Why Are Soap Bubbles So Colorful?

Why are soap bubbles rainbow colored? Iridescence explained both by wave theory and QED (quantum electrodynamics).
Hi! I'm Jade. I'm an Aussie with a Bachelor's degree in Applied Physics. After three years and over 100 lab sessions, I realized I'm terrible at experiments. So now I make physics and maths videos on KZbin :) Check out my channel and subscribe if you like:
SUBSCRIBE / upandatom
Let's be friends :)
TWITTER: up...
Other Videos You Might Like!
Are Forcefields Possible? • Are Forcefields Possible?
Math, When Are You Going to Use It? • Why Math is Important
Would Physics Be the Same in a Mirror Universe? • Charge Parity Violatio...
Want to know more? Here's where I found info for this video:
Wave stuff
www.exploratori...
www.vias.org/ph...
soapbubble.dk/e...
Particle stuff
QED: The Strange Theory of Light and Matter - Richard Feynman
www.amazon.com...

[@taloweryus]

Thanks Jade! This was the best, clearest (no pun intended) explanation I've ever seen about the color of soap bubbles. Please keep up the good work!

[@luzellemoller6621]

Matpat: pun intended*

[@heidim.2462]

Your videos are so underrated! I've been binge watching them over quarantine and you deserve so many more likes. The content is super informative and I love all of your little drawings.

[@KrishnaMishra-fy7dg]

I feel these videos deserve way more views and appreciations. Thanks Jade.

[@bradleybobbs]

The wave interference depends also on angle of the bubble surface, which changes over its spherical shape, and also on viewing angle, which changes as the bubble moves. Hence, even if the thickness were constant, the interference, and hence the colors, would still change over the bubble and over time.

[@Mahesh_Shenoy]

I may be wrong, but I think we do know how this happens. And I think Richard Feynman is famous for this. His idea is that photons don't take any specific path from one point to another, but they take all the possible paths. But the probability for each path is not the same. So he came up with some infinite summation/path integral thingy (I have no idea). You can check out the video of his wonderful lectures on KZbin "Fits of reflection and transmission" (lectures on QED) Here is my way of thinking. Today we don't think of light as just particles or just as waves. And neither are they waves and particles (because, face it, that makes absolutely no sense what so ever). Photons (and every other subatomic particle) are so different than classical particles or waves, that it's impossible to conceptualise them using simple models of particles or waves. So it's no surprise that their behaviour is quite different than what we predict. In fact this behaviour in some way is not very different from the famous double slit experiment (the photon version) Anyways nice video :)

[@upandatom]

Hah you're probably right about light not really being particles or waves, but something else entirely that our puny brains can't understand. And I did a google search if we know how it happens, because the book I read it in was written by Richard Feynman so I thought it might be out of date. I couldn't find anything that suggested we know :S

[@Mahesh_Shenoy]

Up and Atom Search KZbin "Fits of reflection and transmission lectures on QED"

[@epicgametime1214]

or todo esta bien con todo

[@Lucky10279]

Up and Atom Wavicles.

[@inamdarshoeb3369]

I have read that book . QED is really a master peice

[@auroremalvezin5883]

I have been watching quite a lot of videos about quantum mechanics, and I think it is fair to say that yours is the 1st I really understand from beginning to end. Concrete examples are really helpful, so the soap bubbles and water waves are the perfect choices. Many thanks!

[@ProfessorSingSong]

Great video Jade! Very fun. Love the animations as well as the live bubble shots. Video suggestion: something related to physics and cats!

[@upandatom]

haha hmm that will be challenging... but fun!

[@frib75]

Didn't understand why the wavy nature of light can't explain the "glass thickness experiment". The reflected wave just comes in phase at certain widths, out of phase at others (and therefore "cancels itself"). Just because we are speaking of photons doesn't make it invalid, we just speak about the "particle wave function" instead of the classic "electromagnetic wave". Or does the glass interaction counts as an "observation" and break the quantum behavior of light particles ?

[@aaroncurtis8545]

You can't use waves to explain Light! That leads to catastrophes! Ultraviolet catastrophes.

[@Last_Resort991]

Light particles do not travel in waves. That would not explain photons interfering with themselves in the double slit experiment. It is a probability wave, not an actual real one as in a water wave.

[@arik9112]

thanks! I've been confused with the concept of 'thin-film interference'' for a while now and it clear some of the doubts.

