The World in UV

UV cameras expose a hidden world and reveal the incompleteness of our perception
The Physics Girl looks at sunscreen: • SUNSCREEN in UV
How to make sunscreen from scratch: • How to Stop the Sun fr...
In summary, ultraviolet light interacts differently with matter for a number of reasons:
1. Some pigments selectively absorb UV so they may appear white in the visible but dark in the UV. The pigments usually dissipate the UV energy as heat, though the breaking of bonds can also occur.
2. Fluorescent molecules absorb UV light and re-radiate that energy as visible light. This makes them look dark in the UV but glowing under black light.
3. Ultraviolet light scatters more than visible light because the wavelength is shorter and Raleigh scattering is proportional to the reciprocal of wavelength to the power of four.
Special thanks to HHMI BioInteractive for their awesome animations of melanocytes and how the melanin in melanosomes protect your DNA. To see the full video explaining how we get our skin color, check out: • How We Get Our Skin Co...
Special thanks to Patreon supporters:
Donal Botkin, Michael Krugman, Jeff Straathof, Zach Mueller, Ron Neal, Nathan Hansen, Yildiz Kabaran, Terrance Snow, Stan Presolski
References:
Overview of main UV effects:
Visualizing Rayleigh Scattering through UV Photography
journals.ametsoc.org/doi/pdf/...
Arctic animals are photographed in the UV to increase visibility and get an accurate count:
Lavigne, D. (1976). Counting Harp Seals with ultra-violet photography. Polar Record, 18(114), 269-277. doi:10.1017/S0032247400000310
Absorption spectrum of melanin: www.cl.cam.ac.uk/~jgd1000/mela...
"The spectroscopy of human melanin pigmentation," by N. Kollias. In: Melanin: Its Role in Human Photoprotection, pp. 31 - 38. Valdenmar Publishing Co. (1995).
"Optical properties of human sclera, and their consequences for transscleral laser applications," by A. Vogel, C. Dlugos, and R. Nuffer, Lasers in Surgery and Medicine 11(4), pp. 331 - 340 (1991).
"The incidence and time-course of latanoprost-induced iridial pigmentation as a function of eye color," by P. Wistrand, J. Stjernschantz, and K. Olsson, Survey of Ophthalmology 41(S2), pp. S129 - S138 (1997).
Music by Epidemic Sound: www.epidemicsound.com "Spring Moods 5"

[@EpicLPer]

6:00 - I always wondered how scientists flirt with each other... I guess that's a question answered now. _"Your skin looks so good in the visible spectrum of the light"_

[@brokenacoustic]

dont forget taking off your shirt in front of the cute girl...for science, of course lol

[@JB52520]

Or, "He likes the smell of you."

[@LLLadySSS]

Lmfaooooooooooo

[@paradox...]

The #ship sails once again!

[@oliverwilson11]

p sure she has a bf

[@Caracazz2]

- Son, did you apply the sunscreen? - ...yes, mom! *turns on the UV camera*

[@tmBlackWings]

Hahahaha

[@yusha1059]

Nice

[@bigchungusdriplord2301]

Lol

[@WereWade]

Parenting level 100.

[@Longus07]

@@yusha1059 did I just get rickrolled by your about page.....

[@IAmSneak]

if you want to get rid of the fog just turn up your render distance

[@RazoneIsaqt]

And turn down the density and the emission of the cube

[@st4rf1sh36]

Turning off clouds also helps

[@ThetheuxAlbuquerque]

not every one has a nasa pc at home dude... some of us play at low

[@najwafitri9798]

XD

[@penninna]

And turn on ray tracing…

[@totallynoteverything1.]

8:10 dude looks like he's covering himself in mud to not get detected in a covert mission in Nam

[@chrispersinger5422]

Black face? Lol

[@totallynoteverything1.]

@@chrispersinger5422 dude looks like he's covering himself in mud to not get detected in a covert mission in Nam

[@totallynoteverything1.]

@@chrispersinger5422 unoriginal joke, so I just made Vietnam joke because of how the dude is putting it on his face

[@chrispersinger5422]

@@totallynoteverything1. Yeah I was joking about the black face lol

[@chrispersinger5422]

@@totallynoteverything1. Ah yeah the totally original Vietnam joke lol

[@FilliamPL]

*talking to a girl* "You're so beautiful... just not in the UV spectrum"

[@Brashnir]

and what if I've got a thing for freckles?

[@Ray-ei2ro]

"You're so beautiful..." Under UV light she looked evil as hell.

[@MaDrung]

I thought he was going to find remains of sperm :D

[@stevethea5250]

@@Brashnir damn his skin 8:14

[@confusedwhale]

@@Brashnir: They aren't freckles. They are Sunspots.

[@Master_Therion]

Will enough UV exposure cause heavy damage to the skin? Or will it only cause... light damage?

[@thenight1732]

Yes

[@benoitm2810]

Badum tss

[@Twas-RightHere]

I see what you did there.

[@HACKINGMADEFUN]

Pun and all

[@JoeARedHawk275]

National Trolliosis Foundation No, but you can stop a shut-in

[@davinci69]

What I find particularly fascinating is that if we could see UV light we would most likely also see colours there. This would of course only be the case if we had multiple photoreceptors for different UV wavelengths but it is still quirky to think that colours are actually just illusions.

[@egg4444]

it really just depends on what you count as an illusion; the brain filters and creates a lotta stuff

[@davinci69]

What i mean is that colours are only some certain wavelengths. There isnt a colour for every wavelength. That means colour is not a physical property of light.

