Why white things are white

[@SteveMould]

Sorry about the nipples. The sponsor is Skillshare: For a limited time, use this link to get a free trial of Skillshare Premium Membership skl.sh/stevemould11201

[@thenoble1]

We like the nipples :)

[@Tensho_C]

@@thenoble1 Speak for yourself. I LOVE them (No homo)

[@euclideanplane]

lol nice click bait

[@water4039]

I almost failed NNN from them ngl

[@Matty0311MMS]

😅

[@JackLe1127]

Is the uncensored version a Patreon exclusive?

[@patzminihd]

@@23Scadu xD

[@aivkara]

Bwuahahaha!!!

[@Sheriden.]

I'd pay

[@tudormuntean3299]

I think it is from only fans

[@madkirk7431]

@@23Scadu no, it's a (insert funnier thing here) exclusive

[@McPhysX]

6:30 We actually know very well why! A *Colloïd* is simply a name given to any object that has a size from 1nm to 1µm. When you shake water and oil together you are creating droplet of oils that are colloïds! Colloïds are unstable by nature because of surface tension. Oil droplets will naturally do two things: 1) If they are less dense than water, *rise up to the surface* 2) *Merge into bigger droplets* , because bigger droplets are more stable in regards to surface tension For your colloïd suspension to be stable you therefore have to counteract both effects. 1) is easy. A particular property of colloïds is that they are so *small* , that natural random movement that all molecules have become non negligible. Therefore if the speed at which they rise up to the surface due to archimedes is lower or equal to the speed of their random movement, they won't rise and will fill the whole volume, like a molecule would. This is mainly dependent on their size, the *smaller* they are, the more they *diffuse* and the less they rise. 2) Is harder but essential. Surface tension will merge any colloid suspension, unless you have particular molecules that stabilize the suspension. Which is the case in your alcohol! *Proteins* , soaps, surfactants,... any molecule that has a *hydrophilic and a lipophilic* part will place themselves at the *boudaries* of these tiny droplets, *reduce surface tension* , and make the droplets repel each other, therefore they will stay small and never merge. It is a well studied phenomenon, especially in *biology and pharmacology* , where you often want *oily molecules to be suspended in a water solution* for delivery, and you don't want your medicine to divide into a fine layer of high concentrated oily molecules and a deep layer of useless water.

[@chawndel8279]

I followed most of that, but did you mean to say archimedes? If so, can you explain what that means? Or, if it was an autocorrect error, which word did you intend? Btw, thank you for the detailed explanation, it's very informative.

[@McPhysX]

@@chawndel8279 I meant by that the resulting force from buoyancy and gravity which is sometimes referred to as archimedes push in french idk if you guys use that. you're welcome

[@BruceNJeffAreMyFlies]

"Therefore if the speed at which they rise up to the surface due to archimedes is lower or equal to the speed of their random movement, they won't rise and will fill the whole volume" But the random movement cancels itself out in all directions, so it will still have the added force of buoyancy lifting it. Colloids were a bit part of my job when I was making biofuel, and one problem we struggled with was, regardless of size, the particles would eventually separate even with an emulsifying agent. I still don't think the company has a way of keeping the colloid submerged and colloidal without agitation.

[@imbored742]

Small droplets of oil suspended in water and stabilized with a surfactant are referred to as emulsions. A common emulsion that most people are familiar with is mayonnaise, which incidentally is white for the same reasons stated in the video.

[@NachitenRemix]

​​​@@imbored742But mayonnaise has a slight yellow color, I guess because of the egg yolks and/or oil it is made of right?

[@yaqxs]

There is a technique in animal and organ preparation called Spalteholz preparation. By matching the refracting index of the conservation fluid and the outer layer of the object the object becomes translucent. So you can study the inner parts of your object without a section. It's called after its inventor Werner Spalteholz and I don't know if it's known outside Germany.

[@SteveMould]

Interesting!

[@yaqxs]

@@SteveMould when I once visited the medical history museum of the Charité Hospital in Berlin, Germany 10 years ago, I saw such preparations of animals or parts of them, where as much of the body fluids as possible where exchanged by the preparation fluid, so the tissues became more or less translucent, and I remember taking pictures of it, but sadly I don't find them anymore.

[@piteoswaldo]

I've seen specimens preserved by diaphanization, that make the exterior transparent. Do you know if it's a similar technique?

[@avariciousaxolotl]

That's smart!

[@yaqxs]

@@piteoswaldo yes, I look it up and that's the proper English term for that preservation technique.