[@carboxysome2630]

Can you talk about physical constants? I mean it's pretty weird they even exist,and why are they so...well,constant and universal across the universe? o.O

[@upandatom]

Oh that's an interesting topic. I've never really even thought about. They kind of just seem like the universe came up with a number and we're just like "Oh ok..." lol

[@carboxysome2630]

Yeah,and I wonder if we will ever be able to change those constants with our future technology somehow,like changing the values of fundamental forces in a couple of atoms or even a large object,then even perpetual motion would be possible,but this is pretty much the line at which my brain can't handle it anymore xD

[@upandatom]

I'm not sure about the value of forces, but I don't think a perpetual motion machine will ever be possible. It violates one of the most robust laws of physics (the second law of thermodynamics) and this law goes preeeeetty deep. But who knows, maybe the robots will figure it out when they take over the world :)

[@AirCicilia]

Just wondering: isn't the universe itself iń perpetual motion?

[@martinphipps2]

@@AirCicilia I was going to say no but actually dark energy is spontaneously created as the universe expands. In a PBS Space Time video they explained why dark energy could not be used to make a perpetual motion machine but I don't remember what they said.

[@BoxmatchaAbyss]

The colors show the time of how much they can survive in air Purple:5 secs to survive , when turning to orange:2 Seconds , Turns to gray because has absorved the soap inside the bubble and turns to water Gray:1 second , Has turned onto water bubble and loses gravity , then explodes

[@conjecturemm]

Very cool, the fact that there are two layers of soap which reflect the wavelengths! I love learning about color :)

[@stevesloan6775]

That was a cool video... added a few dots in the whole scheme of things.

[@scarlettestanley3391]

I absolutely LOVE this episode! I'm just about to go make some GARGANTUAN bubbles and I'm studying light behavior, so you've just helped me and my bubbles absorb more WAVELENGTHS to sync & sine! And I think the answer to all of those questions may just be that light is conscious and it loves to emote colour! It seems to have creative free will to reflect or absorb in collaborative wave expression...light beings making art?

[@Dunderpunch]

Great video! The sound went all over the place at the end, but I liked the track too.

[@drewilger2049]

I really like your work - I would like to see video on X-ray diffraction and crystal structure - Drew

[@scarlettestanley3391]

Thanks for this show by the way! It really sparked my thoughts?

[@cheako91155]

How r they measuring the thickness of a soap bubble? If light is used, that seems circular... They would be saying the light refracts because this refracting light tells us the change in thickness. I wonder if it's closer to how a sunset looks red, because it's geometrically provable that the atmosphere at that angle would be thicker.

[@shenjiebao2876]

study for thin-film interference and come here. Very illustrative video. Thank you! Love this video.

[@aravindmuthu95]

Hence proved: A full lunch + Science video in KZbin = ASMR

[@stevekeller7696]

You really are exceptionally good at this. I read Feynman's QED several times. Of course he's quite skilled at explaining such things as partial reflection, but you: no less so.

[@jayemeljay2117]

"How does the foton knows?!?!" Jajajaja amazing!! I've been telling Destin from Smarter Everyday to explain us this!! So I really enjoyed all your explanation!! Cheers from a new subscriber from Argentina 🇦🇷!!

[@Duraludon884]

What if the light particles are reflected off of the underside of the top layer of glass, after going through the top layer and reflecting off the bottom layer once? Couldn't some photons bounce between the two sheets of glass forever, or at least until they release all of their energy as heat?

[@devanshisoni6649]

Awesome video jade! Love your shirt by the way😀 luv u!

[@letsalllovelein]

I'd never taken interest in the process behind the color of bubbles before, but this video alone has me thoroughly intrigued now.

[@tasfa10]

I would've bet that at least part of the reason why soap bubbles are colorful would be because of different wavelengths reflecting in different angles. Why do different wavelengths refract at different angles but all reflect in the same angle??

[@Mrjarnould]

Great video! Have you considered making a video on Quantum Cryptography?

[@upandatom]

Yes I have that was actually the plan for my next video! Looks like it's your lucky day :)

[@buzbuz33-99]

Back when I was forced to wash dishes by hand, I amused myself by observing the soap bubbles. I noticed that, just before they popped, they became colorless. This video provides an answer to that childhood mystery while adding a new mystery.