[@nmatavka]

There are people that can see UV (have an eye that can handle it). It's not THAT rare, about 1 in 10 I think... but that 1 in 10 can ONLY see it if they ALSO have a missing eye lens or a prosthetic eye lens. This means if someone like that looks at light through a prism, his "violet" will stretch out a bit longer than yours, but he'll need to wear sunglasses when he steps outside so as not to be blinded.

[@kreaturen]

I'm also curious how the brain would represent it, especially the so called color wheel. I mean, blue blends into red only because of brain magic. If we could see UV, surely some other color would blend into red instead of blue. Or, perhaps, instead of new colors, the color spectrum would simply get shifted (to account for the broader spectrum), i.e. UV would become blue, and current blue would become more greenish.

[@kreaturen]

@@GabrielsEpicLifeofGoals It is an illusion, because visible light doesn't actually have any "color" properties, anymore than gamma rays does. It's all a mind trick.

[@dbell95008]

After losing the lens from one eye after surgery (and none was implanted), I discovered how much more I could see into the near UV. A common fluorescent "black Light" tube is barely visible in daylight with normal vision. With my "lensless" eye (and a contact), I could easily see a lighted tube as a purple-white glow from tens of feet away in full outdoor daylight.

[@MacDaniboi]

This is why I desperately want eye surgery.

[@tietosanakirja]

Wow

[@blackmber]

Does that mean the lens was absorbing UV light before it was removed, protecting the retina from damage?

[@renziie2804]

wait does that mean you see the world in 2 different ways?

[@aryapatel7615]

@@renziie2804 cool man

[@radicalxedward8047]

Sunscreen companies should do this as an ad. I would have been WAY more likely to use it as a kid if I could see that it actually does anything.

[@nikolaos6083]

^

[@rubyrules]

^^

[@nippelfritten2312]

^^^

[@TheGiantcube]

In the Netherlands I've seen an ad like you described of people on the beach and a UV camera

[@lasarousi]

Using it once and using your eyes is kind of enough to know it actually works.

[@samthachamp5035]

I wanna be as happy as he was when the soda started bubbling

[@jamessouza7065]

then do it? Be happy!

[@catgirlsleepy]

@@jamessouza7065 its not that easy...

[@stevethea5250]

@Orion D. Hunter timestamp

[@kyrlics6515]

@@catgirlsleepy yes it is

[@catgirlsleepy]

@@kyrlics6515 not it isn't Lemme ask, how old are you?

[@Selfg12]

This actually shows me how well sunscreen actually works.

[@mel0dymak3r]

it's hard to wrap my mind around birds being able to see in ultraviolet as well as normal color vision...

[@MrMegaMetroid]

I mean technically uv light is no different at all, its not a different kind of light, just a different colour. We are to birds what dogs are to us, unable to see specific colours

[@shadowcween7890]

@@MrMegaMetroid it's the qualia problem

[@MrMegaMetroid]

@@shadowcween7890 not really. The qualia problem revolves around the idea that two people can have different ideas of the same colour, without ever having a meaningfull way of communicating this idea. This is not so the case here. We know uv light is just another colour we cant see. Its an entirely different, completely new colour on the same spectrum. Uv light is not an entirely new vision, as the other commenter has pointed out, nor is it a debate about human vs human perception, as you stated

[@renanmendes1299]

@@shadowcween7890 play amongus

[@renanmendes1299]

amongus

[@ErhanGaming]

In an alternate universe: 'The World in Visible Light" - "Why is visible light so clear compared to our normal hazy atmosphere?"

[@sygeno_yt]

It wouldn't be called visible light in an alternate universe where UV light is normal and visible

[@Nico-dt5hu]

@@sygeno_yt and our visible light will be their infrared

[@rinnegone377]

@@Nico-dt5hu how about their infrared?

[@Architector_4]

I know it's a joke, but to think of it, if humans were to see things in UV, everything would be wildly different. We wouldn't be using glass, and having transparent/translucent surfaces would probably be a bigger hurdle for the progress of science. Or maybe we'd die out as a species as we developed seeing these particular shades of color specifically because they helped survive the most lol

[@theincarnateofkurro]

@@rinnegone377 *visible light*

[@physicsgirl]

"How do I put this..." at 6:05. Nice Derek, nice.

[@mukil_saravanan]

Lol

[@kevinhart4real]

:P

[@D4N50M3]

Dadbod

[@veritasium]

#unscripted

[@avetiszakharyan]

this is happening!!!!

[@Musicswagg86]

Miss you PhysicsGirl, I hope you feel better soon

[@procatprocat9647]

8:00 How long until mobile phone cameras have a UV mode to check how well you've applied sunscreen! This could save a lot of skin cancer issues.

[@el-il2kc]

this is so smart

[@clb4947]

you'd need a filter on the lens and Idk how hard/expensive that would be to do for manufacturers

[@Chimera_Photography]

@@clb4947 actually, you don’t need to add a filter, you need to remove the existing UV filter from the sensor. It would be cheaper...

[@clb4947]

@@Chimera_Photography that's actually pretty cool, thanks for the info ^^

[@LaKoeps]

@@Chimera_Photography you could attach a slide to the internal UV filter so you can slide it away from the main lens if needed.

[@nebvbn4504]

So sunscreen is basically... Paint? In the UV spectrum.

[@alexgratzaTV]

yes.

