Why Things Look That Way Under a Blacklight

[@DragonGirlFire]

Hank getting so excited about the topic that he has something to add off script is probably my favorite part.

[@chursius9112]

Hank, I'm a researcher at Oregon State University developing a diagnostic assay for Agrobactetium tumefaciens (bacteria causing crown gall disease) using a CRISPR-based technique that acts almost exactly how you described in your "off script" bit. It was very cool to hear you talk about that!

[@barrydysert2974]

About 15 years ago i was involved with a raspberry planting operation. We were pretreating our rootstock with Agrobacterium, the non-crown gaul inducing kind, with the goal of out competing Your bad boys. It was reasonably effective. It's a marvel to me to have randomly found Your post about having a career studying this disease !:-)

[@TheKrispyfort]

Um, mate, I am assuming you meant to say you're working on an "assay" and not an "essay" to detect the agro-whatever my area was endocrinology and TBI means I've already forgotten the rest of your targeted lifeform - soz. Unless, you have designs to develop a detection essay, in which case how is the subject supposed to read the essay, and are you going to be using laughter or snoring as a positive result? Detection essays 😂 (sorry, it's been stressful, I'm tired and so I think I'm a comedian. I'll go to sleep now. Good luck with your research 🎉)

[@TheKrispyfort]

Question: how does the level and intensity of direct and indirect sunshine affect the capacity of the agrobacterium (I remembered! yay)? I ask because the sunshine that raspberries are exposed to here in Australia is a very much different beastie to the northern hemisphere sunshine. A lot of northern hemisphere full sun plants have to have partial shade here or they don't do so well

[@TheKrispyfort]

​@@barrydysert2974 there's possibly some microbiome action going on for the roots of the plants

[@chursius9112]

@@barrydysert2974 What a coincidence! Thank you for sharing! Another one of my research endeavors was testing a naturally-derived product that prohibited crown gall formation at sites of infection with Agrobacterium, and as part of my background research, I read about exactly what you described above. A fascinating little bug, for sure!

[@annekeener4119]

Fluorescence is also used for multiple microscopy techniques and molecule labeling tricks. GFP is green fluorescent protein and it is commonly used to label molecules. Fluorescence resonance energy transfer or FRET literally uses the fact that fluorescent molecules release lower wavelengths of light to test if two molecules are interacting by having one molecule with a label that excites a a specific wavelength of light and emits light at a wavelength that will excite a molecule with a second label, creating 2 different colors that can be detected if the molecules are in close proximity or directly interacting.

[@OMGitshimitis]

For those who are interested the reason Phosphorescent chemicals release light over a longer time is that the different energy levels the electron sits at in a Phosphorescent chemicals also have different angular momentums so to transition between the states requires more random luck.

[@TheKrispyfort]

5 points each. For sheer dumb luck

[@cassandrakarpinski9416]

Fluorescence is also useful for analytical chemistry. A fluorospectrophotometer can be used to determine the quantity of a fluorescent molecule within a sample (sometimes with a standard curve for calibration). It differs from standard spectrophotometers by having the detector and source set to different wavelengths (in spectrophotometers, these are set to the same wavelength and the change in intensity gives the absorption, and thus we can calculate the concentration). The sample absorbs the source wavelength and then the detector measures the intensity of the fluorescent wavelength to determine the concentration (which is where the standard curve comes in. By measuring known concentrations of the molecule in question we can plot a graph, then utilise the line and/or formula of the line to convert the fluorescence of the sample into a concentration)

[@Mikearice1]

It doesn't have to be ultraviolet light to cause emission. It just has to be a higher frequency. Violet and blue light will make green and red fluorescence work. You can test this with a violet 405nm or a blue 455 or 445 nm laser. (none of those emit UV light) but they all work. Just point them at different colors of fluorescent paper and see if you see a different color than the laser. A red laser won't make anything fluoresce, however. A green laser will work on orange or red fluorescent paper.