[@anniespacethetic6908]

Uk what ? At first I came here with an intention of cramming all my physics chapters but now I smh see the beauty of physics

[@Edgard422]

This is something similar to what I read about the anti-reflex coating that optics put in some glasses. The thin coating had to be some multiple of the wavelength to successfully prevent more light been reflected. The additional light that passed was only a small percentage so I figured I didn't needed it.

[@CuriouslyHere]

I love this question, it's one of those little mysteries no one ever asks about... Thanks for the great content Jade!

[@upandatom]

Thanks Nick! I see you've uploaded some new videos. They're great! You got really good at editing in a really short amount of time lol :)

[@nootums]

Hey jade! In the glass experiment, how did the scientists ensure that light would behave as a particle?

[@aaroncurtis8545]

Sorry I'm not Jade: but my quick answer is *The Ultraviolet Catastrophe*

[@irrelevant_noob]

@Aditya Sharma i'm not Jade either, but i think they in fact _DIDN'T_ ... since the light destructively interfered so as to make reflected "photons" vanish for some thicknesses.

[@luzellemoller6621]

About the glass patern... I always thought when I was younger that everything is in well basicly a super position and it tries to hide that from you by when you observe it gets out of the super position

[@srikanthtupurani6316]

this is something which used to fascinate me when i was a child.

[@wrathofsocrus]

I just kept thinking of Sheldon from Big Bang Theory saying "It's a wave!" I guess with the slowdown of CPU advancement and having problems with electron tunneling and looking towards quantum computing that there are probably some good video ideas in there. Great video as always!

[@upandatom]

Thank you! Maybe something about quantum tunneling?

[@panagsaganpiano]

I started reading Stephen Hawking’s A Brief History on Time and the part about duality of light and the soap bubble example really got me confused. (Barely know anything about physics) But, I’m glad I was able to stumble upon this! Nice video!

[@BensLab]

What a cool video! I love how sometimes we just don't know the answers.

[@christianmarquez3143]

I'm sooo glad I got referred to your videos by physics girl channel. I like you videos a lot. Thank you so much. =]

[@evildracko]

Here are my two suggestions: Q&A. The Biggest Unsolved Mysteries in Physics

[@upandatom]

Oh I like that! I actually had a plan to do an "Unsolved Mysteries in Physics" video and thought it would be a good format for a collaboration. Stay tuned!

[@epicgametime1214]

ok

[@piyushkalyani3384]

Realy love your video i like some weird thing like incresing glass thickness video and electron interference those are part of your video which amaze me

[@mard5294]

This video is underrated!

[@TriptoPal]

A video on Computer Algorithms.

[@david21686]

Do a video on how a car works. Like, every little thing that happens between stepping on the gas pedal and feeling the car accelerate.

[@NoorquackerInd]

5:44 Finally, something that's not quantum mechanics? _Oh_

[@orangutan6982]

Why don't we see colours due to Thick film interference?

[@geneseenelson36]

Okay, sorry for the random question, but where did you get your shirt? I really want one!!

[@newtonshaji4654]

Its due to interference of light waves reflected from the surface of soap bubble.

[@AirCicilia]

I "believe" that wave pattern of double reflection can be explained by the wave properties of electromagnetic radiation.

[@Thirstyguerilla]

thank u for this QED lesson, it really makes that intro chapter much more comprehensive. ...university of KZbin lol

[@QuarkYifu]

I wonder what would happen if you did the experiment and varied the temperature of the glass.

[@siyaramkumar6337]

Hey I saw something strange At (5:21) , if you focus on the front end of the graph , as it moves, it appears as there are two front ends(two heads of that moving snake)... But that's not whats happening right... So why did I see that ?

[@cosmicwarriorx1]

Informative... Thanks.. 👍👍👍

[@akshaynadig1893]

Is this explanation given in the book QED by Richard Feynman

[@filhotesonline3905]

I LOVE it. Thank you

[@david21686]

Does the number of reflected photons depend on the wavelength of the light source compared to the thickness of the glass? I would think that the primary mechanism of action for that weird result would be destructive interference of the electromagnetic wave.