[@jojo35996]

Black face*

[@AllTheArtsy]

No

[@dat_killaz1094]

A “protective” paint

[@kaaiplayspiano7200]

@@sriramn1809 so... it's magic.

[@a2rhombus2]

I'd love to see a video like this for infrared as well

[@jaystarr6571]

1. Get a remote control and your cellphone 2. Turn on your cellphone's camera 3. Push a button on the remote and point it at the camera lens 4. Look at your phone's screen while doing step 3

[@PabloAM93]

Jay Starr seeing the pulse of an IR led in a remote is not even close to something like this video.

[@PabloAM93]

A to Rhombus You could do it yourself. Buy a old inexpensive digital camera that records video and search on how to remove the IR filter that sits in front of the imaging sensor.

[@a2rhombus2]

I don't just wanna see IR ya dork. I wanna see a video like this where he talks about cool sciency stuff.

[@NickyNiclas]

Lets spice it up with the whole spectrum mixed together, I honestly don't know what that would look like, it might be a terrible mess.

[@Broadpaw_Fox]

At 1:33 - the 'haze' with a UV camera is a great demonstration of why the sky is blue. It's showing that the UV light refracts more than the lower frequencies, and since the blue/violet spectrum of visible light is the highest frequencies, they scatter more. A UV camera isn't picking up those lower frequencies, so it can't see anything through the 'haze'. :) **edited for spelling because autoderp**

[@Broadpaw_Fox]

@Elegance - well, the blue and violet are the highest frequency light we can perceive, though the violet is right at the edge. It will technically scatter more, but it's harder to perceive and overpowered by the blue. Think about sunset though- as it gets darker the sky goes much more towards purple, though it's a deep relatively dark shade. That's when it's most easily perceived, because you're getting more of it scattered in from the brighter part of the atmosphere and the more easily seen colors aren't as powerful because they scatter less, and are further away. Also, to be clear - I'm talking about the deepest, latest stage of sunset, in the twilight before full dark. That's when the violet is most visible. 😀

[@Broadpaw_Fox]

@Elegance - that one is a bit different. Red light is the other end of the spectrum, the lowest frequencies visible. Those are much better at staying coherent and "punching" through the atmosphere, and when the sun gets low in the sky, or when there's a lot of particulate in the air (like smoke from a fire) then the red frequencies are the most able to get through that obstruction. At the beginning of sunset there's a lot of the atmosphere between you and the sun, and that means there's a lot of various particles it has to go through, and that colors the light by scattering it around, and only the lowest frequencies (red for the visible light) gets through. You can watch it happen as the sun sinks lower - it starts out a bright gold, then fades to red until the sun is dim enough to look at directly with naked eyes (only that last minute or so) and it's a deep red. But that's only the atmosphere causing that color shift - the sun is still the same color all day, and always emitting the same amount of light energy. Even though it looks red sometimes, it's still basically white. It's just our dirty air that colors it at times. 😀

[@HotCupOfEarlGray]

They litteraly said that in the video

[@cjspellsfish]

We rarely study UV (with enough detail) in schools, but you were right, it is a lot like visible light (which we study more), so this video is very easy to understand. I also noticed some similarities with sound waves, *I wonder if "the shorter the wavelength of light, the more likely it is to bounce off tiny molecules in our atmosphere" **9:10** is something similar to high-frequency sound waves falling off faster in reverb?*

[@htme]

Great video and thanks for the shout out! I was wondering why our UV footage at Death Valley was so hazy in the distance, now I know why!

[@veritasium]

How To Make Everything yeah I originally thought the reason for the haziness was going to be lame and ruin all the shots but I was pleasantly surprised with the Raleigh scattering answer

[@scelestus6930]

Veritasium, Very good video! It was really fascinating to see in the ultraviolet spectrum, your faces and especially the sky. A tiny mistake? It's called Rayleigh scattering, if I'm not mistaken. Love from Norway.

[@henil0604]

@@veritasium Hello sir

[@baagiibaterdene5570]

Ooo option to

[@kospap92]

@@veritasium Great video! We need a "The world in Infrared" now to make it complete! It would be really interesting to explain why we see better through fog or why veins are clearly visible in near infrared.

[@Karabetter]

SOOO *OZONE* is supposed to block UV... An interesting experiment would be: Set up an electric arc (which will normally create the "ozone smell") and see if there is a stream of ozone emanating in dark waves with your UV cam ???

[@takumi2023]

i don't know how effective that would be because of how scattered the molecules are from the arc. you have to collect it first in order to make it work.

[@ChadEichhorn]

Seems exactly like the kind of video I would expect from Smarter Every Day

[@missclarestube]

From what I have read ozone blocks uvc. Maybe someone can confirm that?

[@realw98]

Ozone blocks far UV spectrum with shorter wavelengths. What we see in this video is near-UV which is not blocked by atmosphere so we can... see it.

[@SzDavidHUN]

+missclarestube UV-C [...] is entirely screened out by a combination of dioxygen (< 200 nm) and ozone (> about 200 nm) by around 35 kilometres (115,000 ft) altitude. en[dot]wikipedia[dot]org/wiki/Ozone_layer#Ultraviolet_light

[@Arutemysu]

For a long time I always wondered why I was near blind during day, and especially during summer. Doctors thought my eyes were photophobic, so I used normal sunglasses without UV protection, but everything was still hazy, I thought it were the glasses from the sunglasses. Few years later I went to the doctor again and they did further tests, I was suppose to look at different lights in the colour spectrum, only to be able to see the UV lights as their true colour. Since then I always wear glasses during day that block majority of UV light so I can properly see during day. It's always weird being able to see colours most people can't. Where I am able to see a certain colour. Most people either see bright pink or dark blue, some even see just greyish black. I do have a massive advantage at night, where I see near clear without extra lights, other people always need extra lights to see normal. Also the sky for me is more UV coloured than blue.