[@MrNicoJac]

Do you know what happens to the additional energy? :) Like, a photon of XYZ wavelength hits a surface/molecule, all of its energy is absorbed to make the electron jump up a (few?) tier(s), and then a tiny moment later the electron emits a photon of XYZ-ABC energy (meaning a longer wavelength), which we perceive as fluorescence because it's got a different color. Where does the ABC part of the initial energy go? 🤔

[@alexbrewer9930]

Well, a red laser can probably make things fluoresce, it just won’t be in a wavelength we can see 😢

[@Samu2010lolcats]

@@MrNicoJac IIRC when a fluorescent material absorbs a photon, the electron jumps up two (or more) energy levels at once. Then the electron jumps down each level individually emitting a lower energy level photon each time. So for every high energy photon you get two or more lower energy photons.

[@PJ-oe6eu]

​@@Samu2010lolcatswill the energy gained of the electron that shot up a few levels always be divisible by what it losses going down levels? If not then what happens to the leftover energy?

[@franck3279]

In non-visible range, X-ray video machines use UV CCD coated with Xray-absorbing material.

[@AaronGeo]

My body after licking some weirdly green clock hands:

[@v.xien.]

Or brushes with radium

[@mattressbordi]

@@v.xien.makes the brush sharper

[@ArchFundy]

Many of the gals who painted the radium dials on watches and clocks died of cancer in their mouth area. They used to lick the brush tips to keep them sharp.

[@lashadi1445]

Lol shtaaahp... if you stop eating that radioactive paint, I'll stop eating all the old oil paint I found in a box. Mmm...Naples Yellow...

[@victoriaeads6126]

Ohh, your bones are gonna glow even after you die if you've been licking radium 😬

[@SmilesBot]

After having an artificial lens put in my eye to address a juvenile cataract (T1 Diabetic), that eye now sees slightly past the normal visible color spectrum. I see more purples and blues in that eye and more than other people, but here’s the really weird part: a black light looks light a normal fluorescent light to me, just with a hint of lavender color. Most things don’t glow the same way either unless I close that eye and look at it with only my natural lensed eye. Makes cosmic bowling really trippy.

[@cachecow]

I prefer the soft glow of radium in my watches and dyes

[@gabbysmith7579]

My jaw fell off reading this 😢

[@Boolarramob36]

That goes on my cereal. I look directly at the sun to tell the time!

[@MaximumBan]

@@gabbysmith7579 I hope 99% of Hank's viewers will get this "joke". [hint: Playing golf was never so decaying]

[@gabbysmith7579]

@@Boolarramob36 wait a minute 🤔u might be onto somethin

[@Add_Infinitum]

5:59 I thought he was about to say "and THAT'S pretty cool."

[@JoeC92]

Love that guy's stuff haha

[@BuildinWings]

People without a lens (aphakics) can actually see this kind of light directly, with no refraction. It's described as purple sunlight.

[@MrNicoJac]

Omg.... How bad would it be to lose a lens? I'd lowkey wanna test it out before I die, just to know :/

[@TheMooseNextDoor]

Neat

[@evanburke499]

I was born with a cataract in my left eye they removed the lens when I was only a few days old. I'm legally blind in it but have always liked the way black lights look through it.

[@dandoriii2842]

This ability was used (allegedly) by the French underground to fight the German occupation. Young German soldiers patrolled the shore lines. When the resistance wanted to bring in materials and people from the sea, the boats at sea at night would signal with UV lights. Watchers on the coast included older people who had cataract removal surgery. Without the lenses, they could see UV light. People with lenses couldn’t. If no patrols were nearby, the “coast was clear” and the offshore boat was cleared to approach.

[@gabbysmith7579]

@@MrNicoJaclet me know also can I have the lense when you’re done I’ve always wanted to try one before I die, I feel like it would be like a umami gummy candy 😂

[@makego]

It's also interesting to note why fluorescent materials "pop" more under sunlight. Other materials are reflecting a certain amount, but a fluorescent surface next to them is both reflecting visible spectrum and radiating _more_ visible light energy that it's grabbing from the UV domain.