[@upandatom]

Good question. So this is what I think but it is by no means 100% correct. The number of reflected photons is not affected by the WAVELENGTH of the light source, it's affected by the INTENSITY of the light source. Here is my reasoning. The intensity controls how many photons are emitted per second. Obviously the more photons emitted the more photons reflected, because we are talking about percentages here. In the video I talked about how many photons were reflected every 100 photons that were emitted, and this cycled between 0 and 16. But these were percentages, so of every 1000 photons between 0 and 160 photons would be reflected. HOWEVER, this cycle will be different for different wavelengths. It will still always cycle between 0 and 16%, but it's relation to the thickness will change. For example, red light may complete one cycle from 0-10 nanometers of glass thickness, whereas blue light will complete a cycle between 0-7 nanometers (I just made these numbers up, but hopefully you get the point). So the cycles vary depending on the wavelength of light, but the number of reflected photons stays the same as long as the intensity stays the same. Does this answer your question?

[@DavidMaurand]

i've actually been coming to the conclusion that photons are actually a property of waves, not actually a particle.

[@bhavini8212]

What software did you use for editing?

[@JakeHarris0]

I would love to see the quantum eraser experiment supplemented with this thin film interaction compared to the double slit experiment. Anyone know if this has been done before?

[@petersvideofile]

Just curious do you have a link to the paper where they discuss the glass thickness vs reflected photon count? I'de like to take a look. If not did you read about it in a book? Perhaps the one linked in the description? QED: The Strange Theory of Light and Matter - Richard Feynman

[@petersvideofile]

Found the reference in the book QED: The Strange Theory of Light and Matter - Richard Feynman on page 20-34. Not sure which acamdemic paper he was referencing though, but it seems newton was one of the first to observe the effect based on the book...

[@BensLab]

Topic ideas: biophysics, chaos theory, Schröedinger's Cat.

[@evaldasc]

Sorry for nitpicking, but blue and and red make a beautiful shade of *purple* as violet has its own wavelength :) Great videos I am discovering here btw, really informative and interesting. kudos!

[@payalchauhan7656]

Woahhh good work

[@ReevansElectro]

Chaos theory with everything.

[@ElectricChaplain]

Saying that glass is 4% reflective is slightly misleading, because the fresnel equations show that the ratio of reflectance vs transmittance is a function of the angle of incidence (for non-magnetic media, which includes soap bubbles). In fact, when the angle of incidence is over the critical angle there is no transmittance and only reflection. So for what angle of incidence is glass 4% reflective?

[@explorerars4208]

Brilliant explanation

[@oMKBhogata]

can I excuse? can we called the bubbles are common example of grism grism that visible the rainbow

[@mrmotl1]

Seems obvious to me I find it hard to believe I'm the only one. It's obviously the thickness of the transparent medium needs to be of hole integers or multiples of the light wave to reflect the maximum amount. Therefore if you have a plane of glass that's the exact thickness of the wave it will reflect 16 whereas if you have a double thickness it'll have 16 if you have a triple it'll be 16, but anywhere between that it's going to have some amount less than 16. Because it's creating an interface between both sides connecting a standing wave between them. It's like an antenna of which each side needs to be half of the wavelength to eliminate destructive interference with itself and allowing each half to perturbate on a positive and negative divergence from each other, whereas material such as glass would need to be the sickness of a whole wave to contain the whole wave inside (it could be half, but my intuition says it would more likely be a whole being one piece instead of two like the antenna). Now every time it's less than a whole multiple of the wavelength is where you also would get the alternating color spectrum in the bubbles and that's due to the curved surface implying this different thickness ideally throughout and the difference manifests as the color wave associated with the ratio between full multiples. You can consider it like the waves in the sand of the desert, except with the underlying radiation instead being polarized in bands of inverting polarities.

[@iMshadab]

You do all these animations? 👌👌

[@upandatom]

yes I do :)

[@bhavini8212]

It's really good editing

[@jasonbone5121]

Not sure how to ask, but here goes... 100 particle goes through first layer and 4 reflected by first layer, and 4 reflected by 2nd layer. Of the 4 reflected by the 2nd layer, are any of them (4 out of 100) reflected by the first layer, back down to 2nd layer? And does that continue, with most making it back through the 2nd layer but some reflected back to the 1st layer, where most exit, but some are reflected back to the 2nd, and so on? Making a thin layer of particles traveling in between the 2 surfaces? Now my brain hurts. :)

[@TheScienceVerse]

What software do u use for the green screen effects ?

[@upandatom]

Adobe premiere pro. Why do you ask?