[@Empika]

Woah

[@shi_mo_neta]

As much as I want to believe this, I'm kinda skeptical.

[@m4heshd]

This is some Reddit worthy stuff. You should write a post.

[@Arutemysu]

@@shi_mo_neta just because you yourself doesn't have it or see it doesn't mean it isn't possible. If everyone was the exact same the world would be rather boring.

[@itsoktoberight4431]

@@shi_mo_neta same thing happened to my father in law after he had his cataracts removed, it's like a little superpower 🤣

[@glasslinesmadhes]

UV and visuvals clearly explained. I love this video for its simplicity and clarity about UV .

[@hoangtran4736]

do not, under any circumstances, shine uv light in a bedroom.

[@goombacraft]

why? i wanna do this now

[@atulshukla7128]

@@goombacraft germs. Germs everywhere.

[@allensnea9335]

Did you watch one of the Gordon Ramsay videos about bad hotels He actually has a KZbin channel on that genre

[@pappu2490]

@@goombacraft bodily fluids are illuminated in uv/blacklight

[@ahumanbeingamnayplaceholde1746]

@@pappu2490 Lol

[@starlightx3052]

UV camera is a best way to do advertising of sunscreen )

[@pim3089]

nivea did it

[@redpoint6870]

Royan Mangeli in fact, clear skin has it's advantages. (There is a reason why we evolved to have it)

[@ChristopherChapelle]

Then it might look a little racist

[@Keesha_Hardy]

Red Point Um, you evolved to have PALER skin, not clearer, only because living further away from the Equator means less Sun and UV ray exposure, and the need for melanin decreases. That's why racism is so stupid. If all the European and Asian people moved back to areas closer to the Equator, everyone on the planet would have the same skin tone after several centuries and vice versa.

[@redpoint6870]

Docbndgrl9113 you make it sound like there is a problem with it. We are clearly different, adapted to different things... Like cebras and horses, not better or worse just different

[@itsTomate]

The most amazing thing to have learned or to think about is that the sky is just a… haze. Like, it makes sense once you said it, but like… that’s just so strange to think about- it’s just the sky, the sky is blue, but the sky is a blue haze.

[@GraveUypo]

well, you already knew it if you ever saw a picture of low earth orbit. you just didn't connect the dots, apparently.

[@mishak38]

@@GraveUypo u got quite an ego.

[@Akash-qf2yn]

The most amazing part of the video is the one doing the transition from Vis to UV and vice versa. Nice editing.

[@mathewgonz]

So can we promote cellphones to incorporate this? Everyone could use this at the beach to make sure they’re covered properly

[@dogon3]

I love how you made knowledge into a practical use.

[@cleavage2697]

I think there is commercially available filter to cameras. Maybe also to phone cameras. And definitely some "software" could fake it.

[@dogon3]

@no u trash UV is almost everywhere, during daylight hours. Most of the harmful rays degrade when they hit inanimate objects. Human bodies have a certain amount of natural protection, because the outer layer of skin is already no longer alive.

[@dogon3]

@no u trash Not likely. It depends on the intensity and dose.

[@alterego3734]

@Mathew Gonzalez Idiots have taken over your comment's comment section :(

[@crazylazybros2473]

buzzfeed: is putting on sunscreen blackface?

[@RudraJain]

You put a comment on lazarbeams vid? It was in his video

[@curlygurly2112]

Sunscreen is RACIST??

[@konfunable]

I demand to stop sunscreen because it is racist.

[@GpD79]

Now isn't this the epitome of cultural appropriation, white people appropriating the essence of an entire group of marginalized people: their blackness.

[@liamryan7239]

GpD79 What are you talking about?

[@reemeruxd]

i woke up from a terrible nightmare and went on youtube as one does. saw this in my recommended so i just threw it on. and i felt like i was back in class watching a video the teacher put up. it was chill, informational and oddly nostalgic. it put me at ease. thank you, i subbed :)

[@713houstontx4]

His laugh when the tonic overflowed 💀💀

[@icanbreathe9161]

He was trying to imitate how his gf laughed when he “overflowed” early

[@lordfeish1927]

that moment when you realize that sunscreen companies are secretly making you wear blackface

[@JustinDrentlaw]

Lmao can't believe this is the only comment about this xD

[@ChronicNewb]

I came to the comments looking for this

[@avrgegmer1396]

That's kinda the point of how it blocks uv light. Just how when you get a tan or people who work in hot clinates have darker skin. It is the dark pigment that is essentially blocking the uv light. It is part of its nature. Like how white color repels sunlight but black absorbs it.

[@ozziesheppard17]

wait until cnn finds out about this.

[@anduro7448]

Secretly racist

[@_baller]

Fact...everyone looks sunburnt and aged in UV light

[@stevencorrea6946]

Love the stuff 47 looks 25.

[@AllTheArtsy]

Yeah, skin aging is caused by UV

[@erica_9999]

So is sunburn

[@GpD79]

8:14 Not if you wear sunscreen. This kid's face is flawless. Or, if you're black 8:06.