[@proudtoberainy]

We're a company that makes a hydrophobic coating designed to create art that appears when it rains. Our process relies on the fact that concrete gets darker when it gets wet. I've dug into why this happens several times but your video provided a more clear explanation than I've been able to find before, thank you! Interestingly, hydrochromic paints list silica as an active ingredient, which is also an ingredient in our hydrophobic coating. It's wild that silica can act as a white-to-transparent ingredient as well as a hydrophobic ingredient. If you ever made a video about the stunningly varied applications of silica, I'd be extremely interested to see it!

[@louisvictor3473]

I wonder how useful this is 2 years later, but the main difference is that hydrophobic silica isn't pure, it is bounded to hydrophobic agents. Meanwhile, silica/fused silica (i.e. quartz) has a refractive index closeish to water (water 1.333..., silica 1.5 down to 1.4 ish), while air is about 1.0, so you get less dispersion in water). Specially if the layer is thin.

[@kwertie133]

​@@louisvictor3473AYY it's so wholesome to see this reply even tho it's after 2 years haha

[@JackFoxtrotEDM]

I mean it makes sense, isn't silica what's used to make aerogel?

[@davidioanhedges]

A patent for one of the types of hydrochromic coatings lists the active water activated hydrochromic materials as : sodium aluminum silicate, alumina trihydrate, micronized amorphous silica gel ...

[@SteveMould]

Thank you!

[@TheChuDragon]

Made from ground up Buddha's

[@Kanitoxx]

I was about to comment that it could be similar to the silica gel plates used in labs for thin layer chromatography, although, it will not show UV fluorescence (probably)

[@jedshambeda4172]

@@Kanitoxx A fluorescence check could be really interesting actually. Silica doesn't fluoresce on its own but there are a bunch of different additives that make that make TLC plates UV active. On top of that, one of the primary means of seeing a spot under UV light is the material in question de-activating the fluorescent material - basically canceling out the additive. Ooh, and there's the fact that pure quartz is somewhat opaque to UV...

[@Z-Ack]

So what makes lsd fluoresce when dropped on blotter paper? Or why does Peruvian flake (fish scale) cocaine also fluoresce when its the exact same chemical extracted from a plant but just extracted with acetone to separate it from the plant fats? Lsd is perfectly clear and so is cocaine when in liquid state except lsd will evaporate rather than condense into the powder form we see cocaine to be...

[@matthewpetty7955]

I bought a similar 'Buddha' board in China for practising writing Chinese characters using a wet brush. The top coating of this one is actually a thin layer of fabric (assuming cotton) over a black rubbery plastic to create the effect.

[@theeversor69]

Gioven all that was said it makes perfect sense!

[@plinkage]

"titanium white" makes alot more sense now as a color name.

[@wbfaulk]

And the previously used white pigment was a lead compound, which is why there's lead in old paint.

[@lickit77]

You mean "titanium hwite"?

[@protheu5]

Most of the titanium mined is used to make paint.

[@capivara6094]

my dad works with paint, and, one time, when I was bored, I found this color and I was like "wtf?" I asked him why it has this name, and he answered "I have no idea." Now I get why it's named like this.

[@YounesLayachi]

Toothpaste

[@jans1982]

"Ooh! That's why!" - Me in every Steve's video

[@UselessDuckCompany]

8:16 that face

[@joonasfi]

I love your name and your videos 😍

[@zanemcelroy7910]

::throws beads::

[@Oscar4u69]

thought the same 😂😂😂

[@TheMorpheus017]

I'm sorry for one, who had to edit this moment.

[@alejotassile6441]

**You can start to see my n i p p le s**

[@peterryrfeldt8568]

1:00 amen brother tau is the true circle constant

[@dafoex]

Certainly agree for working in radians

[@Scuuurbs]

I have no personal stake in the debate insofar as usability or objective superiority is concerned, but imo pi is more aesthetic than tau. It's easier to distinguish when dealing with colleagues', ah... _questionable,_ penmanship.

[@6.28]

RAAAAHHHHH

[@mduvigneaud]

I used to work for a paint manufacturing company a while back and the TiO2 slurry was one of the most significant ingredients in the paints.

[@PK-hs7up]

Hi Steve, I would guess that this hydrochromic image is just coated with silica gel or something like that. Maybe you want to test this: Take an image, apply spray glue on it and dust some silica powder over it. Maybe it is something with an RI even closer to water instead of silica, but ... just a guess.