[@TheScienceVerse]

Up and Atom just curious

[@TercesKun]

its easy: the up and down that is cyclo repeating (as shown here as the mysterie) is the bouncing back and forth probability expressed as a stochastikal result shown as a wave function i did it 314 666 161 112 110 1312 1017 brick squad

[@TercesKun]

ps love you and your channel up and atom girl, we are so similar

[@VishalParmar-wc9rb]

Why is light so fast ? This is something that bugs me. I’m not a physist but I’m interested

[@upandatom]

The answer to that is actually really interesting :)

[@epicgametime1214]

bueno

[@DelfinaKS]

Now we want to know that - fast, fast!

[@shaun_rambaran]

Light is timeless. Why should it be surprising that it already "knows" what it will encounter later in its path? ie, If past, present, and future of a Light ray exist simultaneously for some infinitesimal instant, why should it be surprising that it already knows its 'future'? The behaviour only looks bizarre to big, bumbling creatures as we, who are so heavy that we're limited by Time.

[@loltv7469]

This universe is full of weird

[@bcddd214]

Just keep making videos cutie. I could listen to you all night long.

[@73eagleeyes]

Thanks this was awesome

[@upandatom]

:)

[@nopenope3289]

ok but where is your shirt from?!

[@sh0_rk]

DAMNNNN as a 12th grader this cleared my concepts so well, I was awestruck the whole time!

[@Aardvark892]

Of course it's pretty. Knew that when I saw you!

[@richardcottone6620]

I was just thinking about this, because I doing a painting with bubbles in it

[@openheart6113]

This is not exactly right bubbles made from some dish washing liquids does not make coloured bubbles so thickness is not the answer to making the colour. It's just theory not fact.

[@sanjanaakshra3623]

What is the equation on ur tee shirt🤪I am more curious about the equation on ur tee rather than soap bubble colour

[@martinphipps2]

"Who knew quantum physics could be so pretty?" I have been saying this ever since finding this channel.

[@Артем-м1ю5с]

I saw the effect on the bubble too but i didnt saw on bubble i did saw on puddle in winter

[@DonaldSleightholme]

can a laser pop soap bubbles 🧼🤔🙂

[@QuarkYifu]

Or used melting glass?

[@amandaclaireon4065]

scientist dont know why the glass reflects 16 or none of the photon particles but i believe it to be chaos magic , i know what your thinking i might sound crazy or unenlighten but the more i see reality and learn about it the more magical it becomes to me , hell after all there is a quark / subatomic particle named charm quark, hmmm i wonder why , magic is all around us if you know what your looking at, most wont take this comment seriously however

[@Amethyst_Friend]

Very funny T-shirt! Maths and cats.

[@RevdUp.Art.Fotografer]

Love the video. This broke it down to chewable pieces… perhaps only somewhat digestible for me.😵‍💫😄 I do have questions for you, if you’d be so kind. I’ll pose these through my, occasionally, insurmountable ADHD filters. Baby steps…not trying to be a pain. Ok… You said that particles do not interfere with each other. The example you then used were billiard balls… What I saw were billiard balls colliding with each other. *Is that what you saw? I believe this caused them to go in directions different than their original trajectory. *Is that what you saw? Believe? *Is that not interfering? (Purposely sidestepping the word interference.) OR…(Bigger Picture) what only appeared to be random contact was, in fact, intentional thereby sending the balls further on their actual trajectory… therefore not interfering at all. (I don’t believe in coincidence… Universal bank shot, side pocket.) Again I’m not trying to be a pain…much.

[@luzellemoller6621]

WHAT profile picture was magnet just 2 minutes ago now its your fave

[@kartykeya7741]

Why sea is blue?

[@feynstein1004]

Woo hoo. PBS Space Time and Up and Atom on the same day. Well, for me anyway. :)

[@upandatom]

:)

[@janicenelson4235]

What about 3 surfaces

[@ashutoshraj1367]

Can you please explain why I got in love with you at your first sight... Is physics is involved here too.. 😅😅😍😘

[@PhysicsEducationchannel]

Before watching and after watching no change Plz conclude strongly & pin pointed ma'am U try to explain but we don't reached

[@gauravjaat7539]

Your explanation is as pretty as you are..

[@evildracko]

Wait up and atom, asking and answering the question right away?

[@upandatom]

lol huh?

[@Yathuprem]

IS that Schrodinger cat on your shirt ??

[@upandatom]

haha sure why not :)

[@hannahpumpkins4359]

Neutron stars- they are so strange!