so seeing purple in this LED case means there is some UV.
A conclusive test is when dyes that are daylight fluorescent are glowing in a light source, it is putting out UV. Another test is that many washing detergents have brighteners in them, and if your shirt glows a bit bluish under a purple streetlight, that is a sign the detergent residue is reacting to UV hence there IS UV.
Ah troll, I cited the mayor and the police chief. I did not lie; by the rules of English grammar and by statements by the mayor and police chief, my post was valid. It is you who constantly lies to people, which shows you are a sociopath as does your comment history.
Gee, how do you have time to troll, when your day is tied up fucking your mother, which is probably permitted in your religion.
Lol at the troll bullshit, I'm immune. Your comment history is an amusing record showing all the people you troll, and you have zero impact on me. Say hello for me to the masters who pay you to troll The Donald. Of course the other possibility is that you are merely a bearded Cheeto eater in mom's basement typing with orange stained fingers and have a dick stained in orange too. lol. No one takes you seriously.
Household LEDs are of less concern because their power levels are far lower than street lights, hence home bulbs don't degrade to leak UV as fast. Street lights run so hot that they need heat sinks for the LED arrays. When they get really hot, over time it breaks down their phosphors. Home LED bulbs not so much, at least.
I actually have some respect for you, so I will not give a snarky reply. Here's my background and indeed, one example:
- I worked for an LED street lighting technology supply company so I know as someone in the industry what goes wrong.
- Here's just one of many analyses of the purple lights: https://www.nbcdfw.com/news/local/why-are-there-purple-streetlights-around-fort-worth/3192354/
The guy is mostly correct on the cause, degradation of the phosphor (not phosphate though). But he's wrong in that the degradation doesn't turn the LED itself to UV - that is fixed forever by quantum mechanics factors. See #3 below.
- ALL white light LEDs start with a UV LED emitter - we do not know how to make LEDs that emit white light themselves. It's a quantum mechanics thing, there is no band gap that gives out pure white light. In other words, the base LED for white light is actually always designed as a UV emitter. That part never changes. (red, green yellow LEDs are different, they give out RGY light from the start, they have no phosphor. Blue LEDs are kind of mutants and close to UV.) If you look at many LED lights you will see that the unlit COB LED looks yellowish. That is because there are two coatings on the LED itself. One is the bottom layer over the LED chip; it is a light emitter that takes in UV and outputs white light; the top coating over it is yellow to filter out any UV that passes through. In the shitty Chinese LEDs, they make them with bad chemistry for the top layer and it degrades because any UV leakage actually destroys the yellow dye compound over time.
I dunno. I liked the Cyanide Lizard Soup and the Roast Baby Liver and the Live Monkey Brain with Lector Secret Sauce. But the Ben&Jerry Goat Testicle dessert seemed a bit over the top.