[@fengyouliu8937]

P K front end dev be like

[@Marko_Djuricic]

import React from 'react'; import PropTypes from 'prop-types'; import parse from 'html-react-parser'; const CommentComponent = ({comment}) => { return {parse(comment)}; } CommentComponent.propTypes = { comment: PropTypes.string } export default CommentComponent;

[@General12th]

You can make text italic by putting underscores around it. I _guess._

[@Slekejkwls-1819]

_ Guess _

[@SteveMould]

@@Marko_Djuricic I can parse html natively thank you.

[@robertwilliams5979]

The blue shower gel reminds me of how all mirrors are a tiny bit green, but you can only notice it from a really extreme angle

[@KallePihlajasaari]

Regular plate glass is green. You can see if you look edge to edge. Front surface mirrors do not have the light pass through the glass (twice) and appear 'brighter' and do not have the loss of sharpness due to (multiple) reflections from the glass surface.

[@AlRoderick]

If you've ever watched hard candy making, like the stuff made by Greg from Lofty Pursuits here on KZbin (okay it's actually made at his shop in Tallahassee Florida but he puts the videos on KZbin) he makes white hard candy by pulling the molten candy on his stretching hook or his taffy pulling machine to aerate it and put a million tiny air bubbles in it.

[@itsawonderfullife4802]

Good mention. thanks.

[@ClaireMooreSteel]

Also see mayonnaise. 3 yellow ingredients whisked together to make a white mayonnaise. I remember seeing a video where they whisked marmite until it was white too.

[@deesync7203]

Speaking about presentations... It's just amazing how far you've come to make explaning such things look so easy... You're an idol Steve! Keep up the good work!

[@shadyganem5448]

That's so interesting. I learn so much from this guy. He is also the right amount of funny.

[@j.dietrich]

In metal polishing, we sometimes aim for the opposite of this effect. A "black" polished surface is so smooth that it no longer scatters any appreciable amount of light, acting like an almost perfect first-surface mirror. From certain angles it will appear completely black, because all of the incident light is reflected away from the viewer. It's most often seen on components in high-end mechanical watches, but we use the technique a lot for injection moulds for plastic optical components.

[@Pants4096]

Aha! There's a name for the nanoemulsion formed by diluting alcoholic solutions: the ouzo effect. It has its own wikipedia article. ◡̈

[@CivilChristoph]

Come on, you made that up,, created the wiki just for this! Tequila, anyone?

[@quattovallor71]

Uhhhhhh... yeah, that’s what I thought... ...I’ll take a shot

[@TheExplosiveGuy]

I love Ouzo, with a sugar cube and cold water, amazing stuff. If you freeze ouzo for long enough crystals will start to form inside as well, they're beautiful looking...

[@Agnes.Nutter]

Came here to say this!

[@austindenny7094]

As a chef you get a sort of intuitive feel for when different oil emulsions will remain stable for certain periods of time. Alcohol, amphiphilic additives, ratio of oil to water, dissolved solids such as sugar and gelatin, all have different effects. Too complicated to write it all down so you just go by feel and experience. Anise based essential oils in liquors are a special one I don't have as much familiarity with since you can't really "cook" anything with that effect.

[@gigglysamentz2021]

6:20 I did a little controlled experiment: turns out ethanol helps stabilise oil in small droplet in water, turning the water cloudy. Maybe the ethanol molecules act like amphiphiles ("ethan" part towards the oil, "ol" part towards the water). A bit like soap dispersing the oil throughout the water. Maybe it prevents coalescing of the oil because the ethanol layer needs energy to be broken.

[@abrahamwondafrash7549]

1:34 the microscope disappeared!😜 I love the sticky tape on a frosted glass trick...I can't wait to try it out! 10:10 the microscope appears!...11:13 disappeared again.

[@lucassamuel6069]

Haha, good observation

[@CivilChristoph]

Matrix glitch

[@junkmail4613]

Abraham Wondafrash 2 hours ago (edited), "1:34 the microscope disappeared/reappeared ..." Surely NOT "miracles of modern editing" but rather "MAGIC OF TROLLS UNDER THE BRIDGE!!!"

[@abrahamwondafrash7549]

@@junkmail4613 😂yeah definitely not a miracle but it's very hard to miss...I just couldn't resist mentioning it.

[@beskamir5977]

Reminds me a skit jack made nearly a decade ago kzbin.info/www/bejne/qITRdKhqaLatm7s

[@ChubbiestLamb6]

1:03 "the superficial explanation" Superficial - existing or occurring at or on the surface Very appropriate wording there, Steve...

