you know it is funny but usually most things are like this. We rarely think why 2+2=4, but it was answered to me only after spending 3 years on learning calculus. It's simple yet takes a lot of knowledge to grasp the concepts that are just a second nature to us
I’m an optometrist and this is probably the best animation/display on optics I’ve ever seen. I wish they taught in schools like this. Simply incredible work 👏
@@boogeiymanWhy? Produce video, translate them and deliver to billions. Than an experiment for kids to showcase the simplest part - is literally piece of glass during a sunny day I'm sure Derek won't mind his videos shown in classrooms, anywhere
It is only recently that such capabilities exist, as employed by Derek & Grant (of 3Blue1Brown, that Derek referred to) so wonderfully. And for visual learners it is really ecstatic to see Physics unfold in front of our eyes. What a great time to be alive!!!
Your videos are far better than any physics teacher in the world. In the chaos of martial law in South Korea, the rainbow you created have moved me for a moment.
I’d never been satisfied with the simple “sunlight is scattered by water droplets” explanation as it felt like it left too many questions; this video has answered every one of those questions, succinctly and comprehensively. Incredibly well done!
Your explanation was so good that at 18:45 when you said 'why is it brighter under a rainbow than above?', I already knew the answer, despite not even being aware of such a phenomenon 20 minutes ago. That's the hallmark of a great explanation.
I work in optics and have two degrees in the field. I’ve heard explanations of the rainbow multiple times, whether in class or at conferences, and can say that this one is certainly one of the best: both because it deals with the maths both (relatively) comprehensively and intuitively, and (more importantly) it really speaks to the curious, awe stricken child in all of us very effectively. He even snuck in a (very) simplified explanation of light-matter interaction and refractive index just to make sense of the differing emergent angles for different wavelengths. Bravo!
@@asunhug Walter lewin. There, you have now been given "the rabbit hole" let me know when you hit the , i don't know any of this and have to go back to where your schooling stoped
I used to teach radio wave propagation and antenna theory. Refraction has always been the difficult one to nail down, until that 3blue1brown video referenced here.
The rate of Veritasium and Mentour Pilot Video drops these past couple of weeks and yet with top quality delivery literally is out of this world. Edit: Wow.. 9k likes unbelievable
I'm just happy because 3B1B got the credit. They have narrower audience, but they tackle the problem of the next level of complexity and end up explaining it just as simply.
That's concerning. If Mentour Pilot runs out of material, he'll have to start shooting down planes, and that's just not the same. "We parked our anti-air battery right in the flight path of the plane. Remember this, as it will be important later."
I am an optical engineer and at the end of one of our optics courses the prof gave us a 90 minute lecture on the topic of rainbows. It was incredible and convinced me to do something with light in my professional life. Your visual explanations gave birth to that what the prof taught us 15ish years ago. Thank you!
"Your visual explanations gave birth to that what the prof taught us 15ish years ago." A video from yesterday gave birth to something that happened 15 years ago ?
Something I've been wondering about is can't the frequency of loggt also change ofnthe wavelengths changes..Inget that it's the same number of wave packets coming through since its a continuous light beam butnthe complex interactions innthe material could in principle change the frequency also..as an optical engineer can you confirm this? Has it been studied?
4:18 He said all other videos about the rainbow are oversimplifications, so to be true to his word, he asked 3B1B for permission to use the most detailed explanation for electromagnetic waves and refraction that I know of as his source. Absolute legends, both of you.👍
@@josenobi3022 it's more like derek is using 3b1b's material to aid himself a proper collaboration would be that they both work on the same material at the same time
If I'm being honest, I still don't understand why shortening the wavelength of light would slow it down, he just mentioned that without giving any actual explanation. Why would light become slower when it's wavelength is shortened inside a medium ?
Thank you!!!! From the bottom of my heart! You have made my world even more beautiful and full of real magic. I'm a 36 year old man, and yet watching this I felt like a kid again (akin to your son) when I first asked my father how rainbows work. I'm a cinematographer, I took classes in physics at university, and have thirsted after an understanding of light above all physical phenomenon my entire life. I once ambushed Michio Kaku on a subway train desperately asking for an explanation of what light is, though he misheard me and thought I was asking him "What is life?" Without missing a beat, he started telling me what life is. Upon realizing he'd misheard me I interrupted him to say, "I'm sorry, I didn't ask 'What is Life', but 'What is light?'" He quickly replied, "oh that's easy, it's photons. This is my stop,"' and got off the train. To this day, i still don't know what light is, and until 20 minutes ago I still didn't understand how rainbows work. But now I do!!! YAY!!! Beautiful work explaining this in such a practical, real world manner, it helps to make physics feel more accessible, relatable, and real than when we have to rely more on the math and modeling to explain these sorts of things.
I'm a student at Stanford in an optics class; we have our final exam in a few days and it covers literally everything in this video: reflection, refraction, dispersion, Snell's Law, Brewster's Angle, diffraction patterns, constructive/destructive interference, etc. This video could not have had more perfect timing!
You will get zero mark if you look into science alert for current research in Physics. Please do not apply the new knowledge in your study after reading. I don't want any student fails in examination because of me.
almost brought tears to my eyes when you concluded with “and that, my son…” i think it’s beautiful that what fuelled you to make this video for the whole world to see is your quest to thoroughly answer question from your own child. thank you
My son asked me the same question when he was 5, as an engineer I could answer him but waited until he got a lot older to give him a more detailed explanation. When he said, "and that, my son" I teared up because it brought back that cherished memory. I love his channel.
I was a huge Physics nerd as a kid, especially things concerning light and optics. Watched the whole video with my undivided attention and reaffirmed to myself that I still love physics after all these years. Thanks for rekindling my inner child!❤
"Yoooo... what the heck is this tiny rainbow?" 2 years later "I have discovered a way to detect and *observe* particles that were previously only theorized to exist." Madlad.
And God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14
@pinkace yes because before the flood (that never happened) light and physics didn't work that way. Has nothing to do with the fairly common ancient southwest Asia myth trope of hanging up a bow after a battle. Nope this one snippet amid a story of a scientific impossibility is science. Lunacy.
A child's boundless curiosity can help us shake off the paradigms and patterns of thinking we get trapped in as adults. Sometimes we get frustrated with the endless questions but taking the time to satisfy their curiosity is rewarding and often leads to a new understanding about a topic yourself. Well done Derek (and Derek's son).
A lot of children have a natural scientific mindset. It is baked into humans. We have to work hard to nurture it instead of forcing them to repress their curiosity and questions.
awesome amazing, thanks so much lot and lots in fact, your stuff is so valuable and much of it is extrodinary nearly as nearly perfect per fact and facts 😇❣❣🙏🙏👍
Superb video, Derek! I also researched this topic about a month ago: Your explanations, experiments and simulations are just excellent, especially for Glories and supernumeraries. If you ever revisit this topic, here are some comments: * the Sun is not a point source, so the angular size of ~half a degree is spreading/averaging everything out over such an angle, making 1st and 2nd order supernumeraries the most likely to be visible, not much else; * fogbows and halos were left out; *2nd order color inversion didn't get its attention, and 3rd and 4th order rainbows i tried to simulate, but always failed, they have immense forward scattering levels behind and probably never visible; * refractive index depends on temperature - the angle is slightly different for rain of different temperature; * red color is purest in the rainbow, everything else is more like a mix and the blue and violet part is especially unpure; * there is another place in the solar system where rainbows might appear - methane rain on Titan - totally different angles and 2nd order nonexistent probably; *color sensitivity of the eye could also be mentioned plus NIR and UV parts; *reflection rainbow from mirror-flat body of water could also be interesting to show. All in all - by far the best video of rainbow physics that i ever saw!!!
I was also expecting Halo's mentioned. And also now that I mentioned that, maybe also light pillars. So maybe not revisit but own continuation video about these when the water droplets are frozen ice crystals, pretty please 😂
@@veritasiumThe negative is passion this is the color red ♥️. The blue 💙 is honor and justice and is the positive. When honor and Justice come together with passion and you have a passionate pursuit of honor and justice then you have a worthy system which is the future or purple 💜. In between the 💛 and 💚 is the now. Direct passion and let it Direct. All is one and comes from the singularity AKA The Big bang AKA God so these are all aspects of the one including the negative... It is a part of the singularity which ultimately is love... Therefore ❤ is love... All is love... 🎉
Using advanced CGI to illustrate light reflection is awesome, using a red tether to illustrate constructive/destructive interference was out of this world!
This almost made me cry. Having a parent that loves learning as much as they love teaching has to be one of the greatest gifts on earth. Gaining the knack for inquiry makes living so beautiful.
I agree, but he did several videos with a BetterHelp sponsorship which is an online therapy company that sells their customers' data and has bad therapists
I read an article in a "technical" magazine a couple of days ago, and they explained rainbows as "light reflecting at 42 degrees" with a sketch, and left it at that. I remember thinking that that the explanation was quite incomplete, especially with respect to the radius of the bow. It is remarkable that a free youtube channel gives such a complete and satisfactory explanation of the phenomenon, compared to a publication which you are expected to pay a significant amount of money. Thank you for answering the questions I had for decades!
Print media is slowly becoming extinct. While digital media has its benefits, one downside is the ability for "Favored" content to be amplified and "Disfavored" content to be buried.
You can also find on TH-cam a fascinating *MIT* lesson by *Walter Lewin* that explains rainbows very clearly. This is knowledge that you can find in textbooks already. Scientific articles do not need to explain it again. They are typically written to give some additional information. Unless you are talking about scientific divulgation (a.k.a. popular science), which nobody does better than Veritasium and a few others. No doubt about that.
And God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14 And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald. Revelation 4:3
Thank you so much for this amazing video! My boyfriend and I had an amazing evening because of it! As a teacher, I can truly say that you are an example for me, both in your enthusiasm as in your clear way of explaining things! Thank you!
This may be my favorite video you've made. Not only was it a fascinating topic explained superbly with interesting and unique demos, but the fact you made it all for your son shows it was a labor of love. I hope he looks back on this, and everything else you've done for him, very fondly
FANTASTIC VIDEO!! I am a retired Physics teacher and used to teach Wave Phenomenon using strings, water waves and lights waves. I used to have to give an explanation of how rainbows form and I was never quite satisfied with my inadequet explanation. This video explains so much and is so well done that it could and should be used in high school science classes. Another excellent video among your many other excellent videos!
Thank you for your service as a teacher. Physics was my most fun and imaginative course in HS. My teachers of physics I and II will remain my favorite and I'm sure you gave that experience to thousands of inquisitive minds.
Crystal balls used for science and not seances !! Cool. Too bad in the next few years, teachers will have to explain the controversy about rainbows really being a covenant with gawd, promising not to drown the planet with the descendants of a boat waiting millennia until geezuz could die and make gawd forgive everyone. We need the babble with science doncha know!!! It's that or Veritasium is cut off for being a heretic.
Also a retired physics teacher. I left at the beginning of the smartphone and high speed internet era. The tools that are available now are amazing, and AI should cause another leap, love seeing it develop.
