I used to have a collection of colored light bulbs. outside of the blacklight, my favorite was my coated red light bulb. I loved how it made the light creeping in from the outside look blue and made red objects look pale.
Because in school you have to sit there for half an hour (Or more, depending) to learn about the intricacies of the subject at hand, while on SciShow you spend maybe 3-10 minutes to learn just enough to make you look smart at parties.
This was such a satisfying video to watch, I've wondered for so long how it works and worked it down to two possible hypothesises of mine. Turns out both were oddly correct! *mind blown*
Plants do this as well. Chlorophyll is fluorescent, but the emission is either quenched, too weak, or shifted out of the visible range in water. Hold up a vial of chlorophyll extract to the sunlight, and you'll see it turn red! Also, quinine (in tonic water) glows a beautiful cerulean blue
Headphones block sound coming in. Chewing noises come from inside of you. Your ears can hear noises inside your body. With little to no sound coming in to go over your chewing noises, it's all you hear more or less.
A few more things: 1. A material is a phosphor because it just happens to emit visible light when struck by invisible light. All materials that we can see emit visible light in some way. 2. Cathode ray tubes (CRTs) emit electrons at high speed onto a phosphor-coated screen. The mechanism that excites the electrons in this case differs from that of UV radiation. Electrons are excited by absorbing momentum instead of photons. 3. Phosphor materials continue to emit light for a while, the time depending on the material. 4. Phosphorus, the chemical element, glows due to the production of light-emitting molecules in the presence of oxygen. Chemical luminescence like this is different from phosphorescence, and is used by some living things to glow in caves and deep underwater.
A blacklight is basically a fluorescent light without the fluorescent coating and with some filter blocking out any non-UV light instead. Or reversely you could say that a fluorescent light is a UV lamp made from an mercury/argon based gas-discharge lamp coated with a phosphor that fluoresces.
Am I the only one who feels a viscerally uncomfortable reaction to seeing the electromagnetic spectrum arrayed left to right from high to low, instead of from low to high? Maybe I work with audio too much and low to high frequency is always arrayed left to right as low to high... but... something about it feels weird
Exactly why I call them ultra violet lights. "Why do people call them black lights?" We might think about the intelligence of the LSD using people that probably came up with the "trendy word" , the people that always say "drugs are good for you" (as they take more crystal meth or LSD) and the government makes things up about them damage your body, and the government is hiding aliens. I can see people that talk like that calling what is specificly and clearly the opposite of light, light. Or maybe the LSD makes them confuse black with purple. Whatever the reason, probably only a trendy "buzzword".
Why no warnings about eye protection working around UV light for extended periods??? I had to have cataract surgery at a young age due to poor choices while out in the sun AND working around black lights a lot. Your pupils dilate and let even more UV light into your eye. Your lens prematurely yellows and hardens. Your retinas don't like it either. Interestingly enough, UV exposure is *excluded* from OSHA ionizing radiation regulations.
Because while you are speaking normally the sound waves get somewhat distorted, (don´t know the exact explanation anymore, but there is a video on youtube explaining it in detail) To counteract this you can simply but a piece of paper in fron of your ears so the sound waves have to travel all the way around
If I remember correctly it's because when you're hearing yourself speak normally you're also getting the vibration from your voice along the bones in your jaw to your inner ear, which comes in at a slightly different frequency. The combination of your voice reflecting back to your ears through the air plus the vibrations through your skull make it sound different.
They project a light in a part of the spectrum that we can't see, and then the phosphors absorb the light and project it back out lower down in the spectrum so we *can* see it. Yep, that's explaining how.
I mean, he did say how it does it, just perhaps not in the detail you wanted. So let me elaborate: electrons in atoms can absorb light as long as its frequency matches the energy of the electron (that's also how microwave ovens work, by the way, since they use frequencies specific to the electronic configuration of water; but I digress). When the electron absorbs a photon, it gains energy, and if it gains enough, it can jump to a higher energy level. (Electron energy levels are quantized, meaning they can only have energies that are integer multiples of a fundamental amount, they can't have any in-between energies.) So far so good, right? Now, at a higher energy level, the electrons can't absorb the same photons of light anymore because they'd require a higher energy--higher frequency--of light to do so. So instead, they slowly lose the energy they absorbed as they're pulled in toward the nucleus of the atom. But energy can't just be lost/destroyed, so instead, they lose the energy by emitting new photons. These, however, are exactly the amount of energy of a single quantum level of that electron, as opposed to the higher amount of the original light source. So the light emitted is lower in frequency, and thus in the visible spectrum. Hence, glow.
For the sake of education, at 2:05, the correct idiom is actually 'home in on', and NOT 'hone in on'. The idiom derives from the military jargon of the Vietnam War: machine gunners in choppers would 'home' their sights on ground and other targets. In contrast, 'hone' just means 'to sharpen' and isn't logical in that phrase.
The detail level was underwhelming. Not one mention of electron energy levels. The real interesting phenomena happens in the phosphores themselves. A photon, be it UV or in another energy level can be transmitted through (unimportant in this explanation), and of bearing here, reflected or absorbed. Normal color we see is often reflected white light, minus the absorbed wavelengths. The absorbed wavelengths are the photons with the requisite energy to raise the electron to a higher energy level, often skipping over several possible intermediate levels in the process. This energy must be re-emitted as a photon, but is generally done in smaller amounts, skipping down energy levels until it reaches ground state. Because it is a lower energy level, this is often in the IR spectrum, macroscopically felt as heat.(molecularity manifesting a vibration energy) Hence why black shirts in summer get hotter than white ones. With black light's UV-a light there is the possibility for a high enough drop in energy levels to propagate visible light. Given the right compounds that is.