[@existenceisillusion6528]

In 2014 Stefan Hell and others won the Nobel in chemistry for (IIRC) stimulated emission depletion stochastic reconstruction florescence microscopy. I remember because that same year, 2 researchers out of UC San Diego developed a silver based meta-material that directly overcame the diffraction limit.

[@TheKrispyfort]

I used to know what all those words mean I miss lab life 😢

[@BanjoGate]

More 'not in the script' stuff! I like the way you present when not reading off the teleprompter!

[@gabbysmith7579]

That’s what hanks channel is for

[@jjmetrejhon1743]

1:17 I have subtitles so I knew the punchline but Hank's delivery still made me laugh out loud

[@Splizacular]

Videos about light brighten my day!!...my apologies, my dad joke funny bone had a spasm 😊

[@CrossStCroix]

This episode _rocked_ . A _shining_ example of SciShow content

[@Autistic_Artist]

As a fluorescent artist, there is a lot of science behind the art. First in responce to glowing white t-shirts its not the material that glows its actually a fluorescent dye in detergents that "make your whites whiter". One of the fascinating things about fluorescence is the glow is coming directly from the atoms instead of reflecting off an object. So you are painting with light. I have a video where i mixed red, green and blue black light paint to make white! Well almost.

[@Paarthk]

How long did it take you to become fluorescent?

[@Autistic_Artist]

@Paarthk depends on how many body painters I'm working with, 😆

[@TheKrispyfort]

Detergent explanation. YES!!

[@Daniel27182]

the part where he laughs about his son

[@rainbowslinkies]

"glow in the dark stars in your childhood bedroom" ...yes, my childhood bedroom wall only 🤣

[@Adventurealliancekerala]

Fluorite was just minding its business as a crystal, and now it’s a blacklight celebrity. What a flex!

[@grumblefkitty]

fluorite was already my fav mineral. i knew some of this, but not the medical applications. this is awesome!

[@MichaelWalker-hh2xp]

🎸 relation: playing rhythm, and wanting to bust out that solo!

[@EmilyJelassi]

Such an interesting video.. thank you!!😊❤

[@overtoke]

i have a real flouro tube blacklight. when i was much younger i could not help notice, as i held the bulb a quarter of an inch away from my eyeballs, i could see things "swimming" i had no explanation at the time, but it occurred to me years later, that they must have been bits of cells within my eye fluid.

[@franck3279]

There’re usually called floaters. But by doing that, you damaged your vision by giving your retina sunburns.

[@overtoke]

@@franck3279 yes, i have a persistent daytime "floater" it does not "swim" it's in a fixed position. it's a bit irregular shape, not a dot, and out of focus. the "swimmers" in the black light appeared to be inside the light itself. i.e. not out of focus, hundreds of individual points darting about. they did not seem to react to eye movements (sloshing?). i also don't think a black light is harmful. UVA

[@NeonPreservation]

sounds like you're describing the blue field entopic phenomenon, aka "blue sky sprites": en.wikipedia.org/wiki/Blue_field_entoptic_phenomenon

[@jasonseymour4235]

Figured it was worth pointing out, fluorescent bulbs glow due to both fluorescence and phosphorescence. This is why they actually continue to glow for a moment after being turned off. Fluorescent tubes have mercury vapor, which glows due to fluorescence. They also have phosphors. Excited by the orange glow of mercury fluorescence, they begin to glow due to phosphorescence. This phosphorescence is what gives fluorescent tubes their color, rather than the harsh orange mercury provides. The phosphors used typically only continue to glow for mere milliseconds to seconds by design. You don't want them to keep glowing long after you turn them off, of course, but the fact they do continue without additional energy makes them phosphorescent as well. To clarify, this phosphorescence is not the occasional flickering you might see after turning a bulb off. That's just the ballast discharging stored energy, although these flickers can extend the glow from the phosphors.