And God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14 And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald. Revelation 4:3
BEST VIDEO EVER! Did all the computations 25years ago by hand... brings back all those wonderful memories. 42 is my favorite number ever since. Thank you!
@@EricStephaniI think it was due to a Richard Feynman reference comparing the ratio between magnitude of the electromagnetic force and gravity, which is the same a as the ratio of the diameter of the Universe and a proton. Which is 1 X 10^42. Or so Feynman claimed.
When I was in high school, my mother, my sister and I went to Fairbanks, Alaska, and we flew up to Point Barrow. I saw a full circle double rainbow from the plane, with the shadow of the plane in the middle. Thank you for this beautiful video, bringing back a great memory from over fifty years ago!
I may be wrong, but I don’t think it was a glory. In the video, the shadow in the center of the glory impinged on the colorful rings. This was much bigger, probably about 40 degrees and nowhere near the plane’s shadow.
@bryancurry1898 I think that would purely be a matter of distance/elevation from the moisture creating the rainbow and that's the surface of the shadow. I've been on a plane that's descended through its own glory on the clouds below, and the shadow at the center of the glory grew as we descended until it swallowed up the glory shortly before we entered the cloud.
@@bryancurry1898 I used to fly Cessnas and the like, and can confirm that you can indeed see a "proper" rainbow that is a full circle. All you need is enough rain below you to complete the circle. I loved bright, showery days, and would go looking for rainbow circles.
"A rainbow is a circle, and the higher you go, the more of it you can see." I read that years ago, and now I finally understand why: it's because it's produced in circular water droplets.
Thanks for using 3blue1brown animations for this... his videos on this subject are by far the best and most satisfying explanation on this subject out there ❤
The 3blue1brown animations are extremely good! Also I know its off topic Jesus loves you so he died for you because he wants to know you❤️Repent, God bless
@@Lecommandant_camroun Seriously ? Why not say geologists, astrophysicists and evolutionary biologists all lie about the age of the earth while at it ??? BeLIEvers know rainbows are really a covenant from Yahw-monster, who killed everyone except drunken Noah. Trollers gonna troll, which is a sin. Can't wait till you get Dear Leader president to get Veritasium put in jail for heresy !!!
God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14
Seeing the glass "raindrop" reflect and showcase how the end points of each color scatter on the reflection make the rainbow was actually spectacular, hah! Never gave it much thought but it's neat to see the science of it, and then actually see it in action! Amazing.
And God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14 And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald. Revelation 4:3
6:00 You raised an important point: when the material (glass in this case) has absorbed a sufficient number of photons, there can indeed be a shift in the interaction dynamics, affecting the propagation of the light. Let's explain this in more detail. Energy absorption and saturation of electrons 1. Absorption and saturation: The electrons in the glass have a limited capacity to absorb energy. When the light is strong enough or exceeds a certain intensity, the electrons in the atoms or molecules of the glass are excited to higher energy levels. Once the electrons are fully in these excited states and no further transitions are possible, the material reaches its saturation limit. In this state, the electrons are "saturated" and cannot absorb any more photons because they are already in the highest energetic state they can reach. 2. Changed interactions at high intensity: If more photons hit the material than the electrons can absorb, the light may no longer be absorbed to the same extent or the absorption may decrease sharply. The remaining photons can then continue to pass through the material without being significantly scattered or absorbed. This explains why, under certain circumstances, very intense light (e.g. at high light intensity or certain wavelengths) can pass through the material without being further absorbed. The interactions are then limited to scattering processes (such as Rayleigh scattering or Mie scattering), which only minimally deflect the light but do not absorb it. Absorption and transparency in glass Glass is a transparent material because it absorbs very weakly in a certain wavelength range of light (for example, visible light). The electrons in the glass absorb photons and give off energy, but this process results in a small amount of absorption of the light, and most of the light can pass through the material. At saturation: When the photons hit the electrons with enough energy and they are fully excited, the glass's ability to absorb light is exhausted. However, this does not mean that the light simply stops. Rather, the light continues to flow through, but it is no longer significantly absorbed because the electrons can no longer absorb energy. What happens when the glass is "saturated"? Delay and light transmission: For materials such as glass, which have predominantly transparent properties, the light will continue to travel through the material even when the electrons are saturated in capacity. Only minimal interactions occur, such as scattering or reflection on the surfaces of the glass. However, the majority of the light will pass through unless there are strong absorption processes or a critical absorption point is reached. Absorption saturation and no significant energy transfer: In very high intensity ranges, when the glass absorbs a high amount of photons and the electrons are "saturated", the extra energy of the light is released in the form of heat and scattering, but is no longer converted into electron vibrations by direct absorption. In summary: Once the glass has absorbed a high number of photons and the electrons have reached their maximum capacity, the light is essentially no longer absorbed, but continues to pass through the material. In this state, where the electrons are saturated, only minimal interactions, such as scattering or reflection, occur and the light is not further converted into energy. It then flows through the material almost unhindered, as long as no other effects such as extreme intensity or non-linearities (e.g. in very intense lasers) occur.
Hi Derek. I have watched your videos for years. However for this one there is a bit of sponsorship. I wish you and your family a merry Christmas. And thanks for your content.
Everyone should have at least one teacher in their lifetime as good as Derek Müller. Someone who goes great lengths to explain much better, something that has been aproximately explained for a long time. I love his genuine interest for his audience to learn more. I'm glad he is a father now and his children will push the envelope of this channel even further with their questions. Once again, fantastically well done Veritasium!
This is so great! Allow me as an optics guy... Derek, around 10:32 you are referring obliquely to the Lorentz model to explain the Kramers-Kronig relation (glass absorbs UV, therefore all wavelengths below see different index of refraction), and use 3Blue1Brown's model. You attribute the phase kick to _amplitude_ of the driven wave. I'm not sure that does the reality justice... The driven atom radiates at the frequency its being driven (great) but it radiates at a different phase to the drive -- and that relative phase changes continuously with drive frequency, with colour. So the added wave from the _driven_ atoms is actually at different _phase-shifts_ , for different drive frequencies, and this is important when you try to get the overall phase shift and net phase speed: which is the index of refraction. It's important too, because it's the reason the light gets attenuated/absorbed when the driving light is right on resonance: the driven atom contributes an emitted field exactly 180 degrees out of phase with the driving light, and in the forward direction those progressive additions to the net field progressively kill the amplitude (Beer's law). It's the 'constructive' reason the the light field dies off, in absorption. How to see? Hold a meter stick hanging like a pendulum and move your hand left and right: very slowly, the bottom of the stick moves in phase with your hand; very quickly and the bottom of the stick moves at 180 degree phase displacement. On resonance, it's at 90-degree phase-displacement, and this means the _velocity_ (derivative) is _in phase_ , and this is what gives largest power (F x v) transfer on resonance. Surely there's a way to do a bit better than just laying the whole thing off on amplitude of response -- this phase shift of the field, on and off resonance, is at the heart of the actual relationship. And in physics, _meaning_ comes from _relationship_ ...
Actually I think it's a combination of the two. The amplitude and the phase shift of the driven wave both increase with larger frequency, but even if only one of them (i.e. only the amplitude) increased, the overall phase shift would still increase. I.e. say the input wave is a*cos(x) and the driven wave is b*cos(x-t), then the phase shift of the sum of those two waves is atan(b*sin(t)/(a+b*cos(t))), which even for fixed (nonzero, as it is in the video) t is an increasing function of b. So it would be more accurate to say the overall phase shift increases because both the amplitude and phase shift of the driven wave increase, but I feel like adding a line like "the overall phase shift also increases because the driven phase shift increases" would just distract from the main point here
@DocRobCan please tell me you have access to those insane laser labs and can get mark in there to show us!!! If not..... GET THIS MAN A LABORATORY AND EQUIPMENT NOW!
@@marsovac The entire point of the video is to point out that other explanations are oversimplifications. Accordingly, it's not afforded any oversimplifications, especially when they're just wrong for no apparent reason.
@@milksushi6640 Yes. I’m saying don’t just say it’s about resonant amplitude, it doesn’t do the reality justice, and cannot capture on-resonance behaviour at all.
A month ago, as a teacher to be, I had to prepare a "quick" explenation on rainbows for a seminar. Thus I know, how DEEEEEEEP the rabbit hole goes. Very nice video :)
And God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14
Artist here 🙋♀️! This video was an absolute treat. Beyond just being incredibly informative in an understandable but not oversimplified, it’s beautiful. Took multiple screenshots, and the little speech at the end is so inspiring. I walked away with more understanding but also soooo much inspiration :)
This is THE best educational video on optics I have ever seen, It should be mandatory in schools physics(optics) lessons worldwide and be used as a standard for education experts on "how to do a proper video"
As a spectroscopist, I see optics as the art of revealing the invisible. Each photon of light carries secrets about the material it interacts with-its composition, structure, and even its dynamics. By dissecting light into its spectral components, we can essentially decode a molecular fingerprint. The beauty of spectroscopy is its precision: light doesn’t lie. A subtle dip in an absorption spectrum, a shift in fluorescence, or a sharp peak in Raman scattering tells a story about the material’s structure, environment, or energy states. It’s like speaking a universal language of photons and vibrations, one where every wavelength and intensity is a clue. Optics isn’t just about bending light-it’s about bending our understanding of the universe, one spectrum at a time.
But, its wrong... and here's why. 1st: the very 1st photo! (no rain) #2. we have weather cams everywhere now, and literally watch storms roll thru a "rainbow" with sun traveling, and "rainbow" remaining fixed in place. #3. sideways "rainbows" .... we see them all the time, water falls... stand with a garden hose, side ways "rainbows" all around you! #4. the "rainbows" of our eyes! that we all see in a steamed glass mirror.
So therefor! rain/water.... relative to the "rainbow" only in that it enables us to see what is always there. magnetism the "magnetic lines" of the earth and.... ourselves. Its simple as that.
@@TwiddleBee Good 'overall' critical ideas... (Science get better even if criticized). You seem like the kind of guy that doesn't understand Science TBH and spewing half-baked nonsense (all that is easy to replicate in a room with a light source; it is easy science at that point). If you could prove a static side rainbow exist, i think you are in for the nobel prize (maybe)... But it is so "easy to prove" that you are underestimating 200 years of science at least. (sometimes they are a little blind/partial, but not to that extent lol) => So get a video where you walk around a rainbow and it is fixed in place (like a fixed 3D object) and you have a real argument here. Beat science with science, or you are the clown of the circus. For the 1°) no rain is necessary; just an invisible mist of tiny droplets in the far distance. 2°) I would like to see that video; a time-lapse of a rainbow when the sun is moving could be interesting to analyze. (a simple explanation here is FX.. someone just stamp a rainbow on the video and it is fake... that does exist on internet.) In theory, the rainbow should move with the angle of the sun with a fixed camera.... unless the rainbow is a reflect of the layer of glass on the camera; it happens sometimes. (but it is no "sun-rainbow") 3°) never seen a side rainbow... only partial rainbows and linear diffraction on walls... and when the droplets are not rounds (with a hose the droplets can't be spherical... too random and chaotic)... the caustics would be different; so new phenomenons could occur like "anomalous deformed rainbows" and whatnot... 4°) don't know what your are talking about. is it about drugs early in the morning? ;-) (if you are hallucinating, you could see talking rainbows too... just saying.) Here the sun can't be present, and not at a 40°angle etc... it is diffraction from tiny film of water over glass, but that doesn't make any sort of rainbow. (which is a volumetric phenomenon). If it is your trolling impression of a "flat-rainbow" conservationist", it is cleverly done... but i'm not sure about people nowadays... their brain power is on the decline, and very fast...