[@nigerianbaddie]

GpD79 i was literally about to say the black part lml

[@HiddenRealm]

It's honestly awesome seeing invisibly clear sunscreen look like thick black paint when applied on their faces in UV... It honestly really is cool to *see* some sort of effect it is actually having.

[@zes7215]

wrr

[@andrewlazy662]

Idk what up with me, but the way you say "ultraviolet light" is sooooooo pleasing?? satisfying????

[@ratobiajin]

4:58 was unexpected, indeed.

[@rmontz738]

[In Stefon voice] This video has everything...

[@TheBlueSpot97]

Unexpected but appreciated

[@ghhhhhhhhhh]

I genuinely didn't expect a thirst trap in this video

[@SuperVstech]

Wow!bluetooth!

[@veritasium]

How did I miss this?

[@hd_y]

Ba dum tss

[@reggie6339]

SuperVstech Brilliant

[@tutejszy]

Everything becoming better with bluetooth

[@WayneDavisDA_ILLESTalive14]

SuperVstech ... You just did that

[@mdikramuddin1772]

So if our eyes were made to see radiation of UV spectrum our world view of BEAUTY would totally be different.

[@joncarpenter5089]

A great future video would be one showing how plants determined their need for UV production in their coloring and how they communicated that need to successive generations. I think that learning about the process where it recognized that bees and other insects saw with UV, then determined a way to create UV coloring in their cells, would be a great study.

[@refindoazhar1507]

It's called natural selection and heredity. Biologist have been working hard studying and improving both theory for over a century, pretty wild thing.

[@Videohead-eq5cy]

You're getting old, Derek. Now you're awesomer!!!!!! I admire and respect the heck out of you!

[@shobhitkaul8076]

Metal Pappu he is older in uv!

[@Videohead-eq5cy]

Shobhit Kaul he's got a white beard though

[@souravzzz]

You two have really good chemistry.

[@Ragsc]

Really good physics.

[@joeshedler6496]

"You two have really good chemistry." LOL not bad for 2 physicists!

[@CulusMagnus]

They turned their chemistry into classical mechanics

[@coreycourchene7379]

Been addicted to this channel lately, this was so cool to see! 😁

[@markiobook8639]

I love how flowers fluoresce in UV.

[@advait_dhopeshwarkar]

Exactly the reason why most signals in road traffic/airplanes use red. Larger wavelength>>not scattered easily>>improving visibility over longer range.

[@MarkOfArgyll]

Add weirdly (or not) military use red lights because they are harder to detect due to the lack of scattering.

[@beverlyanne5699]

It is because our eye's do not have to climatize to the lens colour as it does in darkness with white lens. This is also why military uses the red lens, it is less detectable too.

[@renedekker9806]

The real reason is because the colour red is rare in nature, and unconsciously associated with danger.

[@j-em5762]

@@renedekker9806 dafuq you talking about lol as a biologist I know that red is everywhere in nature! From fruits, to crustaceans, to insect coloration, to animal fur, hell even blood. If you want a color that is rare in nature, try blue.

[@jasonchu4400]

bruh you trippin' red light scatters easily....because it has a larger wavelength and cannot last long in long distances as high frequency colors my ninja....

[@benoitm2810]

Awesome video. And your editing skills are really good

[@susioeandno1else]

Omg the flirtatious energy is like off the charts

[@ForestFire369]

I LOVE that you used the tree to demonstrate energy transfer, that was really cute hahaha

[@electronicsNmore]

I have a buddy that got his 2 front teeth knocked out playing football years ago. I spotted his with a UV light by accident. Great video as usual!

[@saquibali2513]

lol

[@thanksfernuthin]

But did you notice that every shot of his teeth in Ultraviolet after that initial one looked fine? I'm confused.

[@xavierav6717]

thanksfernuthin yeah

[@Sk0lzky]

Welcome to the squad lol

[@zuris8656]

@@thanksfernuthin They don't. Pay attention to his two frontmost teeth at 8:17 and you'll see that they have the same discolouration as before.

[@AllTheArtsy]

I really need there to be a consumer-level UV camera so I can add it to my skincare routine

[@smithjane9170]

Sunscreenr if you have an android

[@Luthiart]

...aaaand another neurosis is born.

[@DanielTaylorOCMD]

A normal high end DSLR can be modified to remove the UV and Infrared filter on the camera's sensor, then use an appropriate filter to only allow UV or infrared into the lens. The downside? I did this to a camera and really enjoyed the IR end of things but filters for UV are VERY expensive and hard to find. For one thing, just try typing UV filter into a search and you will get nothing but filters that prevent UV rather than allow it to pass while blocking visible and IR. It is for these reasons I have yet to take a single image in UV light.

[@luddity]

@@DanielTaylorOCMD Is there UV in computer screens?

[@mynamehasspacesinit8687]

Cyanotypes are only photosensitive to UV light, so all you need to do is stick some cyanotype paper in an analog camera that can do a long exposure for more than 3 hours.

[@cordellblaine9641]

Very cool! Was neat to see how sundscreen works

[@DlolFace]

1:25 it really looks like that one old COD Modern Warfare Mission

[@annehinrichs22]

All the bees think we're painting our faces black😂

[@DarkTemplar8952]

If they saw only in ultraviolet, then yea. But they actually have pretty similar range as we do, just shifted towards ultraviolet, meaning, UV to them is like our purple, and they can’t see red at all.

[@J45Russ]

Insects only see UVA. It is interesting to see flowers in UVA. Some point to nectar in UVA.