[@countpoolnoodleiii99]

That phenomenon of some alcoholic beverages turning white/opaque has been bugging me for half a year now. Thank you for finally clearing that up. (no pun intended)

[@jakubswitalski7989]

Fun fact: it's called the ouzo effect.

[@countpoolnoodleiii99]

@@jakubswitalski7989 That´s awesome and quite fitting. I actually started wandering about this when I had a glass of ouzo back when you could still go out and have a drink.

[@joeemenaker]

One test you can run on the theory is to foam up the shave gel and then form it into a long line of foam and then illuminate the foam from the far end, opposite the camera. The light it sees should be that which had to pass through a lot of the gel (hence, blue). You may need to put mirrors along the sides of the foam to redirect all of the scattered light back into the foam (or else you might see very little light making it all the way through the foam)

[@jeremiahbullfrog9288]

Good idea. Could probably squeeze it into a stainless steel straw and shine a flashlight through.

[@ciarfah]

0:45 Tau Nice

[@glaucomflecken]

8:15

[@ciarfah]

@@glaucomflecken Also nice

[@Talaxianer]

Still hope...

[@bl4cksp1d3r]

Weird, I see only 2 Pi :/

[@janSimiman]

ah, I see you are a man of culture as well

[@Flokirie]

That Regulators reference took me a while, but was much appreciated. Great video, as always. Got me extra hyped for Unnecessary Detail season 2 as well.

[@prettycillium]

Hey Steve, you ve done an amazing video and clear explanation to the subject. Thanks for that. I'd love to request from you to put captions to the videos you share. Even though your accent is so clear, I sometimes can't understand because of lack of English I have. It'd be great if you consider it for your videos. Nevertheless, it's amazing to watch and learn from you. Thanks a lot!

[@kapowbalw]

Nonsense. Your English is great :)

[@prettycillium]

@@kapowbalw you misunderstood me, his English is great, not mine. That's why I request him to put subtitles

[@Bu11etSp0ng3]

@@prettycillium And your English is fantastic as well, evidenced by your great comment. What you may be lacking is listening comprehension, hence the need for subtitles.

[@patromo]

"Got to be handy with the steel if you know what I mean to earn your keep" I just let out a honk of a laugh

[@InvadersDie]

For being a wave, the photon particle has a very physical way of interacting with the environment

[@maximilianmeyer4905]

Xd

[@MichaelSmith-xo6li]

I shudder to think of the explanation

[@AbstrDistr]

I've always wondered why adding white paint to other colors made it opaque, and I feel like this explains it pretty well!

[@thenamethatwasntaken2314]

Eyes: What color is this? Brain: All of them.

[@JUNIsLuke]

Y E S

[@notchs0son]

MHHH GOOD OBSERVATION EYE

[@Stigstigster]

What an easy man to listen to. Great information on curious subjects delivered in a very pleasant way. Top stuff! This gentleman has the hallmarks of a great educator.

[@ErickTun]

11:08 "You gotta be handy with the steel, if you know what I mean. Earn your keep." REGULATORS, MOUNT UP!

[@Do_Odles]

Glad others caught that :) ...though its stuck in my head now lol. "It was a clear black night...

[@bradley3549]

These are my people.

[@MrKyltpzyxm]

... a clear white moon... because of the scattering of light. It's all connected.

[@satyris410]

G-funk, where rhythm is life, and life is rhythm

[@felipegonzalezlelong7944]

I really like how you don’t avoid answering the questions that may arise from the concepts you present

[@HaraldRevery]

2:31 HEY LOOK!! HEXAGONS!!!! 😁

[@NathanButh]

The bestagons!

[@bodhi_db]

A man of culture

[@JacobRy]

@@NathanButh spreading the religion

[@Shrooblord]

[@Sheamu5]

Must tile the plane

[@thesoupin8or673]

Here after Hexagons are the Bestagons and I couldn't stop seeing 120° angles in the bubble cross-section! Super cool to see

[@tomiticus4967]

Me: "Dad, why is shower gel blue?" Dad: "For the last time, it's because of Rayle... wait, what?"

[@wallabra]

Rayleigh had struck a sponsorship with your Dad. Now that it is crumbled, Rayleigh wants revenge. Hide you--and your dad--in a bunker. Preferably one without sunlight. :D

[@morgansearle3912]

@@wallabra And leave caltrops out for the inner tubes. Oh wait, was that 'Rayleigh' with a 'y'?