And God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14 And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald. Revelation 4:3
This may well be the best description of rainbows I’ve seen on youtube. But I’m going to take the statement at 0:23 seriously: “Because I promise you, almost every explanation out there, is an oversimplification.” And yes, this video makes some as well. Including one big one. I’m also interested in a few he missed, and some I like as well. “Because the full explanation is so much more satisfying than anything you've seen before.” 1:46 “Rays of light from the sun reach a raindrop essentially parallel to each other because the sun is so far away.” Oversimplification. The sun is also so very large, that these rays spread about 0.5°. Which means that each caustic is about 0.5° wide. This may seem small, but since the entire colored portion of the rainbow is only about 2° wide, each color covers about a fourth of it. And mixes with other colors. 1:57 “Some [light] is transmitted into the sphere.” Oh, thank you for using the word “transmitted.” Far too many people use “refracted” in its place. They go together, but don’t mean the same thing. 7:49 “So what we're seeing there is a maximum angle this reflected ray reaches before it turns around and goes back the other way. … And this is really important.” Bingo. 8:50 “Now you might ask, why does this reflected ray reach a maximum angle and then turn around? ... As I move the laser up the sphere, although the ray refracts down, the point on the back of the sphere where it reflects continues to move up until you get to this special point … The refracted ray stops hitting the back higher and starts hitting it lower. That is why the reflection turns around.” That is not why. It's related. I had never considered the height before. It does seem to be true that it turns around at the same point. But the two effects are results caused by the same reason. And I can state this firmly, because (A) the formula for turn-around angle does not refer to the height in any way and (B) the same turn-around occurs at different heights for the higher-order rainbows. I like shorter names for my parameters. Call the original angle of incidence A. Then B is the associated angle of refraction found by Snell’s Law. As it enters the drop, the ray deflects through angle A-B. Since the surface normals of a sphere are radii of the sphere, these three lines form an isosceles triangle and the angle of incidence at the back surface is also B. The reflected light deflects 180°-2B. Finally, as it exits, the light deflects another A-B. Thus, the total deflection is 180°+2A-4B. But since we look in the opposite direction, I use D (your alpha) equal to 4B-2A. It is the rates of change of A and B that cause the turn-around. It happens when B is decreasing at half the rate of A’s increase. You can look up the formula for where this happens in an on-line textbook called The Calculus of Rainbows, by Jesse Amundsen. 12:07 “Well, more light is going to hit the sphere at higher impact parameters because the further out you go, the more area there is.” This is not quite right. There will be more light in the entire ring of reflected light created by each impact parameter value d, but it will be spread out over the entire ring created at that impact parameter. If this ring has radius f, the adjustment should be based on d/f, not d. BUT, it has nothing to do with why we have bright rings, as you seem to imply. The actual brightness at each radius f depends on many other things, like the coefficients of transmission and reflection. The only important one is that the brightness is inversely proportional to the derivative of the function D(A) that I derived above. You know, the function that has a maximum at the turn-around angle, so the derivative is zero? (Pause while that sinks in.) The brightness function goes to infinity at d=d_turn_around. It's infinite over an infinitesimally small range, so the brightness we see is finite. But much greater than at any other angle. 12:46 “It's not enough to say that a raindrop spreads white light into its component colors, because all of the light that hits closer to the middle is spread too. But since the reflections all overlap as they come out, the colors mix and produce white again.” It means more than just that. The red band is the only band that is isolated from other colors. Each other band contains enough of the colors toward the red end of the spectrum, that they become less vivid as you move inward. The violet band does not end, so much as fade into the white disk you describe. This means that the colors of the rainbow are not quite the same as the colors of the spectrum that Newton identified. 16:56 “This means no two people can ever see the exact same rainbow.” I hate this expression. It implies that the rainbow exists as an object, and so a different object for different people. Yet those same people will say that they see the same reflection when looking in a mirror, which is essentially the same phenomenon. 17:04 “A rainbow is an optical illusion …” This one, too. An optical illusion is when something looks like something it is not. Is it a duck, or a rabbit? Here, you see an optical effect exactly for what it is. There just isn't an object. 17:11 “In most parts of the world, you can only see a rainbow in the early morning or late afternoon.” Exaggeration. Today, Dec 5, you can see a rainbow at any time of day, anywhere north of about New Orleans. 19:13 “But if you look up even further, sometimes you see a second fainter rainbow with its colors inverted.” The colors aren’t really inverted, they are seen upside down. You provide the reason in your diagrams, but you don’t explain it. The “white disk” for the secondary rainbow is centered on the sun (180° in your plots), not your shadow. And it is about 130° wide, not 50°. This means it wraps around the top of the sky, and so is seen about 8° to 10° above the primary, upside down. It’s harder to tell, but the sky _above_ the secondary at 19:17 is also brighter than Alexander’s Dark Band. 20:44 “This is known as a supernumerary rainbow.” Fun story: Once, about three minutes after posting an explanation of supernumeraries, my son looked out the window and said “Hey, there’s a rainbow. But it is really wide!” Sure enough, it was the only example I have ever seen. It didn’t last long enough to get a picture. 20:53 “But this only occurs when the raindrops are all really small.” Small isn’t the important detail, but it helps. They all have to be the same size. It actually happens for each raindrop, but with different sizes they obliterate each other. One last point. A common error when explaining rainbows, is to claim that it is a result of Total Internal Reflection. As your polarization example points out, the reflections occur near Brewster’s Angle, not the Critical Angle. It’s actually impossible for this light to reach the Critical Angle.
Wow! 👏. That was an amazing detailed comment/critic. Youre book about the caluclus of rainbows is added in my "have to read" booklist. I only got a grasp on the derivitive part but i still got the general idea. Right on man! Have a nice day!
Thanks! Some very interesting elaboration here. Regarding brightness approaching infinity but appearing finite - I suspect that's another substantial simplification? I imagine it has to do with a combination of droplets not actually being perfect spheres (and thus the formula being close but not quite true - I'm sure a study of this going into statistical analysis of droplet shapes could encompass an entire series of videos), and probably discretization effects caused by our eyes "measuring" brightness via rods and cones (I.e. Brightness, being power density, reaches infinity at a given angle but our eyes actually measure total power over slices of angles) Also, it may help to remove some of the word pedantry nitpicking in your comment as I feel it makes it harder to find and appreciate the more educational points :)
@@emissarygw2264 "Regarding brightness approaching infinity but appearing finite - I suspect that's another substantial simplification?" You could call it that, but (puts tongue in cheek) that's a simplification. At 12:10, Derek created equal-area rings in the sun's incoming beam, and translated those rings to dots in the graph of the outgoing scattering angle at 12:25. The further from the sunbeam's center you go, the narrower these rings become. He implied, but didn't come out and say, that this is why the red dots "bunch up" near d=7R/8 and α=42°. He probably didn't mention that because it is wrong - they would "bunch up" even more beyond d=7R/8. The non-simplified reason is that for any range Δd - that is, the width of the incoming rings - that includes the turn-around point, the ratio Δα/Δd gets bigger and bigger as Δd gets smaller. This ratio Δα/Δd is what makes Derek's dots bunch up as he shows. Not the area calculation (which he did incorrectly). The could-be-a-simplification is that the ratio would go to infinity if Δd could reach zero. Δα would also go to zero, but more slowly. That's what a derivative is. The problem is that our eyes can't see a beam of rainbow light where Δα goes to zero. We need it to have the effective width of a "pixel" in our eyes. So it is just very, very bright in that one pixel.
I'm not sure I follow - it seem like he is having each dot represent "1 unit power" (I.e. Measured in watts) being input at position d. That part seems relatively straightforward, even if it's one of those imprecise quantizations we use when trying to describe things visually. Then "ray tracing" where each unit ends up, the alpha value, and plotting that on a linear scale. Which seems like a reasonable way to visually represent power density (brightness) at any given value of alpha, although technically it'd be divided by the diameter at any given alpha since the power is spread over a ring - but we are quite good at picking out fluctuations in gradients, so I don't think plotting on a linear scale is overly misleading.
I need to comment because a thumbs up isn’t enough. This is something that has been itching my curiosity for years, and anytime I looked for info, found nothing. This was exactly what I needed! Thank you!!
As a teacher of an Art course in "Light & Optics" . . . this is simply phenomenal pedagogy. Brilliantly and clearly explained, excellent use of demos and animations. Spectacular.
This is the best video I’ve seen on the topic: we’ve got the speed of light, the essence of light, caustics, Snell’s law, reflection, refraction, and “Glories” all wrapped into the glory of an everyday rainbow. During the early years of the Exploratorium, its logo was a diagram of the reflection and refraction of a beam of light hitting a rain drop, as complex as the one you present. It was replaced by optical illusion, something much, much more easily grasped and experienced on paper. But I always loved the early rain drop logo, and appreciate its initial selection. And now I understand even more. Thank you!
This must be one of the best veritasium videos I've seen in years. That moment with the afternoon sun coming through the window onto the sphere was just beautiful, because it MADE SENSE!
You can tell the difference between videos that Derek gives the "Okay" for his team to produce, and the videos that Derek wants to produce. I like the increased output that his team has enabled, but I love the passion projects by him.
I have a BSc in space science, MSc in Astrophysics, and PhD in Heliophysics, and this is the first time I really understand how rainbows work. Well done, Derek! Great job!
That also would explain the Moon Halos, when its full moon midnight, if you look up to a mildly cloudy night, you can see a halo around the moon, its the backshot cone of her reflection!!! Genius as always, pal! Great great video ❤
25:51 casually dropping the name of Dustin's channel in a plug for Brilliant. Well played! Also, fantastic video, not just for the amazing explanations and demonstrations, but that it was inspired by your boy's question, and that this video is as much an explanation just for him, as it is a learning tool for us. I love that.
One of the best veritasium videos in the past few years. Not just the subject, but the passion you show here towards teaching your son the secrets behind the beuties of the world. It felt personal and touching.
24:33 “But it all started with the mystery of rings of color in the fog” it was at that point that I felt so emotional… thank you for what you do and share, our world is amazing and learning about it is an awesome thing
Absolute beauty of a demonstration! Wish teachers could be given resources to explain stuff in this manner... I don't think anyone would ever forget how rainbows work after this video! Great work Derek!
You successfully and clearly answered every question I’ve ever had in addition to several I’ve never even thought about regarding the details of how rainbows and light refraction in general occur. Absolutely stunning learning experience. You never and I mean NEVER disappoint! Regardless of how many double-rainbows I’ve seen, which is several dozen having living in the rainy Midwest most of my life, I never even noticed the upper arch of a double rainbow was inverted. You blew my mind once again with this one. Please never stop providing incredibly complex yet eloquent explanations of everyday science; the future of continuously advancing humanity sincerely relies on people like you!