If you were in an All-White room, and you were to use a Black Light, then it would pretty much only be effective for making it dark. But if you're in the dark, and you turn it on, then basically you're just going to be sinking away into the pitch black of darkness.
By the way. "Thanks to all our patrons on Patreon who keep these *answers* coming. If you would like to submit questions to be answered, .." I noticed this quite a while back. Shouldn't it be "Thanks to all our patrons on Patreon who keep these *questions* coming"?
Ah well okay, I always understood it like "the patrons are giving us the answers and we just present it in a nice fashion". I know that's not how it works, but I couldn't get that thought out of my head.
No mention of 1920's Depression glass? Seriously, shit guys! That is the coolest black light effect. Actual radiation emitting from glassware. I got a few at home under a black light. That green glow is lovely.
@scishow loads people claim in videos they can make black lights out of a phone torch. Although all of them have used fluorescent yellow sharpies, not the actual invisible ones. I’m trying to find out if invisible ink actually would illuminate with the right clip-on filter. Would this be possible?
So is this UV light harmfull to people? I've been thinking about changing the lighting in my room from a normal lamp to some blacklights. Is it safe to do this? Or are there health risks involved?
What could happen if i would keep it on for hours at a time? The UV light is better in setting a mood, while watching a movie with a girl over, or even to keep on when playing games etc.
Small correction. At 1:06 you mention that "phosphors are substances that fluoresce" when actually phosphors phosphoresce and substances with fluorine fluoresce. Phosphorescence and fluorescence are two similar but different processes. In particular phosphorescence is much slower hence objects still glowing after the black light is turned off.
YOU DIDNT ANSWER THE QUESTION!! What happens to the energy of the UV light? Does one photon become two? Does the material heat up? Does it ionize the shit out of your stuff?? (I know it it isn't that one but you did not rule it out!) WHERE DOES THE EXCESS ENERGY GO??
Okay, but what about things that glow under....well not blacklight? One might use the example of a transparent yellow plastic cap in a room that is lit with a blue light....WHY DOES IT GLOW!?!? 🤔 And the cap doesn't glow blue, it glows yellow.
Who here remembers blacklight posters, classic rock before if was classic and smoking copious quantities of Colombian, Acapulco Gold, Panama Red, honey oil, etc. etc.? Or am I the only one who'll admit it?
FUN FACT: Real diamonds shine a beautiful light-blue almost cyan light under blacklight(or bluelight) which makes it easy to find out if you been lied to like my dad was when he bought my mom a moon-shaped ring with 'diamonds' only for me 10 years later to aim an uv flashlight at it to find out 1 out of 8 gems was a real diamond. Speaking of diamonds, screw them, they look like joyless glass go for labradorite, moonstone or opal(most beautiful gem trio in my opinion) instead if you're buying a ring for your darling.
"Hey girl you wanna have some fun?" "Hell yeah! What do you have in mind?" "Well, I don't mean to brag.... but I've got some glow in the dark semen if you wanna check it out."
As a bouncer I've also used it to detect people to get drug tested, (at places where they had a zero tolerance politic) Small rim of white at the nostrils was a dead giveaway...
When he said semen, all I could think of was Guardians of the Galaxy when Chris Pratt said "if you shown a blacklight in here, it would look like a Jackson Pollock painting." lol Now I know the science of why.
So I have a blacklight above my bed that I use everynight, not as a nightlight, just as a reading light type of thing. I'm wondering if this can hurt my eyes in the long run
Phosphors, you keep using that word. I don't think it means what you think it means. You really mean photoluminescent materials. Phosphors include materials where the glow is stimulated by things other than electromagnetic radiation. Like by electrons in a CRT and neutrons in neutron detectors.
Scishow needs to do a video about Dmitry Belyev. Spread this around if you agree.(maybe it will help get their attention) If you have no idea who he is look him up. Its really interesting!
My question... how do receipts make credit cards scan? Sometimes, if a credit card doesn't work at the store, a trick to make the machine read the card is to put receipt paper over it... You'd think that would block it, but it helps the machine scan the card... Wut.
I learned this hack several months ago where 3 layers of tape--the first two colored blur in sharpie and the last purple--can achieve the same effect a black light does, causing phosphorous material to glow. why is that?
Due to having petersonomoly as s child, I had to have a lens removed. Now in that eye, I can see some uv light. (It's been proven but it's only a little bit out of the usual.) now it is irritating and Anoying to stand around uv light.
now that's how you disseminate knowledge in a quickie. now wonder you have 4m subscribers. you could easily and cheekily add a 4 sec ad, so why aren't you already doing that?
So UV-A is pretty harsh. It's the bandwidth that gets deep below the skins surface and causes cell damage. I assume this is largely mitigated by the low power of the bulb emitting it. All that said, I definitely feel like I've gotten a light sunburn when in a room filled with Blacklight for too long.
Black light is great for showing up where your cat or dog has peed, also try it out in your toilet and around the floor, you'l soon see where the guys in your home have splashed urine!
Guys pls i have a question i want to put black light and led light in my room in the same time i want the black light effect on the things that have in my room can that work
It is cold where I am I then asked Siri how cold is it he said 1 degrees I don't believe him but I looked how at something and it said that it was 7 degrees now that is believable
