Hank, I'm a researcher at Oregon State University developing a diagnostic essay 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!
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 !:-)
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.
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.
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)
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.
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.
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? 🤔
@@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.
@@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?
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.
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.
@@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 😂
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.
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.
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.
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!
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!)
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 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
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.
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. 😂
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.
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.
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.
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!!!!!!
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.
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
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.
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?
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.
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.
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 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).
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.
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
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...
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."
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.
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?
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.
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)
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.
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.
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.
The term "wavelength" is not the appropriate term for describing the phenomenon of fluorescence, since the physical wavelength of light measurably DECREASES when it encounters a translucent solid, whereas its FREQUENCY does not change (and therefore the color does not change when observed through a solid). Fluorescence is a REACTION, not an exchange. Consider exchanging the term WAVELENGTH with FREQUENCY, and describing fluorescence as the FREQUENCY of light emitted, resulting from the fluorescence reaction, which frequency is LOWER than the aggregate frequency spectrum of the light to which it is exposed. This is also an easier concept for most people to understand. Feel free to comment that I'm wrong. I'm sure someone can reduce it to simpler terms while making the concept clearer than presented.
1:22 "Energy can't be created or destroyed" - true 1:34 "...they [the electrons] use some of the energy" - true Contradiction. So where did the "used" energy go? To heat up the shoelace. The photon energy is converted and increases the molecule's internal energy level [vibration]. en.wikipedia.org/wiki/Jablonski_diagram en.wikipedia.org/wiki/Stokes_shift
Hank getting so excited about the topic that he has something to add off script is probably my favorite part.
Hank, I'm a researcher at Oregon State University developing a diagnostic essay 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!
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 !:-)
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.
My body after licking some weirdly green clock hands:
Or brushes with radium
@@v.xien.makes the brush sharper
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.
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...
Ohh, your bones are gonna glow even after you die if you've been licking radium 😬
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)
More 'not in the script' stuff! I like the way you present when not reading off the teleprompter!
That’s what hanks channel is for
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.
I prefer the soft glow of radium in my watches and dyes
My jaw fell off reading this 😢
That goes on my cereal. I look directly at the sun to tell the time!
@@gabbysmith7579 I hope 99% of Hank's viewers will get this "joke". [hint: Playing golf was never so decaying]
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.
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? 🤔
Well, a red laser can probably make things fluoresce, it just won’t be in a wavelength we can see 😢
@@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.
@@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?
In non-visible range, X-ray video machines use UV CCD coated with Xray-absorbing material.
People without a lens (aphakics) can actually see this kind of light directly, with no refraction. It's described as purple sunlight.
Omg....
How bad would it be to lose a lens?
I'd lowkey wanna test it out before I die, just to know :/
Neat
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.
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.
@@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 😂
Videos about light brighten my day!!...my apologies, my dad joke funny bone had a spasm 😊
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.
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.
This episode _rocked_ . A _shining_ example of SciShow content
Fluorite was just minding its business as a crystal, and now it’s a blacklight celebrity. What a flex!
1:17 I have subtitles so I knew the punchline but Hank's delivery still made me laugh out loud
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.
How long did it take you to become fluorescent?
@Paarthk depends on how many body painters I'm working with, 😆
5:59 I thought he was about to say "and THAT'S pretty cool."
Love that guy's stuff haha
🎸 relation: playing rhythm, and wanting to bust out that solo!
"I never thought I would relate so much to an electron." Big. Monday. Mood.
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!
I could do with a black light shining on me - it's been ages since I've been excited 🤭
Such an interesting video.. thank you!!😊❤
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!)
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.
There’re usually called floaters.
But by doing that, you damaged your vision by giving your retina sunburns.
@@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
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.
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. 😂
This video fluored me.
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.
I used for years as a quality control inspector looking for surface flaws on metal components.
Fluorite is my favourite crystal, especially the green/purple banded variant
Is meth fluorescent?
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.
Soooo heckin' cool!
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.
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!!!!!!
the part where he laughs about his son
3:27 I like to imagine George Gabriel Stokes had a high squeaky voice to go with that visual.
Oh hell yeah my favorite stone!
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.
"glow in the dark stars in your childhood bedroom"
...yes, my childhood bedroom wall only 🤣
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.