[@feeberizer]

I had blacklights back in the 60s when they were all the rage. We turned off all the lights one evening and my mom and dad and I wandered around the house seeing this new view of our world. Then we got to the kitchen. Mom was furious seeing stains all over her "spotlessly" clean stove. And, when I looked at her teeth... Well, you could see all the dental work she had which made her even more furious. Oops! Blacklights were relegated to the attic after that. 😂

[@ScaerieTale]

"I never thought I would relate so much to an electron." Big. Monday. Mood.

[@ThomasForthewin]

You gotta give some probs to the SciShow set designers. I love this set style with the table, it gives off a kind of D!NG/Hankschannel vibe which has this casual tone, that makes it feel so much more casual, personal and friendly, but it's still set up so professionally, with the props the lighting and the color palettes, which make it very pleasant to watch and give room for cool object demonstrations like with the fluorite crystal. (Although this is surely also to showcase the advertised product which doesn't lesser the demonstrative value though) From a teachers perspective this set design is such a didactic masterpiece!

[@sydhenderson6753]

Blacklights are useful for finding scorpions since their exoskeletons are fluorescent. Phosphorescence is partly responsible for the discovery of radioactivity. Henri Becquerel was investigating whether phosphorescent materials emitted X-rays. (It made sense at the time since people were trying to figure out how x-rays work.) The material he chose happened to be a uranium-containing metal. (Several uranium salts are phosphorescent.) After several cloudy days, he decided to develop a photographic plate the sample had been sitting on, presumably as a control. He discovered that the sample emitted radiation even when not exposed to light, The rest is history.

[@christophergilgour714]

Have there been studies on the long term exposure to blacklight & phosphorescent light? I work in a specific industry where i have been working exculsively in black environments, lit only by phosphorescent light. This was months of exposure, day after day, for upto 15 hours per day. Personally, i specifically noted very intense colorful dreams of varied content over that time. I cant speak to other psychological changes, but specifically dreams were extreme.

[@TheKrispyfort]

And, thank you SciShow Team for sharing this with us ❤

[@MikkellTheImmortal]

A mineral that can emit phosphorescent light that most people are unaware of is diamond. They're classed as iib diamonds and can glow in a variety of colours including blue, yellow, red or green. They are naturally white and indistinguishable from other diamonds unless you use a uv light. The glow can last up to 2 seconds, depending on the structure of the crystal and it's inclusions. Other gems that glow brightly but are instead fluorescent are corundum (Ruby's and Sapphire). Lapis lazuli has inclusions that will glow a brilliant orange. And I'll finish off with calcite, which glows green.

[@earlaker]

I can hardly wait for my next Rockbox and light it up with my uvBeast V3 365nm! I've been waiting for this one! Some of my other Rockbox minerals or their matrix have also fluoresced. (Particularily the white matrix (I believe it's calcite) on the pyrite crystals from Ojuela, Mexico [May 2024], which fluoresced a bright pink/red!)

[@3800S1]

I used not just fluorescence but also phosphorescence to identify a mystery mineral crystal in my collection I was given some 15-20 years ago as variety of calcite, the unique colour a crimson/salmon red glow and bright after glow that lasts a few to several sec after being hit with a 405nm laser allowed me to pinpoint it to a type of calcite, where all other forms I have look nothing like it, nor fluoresce for the most part (some slightly purple/white), and none phosphoresce. I also found that only the local Australian opals do both, where the same looking opals from other counties don't do either. Also a tidbit of info. Hit most calcium or phosphorus containing minerals with a xenon flash like that of an old camera, they phosphoresce for a sec or two in the classic glow in the dark green, including your TEETH! But I have not been able to replicate this with UV, even with an intense source like a UV laser, so the xenon lamp seems to have that same pump effect used in old ruby lasers etc...

[@zacharydefeciani7890]

This set is giving Technology Connections

[@Trag-zj2yo]

I used for years as a quality control inspector looking for surface flaws on metal components.