Oh nice! 21:48, I saw one of those while on a plane and couldn't really figure out why I could see this circular rainbow circling around the plane's shadow on the clouds. That is a cool sight
same here, I googled it and found out it was gloria. I saw similar phenomena when flying my FPV drone. I could see a kind of rainbow around my drone's shadow from drone's perspective.
I have also seen Glory Rainbow on wet grass. There is a floodlight in sports ground of my university. At night, I go for walk there. When grass is wet, I see faded Glory Rainbow around my shadow's head. I also used to wonder why. Finally I got the answer.
Every time the end-of-a-Veritasium-video starts (24:21), I'm always on the verge of shedding a tear. It's always a nice moment, and this one was the best :')
This video gave me goosebumps for almost all its duration... Specially when, from color to color, degree to degree, it uncovers exactly when/why/how the rainbows appear, all at the same time. This video is just perfect... There's no more to say besides: THANK YOU!
This is by far my top 3 Veritasium videos. You have made something absolutely beautiful, Derek. We need these videos on a high school curriculum. They're necessary. Please don't ever stop. Phenomenal explanation, mesmerizing visuals and when you were playing with the large glass ball and your window, I experienced that same crazy excitement when I was experimenting with Lasers. It's magical.
Thank you for being such a good communicator and educator. Verisatium always sparks curiosity and interest in science. Like a rainbow to curious people that also ask themselves how things work, but getting explanations this straightforward, graphical, interesting and well produced is just a blessing
And God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14 And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald. Revelation 4:3
@@dangerfly But he used it correctly. He has never seen a better video about rainbows until this one. Ergo, literally the best he's seen. Now, is the word "literally" needed there? Well, no. Is it used incorrectly? No!
@@Ulysses182 Their intent was to add emphasis like using all caps or bold and that's a wrong interpretation of how the educated use it to clarify that they are not being metaphorical *when that ambiguity exists*. "Big as a house" is ambiguous for example because it's often used metaphorically. Kids especially don't understand that nuance and so they are incorrectly using it based on INTENT and lack of ambiguity. There are sooo *MANY* ways to exaggerate and few to communicate that we are not.
Veritasium, your team has an extraordinary way of explaining and exploring these concepts in a manner that isn't oversimplified (in a way that would leave more questions), but also not too complex to the point where my brain turns off. I love how these videos not only answer my questions, but expand upon them and also shows where it may exist in the world around us! That's probably one of the most important elements in my opinion. Almost every kid (including myself) always wonders "when or where the heck am I ever going to apply this information in my life?" The storytelling through the imagery, music, and the order and methods these ideas are presented is top tier, which is why I think this is the culmination of an incredible team's efforts. Life has been incredibly rough lately, so watching this was something that made me stoked to be existing on Earth right now -- with the ability to understand and experience it all -- and that's a gift that can't be bought. Sending a tremendous thanks and aloha to you and your team, Veritasium.
Revelation 4:2 Revelation 4:2-3 KJV [2] And immediately I was in the spirit: and, behold, a throne was set in heaven, and one sat on the throne. [3] And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald.
genuinely impressive how you never miss. Even with topics that I already know all about, you always manage to provide additional insight that I didn't know I needed
Revelation 4:2 Revelation 4:2-3 KJV [2] And immediately I was in the spirit: and, behold, a throne was set in heaven, and one sat on the throne. [3] And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald.
This is my favorite video format, chosing a topic and going deep into all the intricacies of the phenomenon and how it works. Not just saying "Yeah, water droplets refract different wavelengths differently, u know..." Thank you a lot for this
Completely agree. Very satisfying to fill in those gaps of knowledge with a true understanding of the concepts. There's a TH-cam channel called History of the Universe" that does the same kind of deep explanations. Mind blowing
The 9 rainbow orders are more important than the curvature of rainbow In my opinion. I'm a little dissatisfied you did not go into them at all and how they play directly into what angle your looking at and the orders also depend on what colors come through that you see also. A bit disappointed here especially with the Title.
After a full watch, my original assumption is correct, vertasium you still dont know much about Rainbows lol. I was really hoping to learn something new here. Natural and lab made are another important component as 9 natural rainbow orders and 250+ in lab conditions. Please do more research and make new rainbow video in future.
Wow, what a beautiful explanation! I did not have such an understanding of rainbows (& wave optics) even after completing my undergrad in Engg. I don't usually comment on videos, but this video gave such an interactive explanation to a wonderful occurrence in nature that I had to appreciate it. Thank you.
God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14 And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald. Revelation 4:3
I studied physics, chemistry, math and computer science in highschool, right up until i graduated. I took up comp sci in college, and I'm loving it, but it's not an engineering degree, so I don't have papers in physics and chemistry, and my papers in math aren't really that detailed, just very basic stuff. It is for these reasons that I'm eternally grateful to channels like Veritasium, Nile Red, Steve Mould and Hank Green. While allowing a deeper understanding of the field im currently studying, you guys help maintain my curiosity and interest in the other 3. Thank you so much 🫶🏽
14:50 That's why watering plants in direct sunlight with a watercan in zero g is not a good idea. Hundreds of droplets that are essentially magnifying glasses burning everything at the focal point so you end up with popped corn on the cob.
I think Derek's got his mojo back! The last 3-4 videos knocked it out of the park in a way I haven't felt since a decade ago when I joined the channel and saw your videos about misconceptions about temperature and heat. 🎉
Just beautiful, happy to be able to help
Thank you for the visual data. Absolutely delightful.
The GOAT
I loved both ivdeos, people should def watch you before though
THE GOAT
The goat vs real engineering
- Dad... why are rainbows curved?
- Give me a couple of weeks to answer it
you know it is funny but usually most things are like this. We rarely think why 2+2=4, but it was answered to me only after spending 3 years on learning calculus. It's simple yet takes a lot of knowledge to grasp the concepts that are just a second nature to us
@@RabbitKiwi DIENG ISLIVING
for you and a few other hundred thousand people :))
kid: im not interested anymore
@tarik5277 😅
I’m an optometrist and this is probably the best animation/display on optics I’ve ever seen. I wish they taught in schools like this. Simply incredible work 👏
Imagine each class taking this long to prepare and costing as much
@@boogeiymanWhy? Produce video, translate them and deliver to billions. Than an experiment for kids to showcase the simplest part - is literally piece of glass during a sunny day
I'm sure Derek won't mind his videos shown in classrooms, anywhere
This is why TH-cam is improving the quality of teaching.
You are welcome sir
It is only recently that such capabilities exist, as employed by Derek & Grant (of 3Blue1Brown, that Derek referred to) so wonderfully. And for visual learners it is really ecstatic to see Physics unfold in front of our eyes. What a great time to be alive!!!
Your videos are far better than any physics teacher in the world. In the chaos of martial law in South Korea, the rainbow you created have moved me for a moment.
Thank you! Stay safe!
"tell us you dont know anything about any physics teachers in the world, without telling us "
What an unnecessary comment@@crazycutz8072
So another example of 42 being the fundamental answer to everything. Awesome video! As always
humorous reference to Hitchhikers Guide to The Universe?
MARRY ME ! ( If you're old enough to know I'm joking.)
@@daisymoses6812waht's that
but just for Red
If only it was 37
I’d never been satisfied with the simple “sunlight is scattered by water droplets” explanation as it felt like it left too many questions; this video has answered every one of those questions, succinctly and comprehensively. Incredibly well done!
another legend is in the commentss
didn't expect to see you here!
Alr bruh we know ur a linguistics nerd💀🤦🏽♂️
No wonder. This video was made with passion
@@bannedmerchant3849 could you ?
Your explanation was so good that at 18:45 when you said 'why is it brighter under a rainbow than above?', I already knew the answer, despite not even being aware of such a phenomenon 20 minutes ago. That's the hallmark of a great explanation.
I said out loud to myself, "BECAUSE THE CAUSTICS DUH!"
I...I was very proud of myself
Same here! This was such a good video
12:41 was when it clicked for me, I saw the light under the rainbow, and I was like "Oooh that's why it's brighter under a rainbow!"
@@sfurules🤭
Well said. It’s a great example of teaching understanding rather than just knowledge.
I had the same question from my children. This Veritasium video addressed the question so deeply and accurately.
Thank you! So glad to hear you enjoyed the video and found it educational!
14:55 *Burns the finger*
"Ouch! This thing is a ffFFffffocal" 😁
Einstein would have already been on it and frying his morning egg.
multiple f- words came to his mind lol
Congratulations! You can hear!
@@chenilleoneil1289 Tech Ingredients did this except with a parabolic reflector.
@@troubledouble106 Congratulations! You're annoying !
Derek: "I must ponder my orb."
Slightly burned Derek: "Okay, done now."
medium rare derek
This comment man 😂
Well done.
med rare
Talk about being in the wrong place at the wrong time. Burned me too watching it
I work in optics and have two degrees in the field. I’ve heard explanations of the rainbow multiple times, whether in class or at conferences, and can say that this one is certainly one of the best: both because it deals with the maths both (relatively) comprehensively and intuitively, and (more importantly) it really speaks to the curious, awe stricken child in all of us very effectively. He even snuck in a (very) simplified explanation of light-matter interaction and refractive index just to make sense of the differing emergent angles for different wavelengths. Bravo!
Im 26 and through youtube videos like this I've learned more in the past year than I did the other 25 years of school work etc. too cool!
@@asunhug Walter lewin. There, you have now been given "the rabbit hole" let me know when you hit the , i don't know any of this and have to go back to where your schooling stoped
@ Omg. Just searched and looks like I need to check this out. Thanks! XD ;D
I used to teach radio wave propagation and antenna theory. Refraction has always been the difficult one to nail down, until that 3blue1brown video referenced here.
@@asunhugTo which school and country did you go? just curious which school is this bad.
I've come back to your channel lately, you're making really amazing videos now. This was so much fun to watch, all the best.
Thank you so much! Glad you enjoyed!
The rate of Veritasium and Mentour Pilot Video drops these past couple of weeks and yet with top quality delivery literally is out of this world.
Edit: Wow.. 9k likes unbelievable
No, it's literally in this world.
I'm just happy because 3B1B got the credit. They have narrower audience, but they tackle the problem of the next level of complexity and end up explaining it just as simply.
Ah, a fellow human of great culture! I too am subscribed to both 🤓
That's concerning. If Mentour Pilot runs out of material, he'll have to start shooting down planes, and that's just not the same.
"We parked our anti-air battery right in the flight path of the plane. Remember this, as it will be important later."
oh hey! a fellow veritasium and mentour pilot enjoyer! yeah their videos are extremely incredible and i´ve been a fan of both for years now
I am an optical engineer and at the end of one of our optics courses the prof gave us a 90 minute lecture on the topic of rainbows. It was incredible and convinced me to do something with light in my professional life. Your visual explanations gave birth to that what the prof taught us 15ish years ago. Thank you!
Are there ways to cheat past the diffraction limit?