0:16 Fluorite is CaF2 .aka. Calcium Fluoride
Bone is 20% Calcium...
4:33 1:50
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
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.
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?
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.
Is it the same principle used in crime scenes ? Because if it’s the case we can thank that crystal for a lot more
Opossums glow magenta under blacklight. You're welcome 😂
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.
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.
@ thanks. I learned something new
@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).
@ thanks. Definitely have to reopen a chemistry textbook or two. Really appreciate the answer
Guess I should drink a few gallons of radioactive paint… for science!!!
1:30 Wait, what are electrons using energy to drop energy states for? Where does the used energy go?
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.
C'mon scishow, tell us an update on Hank's curvy hair situation!
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
Aaaa the glowing review lol
Hank’s poor son! Let him sleep, phosphorescence!
I have an old but still really beautiful fluorite point pendant necklace that I call my dance necklace💃
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...
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."
Pound rocks...
Hank: "Jesus christ marie they're minerals"
Going by the thumbnail, I thought this video was about feds.
Never use one in a toilet, it will reveal horrors that are best left unknown
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.
Arnold: *It’s not a tumor!*
The cool part about fluorescein is it can be easily found on eBay. That's actually what my profile pic is of.
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.
my room after lil bro has 3 seconds in it:
Life itself seems a bit unnatural or example counter entropy. But gravity is counter entropy
I was your son when I was a kid 2:40 😎
"Glowing review" uuuuuggggghhhhhh
never that the term grounded could be related to electron being in low energy state or other way
We all emit light apparently 🎉
PS - also the photon appears to be an EYE
Go figure
i know someone with an implant tooth and it *doesn't* glow in blacklight which is kind of a giveaway
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?
Fortunately (except for that particular purpose),our athmosphere is eather good at blocking UV light.
@ ok so no black light rainbow then
Bro... What a teaaaase 😂 has a fluorescent crystal in front of him for 6 minutes and doesn't shine it with a black light once? 😅
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.
There are fluorescent scorpions in Australia. The theory is that it helps them sense if it's day or night (they're nocturnal).
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)
is 365 or 395 better for finding scorpions?
i saw somewhere that 365 might be better... but jsut wondering you knew.
I... I knew most if not all of this...
Do i watch too many science videos?
was excited for rock box.. rock box sold out 😢
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.
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.
😏
Fluorite is my favorite crystal, and I was tempted for a moment...until I remembered you charge $35 for *one rock.*
Since when do bowling alleys have blacklights?
We don't call them that, but white LEDs are also fluorescent lights.
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.
Time for a video about fluoride?
Lol, I noticed you didn't use a motel, or hotel room as one of your examples… I get why, lol again
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
It’s not the white t shirt, it’s the chemical in your laundry detergent
It's too bad fluoride and fluorite are so different. In an alternative universe somewhere people drink glowing water
Why are florescent lights white then? Shouldn't they be monochromatic?
Hey off script Hank, is that how they could tell the difference between strains of COVID?
"Everything in nature wants to be at rest whenever possible."
Umm, no?
Is Black Light an Ultra Dark Indigo Light
I came here for the came jokes
Nicr
There is no such thing as black light.
The term "wavelength" is not the appropriate term for describing the phenomenon of fluorescence, since the physical wavelength of light measurably DECREASES when it encounters a translucent solid, whereas its FREQUENCY does not change (and therefore the color does not change when observed through a solid). Fluorescence is a REACTION, not an exchange. Consider exchanging the term WAVELENGTH with FREQUENCY, and describing fluorescence as the FREQUENCY of light emitted, resulting from the fluorescence reaction, which frequency is LOWER than the aggregate frequency spectrum of the light to which it is exposed. This is also an easier concept for most people to understand. Feel free to comment that I'm wrong. I'm sure someone can reduce it to simpler terms while making the concept clearer than presented.
1:22 "Energy can't be created or destroyed" - true
1:34 "...they [the electrons] use some of the energy" - true
Contradiction.
So where did the "used" energy go?
To heat up the shoelace. The photon energy is converted and increases the molecule's internal energy level [vibration].
en.wikipedia.org/wiki/Jablonski_diagram
en.wikipedia.org/wiki/Stokes_shift