[@astralb.2647]

Fluorite is my favourite crystal, especially the green/purple banded variant

[@MaximumBan]

Is meth fluorescent?

[@tomhossain2099]

Ok how do fluorescent materials absorb and emit at different energies? It’s my understanding that absorption and emission spectra are complimentary because electron energy levels, like all quantised energy levels, are discrete.

[@robertfindley921]

People use UV light to look for yooperlites, fluorescent rocks, at night along the coast of Lake Superior. They were formed around a billion years ago when volcanic activity created pockets of fluorescent minerals within cooling lava.

[@vanessaryan3103]

Don't forget lichens! Some species glow under UV light. They glow lots of different colours - I've seen blue, yellow, orange, pink and red. It's actually one of the features lichenologists used to identify them.

[@victoriaeads6126]

PBS SpaceTime made a glow in the dark shirt for the April 2024 Solar Eclipse. It is printed with the phases of the eclipse. I wore it on Eclipse Day, and it was glowing during totality!!!!!!

[@skybluskyblueify]

Stokes's ideas as to what would cause this glow would be interesting to hear, but I am a science-history fan, so I understand things need top be cut or not even mentioned. Boy did early-modern scientists and modern scientists early in the modern era have wild ideas. Yikes.

[@macaylacayton2915]

A common form of fluorescence used for medical imaging and cellular imaging is indeed Indocyanine green, but also GFP or green fluorescent protein which is found in jellyfish. Sorry the biotechnology part me had to bring it up

[@gmsherry1953]

I am unexpectedly confused. I'd never heard that an excited electron emits a lower-energy photon when it returns to its original orbital (which means, obviously, I had no idea how fluorescence works). But ... doesn't a reflection in a mirror also entail atoms absorbing and emitting electrons? I just got through trying to research this, and for mirrors, sources talk about light as a wave instead of a particle, but of course it's always both, so how do photons bounce off a mirror? Aren't they absorbed and emitted by the silver (or whatever)? If so, why don't mirrors change everything's color? If absorption and emission makes ultraviolet into purple, why isn't the reflection of a blue object green and why don't red objects disappear entirely?

[@lunkel8108]

Refraction and reflection of light do not involve absorption. Absorption and re-emmission would result in light going off in random directions and in both refraction and reflection the angles are clearly not random. We can understand them pretty well using just the classical classical wave theory of light. Light consist of wiggling electric and magnetic fields, which wiggle the charges present in materials, which in turn cause the electric and magnetic fields to wiggle in different ways, causing refraction and reflection. The channel 3Blue1Brown recently made a series where they try to explain the process visually.

[@gmsherry1953]

@@lunkel8108 Thanks. I'm still not sure I understand, but you did a good job. I agree about the "random directions" thing--I guess I thought there must be something special about silver and other materials used to make mirrors, that they don't emit in a random direction? It's amusing to me as a layman that, in effect, we can pick and choose whether light is a particle or a wave, depending on which makes for a better explanation of a particular phenomenon. Thanks for the referral to 3Blue1Brown.

[@romulusnr]

I bought a Techmoan T-shirt and I had no idea it was glow in the dark until I wore it to bed and I could see under the covers.

[@ZackRToler]

I'm in my 30s and there are those green stars and planets above my bed. I didn't put them there. Someone's kid did from whoever was here before me. But I like them so I never bothered to take em off

[@leviholt4557]

Oh hell yeah my favorite stone!

[@SB-qm5wg]

flying squirrels under a black light are wild

[@PLuMUK54]

I could do with a black light shining on me - it's been ages since I've been excited 🤭

[@rudolphrobbertze792]

How do electrons use the energy? I was hnder the impression that it can jump up two e ergy levels then drop back one at a time releasing photos of longer wavelenght.