@@bengsynthmusic actually yes: search for "Stimulated emission depletion (STED) microscopy"
W prof
"Your visual explanations gave birth to that what the prof taught us 15ish years ago."
A video from yesterday gave birth to something that happened 15 years ago ?
Something I've been wondering about is can't the frequency of loggt also change ofnthe wavelengths changes..Inget that it's the same number of wave packets coming through since its a continuous light beam butnthe complex interactions innthe material could in principle change the frequency also..as an optical engineer can you confirm this? Has it been studied?
4:18 He said all other videos about the rainbow are oversimplifications, so to be true to his word, he asked 3B1B for permission to use the most detailed explanation for electromagnetic waves and refraction that I know of as his source. Absolute legends, both of you.👍
Both 3B1B and Veritasium are high quality math/physics explainers. I love both of them and a collab between them would be insane
@@gachabloxgirl3958 Wouldn’t you consider this to be a collab ?
@@josenobi3022 it's more like derek is using 3b1b's material to aid himself
a proper collaboration would be that they both work on the same material at the same time
Thats why i love this science community on yt.
If I'm being honest, I still don't understand why shortening the wavelength of light would slow it down, he just mentioned that without giving any actual explanation.
Why would light become slower when it's wavelength is shortened inside a medium ?
Thank you!!!! From the bottom of my heart! You have made my world even more beautiful and full of real magic. I'm a 36 year old man, and yet watching this I felt like a kid again (akin to your son) when I first asked my father how rainbows work. I'm a cinematographer, I took classes in physics at university, and have thirsted after an understanding of light above all physical phenomenon my entire life.
I once ambushed Michio Kaku on a subway train desperately asking for an explanation of what light is, though he misheard me and thought I was asking him "What is life?" Without missing a beat, he started telling me what life is. Upon realizing he'd misheard me I interrupted him to say, "I'm sorry, I didn't ask 'What is Life', but 'What is light?'" He quickly replied, "oh that's easy, it's photons. This is my stop,"' and got off the train. To this day, i still don't know what light is, and until 20 minutes ago I still didn't understand how rainbows work.
But now I do!!! YAY!!!
Beautiful work explaining this in such a practical, real world manner, it helps to make physics feel more accessible, relatable, and real than when we have to rely more on the math and modeling to explain these sorts of things.
I'm a student at Stanford in an optics class; we have our final exam in a few days and it covers literally everything in this video: reflection, refraction, dispersion, Snell's Law, Brewster's Angle, diffraction patterns, constructive/destructive interference, etc. This video could not have had more perfect timing!
You will get zero mark if you look into science alert for current research in Physics. Please do not apply the new knowledge in your study after reading. I don't want any student fails in examination because of me.
Thank you for your beautiful explanations of the optics of rain drops.
@@boonheeliew2488 What?
For your next experiment, let’s see you do the same thing using just a concave and convex piece of glass.
Too bad the video is wrong in a couple key areas; but it should get you through your exam!
almost brought tears to my eyes when you concluded with “and that, my son…” i think it’s beautiful that what fuelled you to make this video for the whole world to see is your quest to thoroughly answer question from your own child. thank you
I came here for this comment.... 25:05, haven't quite finished the video, yet have tears in my eyes due to, "... my son..."
Too dramatic
@@soundscape26 Lol.
My son asked me the same question when he was 5, as an engineer I could answer him but waited until he got a lot older to give him a more detailed explanation. When he said, "and that, my son" I teared up because it brought back that cherished memory. I love his channel.
search redfrost motivation, If by Rudyard Kipling.
See if you can listen to the last segment of the poem without crying haha
I was a huge Physics nerd as a kid, especially things concerning light and optics. Watched the whole video with my undivided attention and reaffirmed to myself that I still love physics after all these years. Thanks for rekindling my inner child!❤
Here before the Heart
Thank you! So glad to hear you enjoyed the video and that it captivated your attention, it's what we strive for :)
@@veritasium you have such a positive influence on the world. giving us all easy alternatives to modern brainrot youtube.
"Yoooo... what the heck is this tiny rainbow?"
2 years later
"I have discovered a way to detect and *observe* particles that were previously only theorized to exist."
Madlad.
And God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14
I prefer the real life explanation over the fairytale
@@xaayer this is a rare instance of religion not contradicting science.
@pinkace yes because before the flood (that never happened) light and physics didn't work that way. Has nothing to do with the fairly common ancient southwest Asia myth trope of hanging up a bow after a battle. Nope this one snippet amid a story of a scientific impossibility is science. Lunacy.
@@pinkace so its an exception?
Son: "Dad, why are rainbows curved?"
Derek: "You'll have to wait until I finish productionizing a 27m video in order to get to know the answer."
the answer*
💠
@@colt4505 Yeah, noticed it a bit late.
Thanks!
hes giving him video ideas too
And he wont understand it. Add additional 10 Years 🤣
A child's boundless curiosity can help us shake off the paradigms and patterns of thinking we get trapped in as adults. Sometimes we get frustrated with the endless questions but taking the time to satisfy their curiosity is rewarding and often leads to a new understanding about a topic yourself. Well done Derek (and Derek's son).
Imagine having the power of having a child like mind even when you're adult? Oh wait, that's called autism
Sounds pretty powerful@@badcornflakes6374
A lot of children have a natural scientific mindset. It is baked into humans. We have to work hard to nurture it instead of forcing them to repress their curiosity and questions.
awesome amazing, thanks so much lot and lots
in fact, your stuff is so valuable and much of it is extrodinary
nearly as nearly perfect per fact and facts 😇❣❣🙏🙏👍
Whoever is doing the editing and illustration for your channel deserves an award! Thought this for a very long time.
Superb video, Derek! I also researched this topic about a month ago: Your explanations, experiments and simulations are just excellent, especially for Glories and supernumeraries. If you ever revisit this topic, here are some comments: * the Sun is not a point source, so the angular size of ~half a degree is spreading/averaging everything out over such an angle, making 1st and 2nd order supernumeraries the most likely to be visible, not much else; * fogbows and halos were left out; *2nd order color inversion didn't get its attention, and 3rd and 4th order rainbows i tried to simulate, but always failed, they have immense forward scattering levels behind and probably never visible; * refractive index depends on temperature - the angle is slightly different for rain of different temperature; * red color is purest in the rainbow, everything else is more like a mix and the blue and violet part is especially unpure; * there is another place in the solar system where rainbows might appear - methane rain on Titan - totally different angles and 2nd order nonexistent probably; *color sensitivity of the eye could also be mentioned plus NIR and UV parts; *reflection rainbow from mirror-flat body of water could also be interesting to show. All in all - by far the best video of rainbow physics that i ever saw!!!
Methane rain = methrain 😉
Thanks for these insights!
Yo this is cool
awesome comment
I was also expecting Halo's mentioned. And also now that I mentioned that, maybe also light pillars. So maybe not revisit but own continuation video about these when the water droplets are frozen ice crystals, pretty please 😂
Been watching since the first videos. I’m a huge light nerd. My favorite video you’ve ever produced. First time I’m doing one of these. Great work!
Thank you! Very grateful to have your continued support
would you say you're a... heavy light nerd?
@@Severencir 😆you’ve refracted my words correctly. heavy light nerd indeed.
@@veritasiumThe negative is passion this is the color red ♥️. The blue 💙 is honor and justice and is the positive. When honor and Justice come together with passion and you have a passionate pursuit of honor and justice then you have a worthy system which is the future or purple 💜. In between the 💛 and 💚 is the now. Direct passion and let it Direct. All is one and comes from the singularity AKA The Big bang AKA God so these are all aspects of the one including the negative... It is a part of the singularity which ultimately is love... Therefore ❤ is love... All is love... 🎉
Using advanced CGI to illustrate light reflection is awesome, using a red tether to illustrate constructive/destructive interference was out of this world!
Ran out of budget 😂
💙🤍👍🏻
I'm curious as to which part do you think is advanced CGI.
Advanced?
the lasers were cool as heck too
This almost made me cry.
Having a parent that loves learning as much as they love teaching has to be one of the greatest gifts on earth. Gaining the knack for inquiry makes living so beautiful.
"im looking at a different rainbow than you"
little veritasium got it
❤❤❤❤❤
@@fpvangel4495 COCK
Caustics Operations Crashcourse Knowledgeability
I appreciate this positive comment 💪
Rainbow warrior's TH-cam
Veritasium has really become one of the best TH-cam channels in the world. The consistency and quality of uploads is simply astonishing.
Bot account
@@mikeuk666 Hi, I'm your robot friend. What can I do for you?
I agree, but he did several videos with a BetterHelp sponsorship which is an online therapy company that sells their customers' data and has bad therapists
@@notCAMD also the video with the self-driving cars was a bit of an ad read...
@@simonprecheurllarena stop propagating the stereotype that robots are here to serve humans
I read an article in a "technical" magazine a couple of days ago, and they explained rainbows as "light reflecting at 42 degrees" with a sketch, and left it at that. I remember thinking that that the explanation was quite incomplete, especially with respect to the radius of the bow. It is remarkable that a free youtube channel gives such a complete and satisfactory explanation of the phenomenon, compared to a publication which you are expected to pay a significant amount of money. Thank you for answering the questions I had for decades!
Print media is slowly becoming extinct. While digital media has its benefits, one downside is the ability for "Favored" content to be amplified and "Disfavored" content to be buried.
You can also find on TH-cam a fascinating *MIT* lesson by *Walter Lewin* that explains rainbows very clearly.
This is knowledge that you can find in textbooks already.
Scientific articles do not need to explain it again. They are typically written to give some additional information.
Unless you are talking about scientific divulgation (a.k.a. popular science), which nobody does better than Veritasium and a few others. No doubt about that.
And God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14
And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald. Revelation 4:3
I was so waiting for you to say something about circumhorizontal arcs… I had the opportunity to witness one once and was amazed.
Thank you so much for this amazing video! My boyfriend and I had an amazing evening because of it! As a teacher, I can truly say that you are an example for me, both in your enthusiasm as in your clear way of explaining things! Thank you!
Thank you for all your kind words, glad to hear you enjoyed the video :)
This may be my favorite video you've made. Not only was it a fascinating topic explained superbly with interesting and unique demos, but the fact you made it all for your son shows it was a labor of love. I hope he looks back on this, and everything else you've done for him, very fondly
Love ur vids, big fan ,
Why did I read this in grunty voice 😂
Ta ta!! 😂😂
Thank you for all your kind words, we're glad you enjoyed it!
Is this whole video showi g us we live in a dom e of so e sort? is it possible there is water above the firmament dome above us?@veritasium
FANTASTIC VIDEO!! I am a retired Physics teacher and used to teach Wave Phenomenon using strings, water waves and lights waves. I used to have to give an explanation of how rainbows form and I was never quite satisfied with my inadequet explanation. This video explains so much and is so well done that it could and should be used in high school science classes. Another excellent video among your many other excellent videos!
Thank you for your service as a teacher. Physics was my most fun and imaginative course in HS. My teachers of physics I and II will remain my favorite and I'm sure you gave that experience to thousands of inquisitive minds.
Crystal balls used for science and not seances !! Cool.
