How Do Blacklights Make Things Glow?

[@fr2ncm9]

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.

[@AmigoAklito]

This is one of the best channels on KZbin, I swear!!!

[@AmigoAklito]

Loved this video btw!!*

[@abdullaahmed4676]

Sir am afraid we are going to shutdown your account for two days because you liked and replied to your own comment

[@aminchitsaz4806]

vido sex

[@mechasentai]

yes.

[@vedritmathias9193]

I think you should have gone a little more into detail about why things glow certain colors and the common methods for creating the UV radiation.

[@donvaldez6773]

Scorpions etc.

[@chrisv4496]

That shirt would be crazy as hell under a black-light, Hank... You should have totally done part of the video under a black-light.

[@Ideklikuh]

Why do I find this channel a lot more interesting than school

[@UnknownUser-gd3ls]

because school is trash and outdated.

[@JoeCrush_]

unknown ? Lol k

[@MrDelord39]

+unknown ? so true

[@jetison333]

probably because your forced to Learn at school, while here you get to choose what to Learn and you want too

[@crazyj10agains]

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.

[@tomboz777]

"Never use the honeymoon suite" - Gordon Ramsey

[@mspeir]

Why wasn't this video shot under blacklight? Fail...

[@ahtzee9078]

He might have hair gel. Lol

[@nahyanrajee198]

Exactly!

[@EVRLYNMedia]

XD

[@harryjones8988]

He forgot to play with a stick 😂

[@rbcv841]

Mark Speir this WAS shot under a blacklight. what u see are the glow from objects that otherwise are invisible, including the presenter.

[@112233jjooee]

Backlights matter

[@aliciastrouth8584]

Wow very punny

[@reasonnottheneed]

wave or particle?

[@Iruparazzo]

depends on how you look at it

[@derpyhooves7349]

Feeling the bern, huh?

[@adanaladdin2807]

+Connor.NJT || CondorK fuck trump

[@donnierussellii4659]

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.

[@cyclenut]

In the 70s and early 80s I had black light posters, rug, bedspread, models, and stickers on the ceiling. Being a teen back then was fun.

[@pvtpain66k]

That shirt would be bitchin' under black light, Hank...

[@DavidPackluvr]

Agreed! I thought he would shine a blacklight on it before the vid ended!!

[@ptw783]

He didn’t want to expose the hank stains

[@bryanwan6169]

All these comments don't really...shine.

[@bryanwan6169]

What a bright pun I have made.

[@Sophiec166]

shame you didn't get the glowing response you hoped for

[@techtonik25]

My face just lightened up seeing these puns.

[@Master_Therion]

True, but I'd give your comment a glowing recommendation.

[@bryanwan6169]

You all must be pundits in the joke world...

[@antivanti]

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.

[@NickRoman]

This is something that I should have already known. Thanks for posting.

[@rubybooboobear8830]

Thanks for the info. You helped me write a whole paragraph on black lights for my project!

[@cm374787]

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*

[@nylonsteel]

"oh baby .. ! Im... Im ..gonna Phosphor !.. "

[@lewismassie]

'...uses other than checking your bedsheets for fluids...' - That is actually a really good idea

[@VividNation]

Am i the only one who waited eagerly that he turns blacklights on and all of his Shirts dots glows like stars in the night?

[@CCBovell]

Wow it took until the 8th semester of my chem degree until this topic came to light

[@montanawarren8462]

LOL

[@alexbutton2878]

A level chemistry soon and I'd like to see something on atmospheric chemistry such as the formation of radicals and what they actually are

[@Orsbore]

Certain minerals glow under a blacklight.

[@paulwebb2078]

+DeadLink My bed also lights up when I cumin it

[@TheCarterhcole]

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

[@houselightkell]

Orsbore my bathroom is full if minerals

[@TheChunguTube]

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.

[@ockertoustesizem1234]

good to know

[@pix23]

Hmm for a SciShow video, I expected a little more nerdiness about the absorption and emission side of things.

[@EugeneKhutoryansky]

"Black light" is actually a contradiction of terms. Black is what we see in the absence of light.

[@newgothwhosdis]

an oxymoron*

[@jouvani332]

+gamerchunk1 that's literally the same thing.

[@fireandbombs12]

In the video it said that black lights mostly emit UV light which is invisible to us. So it could be taken as an absence of light.

[@_hector__]

Um, something that is dark, black absorbs most of the light. You cannot say black with the word light after it as it contradicts itself.

[@maythesciencebewithyou]

Black is what what our brains create in the absence of visible light

[@kimlibera663]

Finally someone to talk about UV light & how it aid in a pandemic.