[@wallabra]

@@morgansearle3912 Hehe!

[@JohannaMueller57]

you thought everything that's blue is subject to rayleigh scattering? LOL. dumbo

[@brightoff]

I think my favorite example bubbles scattering light is with candy. To make white hard candy you take molten sugar and folder over itself continuously, essentially folding air bubbles into the candy which lightens the color. (The same works for turning a- say- dark blue colored candy into a light blue candy.)

[@osar7664]

In the foam, the amount of light that reaches the inside of the material is lower because there are so many surfaces that reflect light before enough thickness of the material is encountered. Less light reaching the gel means less red & green light is absorbed. Also, the total brightness reaching the eye is higher, so the remaining blue photons are more diluted

[@nicotronics]

8:55 that secret deserves a call to @JerryRigEverything, if i remember correctly, he has an element analizer, he has a video analizing his gold youtube play button

[@ViiKing_]

This was cool but can you explain glue? it's white when it's wet but gets transparent when it dries, how?

[@blackmber]

Interesting question! Mind if I take a guess? In a water based glue, the adhesive agent may be emulsified in the water in a similar way to the essential oils described in the video. The particles scatter light against the water because they have a different refractive index. However, once the glue dries there is no water between the adhesive and the light travels through. tl;dr The water makes it very cloudy but when the water evaporates, the glue becomes clear.

[@mrkrunch4340]

Science!

[@ViiKing_]

@@blackmber that's a smart guess, I never thought about that

[@Hypercube9]

When I was a kid, we used to break our crayons, put them in our Elmer's glue, and then shake them to make the glue change colors. Years later, that became an actual product you could buy in stores. LOL

[@Ducky69247]

It doesn't dry clear if you use too much, and it's only barely clear when you use the right amount.

[@TheGoupil19]

Pernod or pastis in general does eventually become clear. Just like any emulsion, eventually it separates into two layers. That said in pernod there is only little "oil", these insoluble particules might form micelles or other arrangements that stabilise the emulsion form

[@kalpanapatel2387]

10:47 People who watch Tom Scott might be aware of this. 😂

[@nosferathu258]

I really like when the KZbinverse connects

[@sjallard]

Or the Scillabus channel too, in French though : kzbin.info/www/bejne/a3qpl6Wiltuspsk

[@StayMadNobodycares]

or maybe the ActionLab guy

[@TheEgg185]

I also pronounce it Jif. That was the way I heard it in my head the first time I saw the word.

[@_modnar_]

"I've got Titanium Dioxid on my walls!" sounds way better than "My walls are white."

[@HelloKittyFanMan.]

When did "[t]itanium [d]ioxid[e]" supposedly become a brand, according to you?

[@_modnar_]

@@HelloKittyFanMan. You missunderstood me: I never called titanium dioxide ["Titan(IV)-oxid" or "Titandioxid" in my native language] a brand, just a thing on my walls.

[@HelloKittyFanMan.]

@@_modnar_: I didn't misunderstand you. You capitalized it mid-sentence. If you don't think it's a brand or title then why did you capitalize it?

[@_modnar_]

@@HelloKittyFanMan. Because we call it Titan and Oxid in my native language (german). So please excuse me for making a small mistake in a foreign language :D

[@HelloKittyFanMan.]

@@_modnar_: Oh, you were writing in "Germlish," huh? I see, kind of like "Spanglish" is Spanish mixed with English (Espangles). And I've heard that German capitalizes all nouns for some odd reason.

[@leuenbergemo]

But the question is, where did that microscope thing in the background went at around 01:34?!

[@TarekMidani]

It went here 8:35

[@snork_games]

And here 9:58

[@RedHillian]

It got wet, changing its refractive index.

[@mrakalin]

This was a great explanation on transparency of the materials and white color apparience on matters, better than other explanations like electrons jumpimg to different orbitals. Thank you for all.

[@jaredf6205]

"Oh my god Karen, you can't just ask people why they're white"

[@nasonguy]

"Git! Scram! Scatter!"

[@yojon75]

beat me to it

[@zanemcelroy7910]

Just put sticky tape over your whole body. No one will be able to tell what color you might be. Bahah

[@misterscott]

Titanium dioxide

[@StayMadNobodycares]

Nick Cannon**

[@lyubenkoa]

I love how you used a beaker for the t-shirt demo, that way everyone knows its not just crass entertainment...ITS SCIENCE!