[@lunkel8108]

No, that's generally not how that works as far as I'm aware. Light can't just excite electrons between energy states but also confer vibrational and rotational energy to the molecule that absorbs it. So a molecule can absorb light that has enough energy to excite an electron + enough energy to cause it to "wiggle" a little bit. Some or all of that vibrational energy is however often very quickly lost to other molecules around it as heat. Thus, when the molecule re-emits the light, it does so at a lower energy. These processes can also occur in the opposite order: The excited molecule re-emits light with the energy of the electronic transition but leaves some vibrational energy with the molecule, which is then dissipated as heat.

[@rudolphrobbertze792]

@ thanks. I learned something new

[@lunkel8108]

@rudolphrobbertze792 There's also an additional effect that happens in polar solvents like water. If the excited state has a different dipole moment than the ground state, that can result in an electric force on the water molecules, causing them to rotate to align with the new dipole moment and again leading to the molecule losing energy to its environment. We can actually make use of this to for example tell whether a fluorophore on a protein is exposed to the water or hidding in the less polar inside of the protein, which can tell us something about the protein structure (though this is a pretty niche technique).

[@rudolphrobbertze792]

@ thanks. Definitely have to reopen a chemistry textbook or two. Really appreciate the answer

[@rodrigorocha5586]

Is it the same principle used in crime scenes ? Because if it’s the case we can thank that crystal for a lot more

[@jammbbs1688]

So in a round about way your saying someone with an astigmatism can visibly see more excited particles in light waves? Or is it just me thay the shorter the wave length of light the worse my eyes see it?

[@ernmalleyscrub]

Fluorite is not just a pretty facet, but a hard working medical and industrial ingredient….

[@crimsonraen]

Soooo heckin' cool!

[@Moleculor]

1:30 Wait, what are electrons using energy to drop energy states for? Where does the used energy go?

[@PrefaceofDysphoria]

Hoping i understand your question correctly, it has to do with the amount of energy to overcome the states, releasing the energy as light. this process is known as quantum leap.

[@Rubrickety]

3:27 I like to imagine George Gabriel Stokes had a high squeaky voice to go with that visual.

[@monzpush9354]

0:16 Fluorite is CaF2 .aka. Calcium Fluoride

[@monzpush9354]

Bone is 20% Calcium...

[@monzpush9354]

4:33 1:50

[@ExburneLightDarkness]

Guess I should drink a few gallons of radioactive paint… for science!!!

[@Vort_tm]

Every time I see your Rocks Box episodes I so badly want to sign up. I need to organize my house so I can collect rocks without looking like a hoarder. UGHHH

[@justayoutuber1906]

This video fluored me.

[@NthMetalValorium]

Hank: "Jesus christ marie they're minerals"

[@fruit3193]

Hank’s poor son! Let him sleep, phosphorescence!

[@AdamShaiken]

Pound rocks...

[@janetf23]

I have an old but still really beautiful fluorite point pendant necklace that I call my dance necklace💃

[@victoriaeads6126]

Opossums glow magenta under blacklight. You're welcome 😂

[@TheKrispyfort]

Fluorescent immunohistochemistry 🥳

[@LordBrittish]

Arnold: *It’s not a tumor!*

[@grkuntzmd]

Warning, kinda gross: George Carlin had a comedy routine in which he talked about boogers. He said that if they were fluorescent, you would have to walk down to your local head shop (where they sell paraphernalia for dr*g use) and wipe the boogers off on neon posters.

[@alacranberryy]

Aaaa the glowing review lol

[@romulusnr]

i know someone with an implant tooth and it *doesn't* glow in blacklight which is kind of a giveaway

[@LogicalThinking-p2s]

Life itself seems a bit unnatural or example counter entropy. But gravity is counter entropy

[@spilbee]

I’m so blind.. I can actually see shadows of my eye cells. Not sure if it’s my eyes or my brain… but, I can see my cells.

[@mairoberts1247]

my room after lil bro has 3 seconds in it:

[@fungalcoffee]

I have shirts that glow, very annoying to sleep in, its bright enought to be distracting but not bright enought to light the way when i need to pee at night.