[@ThomasGrillo]

Oh, how I miss my vintage LZ poster! Thanks. :)

[@MrAlice]

He mentions fungus; In our animal shelter, its the first way of checking an animal and diagnosing it during intake for Ringworm. While generally not such a horrible infection for people (put cream on it, slap a bandaid on, good to go) it is EXTREMELY infectious to cats (and to a far lesser extent, dogs). Blacklights help us stop one of the worst things possible in a cat shelter (this is assuming all cats are vaccinated against other diseases, such as panluke.) Thank you, Black light gods.

[@munawarlaljoshi3731]

3. Can fluorescence and phosphorescence be exhibited simultaneously from the same materials?please answer me

[@AdityaBangalore]

I can keep a scenic painting in my room that turns into a cool looking skull when partying!

[@purpleorphan9504]

dude i was seriously thinking about asking for you guys to do an episode on thiss like 4 days ago,spooky,you guys are in my head,well whomevers QQ it was,was in muh head!

[@zachcrawford5]

I had a bumble bee hanging out around my blacklight one time (they really like the UV) and I noticed that the yellow parts of its body flounced a bright (but not a"neon" looking) shade of yellow. Ot was really neat and seems to happen with every bumble bee that has gone near the black light so far.

[@captainredbeard261]

Thanks for doing what my boss isn't competent enough to do and teaching me how to check for counterfeit bills.

[@bozzaza99]

Why is my chewing super loud when I have earphone in???

[@yungtravis8683]

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.

[@kLuMzyOwl]

yeah it's the same reason why you can hear yourself sing louder when you cover your ears

[@matthewmccloy4283]

What a happy surprise.

[@diedie5]

Did anyone else think that they were going to demonstrate with that crazy shirt that Hank was wearing?

[@gorillaguerillaDK]

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...

[@Berserker69]

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?

[@Xiefux]

i wouldnt keep the blacklights on all the time, but it should be kinda safe

[@Berserker69]

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.

[@Xiefux]

Jasper Beuls you could get cataract and go blind

[@vmobile890]

I found best black black light is 1 or 2 on a simple shop light fixture 4 feet long or best known as F30T8BLB . Use when dark and shows how dusty or many things on surfaces you might not want to see .

[@mike0rr]

When you wear such an awesome shirt, I'm gonna notice it 15 episodes in a row! :P

[@kimnorae6982]

Excelente vídeo, muchas gracias por el excelente trabajo.

[@Sam-lh2ls]

Why am I here you ask? well, I was feeling a HANK-ering to watch scishow

[@BeCurieUs]

We also use the same trick in radioactive signs, gun sights and key chains. Weak radiation from tritium gas will activate phosphors that release the energy via visible radiation, IE, light!

[@RedX8477]

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.

[@winproduction7585]

Thank you sir

[@legendofshaun]

I want an episode on Whirlpools and other water votrecies!

[@johneygd]

Blacklight feels & is pure magic.

[@megaminimax16]

Hank is basically just an adult, American me. That's pretty cool; I'm in some ways similar to hank!

[@charlesachurch7265]

Electron spin reversal and the science of fluorescent pigments is an interesting topic if you want to delve deeper.

[@bramdegraaff4234]

@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?

[@egalomon]

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"?

[@mspeir]

Nope. Patreon subscribers keep the videos with the answers coming.

[@JasAfterAll]

Well, they do fund the show, and therefore, the answers that come out of it.

[@egalomon]

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.

[@JasAfterAll]

+egalomon Your way makes sense too, don't worry.

[@MasterFluffybumkins]

Hey Hey Hey! @SciShow I GOT A QUESTION! "If you stopped eating actual food and just took vitamin supplements for say a year or 2 what would happen to your body or would you be able to even last that long?"

[@xMr_Smiley]

man.. So if I use a blacklight in my room it would be so professional as Jackson Pollock artwork?!?!

[@Forssa1]

I, too, watched Guardians of the Galaxy.

[@TommysLittleWilly]

To be fair, that joke has been around since Jackson Pollock. I groaned when I heard it for the 900th time in Guardians :(

[@lilswissstrider5965]

Hank would you do a video on Bohmian mechanics? Or maybe Schrödinger's wave equation?

[@Hailiums]

We also use UV lights to help treat Jaundice.

[@cathrynross9045]

I love Hank's shirt

[@NvrchFotia]

I would've said "magic", but I feel this is a much better explanation.

[@connorshaw8709]

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!

[@FknNefFy]

Why thank you!

[@VapidVulpes]

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

[@Graymenn]

Just stand upside down silly

[@amanuelyohannes4762]

Why does my voice sound different on recording?

[@gewurzgurke4964]

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

[@mattl1221]

I hate recordings of my voice

[@mattl1221]

I hate recordings of my voice

[@bentoth9555]

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.

[@teamskrub2292]

They already made a video about that...

[@epiphi]

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.

[@luckychonk9527]

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?

[@evilynthecommenter2094]

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.