[@Slushee]

8:27 bc you have your render distace low 😂

[@petergeramin7195]

Lol

[@b3gabriel66]

fakin potato pc

[@Incognit0777]

*Visible light master race*

[@yinyang1217]

@@b3gabriel66 ikr

[@Nico-dt5hu]

i thought he was playing roblox not minecraft

[@agarmitzi8770]

Thank you so much for all this info!! I am doing research for a short story where an alien that sees in UV comes to Earth and this was SO useful :D

[@lassoatrain]

This is a very helpful video about a subject i have so many questions about. I came across an old study on line a while back done by the bureau of weights and measures in a 1932 publication of theirs. It was highly sophisticated for the time and included all the data they collected. I think the title was " an investigation into the measuring of extreme ultraviolet solar radiation to reach the planets surface. In the report they claim that one day smoke from a nearby forest fire had drifted over their measuring instruments and that the extreme u/v more then doubled in intensity. They at first were baffled but later discovered what had happened was that instead of the occasional ray to reach the surface of the planet the smoke allowed the extream portion of the u/v to i think the word used was defuse but i am probably wrong .it allowed the u/v to scatter which made the whole sky become the source of U/v instead of the ray . Later i thought it must be the same phenomenon that allows people to get sun burned in the fog. So if this is correct would the intentional blocking of sunlight by scientist by injecting especially water vapor into the atmosphere actually harmful to living organisms? They do this often in California and i have plenty of evidence that they do. One more thing that your video touched upon was the u/v and the flowers. Bee's see in the u/v and they have been losing bee colonies rapidly. Is it possible that increased U/v could be responsible for their plight ? Great video .

[@ShayerSUtsho]

Please make "The World In IR"

[@mcmb8254]

Shayer S. Utsho what is IR?

[@ShayerSUtsho]

@@mcmb8254 Infra Red

[@mcmb8254]

Shayer S. Utsho thank you, btw that does sound really interesting

[@superknightlol]

army has been using ir flashlight and goggle since ww2, people without those special device cant see the ir flashlight but army can and it give them special advantage. its basically invicible flashlight or spotlight. ir can also be use to detect heat signature from tank usually in black and white, white being the hottest. ir is the most useful thing.

[@ShayerSUtsho]

@@superknightlol Thanks! I learned something there.

[@vtron9832]

Please do Infrared next time, this was awesome

[@jasonglaser1752]

2:20 Tonic on the left ^^ Good job natural eyesight ;) 5:59 Damage aka cancerous mutations. Did not expect the reason behind why seeing the world in UV would be diffraction. Mankind would never have never looked up to the sky and wondered what laid beyond the stars… we never would have seen them in the first place if we only saw in UV.

[@LetiziaCamboni]

I cannot believe I guessed the Rayleigh diffusion phenomenon. I'm trying to train my brain to understand colours better and I'm happy you put it to the test. 🤗 Thanks for this video ❤️

[@vitocorleone3764]

"It likes the smell of you" *awkward look-away *awkward look-away I so ship it

[@MasterRoshi1231]

Vito Corleone even in a committed relationship, us nerds get socially around attractive individuals.

[@Not.Your.Business]

was looking for this

[@jacobgasser377]

Maybe im remembering wrong, but I thought Derek was married? He isn't wearing a ring in the video, but I swear he's mentioned it in previous vids.

[@abdulazeez.98]

jacob gasser As fas as I remember, he's indeed married and have two children.

[@asebaninja]

Disappointed you didn't talk about the camera itself :(

[@schitombite]

A Seba he showed the filter that filters out visible light and let uv through

[@aseliatheeternal202]

A Seba I am also really interested on the exact camera and filters used on this...

[@TheCls63]

its easy the camera is a simple 4k camera he just put a UV lense on it, you can do it on your own phone

[@aseliatheeternal202]

Usual digital and phone cameras comes with internal UV (and IR) blocking filters. Usually one have to remove the UV filters in order to make it to work. *the removal of UV blocking filters is way harder than one may think because in most of cases it is a coating on the camera lens and sensor itself. So the risk of breaking it is very high.

[@Eralen00]

I modified an old point-and-shoot camera into a UV/IR camera. There's a filter that blocks UV/IR light that lies between the lens and the sensor. Remove that and use either an UV or IR-pass filter or any dark lens filter (i used a dark red photography filter for IR)

[@arassaplys5813]

i don't know what it is, but u make science interesting again. i think i have seen about 15 of ur videos in the past 3 days. they are awesome. I especially loved the one about the kid that made the nuclear reactor. i am a new viewer

[@firstlast4592]

Longest Sunscreen ad I've ever seen!!! haha great video. Another one to the list.

[@Atypical-Abbie]

You look 20 years older with UV light, you look like you belong in a Tarantino movie.

[@_Killkor]

Time to see in infrared...

[@bartsshorts]

alans snackbar

[@manuellozano5567]

How would a rainbow look in the ultraviolet? Would there be an "ultraviolet bow" right next to violet?

[@cymaticCS]

Yup, there is always an ultraviolet bow next to the violet bow, but we just cannot see it!

[@TheParablade]

I want a double UVbow across the sky yeah yeaaaah

[@sethleverett8889]

There would theoretically be a inferred radiation rainbow too

[@JeramieCurtice]

UV light is a spectrum of the rainbow. Can light see other light? They are both just frequencies on the nano wavelength scale. Same spectrum, but when rainbow colors combine, we typically see it was white light.