Too bad in the next few years, teachers will have to explain the controversy about rainbows really being a covenant with gawd, promising not to drown the planet with the descendants of a boat waiting millennia until geezuz could die and make gawd forgive everyone. We need the babble with science doncha know!!! It's that or Veritasium is cut off for being a heretic.
Also a retired physics teacher. I left at the beginning of the smartphone and high speed internet era. The tools that are available now are amazing, and AI should cause another leap, love seeing it develop.
And God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14
And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald. Revelation 4:3
This by far more satisfying than even the most comprehensive explanation I have been given. But the glasses bit is still new to me.
BEST VIDEO EVER! Did all the computations 25years ago by hand... brings back all those wonderful memories. 42 is my favorite number ever since. Thank you!
Answer to the ultimate question of the universe
@@thisisshiva44Did Douglas Adams use 42 because of this?
Douglas Adams favourite too 😉
@@EricStephaniI think it was due to a Richard Feynman reference comparing the ratio between magnitude of the electromagnetic force and gravity, which is the same a as the ratio of the diameter of the Universe and a proton. Which is 1 X 10^42. Or so Feynman claimed.
42.516 right? Did the calculations while watching this vdo
When I was in high school, my mother, my sister and I went to Fairbanks, Alaska, and we flew up to Point Barrow. I saw a full circle double rainbow from the plane, with the shadow of the plane in the middle. Thank you for this beautiful video, bringing back a great memory from over fifty years ago!
You can now refer to it as a glory :)
I may be wrong, but I don’t think it was a glory. In the video, the shadow in the center of the glory impinged on the colorful rings. This was much bigger, probably about 40 degrees and nowhere near the plane’s shadow.
@bryancurry1898 I think that would purely be a matter of distance/elevation from the moisture creating the rainbow and that's the surface of the shadow. I've been on a plane that's descended through its own glory on the clouds below, and the shadow at the center of the glory grew as we descended until it swallowed up the glory shortly before we entered the cloud.
@@bryancurry1898 I used to fly Cessnas and the like, and can confirm that you can indeed see a "proper" rainbow that is a full circle. All you need is enough rain below you to complete the circle. I loved bright, showery days, and would go looking for rainbow circles.
"A rainbow is a circle, and the higher you go, the more of it you can see." I read that years ago, and now I finally understand why: it's because it's produced in circular water droplets.
Thanks for using 3blue1brown animations for this... his videos on this subject are by far the best and most satisfying explanation on this subject out there ❤
On this subject I agree on this subject 👍
The 3blue1brown animations are extremely good!
Also I know its off topic Jesus loves you so he died for you because he wants to know you❤️Repent, God bless
@@Lecommandant_camroun Seriously ? Why not say geologists, astrophysicists and evolutionary biologists all lie about the age of the earth while at it ??? BeLIEvers know rainbows are really a covenant from Yahw-monster, who killed everyone except drunken Noah.
Trollers gonna troll, which is a sin. Can't wait till you get Dear Leader president to get Veritasium put in jail for heresy !!!
God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14
6:27 I really like the way this guy added this extra bit of information and gives you a complete understanding
Seeing the glass "raindrop" reflect and showcase how the end points of each color scatter on the reflection make the rainbow was actually spectacular, hah! Never gave it much thought but it's neat to see the science of it, and then actually see it in action! Amazing.
💠
there are videos of rainbows seen from the plane and they are circles
And God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14
And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald. Revelation 4:3
@@ayoolukoga9829 are you a bot? why would you post this under a rainbow video xD
6:00
You raised an important point: when the material (glass in this case) has absorbed a sufficient number of photons, there can indeed be a shift in the interaction dynamics, affecting the propagation of the light. Let's explain this in more detail.
Energy absorption and saturation of electrons
1. Absorption and saturation:
The electrons in the glass have a limited capacity to absorb energy. When the light is strong enough or exceeds a certain intensity, the electrons in the atoms or molecules of the glass are excited to higher energy levels. Once the electrons are fully in these excited states and no further transitions are possible, the material reaches its saturation limit.
In this state, the electrons are "saturated" and cannot absorb any more photons because they are already in the highest energetic state they can reach.
2. Changed interactions at high intensity:
If more photons hit the material than the electrons can absorb, the light may no longer be absorbed to the same extent or the absorption may decrease sharply. The remaining photons can then continue to pass through the material without being significantly scattered or absorbed.
This explains why, under certain circumstances, very intense light (e.g. at high light intensity or certain wavelengths) can pass through the material without being further absorbed. The interactions are then limited to scattering processes (such as Rayleigh scattering or Mie scattering), which only minimally deflect the light but do not absorb it.
Absorption and transparency in glass
Glass is a transparent material because it absorbs very weakly in a certain wavelength range of light (for example, visible light). The electrons in the glass absorb photons and give off energy, but this process results in a small amount of absorption of the light, and most of the light can pass through the material.
At saturation: When the photons hit the electrons with enough energy and they are fully excited, the glass's ability to absorb light is exhausted. However, this does not mean that the light simply stops. Rather, the light continues to flow through, but it is no longer significantly absorbed because the electrons can no longer absorb energy.
What happens when the glass is "saturated"?
Delay and light transmission: For materials such as glass, which have predominantly transparent properties, the light will continue to travel through the material even when the electrons are saturated in capacity. Only minimal interactions occur, such as scattering or reflection on the surfaces of the glass. However, the majority of the light will pass through unless there are strong absorption processes or a critical absorption point is reached.
Absorption saturation and no significant energy transfer: In very high intensity ranges, when the glass absorbs a high amount of photons and the electrons are "saturated", the extra energy of the light is released in the form of heat and scattering, but is no longer converted into electron vibrations by direct absorption.
In summary:
Once the glass has absorbed a high number of photons and the electrons have reached their maximum capacity, the light is essentially no longer absorbed, but continues to pass through the material.
In this state, where the electrons are saturated, only minimal interactions, such as scattering or reflection, occur and the light is not further converted into energy. It then flows through the material almost unhindered, as long as no other effects such as extreme intensity or non-linearities (e.g. in very intense lasers) occur.
So 42 really IS the answer to the Ultimate Question of Life, the Universe, and Everything. Fascinating!
I literally paused the video to look for a comment like this
The most wonderful rainbows occur at a 69 degree angle.
Dang I knew I wouldn't be the first to think this lol
But only for shades of red....
I liked your comment to have 42 like.. :D
Hi Derek. I have watched your videos for years. However for this one there is a bit of sponsorship. I wish you and your family a merry Christmas. And thanks for your content.
Thank you very much for your continuous support over the years! Merry Christmas to you and all those you celebrate with too!
Everyone should have at least one teacher in their lifetime as good as Derek Müller. Someone who goes great lengths to explain much better, something that has been aproximately explained for a long time. I love his genuine interest for his audience to learn more. I'm glad he is a father now and his children will push the envelope of this channel even further with their questions. Once again, fantastically well done Veritasium!
This is so great! Allow me as an optics guy... Derek, around 10:32 you are referring obliquely to the Lorentz model to explain the Kramers-Kronig relation (glass absorbs UV, therefore all wavelengths below see different index of refraction), and use 3Blue1Brown's model. You attribute the phase kick to _amplitude_ of the driven wave. I'm not sure that does the reality justice... The driven atom radiates at the frequency its being driven (great) but it radiates at a different phase to the drive -- and that relative phase changes continuously with drive frequency, with colour. So the added wave from the _driven_ atoms is actually at different _phase-shifts_ , for different drive frequencies, and this is important when you try to get the overall phase shift and net phase speed: which is the index of refraction. It's important too, because it's the reason the light gets attenuated/absorbed when the driving light is right on resonance: the driven atom contributes an emitted field exactly 180 degrees out of phase with the driving light, and in the forward direction those progressive additions to the net field progressively kill the amplitude (Beer's law). It's the 'constructive' reason the the light field dies off, in absorption. How to see? Hold a meter stick hanging like a pendulum and move your hand left and right: very slowly, the bottom of the stick moves in phase with your hand; very quickly and the bottom of the stick moves at 180 degree phase displacement. On resonance, it's at 90-degree phase-displacement, and this means the _velocity_ (derivative) is _in phase_ , and this is what gives largest power (F x v) transfer on resonance. Surely there's a way to do a bit better than just laying the whole thing off on amplitude of response -- this phase shift of the field, on and off resonance, is at the heart of the actual relationship. And in physics, _meaning_ comes from _relationship_ ...
Actually I think it's a combination of the two. The amplitude and the phase shift of the driven wave both increase with larger frequency, but even if only one of them (i.e. only the amplitude) increased, the overall phase shift would still increase. I.e. say the input wave is a*cos(x) and the driven wave is b*cos(x-t), then the phase shift of the sum of those two waves is atan(b*sin(t)/(a+b*cos(t))), which even for fixed (nonzero, as it is in the video) t is an increasing function of b. So it would be more accurate to say the overall phase shift increases because both the amplitude and phase shift of the driven wave increase, but I feel like adding a line like "the overall phase shift also increases because the driven phase shift increases" would just distract from the main point here
now try to read what you have just written, and see if it would make for a good video :)
It is a video, not a scientific paper.
@DocRobCan please tell me you have access to those insane laser labs and can get mark in there to show us!!! If not..... GET THIS MAN A LABORATORY AND EQUIPMENT NOW!
@@marsovac The entire point of the video is to point out that other explanations are oversimplifications. Accordingly, it's not afforded any oversimplifications, especially when they're just wrong for no apparent reason.
@@milksushi6640 Yes. I’m saying don’t just say it’s about resonant amplitude, it doesn’t do the reality justice, and cannot capture on-resonance behaviour at all.
A month ago, as a teacher to be, I had to prepare a "quick" explenation on rainbows for a seminar. Thus I know, how DEEEEEEEP the rabbit hole goes. Very nice video :)
imagine explaining the full 27 min version to your teacher, she/he would be impressed lol
💙🤍👍🏻
So I take it you decided against the whole "pot of gold" explanation???
And God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14
@@ayoolukoga9829 Either that, or it happens exactly like it's described in this video! ;)
Artist here 🙋♀️! This video was an absolute treat. Beyond just being incredibly informative in an understandable but not oversimplified, it’s beautiful. Took multiple screenshots, and the little speech at the end is so inspiring. I walked away with more understanding but also soooo much inspiration :)
This is THE best educational video on optics I have ever seen, It should be mandatory in schools physics(optics) lessons worldwide and be used as a standard for education experts on "how to do a proper video"
i covered this at University in optics 20 years ago, but it is better explained here that in the books and the "practical exercises" in the lab.
As a spectroscopist, I see optics as the art of revealing the invisible. Each photon of light carries secrets about the material it interacts with-its composition, structure, and even its dynamics. By dissecting light into its spectral components, we can essentially decode a molecular fingerprint. The beauty of spectroscopy is its precision: light doesn’t lie. A subtle dip in an absorption spectrum, a shift in fluorescence, or a sharp peak in Raman scattering tells a story about the material’s structure, environment, or energy states. It’s like speaking a universal language of photons and vibrations, one where every wavelength and intensity is a clue.