[@ninja-kq1ih]

HEY GUYS! IF SOMEONE CAN ANSWER THIS QUESTION I WOULD BE EXTREMELY GLAD. okay here it is: if phosphor can absorb the black light and then transmit it at a lower frequency, where does the energy of the black light go? I think it heats the phosphor a little bit but im not sure.

[@FirstLast-fr4hb]

It radiates outward?

[@DrRChandra]

The wavelength shift due to absorption of photons then reemitting them at a lower wavelength is called the Stokes shift.

[@FirstLast-fr4hb]

Or we could just call it a downshift of wavelength.

[@Tiberiumfreek]

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.

[@jabrakoma]

i love this show and this guy make me love science

[@phantasm1234]

Could you do one on cerebral aneurysms?

[@GeahkBurchill]

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.

[@larsfroelich]

would've wanted to see more physics about this.. absorption and "conversion" to larger wavelengths..?

[@nikolasschwendeman5116]

I like that shirt

[@blackwhite4385]

fantastic

[@zippomage]

if flourescing involves converting energy from one kind into another, does it degrade the flourescing substance?

[@typezero8929]

You meant "home" in on a problem. Not "hone" in on a problem. I expect more from you, Hank. ;)

[@lazyperfectionist1]

"...which means you can use black light to check for counterfitting." _This_ is good to know.

[@flatflatspin9855]

Is the Fluorescing of something a chemical reaction? Does it generate heat? Does the paint or whatever breakdown? Will it stop fluorescing in the future?

[@FirstLast-fr4hb]

Good question, I think it depends on the materials involved. Photosynthesis is related to that, and its certainly chemical. I think most of this is a change of energy form without chemical change though. Like loosening or tightening the string on a guitar. Though "glow sticks" for example and certainly a chemical reaction, and those run out of action after some hours usually. You can even boil them in water to get them to glow super bright = ) (Might want to taae precautions though as they're filled with glass which you can hear snap when you break the glass barrier between the two chemicals.)

[@munawarlaljoshi3731]

2. What is the difference between fluorescence and emission?please answer me

[@naominekomimi]

Does looking at blacklights cause vision damage like looking at a powered on lamp would?

So the light absorbed by a phosphor has higher energy than the light emitted by it. What happens to that energy? Are these phosphors heating up or are they emitting other particles?

[@aritmay2327]

can you make a video about Prosopagnosia (Faceblindness) ?

[@Tomyb15]

Do whales and other marine mammals drink the (salty) sea water?

[@FirstLast-fr4hb]

I wonder how saltless water would feel on your skin after spending your entire life in saline waters.

[@TheAccess3333]

Is black light safe? Your not supposed to look at it directly but only where it's present in the area right?

[@anshitagoel5237]

Why is there a formation of thick layer (kinda stuff) in a hot cup of tea?

[@JennieKerfuffle]

I would very much like to know how long it takes for moles to appear...they keep popping up on my face and arms and hands and it's like one day they're not there and the next they are. Am I just being unobservant, or do they really poof onto my skin overnight?!

[@jackoghost]

i like to randomly pause the video and see what Hank's face looks like, some moment are funny

[@tonytattletaleliano956]

just lookin at all the spream jokes....so funny and og

[@SlyPearTree]

Thanks for this video. I am not sure but I think lower frequency electromagnetic radiation has less energy so what happen to the energy loss? Is it transformed into heat as energy "loss" is often (always?) expressed? Does that mean that phosphor under UV light also emit infrared? But IR is even lower frequency than light which would mean another energy leak so now I'm confused which means I'm now so sure about my initial premise. Can someone enlighten me?

[@senya6095]

Hank said that certain detergents contain phosphors , which is why white T-shirts glow under blacklight. Does that mean that a new T shirt that has never been washed won’t glow?

[@DegonTheMighty]

So is the difference between a fluorescent black light and an incandescent black light only in the coating of the bulb?

[@Sveinfyr]

how did you make this question 4 days ago?

[@thesage1096]

YEAHHHH WTF

[@thesage1096]

WHO ARE YOU !?

[@oscarrh8005]

+Sveinfyr smh.

[@spoonbruh741]

yah

[@jr52990]

.... so that's why that one Chris Prat Guardians of the Galaxy quote was so funny.

[@MOLAGAS1]

OMG THANKS

[@rihamesper8758]

love it

[@coolcatsfun3779]

So cool

[@Dontworryimaprofessional]

So what causes the "moving light" inside the buld you can see when you look at the bulb?

[@bandgeek9723]

I recently got a UV flashlight and was taking it around my house seeing what glowed and didn't glow, like you do, when I tried it on a potted plant the leaves showed up as a dark red. What's with that?

[@jacobvanantwerp2001]

Cool!

[@issolomissolom3589]

I love u hanks

[@munawarlaljoshi3731]

1. What makes fluorescent colours look fluorescent?please answer me

[@rooryan]

can you get burned from blacklights? like a sunburn?