[@bspringer]

Exactly, same with infrared next to red

[@fluiditynz]

I've had that thought from around 30 years ago about infrared light. As an inventor type, I'm inspired by learning about effects, reactions and putting them together in novel ways to achieve new things. For example, I've been sitting on a heat to electricity surface conversion process since my late teens that is likely quite close to feasible construction though only in the modern chip fab facilities. Those of us who are inventors with some degree of abstract thought for example, can conceptualize the requirement for thermal stratification in a heat exchanger to counteract the short circuit otherwise developed from use of low thermal conductivity materials. However, it's not the same as working in a dark room and knowing you have cut off all the visible light or of putting a draft stop at the bottom of a closed door because of feeling cold air on your feet. Our inventions are constrained by our environment and our shuttered perception of it. We are very lucky to be able to conceptualize past this into that we don't feel or see. It's one of those go/no go thresholds I think about for space aliens on other worlds and for other species on our own planet that permits development of novel industrialization.

[@Skyteks]

I knew right away it's the same effect which is making the sky look blue, also is making the UV camera view look foggy. I feel so smart right now :)

[@carolineanderson1873]

If you don’t mind can you please explain? I’ve watched videos but I’m confused on how nitrogen and blue waves interact with each other

[@DukeOfEarle88]

"Virtually nothing absorbs in the UV..." Oxygen/O3: 😑👍

[@ericeaton2386]

That's why the ozone layer is so important

[@sallmandar1027]

Ye, but ozone is super high up in our atmosphere so we dont really see it... also low frequency UV light can go easly trough the ozone layer

[@theincarnateofkurro]

i just wanted to understand this comment and its replies im dumb

[@josevitorag]

@@theincarnateofkurro the ozone layer is our ultraviolet shield

[@begemotowa]

@@sallmandar1027 we don' really see CO2, O2 and H2O gas either. And low frequency UV is less harmful.

[@micahphilson]

Aw man, why didn't you film a person with albinism under the UV camera? Their skin would have looked so different! Maybe even someone with melanism!

[@XxPlayMakerxX131]

Micah Philson I was disappointed when He didn’t film a black person in UV they would look even darker

[@xenontesla122]

He does at 8:06.

[@rorymckenzie7110]

XxPlayMakerxX131 pretty sure you don't get people with melanism, just black people

[@Aeikon]

Rory, not sure if you are joking but just in case. A person with melanism would actually look unnaturally dark. It could be argued that some specific races and regions particularly Ethiopians have evolved with melanism, and having the trait has become a norm but even among them there are some people that go past the natural very dark brown skin tone to truly having black skin color.

[@kshitijjhalak1939]

I don't think complete melanism occurs in humans. If melanism occurred in humans then you would have people with extremely dark skin regardless of the skin colour of their parents. Also calling people from Africa melanistic doesn't make sense because melanistic animals like panthers can have fair/normal skinned cubs and you don't see two dark skinned people having a unusually fair skinned child unless it is albinism.

[@niceguy1965]

You know whats funnier, we cannot tell the true collors we could see in UV, because well, UV is outside of our spectrum of visible light, so to counter this we use cameras that use colors of our visible spectrum to kinda bypass the limitations, but even so we still cannot tell how the world would ACTUALLY look like.

[@EricPalmer_DaddyOh]

Derek, love that you have the PhysicsGirl on.

[@LiftPizzas]

The stuff shown in this video would be like if space aliens showed "how humans see" and just combined all the wavelengths in our entire visible spectrum to one "brightness" value at each pixel. I would have liked to see it "interpreted" with different UV wavelengths represented as the colors we know of. And also using the range of wavelengths that insects can see (all of them, not only UV) to combine it into an image using our range of colors to represent what a flower would actually look like to something with that range of vision. I would suspect flowers are far more interesting that way.

[@natejennings4107]

Lift Pizzas Derek actually did put in the ultraviolet colors. It's your fault you can't see them.

[@KuraIthys]

Well, the problem with that is those insects are tetrachromats. As Trichromats we simply lack any context for that, and they'd see billions of colours to our millions. It's like trying to show what colour vision looks like to someone who can only see in black and white. There just really isn't any reliable way to do it that has any real meaning.

[@jetison333]

KuraIthys grabbing three channels instead of just one would be better though

[@xenontesla122]

They would need an even more specialized camera for that kind of video. It may be easier to do with this type of camera by using multiple filters and combining separate photos, but they couldn't capture video.

[@realw98]

I'd like to see in an "extended" diapasone, if we can map IR to the red channel of a video, visible light to then green channel and UV to blue.

[@hawkeyes4768]

this is probably the best video i seen all year

[@puh8825]

10:22 I think that's what makes science so interesting. Being able to not only learn it, but also experience it.

[@nolan4000]

1:06 Once you take a closer look, Jessie, you find... Heisenberg.

[@VaanaCZ]

It would be also amazing to see "The World in Infrared"

[@zx3215]

VaanaCZ, which one of them are you interested in?)) for thermal infrared see the famous Predator movie, although the way Predator sees the world depends on the chosen temperature scale =/

[@xponen]

@zx3215 , no the Predator's thermal camera is a FAKE colour, if you want to see the real infrared image google "Infrared Photography".

[@wilconbarro3469]

wii remote has infrared camera built-in

[@zx3215]

xponen_ everything in non-visible bands is a "fake colour" (quite expectable, because "colour" only refers to whatever is visible), depending on which color scale you choose. what you first find by googling "infrared photography" is gray scale images. For thermography it is also the most common one (the brighter = the warmer). I forgot the name of the scale closest to the one used by Predator - I guess, FLIR call it something like "medical" scale. What is good about it is that smallest temperature gradients become visible. Though the overall scale is somewhat inconvenient to use.