[@andyrharris]

Loving the Nate Dogg/Warren G reference... Regulators! Mount up...

[@jamesallen4050]

Just comment surfing for this! Further trivia; Nate Dog and Warren G sampled it from the movie, Young Guns.

[@EricDenny]

My man you find the most unique things to study! There are some seriously enlightening things hidden in the world where nobody else is looking. I wonder how you actually get places ignoring the sidewalk to travel through all the cracks

[@samtibbitts]

5:10 where do the people go? When will they come back? Am I the only one distracted by them?

[@TheJunky228]

my first thought was The Enigma of Amigara Fault; they found the hole meant for them

[@deus_ex_machina_]

@@TheJunky228 Wow I'd read that before but never knew the name, Junji Ito has quite the imagination.

[@taylor....]

9:58 When I was making paint all of the non soluble materials made the clear liquids a Manila yellow, adding titanium oxide didn't make it white until we added a small amount of this extremely thick blue gel. Because in dyes AND light blue & yellow cancel each other out to white. That's why some expensive headlights have a blue lense.

[@kosmicgr]

Me, after I looked at the thumbnail: Ah yes, many people's favorite album... "DAMP."

[@TechnologyWithSaikat]

Sir, once in my life, I wanna meet u. U r genius! U having knowledge mostly every field. And I also loves to learn new things.

[@ElendirFoxburr]

Really neat, thank you! Any ideas why some plastics turn white as you deform them? (i.e. plastically deform usually)

[@digeon8798]

Idk but that phenomena (prob. Spelled wrong) is called going crazy, maybe same reason?

[@frobthebuilder]

I believe the stress creates tiny voids in the material, which scatter light in the way described in this video.

[@tudormuntean3299]

1:30 Why does that thing in the background disapear?

[@Thesignalpath]

Oh god the thumbnail! :)

[@signalworks]

hey shahriar! you should make more lecture videos on rf design :)

[@GTAVictor9128]

Definitely helps to garner attention 😏

[@althaz]

Absolutely the best pronunciation of skl.sh I've ever heard. Five stars.

[@jacobriddle7230]

Hot thumbnail

[@the_original_Bilb_Ono]

Just like Steve to use his sex appeal to gain views instead of using his intelligence.... tsk tsk tsk...

[@jaredcoffin8702]

This is mind blowing. I’m in the automotive industry and never understood quite how clear coat became less transparent over time. Or with lots of sun. And why water on my truck makes it look a lot nicer. Or… endless possibilities

[@FufuFang]

I am going to have to try these myself.

[@stefantschirren4466]

This takes me back to my year 12 high school physics project. I asked myself the same question about white foam on a freshly poured glass of soft drink and came up with this as my topic. Good to hear it again and confirm my presentation.

[@lidarman2]

It won't work if the frosted part is on your cube neighbors side :(

[@jetison333]

just reach over and quickly slap down the tape. or wait till they are on a bathroom break or something.

[@javierhualde739]

In fact, some frosted glass is made gluing two glasses with the frosted side inside, so the outer sides are smooth.

[@joshuadowdle9691]

It's very thoughtful of Steve to warn those of us who know the real and 100% correct pronunciation of GIF.

[@ronwesilen4536]

I guess the lipids in the perno (or however is called) have some kind of polar molecules that eventually make a little ball around the insoluble lipids so that it separates the lipids from the water. A similar thing happens in your blood to transport cholesterol and fatty acids. (They are called ldl hdl and quilomicrons, all of them being lipoptroteins) i dont know this for sure but it makes sense for me. Edit: turns out perno is not aromatic oil (as i assumed) so probably this is not the reason, the video, specially comparing it to the emulsion of oil in water made me confused

[@kindisc]

they use aniseed resin, which crystallises when water is added, see also - ouzo.

[@ronwesilen4536]

@@kindisc oh yes, i didnt know what perno was and i understood from the video that it was aromatic oil. My bad

[@SteveMould]

I think even said aromatic one one point instead of essential oil. My bad!

[@DarkdeathKnigth]

I once wondered why some stuff made of cloudly and white resin became clear after adding a fresh layer on it, now it makes a lot of sense. Thanks!

[@mwgondim]

Apparently, all sunscreen lotions I've checked have Titanium Dioxide in their composition... Is this scattering responsible for their UV protection?

[@GuyNamedSean]

Partially, yes. The whole point in sunscreen is to be opaque to UV. Most sunscreens that I've seen appear black on a UV image, so it would appear they absorb the light, but I have seen some that reflect the majority of the light.