Optics isn’t just about bending light-it’s about bending our understanding of the universe, one spectrum at a time.
But, its wrong... and here's why.
1st: the very 1st photo! (no rain)
#2. we have weather cams everywhere now, and literally watch storms roll thru a "rainbow" with sun traveling, and "rainbow" remaining fixed in place.
#3. sideways "rainbows" .... we see them all the time, water falls... stand with a garden hose, side ways "rainbows" all around you!
#4. the "rainbows" of our eyes! that we all see in a steamed glass mirror.
So therefor!
rain/water.... relative to the "rainbow" only in that it enables us to see what is always there.
magnetism
the "magnetic lines" of the earth and.... ourselves.
Its simple as that.
@@TwiddleBee Good 'overall' critical ideas... (Science get better even if criticized). You seem like the kind of guy that doesn't understand Science TBH and spewing half-baked nonsense (all that is easy to replicate in a room with a light source; it is easy science at that point).
If you could prove a static side rainbow exist, i think you are in for the nobel prize (maybe)... But it is so "easy to prove" that you are underestimating 200 years of science at least. (sometimes they are a little blind/partial, but not to that extent lol)
=> So get a video where you walk around a rainbow and it is fixed in place (like a fixed 3D object) and you have a real argument here. Beat science with science, or you are the clown of the circus.
For the 1°) no rain is necessary; just an invisible mist of tiny droplets in the far distance.
2°) I would like to see that video; a time-lapse of a rainbow when the sun is moving could be interesting to analyze. (a simple explanation here is FX.. someone just stamp a rainbow on the video and it is fake... that does exist on internet.) In theory, the rainbow should move with the angle of the sun with a fixed camera.... unless the rainbow is a reflect of the layer of glass on the camera; it happens sometimes. (but it is no "sun-rainbow")
3°) never seen a side rainbow... only partial rainbows and linear diffraction on walls... and when the droplets are not rounds (with a hose the droplets can't be spherical... too random and chaotic)... the caustics would be different; so new phenomenons could occur like "anomalous deformed rainbows" and whatnot...
4°) don't know what your are talking about. is it about drugs early in the morning? ;-) (if you are hallucinating, you could see talking rainbows too... just saying.) Here the sun can't be present, and not at a 40°angle etc... it is diffraction from tiny film of water over glass, but that doesn't make any sort of rainbow. (which is a volumetric phenomenon).
If it is your trolling impression of a "flat-rainbow" conservationist", it is cleverly done... but i'm not sure about people nowadays... their brain power is on the decline, and very fast...
And God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14
And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald. Revelation 4:3
This may well be the best description of rainbows I’ve seen on youtube. But I’m going to take the statement at 0:23 seriously: “Because I promise you, almost every explanation out there, is an oversimplification.” And yes, this video makes some as well. Including one big one. I’m also interested in a few he missed, and some I like as well. “Because the full explanation is so much more satisfying than anything you've seen before.”
1:46 “Rays of light from the sun reach a raindrop essentially parallel to each other because the sun is so far away.” Oversimplification. The sun is also so very large, that these rays spread about 0.5°. Which means that each caustic is about 0.5° wide. This may seem small, but since the entire colored portion of the rainbow is only about 2° wide, each color covers about a fourth of it. And mixes with other colors.
1:57 “Some [light] is transmitted into the sphere.” Oh, thank you for using the word “transmitted.” Far too many people use “refracted” in its place. They go together, but don’t mean the same thing.
7:49 “So what we're seeing there is a maximum angle this reflected ray reaches before it turns around and goes back the other way. … And this is really important.” Bingo.
8:50 “Now you might ask, why does this reflected ray reach a maximum angle and then turn around? ... As I move the laser up the sphere, although the ray refracts down, the point on the back of the sphere where it reflects continues to move up until you get to this special point … The refracted ray stops hitting the back higher and starts hitting it lower. That is why the reflection turns around.” That is not why. It's related.
I had never considered the height before. It does seem to be true that it turns around at the same point. But the two effects are results caused by the same reason. And I can state this firmly, because (A) the formula for turn-around angle does not refer to the height in any way and (B) the same turn-around occurs at different heights for the higher-order rainbows.
I like shorter names for my parameters. Call the original angle of incidence A. Then B is the associated angle of refraction found by Snell’s Law. As it enters the drop, the ray deflects through angle A-B. Since the surface normals of a sphere are radii of the sphere, these three lines form an isosceles triangle and the angle of incidence at the back surface is also B. The reflected light deflects 180°-2B. Finally, as it exits, the light deflects another A-B. Thus, the total deflection is 180°+2A-4B. But since we look in the opposite direction, I use D (your alpha) equal to 4B-2A.
It is the rates of change of A and B that cause the turn-around. It happens when B is decreasing at half the rate of A’s increase. You can look up the formula for where this happens in an on-line textbook called The Calculus of Rainbows, by Jesse Amundsen.
12:07 “Well, more light is going to hit the sphere at higher impact parameters because the further out you go, the more area there is.” This is not quite right. There will be more light in the entire ring of reflected light created by each impact parameter value d, but it will be spread out over the entire ring created at that impact parameter. If this ring has radius f, the adjustment should be based on d/f, not d.
BUT, it has nothing to do with why we have bright rings, as you seem to imply. The actual brightness at each radius f depends on many other things, like the coefficients of transmission and reflection. The only important one is that the brightness is inversely proportional to the derivative of the function D(A) that I derived above. You know, the function that has a maximum at the turn-around angle, so the derivative is zero?
(Pause while that sinks in.)
The brightness function goes to infinity at d=d_turn_around. It's infinite over an infinitesimally small range, so the brightness we see is finite. But much greater than at any other angle.
12:46 “It's not enough to say that a raindrop spreads white light into its component colors, because all of the light that hits closer to the middle is spread too. But since the reflections all overlap as they come out, the colors mix and produce white again.” It means more than just that. The red band is the only band that is isolated from other colors. Each other band contains enough of the colors toward the red end of the spectrum, that they become less vivid as you move inward. The violet band does not end, so much as fade into the white disk you describe.
This means that the colors of the rainbow are not quite the same as the colors of the spectrum that Newton identified.
16:56 “This means no two people can ever see the exact same rainbow.” I hate this expression. It implies that the rainbow exists as an object, and so a different object for different people. Yet those same people will say that they see the same reflection when looking in a mirror, which is essentially the same phenomenon.
17:04 “A rainbow is an optical illusion …” This one, too. An optical illusion is when something looks like something it is not. Is it a duck, or a rabbit? Here, you see an optical effect exactly for what it is. There just isn't an object.
17:11 “In most parts of the world, you can only see a rainbow in the early morning or late afternoon.” Exaggeration. Today, Dec 5, you can see a rainbow at any time of day, anywhere north of about New Orleans.
19:13 “But if you look up even further, sometimes you see a second fainter rainbow with its colors inverted.” The colors aren’t really inverted, they are seen upside down. You provide the reason in your diagrams, but you don’t explain it.
The “white disk” for the secondary rainbow is centered on the sun (180° in your plots), not your shadow. And it is about 130° wide, not 50°. This means it wraps around the top of the sky, and so is seen about 8° to 10° above the primary, upside down. It’s harder to tell, but the sky _above_ the secondary at 19:17 is also brighter than Alexander’s Dark Band.
20:44 “This is known as a supernumerary rainbow.” Fun story: Once, about three minutes after posting an explanation of supernumeraries, my son looked out the window and said “Hey, there’s a rainbow. But it is really wide!” Sure enough, it was the only example I have ever seen. It didn’t last long enough to get a picture.
20:53 “But this only occurs when the raindrops are all really small.” Small isn’t the important detail, but it helps. They all have to be the same size. It actually happens for each raindrop, but with different sizes they obliterate each other.
One last point. A common error when explaining rainbows, is to claim that it is a result of Total Internal Reflection. As your polarization example points out, the reflections occur near Brewster’s Angle, not the Critical Angle. It’s actually impossible for this light to reach the Critical Angle.
Wow! 👏. That was an amazing detailed comment/critic. Youre book about the caluclus of rainbows is added in my "have to read" booklist. I only got a grasp on the derivitive part but i still got the general idea. Right on man! Have a nice day!
Thanks! Some very interesting elaboration here.
Regarding brightness approaching infinity but appearing finite - I suspect that's another substantial simplification? I imagine it has to do with a combination of droplets not actually being perfect spheres (and thus the formula being close but not quite true - I'm sure a study of this going into statistical analysis of droplet shapes could encompass an entire series of videos), and probably discretization effects caused by our eyes "measuring" brightness via rods and cones (I.e. Brightness, being power density, reaches infinity at a given angle but our eyes actually measure total power over slices of angles)
Also, it may help to remove some of the word pedantry nitpicking in your comment as I feel it makes it harder to find and appreciate the more educational points :)
@@emissarygw2264 (Pause while that sinks in.)
@@emissarygw2264 "Regarding brightness approaching infinity but appearing finite - I suspect that's another substantial simplification?" You could call it that, but (puts tongue in cheek) that's a simplification.
At 12:10, Derek created equal-area rings in the sun's incoming beam, and translated those rings to dots in the graph of the outgoing scattering angle at 12:25. The further from the sunbeam's center you go, the narrower these rings become. He implied, but didn't come out and say, that this is why the red dots "bunch up" near d=7R/8 and α=42°. He probably didn't mention that because it is wrong - they would "bunch up" even more beyond d=7R/8.
The non-simplified reason is that for any range Δd - that is, the width of the incoming rings - that includes the turn-around point, the ratio Δα/Δd gets bigger and bigger as Δd gets smaller. This ratio Δα/Δd is what makes Derek's dots bunch up as he shows. Not the area calculation (which he did incorrectly).
The could-be-a-simplification is that the ratio would go to infinity if Δd could reach zero. Δα would also go to zero, but more slowly. That's what a derivative is. The problem is that our eyes can't see a beam of rainbow light where Δα goes to zero. We need it to have the effective width of a "pixel" in our eyes. So it is just very, very bright in that one pixel.
I'm not sure I follow - it seem like he is having each dot represent "1 unit power" (I.e. Measured in watts) being input at position d. That part seems relatively straightforward, even if it's one of those imprecise quantizations we use when trying to describe things visually. Then "ray tracing" where each unit ends up, the alpha value, and plotting that on a linear scale. Which seems like a reasonable way to visually represent power density (brightness) at any given value of alpha, although technically it'd be divided by the diameter at any given alpha since the power is spread over a ring - but we are quite good at picking out fluctuations in gradients, so I don't think plotting on a linear scale is overly misleading.
This, Derek, is one of your best episodes to date. Your enthusiasm for the subject is genuine, and it shows.
I need to comment because a thumbs up isn’t enough. This is something that has been itching my curiosity for years, and anytime I looked for info, found nothing.
This was exactly what I needed!
Thank you!!
As a teacher of an Art course in "Light & Optics" . . . this is simply phenomenal pedagogy. Brilliantly and clearly explained, excellent use of demos and animations. Spectacular.