[@XZYSquare]

xponen_ while you can consider the red and blue visualizations of the spectrum fake. Stop and consider the idea of remapping a black and white value from -1 to 1, to a color value such as red 0 to 255. It would show up as a red gradient on the screen. Now instead of mapping it to one color, lerp it; remap 0 to 1, blend from blue (0) to red(1) and what do you get? A gradient from blue to red. But what if we input the values of the UV light instead? "Fake" thermal images.

[@ADIP1598]

Next Episode: The world in Infrared

[@izuix5629]

www.mattlumine.com/kate-ballis-candycalifornian-landscape-infra-realism/

[@martialme84]

+Adip1598 Yeah that was my first thought aswell...

[@Drkwll]

That's just thermal vision.

[@Alien1375]

ADIP1598 So like Predator vision?

[@martialme84]

+Drkwll ...aaand? I don´t get the point you´re trying to make. Also: what do you mean by "just"?

[@Ajjoy.]

"Likes the smell of you"...pause..."yeah"...*awkwardly looks at the ground.

[@dev_invc]

He is cheating on his wife

[@carlo89]

They should use this video as an example of why you should use suncream. Just seeing that, and hearing the explanation of how it works, already encourages me to use it.

[@94nolo]

1:14 your two front teeth aren't purple or darkened anymore?

[@cesarperezargota]

Wait what... You're right. I'm confused now :lll

[@civotamuaz5781]

It's simple. Just like in visible light you have different colors and different color filters you have the same thing in UV, that is different UV colors. On one UV filter they're purple, on the other they're not.

[@bartsshorts]

alans snackbar

[@cesarperezargota]

civota mu az But then shouldn't his two front teeth still stand out from the rest with the other colour filter? They don't, however, which is what confuses me.

[@civotamuaz5781]

Well obviously not since they don't :D

[@robertorivers3453]

It is quite sad how the UV image at 1:20 is kinda realistic nowadays in some cities

[@bobwannabe9141]

More like Minecraft on a low render distance

[@user-pb4bn1eb2j]

Bob Wannabe lmao

[@JaskaranMega]

Imagine seeing these cities in actual UV, total fog

[@protheon]

Kraków in Poland is looking like that in winter

[@VictorSokolovNN]

Damn, at first i thought I have a superpower, like my sight has evolved to be able to see in UV ))

[@SpaceXToMars]

Let wish that PhysicsGirl (Dianna) feels better soon!

[@sarahanderson6126]

omg subscribed when he laughed over the soda haha cute I needed that

[@missclarestube]

Facinating how melanin protects the dna

[@tysaylor551]

I literally just learned how sunscreen works.

[@RockHudrock]

More of Diana the physics girl, please!!! 🥰

[@IAMElectric369]

Yeah, she’s a cutie.

[@Lucascavatoni]

And on the flip side, if you look at the world in infrared, you can see so much further, as if there was almost no atmosphere, because there is so little scattering at these wavelengths, it's really eerie

[@_Bandit88]

Black veritasium from alternative reality.

[@L00PdeL00P]

69 likes kek

[@DuluthTW]

One of the best collab videos series I've seen. Thanks!

[@sgtkat69]

Always such great content!

[@CP-rg5mi]

It would have been interesting to see the amount of time during which sunscreen wears off and also whether the many products advertised as waterproof are any good after being in the water for a specific period of time.

[@dmnkllr22]

"Wear sunscreen. If I could offer you only one tip for the future, sunscreen would be it." - Baz Luhrmann (Everybody's Free) The more you know.

[@PantsB4Squares]

Cause knowledge is power! 🌈

[@memethanYT]

I'm super allergic :(

[@vasundhara8596]

why is nobody talking about the cuteness of harp seal pups? i died.

[@yusha1059]

bye bye old man

[@christopherbristow9108]

I'd love to see you take pictures or video of different minerals with that camera

[@dirkbastardrelief]

Veritasium channel is like a chemistry set, but with a narrator, and you can’t lose the parts

[@rosejuliette9180]

If an alien saw primarily in UV light and then learned how blackface is super offensive it would get so confused when people started putting on sunscreen.

[@alienprotein457]

We wuz ultraviolent and sheeet

[@Lucien86]

If it saw in the infrared it would get even more confused because black skin looks white in infrared.

[@ernestomorales7978]

@@Lucien86 in UV*?

[@Lucien86]

@@ernestomorales7978 Well since sun tanned regions look darker, black I guess.

[@dananskidolf]

This is why we don't see so many bees anymore. They all think we're racist.

[@benjaminvroman5553]

Oh my god SEALS ARE SO CUTE Edit: Also sunscreen looks like UV blackface

[@zaesrvnge9584]

I was waiting the longest to see a black person in UV

[@mariogonzalez9082]

Benjamin Vroman YES, i was thinking the same thing

[@CadenUnnasch]

I was drinking coffee and I almost spit it out at that edit

[@DANGJOS]

Blueseer32 black girl at 8:06

[@earflapphat]

Can we just point out how adorable those seals are?

[@joeltashinian5888]

I must also come clean. Ive been watching your channel for years now but what surprised me is that we have this in common: two front teeth that look a different color under blacklight. Mine were chipped mostly away when i was 10 and were lost to a tremendous pile of pine needles.