[@ronwesilen4536]

@@GuyNamedSean maybe the black ones have the oxide.to.make them white

[@Scandium_quasar]

@@GuyNamedSean Yeah, physics girl and veritasium if I remember correctly looked at different sunscreens with a UV camera and some do reflect instead of absorb the UVR.

[@tiarkrezar]

Well, if it looks white, that just means it scatters the visible part of the spectrum. I'm guessing it probably absorbs UV so that it doesn't reach your skin cells.

[@mwgondim]

@@Scandium_quasar well remembered, I'm gonna check that video again

[@dafoex]

That thing with the tape and frosted glass is a shockingly intuitive way to explain why wet fabric goes transparent

[@KeeperOfKale222]

8:16 What a face

[@benjaminruiza]

This is why we came

[@brided9407]

@@benjaminruiza But it's NNN.

[@PotionsMaster666]

@@brided9407 whats NNN ?

[@brided9407]

@@PotionsMaster666 NNN means no nut November.

[@JimCoder]

Wet T-Shirt contest. One contestant. Guaranteed win! I had to look up "Buddha Board" and Pernod. Learned two things today!

[@InuranusBrokoff]

I was just talking about something along these lines with a friend last Sunday morning. Glad I subd, gotta keep the gears turning up top.

[@evilferris]

8:15 😍 The goods you came to see. Kinda.

[@thofu]

#freethenipple

[@zim_the_vixen]

I learnt about this with a bottle of nail polish base. The bottle was frosted, but when I got the polish on it it became transparent.

[@adamlipare1033]

Thanks for this info! I'll be sure to remember to bring all my tape when visiting the changing rooms that have the frosted doors

[@irkz6690]

*hits blunt Whoah dude. So is the shower gel still blue in the bottle? Since no light can get to it?

[@GodlikeIridium]

Finally someone explained how wet t-shirt contests work! XD Thank physics for this great property of fabric.

[@ioansimion892]

"He does pronounce it 'jif', soo..." :)))

[@paranoidasur694]

6:23 I think it becomes a colloidal solution that's why it doesn't act as same as oil and water solution

[@RedStefan]

Honey I am watching this wet t-shirt contests for research purposes I swear!

[@mavrophor]

Fantastic explanation, very thorough and brief at the same time.

[@danielwarren7110]

so paint your house colours to annoy your neighbours, then cover it in the same paint as the board. and only annoy them when it rains

[@boi829]

6:25 idk anything ab this drink, never heard if it before, but maybe one of the ingredients is an emulsifier? I think it would make sense as that would allow someone to mix it with water which is apparently something people like to do

[@chilldude30]

Why would an emulsification cause it to become coloured?

[@boi829]

@@chilldude30 well i was referring more to how the oil doesn't separate out, but i guess that would mean a bunch of microscopic drops of oil suspended in the water which could maybe still cause scattering though i'm not sure

[@tremkl]

I hadn't heard of Buddha Board before, but when you described it, my mind immediately jumped to frosted glass. I own a frosted glass chess set (half the squares/pieces are clear glass, half are frosted), and after I had used it a fair amount I found the glass had a lot of fingerprints on it and I wanted to clean it. I got a damp cloth and wiped it down, and much to my surprise all of the squares disappeared. Sure enough as it dried, the frosting came right back.

[@LaMirah]

6:30ish: If the droplets don't fall or rise, they are probably so small that their inertia is tiny compared to their cross-sectional area, and thus they react as very low-Reynolds number flows and their buoyancy gets overwhelmed by the Brownian motion. As for the droplets not combining into bigger droplets, it has to do it being an emulsion, where surfactants create a kind of chemical "pressure" which pushes the droplets apart. Once again, their inertia is so minuscule that our macroscopic intuition of particle dynamics breaks down and particles start to behave in surprising, unintuitive ways. Search for "Bacterial Hydrodinamics" on ArXiv for an interesting review of the subject.

[@seanc6128]

"Regulators, mount up"

[@MrSpindre]

I had to scroll way too far down for this

[@BitterTast3]

@@MrSpindre *too

[@doltramir]

It is interesting thing to consider when making 3D graphics with PBR materials. Maybe there should be some way to set material as "foamy" or make roughness mix diffuse and specular inputs. That's interesting thing to think.

[@radicalxedward8047]

Ahhhh! I tried replicating what he was doing and got a bunch of photons in my eyes.