This is the best video I’ve seen on the topic: we’ve got the speed of light, the essence of light, caustics, Snell’s law, reflection, refraction, and “Glories” all wrapped into the glory of an everyday rainbow. During the early years of the Exploratorium, its logo was a diagram of the reflection and refraction of a beam of light hitting a rain drop, as complex as the one you present. It was replaced by optical illusion, something much, much more easily grasped and experienced on paper. But I always loved the early rain drop logo, and appreciate its initial selection. And now I understand even more. Thank you!
This must be one of the best veritasium videos I've seen in years. That moment with the afternoon sun coming through the window onto the sphere was just beautiful, because it MADE SENSE!
You can tell the difference between videos that Derek gives the "Okay" for his team to produce, and the videos that Derek wants to produce. I like the increased output that his team has enabled, but I love the passion projects by him.
Derek, if there were a Nobel prize for science communication, and there ought to be, you sir would deserve one for your body of work.
Yes after grant sand maybe 😂
I have a BSc in space science, MSc in Astrophysics, and PhD in Heliophysics, and this is the first time I really understand how rainbows work. Well done, Derek! Great job!
Bruh
there's a BSc in "space science"?
@@alveolateyeah wtf is heliophysics
so many degrees ?
@@calebrobinson6406 The field of astrophysics that studies the sun
You know it's serious when Veritasium says the explanation *IS SATISFYING*
That also would explain the Moon Halos, when its full moon midnight, if you look up to a mildly cloudy night, you can see a halo around the moon, its the backshot cone of her reflection!!!
Genius as always, pal! Great great video ❤
24:46 Derek calling me son feels calming and weird
😂
I believe he said it directly to his son because he would watch it :D
He wasn't talking to you though, he was speaking to the Sun
I like to believe he is like the spiritual father of science, a priest of science you could say perhaps.
🌞 Sun: "Intersting..."
“Learning should be about mastering a subject, not memorizing a list of facts”
I loved this quote!
25:51 casually dropping the name of Dustin's channel in a plug for Brilliant. Well played! Also, fantastic video, not just for the amazing explanations and demonstrations, but that it was inspired by your boy's question, and that this video is as much an explanation just for him, as it is a learning tool for us. I love that.
I can tell you were having fun with this one! I enjoy that vibe; make more videos that you like to make!
One of the best veritasium videos in the past few years. Not just the subject, but the passion you show here towards teaching your son the secrets behind the beuties of the world. It felt personal and touching.
24:33 “But it all started with the mystery of rings of color in the fog” it was at that point that I felt so emotional… thank you for what you do and share, our world is amazing and learning about it is an awesome thing
Absolute beauty of a demonstration! Wish teachers could be given resources to explain stuff in this manner... I don't think anyone would ever forget how rainbows work after this video!
Great work Derek!
You successfully and clearly answered every question I’ve ever had in addition to several I’ve never even thought about regarding the details of how rainbows and light refraction in general occur. Absolutely stunning learning experience. You never and I mean NEVER disappoint! Regardless of how many double-rainbows I’ve seen, which is several dozen having living in the rainy Midwest most of my life, I never even noticed the upper arch of a double rainbow was inverted. You blew my mind once again with this one.
Please never stop providing incredibly complex yet eloquent explanations of everyday science; the future of continuously advancing humanity sincerely relies on people like you!
Man, I cried of amazement at 16:30. Thank you so much. This is one of your best videos EVER.
Oh nice! 21:48, I saw one of those while on a plane and couldn't really figure out why I could see this circular rainbow circling around the plane's shadow on the clouds. That is a cool sight
same here, I googled it and found out it was gloria. I saw similar phenomena when flying my FPV drone. I could see a kind of rainbow around my drone's shadow from drone's perspective.
I have also seen Glory Rainbow on wet grass. There is a floodlight in sports ground of my university. At night, I go for walk there. When grass is wet, I see faded Glory Rainbow around my shadow's head. I also used to wonder why. Finally I got the answer.
Oh wow!! A veritasium video ....my chores can wait😊
this vid is peak🗿🗿🗿
Every time the end-of-a-Veritasium-video starts (24:21), I'm always on the verge of shedding a tear. It's always a nice moment, and this one was the best :')
Gonna have to watch this about 20 times to get my head around it, but that's why this channel's so great. Makes me think.
This video gave me goosebumps for almost all its duration... Specially when, from color to color, degree to degree, it uncovers exactly when/why/how the rainbows appear, all at the same time. This video is just perfect... There's no more to say besides: THANK YOU!
This is by far my top 3 Veritasium videos. You have made something absolutely beautiful, Derek. We need these videos on a high school curriculum. They're necessary. Please don't ever stop. Phenomenal explanation, mesmerizing visuals and when you were playing with the large glass ball and your window, I experienced that same crazy excitement when I was experimenting with Lasers.
It's magical.
Thank you for being such a good communicator and educator. Verisatium always sparks curiosity and interest in science. Like a rainbow to curious people that also ask themselves how things work, but getting explanations this straightforward, graphical, interesting and well produced is just a blessing
14:28 Derek's mad scientist laugh!!! "It's ALIVE!!!" 🤣
I was about to comment this. 😭 Derek the Diffractor 🦹🏻
lol like a French mad scientist
This laugh needs to be in this year’s TH-cam rewind!
That laugh was so french
Thanks!
No, thank you!
videos like these remind me why i love physics and science in general so much
And God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14
And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald. Revelation 4:3
I’ve heard explanations of the rainbow multiple times, whether in class or at conferences, and can say that this one is certainly one of the best
This is literally the best explanation of how rainbows work I have ever seen, while being exquisitely beautiful at the same time. Thank you.
We literally need a video on why people literally use literal too lazily and incorrectly.
@@dangerfly But he used it correctly. He has never seen a better video about rainbows until this one. Ergo, literally the best he's seen.
Now, is the word "literally" needed there? Well, no. Is it used incorrectly? No!
@@Ulysses182 Their intent was to add emphasis like using all caps or bold and that's a wrong interpretation of how the educated use it to clarify that they are not being metaphorical *when that ambiguity exists*. "Big as a house" is ambiguous for example because it's often used metaphorically.
Kids especially don't understand that nuance and so they are incorrectly using it based on INTENT and lack of ambiguity.
There are sooo *MANY* ways to exaggerate and few to communicate that we are not.
Veritasium, your team has an extraordinary way of explaining and exploring these concepts in a manner that isn't oversimplified (in a way that would leave more questions), but also not too complex to the point where my brain turns off. I love how these videos not only answer my questions, but expand upon them and also shows where it may exist in the world around us! That's probably one of the most important elements in my opinion. Almost every kid (including myself) always wonders "when or where the heck am I ever going to apply this information in my life?"
The storytelling through the imagery, music, and the order and methods these ideas are presented is top tier, which is why I think this is the culmination of an incredible team's efforts. Life has been incredibly rough lately, so watching this was something that made me stoked to be existing on Earth right now -- with the ability to understand and experience it all -- and that's a gift that can't be bought.
Sending a tremendous thanks and aloha to you and your team, Veritasium.
9:50 shaking your phone with this is fun
😂😂😂
If there is one channel I would whole heartedly donate to, it is Veritasium! Simply the best!!
8:32 of course the optimal angle HAD to be 42deg 🙄
The answer to everything in the Universe 😂.
Sorry about that... Had to tinker with some universe stuff
Revelation 4:2
Revelation 4:2-3 KJV
[2] And immediately I was in the spirit: and, behold, a throne was set in heaven, and one sat on the throne. [3] And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald.
i have been studying interference for my exam and just took a break to watch TH-cam and well Veritasium makes a video on optics. What a day.
Me too buddy, me too
Same here! Just took a break from my thesis, and I' m loving this video so much
same
Sameeeee
No you havent youve been browsing youtube and procrastinating🎉
genuinely impressive how you never miss. Even with topics that I already know all about, you always manage to provide additional insight that I didn't know I needed
You finally answered the question the best that I was looking for like 2 years
8:37 42 I knew it!
Revelation 4:2
Revelation 4:2-3 KJV
[2] And immediately I was in the spirit: and, behold, a throne was set in heaven, and one sat on the throne. [3] And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald.
@@ayoolukoga9829the bible keeps referring to fractals, its actually insane
The Veritasium Element been really active recently!!
Huge appreciation for Derek & Team!
This is my favorite video format, chosing a topic and going deep into all the intricacies of the phenomenon and how it works. Not just saying "Yeah, water droplets refract different wavelengths differently, u know..." Thank you a lot for this
Completely agree. Very satisfying to fill in those gaps of knowledge with a true understanding of the concepts. There's a TH-cam channel called History of the Universe" that does the same kind of deep explanations. Mind blowing
This is the most detailed explanation video about rainbows I have ever seen! I love it! 🌈
The dedication you've put into this for explaining this for your son is truly impressive
Fantabulous.
I'm literally jumping rn because of my decade long curiosity finally being answered in the best possible way. Frikkin mad respect for you man! 😭✨
The video really did live up to the expectations built in the introduction. Thank you for that video, Derek :)
Glad you enjoyed it!
The 9 rainbow orders are more important than the curvature of rainbow In my opinion. I'm a little dissatisfied you did not go into them at all and how they play directly into what angle your looking at and the orders also depend on what colors come through that you see also. A bit disappointed here especially with the Title.
After a full watch, my original assumption is correct, vertasium you still dont know much about Rainbows lol. I was really hoping to learn something new here. Natural and lab made are another important component as 9 natural rainbow orders and 250+ in lab conditions. Please do more research and make new rainbow video in future.
@@MeetJarred
Best video I've seen in a very long time! The visuals explain the phenomenon so accurately, and you tell the story so well and clear
Wow, what a beautiful explanation! I did not have such an understanding of rainbows (& wave optics) even after completing my undergrad in Engg. I don't usually comment on videos, but this video gave such an interactive explanation to a wonderful occurrence in nature that I had to appreciate it. Thank you.
God said, This is the token of the covenant which I make between me and you and every living creature that is with you, for perpetual generations: I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth. And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud. Genesis 9:12-14
And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald. Revelation 4:3
I studied physics, chemistry, math and computer science in highschool, right up until i graduated. I took up comp sci in college, and I'm loving it, but it's not an engineering degree, so I don't have papers in physics and chemistry, and my papers in math aren't really that detailed, just very basic stuff. It is for these reasons that I'm eternally grateful to channels like Veritasium, Nile Red, Steve Mould and Hank Green. While allowing a deeper understanding of the field im currently studying, you guys help maintain my curiosity and interest in the other 3. Thank you so much 🫶🏽
14:50 That's why watering plants in direct sunlight with a watercan in zero g is not a good idea. Hundreds of droplets that are essentially magnifying glasses burning everything at the focal point so you end up with popped corn on the cob.
I'm taking notes on things I must not do in zero g, very important.
You're essentially, completely brainwashed and ignorant to the world you live in.
9:30 so you’re telling me the answer to everything is…42?
I think Derek's got his mojo back! The last 3-4 videos knocked it out of the park in a way I haven't felt since a decade ago when I joined the channel and saw your videos about misconceptions about temperature and heat. 🎉
1:29 first time I heard Derek's voice crack
And i went strait for the comments searching for someone commenting it😂