[@turquoisewitch.wild-owl]

It's weird, but it looked like the "rock" you had on this show was amethyst. When I looked up "fluorite vs amethyst," this is what it said: "Amethyst is usually purple, but can range from lilac to lavender to dark purple. Fluorite can be colorless or transparent when pure, but can also be yellow, green, white, blue, gray, or black."

[@woody4077]

"Glowing review" uuuuuggggghhhhhh

[@mattduncil]

Veritasium just did a video on rainbows. So if we placed a satellite with a really big black light aimed towards us and weather conditions were favorable could we make a black light rainbow?

[@franck3279]

Fortunately (except for that particular purpose),our athmosphere is eather good at blocking UV light.

[@mattduncil]

@ ok so no black light rainbow then

[@DanskerneFraDanmark]

Wait you can’t see the light from an ultralight ????

[@BackYardScience2000]

The cool part about fluorescein is it can be easily found on eBay. That's actually what my profile pic is of.

[@MrNicoJac]

2:20 WOAH WHOA WOW Hank Not so fast....! You _just_ said a minute earlier that energy cannot be created or destroyed. So when the electrons use _some_ of the energy that they got, *_what happens to the rest of that energy???_* Like, it does not get converted to heat, right? Black lights don't make my clothes feel hotter, in my experience...

[@cRazYhYPerPenGuin]

when they treat mice for cancer, do they give the mice cancer first?? like are they just sticking rodents into a radioactive box and hoping for the best (worst)

[@BracaPhoto]

We all emit light apparently 🎉 PS - also the photon appears to be an EYE Go figure

[@joepalmer1594]

It is not the T-shirt that is florescent. The detergent used to wash them with has "UV Brighteners" added. Hunters and military frequently wash clothing without the brightener added.

[@Andre-qo5ek]

is 365 or 395 better for finding scorpions? i saw somewhere that 365 might be better... but jsut wondering you knew.

[@bensoncheung2801]

🪨🪨🪨

[@Aragorn7884]

😏

[@Dwafiz]

The atomic process behind fluorescence makes sense (electrons absorbing photon energy, then emitting lower-energy photons to return to rest), but then why don't all objects emit lower-energy light when hit with light? What is it about teeth, white fabric, etc. and the color / properties of any object that determines whether or not it glows? I would think black objects would be the most likely to glow, since they absorb the most wavelengths of light (exciting electrons the most), but they don't.

[@franck3279]

It is somehow linked, because absorbed light energy has to approximatively match a difference in electron energy levels, but the thing is atoms have a lot of those levels and a common case is that the absorbed photon raises the energy by several levels at once that will be reached on the way down, turning a visible photon into several infrared ones.

[@MrOhitsujiza]

I... I knew most if not all of this... Do i watch too many science videos?

[@kellydalstok8900]

I remember girls’ white bras glowing under their tops in what was then called disco, but is now strangely called nightclub, even though a nightclub used to be the kind of place where scantily clad young women were paid to dance on a stage.

[@ExhaustedOwl]

There are fluorescent scorpions in Australia. The theory is that it helps them sense if it's day or night (they're nocturnal).

[@michaelmayhem350]

It's too bad fluoride and fluorite are so different. In an alternative universe somewhere people drink glowing water

[@Napoleonic_S]

C'mon scishow, tell us an update on Hank's curvy hair situation!

[@MariaMartinez-researcher]

Time for a video about fluoride?

[@veryberry39]

Fluorite is my favorite crystal, and I was tempted for a moment...until I remembered you charge $35 for *one rock.*

[@HotelPapa100]

We don't call them that, but white LEDs are also fluorescent lights.

[@AidanRatnage]

Since when do bowling alleys have blacklights?

[@lruddy8820]

cant believe you spent all episode talking about how "cool rock glow" with the cool rock in front of you and not once did you make it glow

[@stranger-mu9nb]

never that the term grounded could be related to electron being in low energy state or other way

[@markedis5902]

It’s not the white t shirt, it’s the chemical in your laundry detergent