[@Braeden123698745]

The glare on the liquid was an amazing demonstration. I instantly understood at that point

[@gpowell511]

You should try adding Pernod to heavy water, Deuterium, and see if it separates out then

[@sageinit]

Why?

[@gpowell511]

@@sageinit Because the droplets did not coalesce in normal water and he stated "nobody knows why" so by changing 1 parameter (the density and not the chemical reactions associated) we can possibly gain a step towards understanding why.

[@kevinmartin7760]

The more precise explanation of why the colour of the bulk material doesn't show when it is a powder or foam is that the light path from when it enters the foam/mass of powder until it is all backscattered is substantially through air and only a fraction of the path is through the bubble walls/crystals so it is similar to looking through only a very thin layer of the bulk substance.

[@stupidgenius107]

Now explain Elmer's glue. White when wet, dries clear. 🤔

[@duodot]

Something in the wet glue is suspended in various orientations, scattering the light, but orients into a shared direction when it solidifies, making it transparent? Edit: Another comment I found hypothesized that the adhesive being emulsified in the water scatter light while suspended in the water, but when the water evaporates, it becomes less refractive.

[@stupidgenius107]

@@duodot The second one makes more sense to me in the context of this video. I don't think it has anything to do with alignment, because then I would think it would only be clear from one angle (or 2 parallel angles). 3rd option: magic.

[@duodot]

@@stupidgenius107 Yeah, seems so to me as well. I work with metals, so crystal formations was the first thing to pop knto my head lol

[@kurtrichter1732]

And that is why you need to polish the metal samples before you can see their structure under the microscope. Now it makes sense to me.

[@styxwessel5930]

I think you forgot to consider the way a river stone appears very dark until you pull it from the water and it dries off. The Buddha board might just be one material that simply has a roughed up surface that, like you said, fills those gaps to appear darker than it is when dry.

[@bl4cksp1d3r]

Typical, Steve Mould perceives the first three number of 2 × Pi as art xD

[@ca-ke9493]

Just say Tau

[@bl4cksp1d3r]

@@ca-ke9493 nah, I'm fine

[@analogicparadox]

I'd like to note that IOR and surface roughness are also the reasons that paintings/rocks/plastics have higher saturation and contrast in their colors when wet or covered with a glossy finish.

[@gehteuchnixan69]

Steve: _Pernod_ My ear: *Porno?*

[@alexanderthomas2660]

Porno usually only turns white at the end…

[@dixitkhanal8885]

at 2:56 does the parallel beam of light just pass parallelly through the bubble surface? won't it also bend?

[@kylesmorgabord5592]

You’re the new Vsauce. There I said it.

[@DavidLindes]

0:45 - the tau of the Buddha board. Nice. :)

[@andyman127]

"He does pronounce it JIF," nope. Can't watch that.

[@IndigoGollum]

Didn't the creator of the GIF say it's jif?

[@onemadscientist7305]

@@IndigoGollum Well he's factually wrong, since that's not how language works. You can't just single-handedly decide how a word is pronounced.

[@diynevala]

@@onemadscientist7305 Well, if they own the format, they can suggest it - but I agree with the hard G. GIF is a gift that keeps giving.

[@SOULarLioness]

@@onemadscientist7305 Giraffe.

[@orientalmoons]

Great explanation of why foams are white. It would be interesting to try to create several intermediate levels of liquid/air ratios before reaching the finished white foam to see the colour changing. This reminded me of a disagreement a few months ago between a baker who had a 'hack' for creating cake frosting with less food colouring for the same shade. To do this she made a whipped frosting which was pale and then blended it up which made it darker. A content creator that does debunking then came along as said "yes, but you now have less frosting, so you will need to use more frosting to cover the cakes and that frosting will need food colouring too". The original baker said no, the colour would now stay the same if it was re-whipped and regained the same volume (which is actually difficult to do). This to me sounded incorrect but I couldn't have actually explained why it was incorrect. Now I know that air in a foam creates scattering, if the colour is stronger there must be less scattering and therefore less air in it.

[@TusharGoyal1997]

Last time I was this early, votes were still being counted in Nevada! :P

[@Matty0311MMS]

And they will keep counting them until they get the last ballots on Tuesday, November 10th. 🙄

[@Matty0311MMS]

@Dr Deuteron As a german polling clerk, my commemt was just a jab against the slow counting going on. We have a lot more voting centers here, so the counting can be done quickly. Sorry, if you felt attacked by it. 😞