Color and Refraction

What is color? What is it that determines the color of an object? And what the heck is refraction? Good thing we just learned about electromagnetic radiation! Especially the visible spectrum. Let's take a look.
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[@mtg5009]

I was struggling to learn this all week but he explained everything clearly in 5 mins... idk why i go and waste hours at school now lol

[@chipmunkalvin1million]

I think this is more informative than my school- lol

[@soccerverse88]

Tf man😂

[@ricks2907]

Education in the institution for knowledge similarly as college where implicit teaching make a mole hill into a mountain. They teach in such a way that makes learning much more difficult than need be so the professor can slap his back about how many students fail to learn. Then they believe they are special because they are so smart to be able to diverge the facts where mAny fail that they can teach such a convoluted topic such that they have a 66% attrition rate. The more students they can fail the subject the more it shows how smart they must be. Is a true self aggrandizing proof of a superior mind such as they have as they are the king of the mountain. Thanks buddy Ricky 💃🕺🏼🎶🐈‍⬛🎸🐊😎💥✌️😈

[@i-pad2534]

True Dude

[@kurdicodes9167]

Yeaaaaaaaaaa sameeeeee

[@tinatseyi]

Bro......now i understand colors on a whole new level....Thanks ....you the best gee

[@thechaosgardener]

Concise and clear. Thank you, I will be using this to introduce colors to my physics class today.

[@a-techworld4991]

Really amazing teaching. Thanks this helped me a lot !!!!!👍👍👍👏👏👏

[@sharonkende4774]

When you mentioned that light refracts and "fans out so they are individually visible" that was so helpful. First time I heard it explained that way.

[@n.v.n.prasad132]

Hello sir! I've watched many of your classical physics videos and let me tell you, they were a ton of help! Just one request: I'd be happy if you create a playlist on ray optics (or optics as a whole) because I have lots of confusions in that subject. It will also help other students (including me) who need a clarification in optics! You can take your time and considering making one.

[@user-ur7pe3lz2r]

Now my mind is open i answer my questions cus of u professor dave thank u so much

[@user-mf9ex6pu8p]

POV: This is your homework

[@user-mf9ex6pu8p]

And you failed

[@mintilz_6614]

Hi whiteyyy

[@user-mf9ex6pu8p]

Henry Lancaster yoooooo this isnt my main account btw

[@b0nb0n]

Ollie White oof well that’s relatable

[@danielcometa8241]

yes.

[@dermdoc3637]

this is the type of explanation that one should pay for.. very good

[@Kholanee]

thanks a lot really helped my teacher explained this for an hour and i learnt nothing thanks again

[@rickmoremaseko8251]

well done man. you did a great job here. much appreciated. God bless you.

[@TylerSimonds]

Great for a five-minute vid. I’m still so curious! (Not having heard about red, yellow, and blue as I was taught to be the primary colors.)

[@carultch]

Red, yellow, and blue is an oversimplified explanation of primary colors for kindergarten-level understanding. Red, green and blue are additive primary colors, that apply for mixing light sources. Cyan, magenta, and yellow, are the corresponding subtractive primary colors, that apply for mixing pigments. Red, yellow, and blue is close to what you get with cyan, magenta and yellow, but blue is oversimplified cyan, and red is oversimplified magenta.

[@yyfroy]

Excellent! Need to review it!

[@spectacularmma.9669]

Amazing lesson 👌

[@pa800korg92]

Professor Dave, YOU ROCK ! This is fantastic.

[@matyldalinkova2553]

6 year old video just speared me hours of research for my presentation. Thank you!

[@shubhamjoshi9624]

Thank you professor dave, very good explanation

[@ricks2907]

I just subscribed. Hope you have cool longer lectures

[@Valley__]

Everytime at night when I’m driving I see a cast of purple in the distance. Like if I see an apartment ahead I will think someone has a violet color but as I drive closer it disappears. It happens anywhere where light is. It’s super frustrating

[@gwnaker]

The speed of light is a constant, correct? So saying light "slows down" is not really correct, is it? I think I understand that media, such as water or glass, refracts the light so that it travels longer or shorter paths and is therefore 'refracted into its different wavelengths or colors. Is that what is really happening?

[@deltaprime_]

the speed of light is only constant in a vacuum, it can slow down in different media

[@Rhannmah]

Here's an interesting question : WHY do different wavelengths of light refract differently when crossing from one medium to an other?

[@ProfessorDaveExplains]

a great question! the higher the frequency, the more the light is slowed down by traveling through the medium, i think this has to do with more absorption and re-emission happening than it does for the lower frequency/higher wavelengths. the more the light slows down, the greater the refraction angle.

[@sulagnadassarkar9538]

@@ProfessorDaveExplains I love the fact that you replied to everyone's doubt. It shows that you are genuinely interested in teaching. Good work with the video.

[@bohanxu6125]

I'm fine with simplistic explanation as long as complications are mentioned, so people don't take what you said with absolute certainty....which will leads to confusion down the line. For instance, I got quite confused by the relation between reflection and transmission. Why would something that has large band gap (doesn't interact with light, ie not reflecting light) appear to be white? This is because macroscopic reflection include both microscopic reflection and microscopic transmission. This fact should be mentioned without going into the details, so the audience know that the language of reflection is ambiguous, so they won't confuse it with microscopic reflection.

[@alexvalenzuela5551]

Please come teach my modern physics class, you explain these complex topics in a way that is understandable and not monotone smh

[@tomasnovellino5980]

Now I understand why old computer models used cyan magenta and yellow.. they were using the subtractive primary colours. Which makes sense because on screen you want to easily generate black background. It is also weird because as a child I was thought the primary colours to be yellow, blue and red.. which applies for paint and crayons. Etcétera... but not light. I think in the end, you could argue that colours are like an algebraic formula. Where Y, B, R are commonly named as primary colours but are form of 2 additive and 1 subtractive primary colour ... hence all mixtures could be represented as an algebraic formula ... Nice 👌

[@carultch]

They probably teach you red/yellow/blue are primary colors as a child, because it's too complicated to teach children what cyan and magenta are, and very hard to get perfect cyan and magenta that can mix with yellow to get black. Since most of what the child will mix are pigments, they teach red/yellow/blue as primary colors, and call it "good enough for government work" and move on.

[@neekox]

If you pass a complementary color through a prism at the right angle, will the refracted colors consist of the primary colors that created it? Or will you just get the original complementary color?

[@jaishkhan7442]

You'll get shades of the same color

[@jaishkhan7442]

Including the ones that made it

[@carultch]

It depends on whether your original color was monochromatic or not. If you pass pure monochromatic yellow through a prism, you will get a single yellow color on the emerging ray. By contrast, if you pass a mixture of red and green light that look yellow to the human eye, you will get both red and green light separating from each other in the emerging ray. If you pass a continuous spectrum from red to green that looks yellow to the human eye when concentrated in the indicent ray, you will get a spread out spectrum of red/orange/yellow/green in the emerging ray. The same would also happen with the equivalents of cyan. Magenta on the other hand, doesn't exist as a single color of light, so you'd get both red and blue light separated from each other, if you pass magenta light through a prism.

[@nouraebrahim7284]

Please explain why apple appears in black colour when you look at it through a green or blue transparent glass sheet

[@philipp6634]

So when you mix two colors together, why does it change color then? do the two colors reflect two individual wave lengths due to theire molecular sturcture which combined make a nother color? im confused

[@carultch]

The reason why mixing colors works, is that the cone cells in your eyes are evolved to infer a mix of input colors as the in-between colors between the nominal colors of each of the three cones. Mix red and green light, and you will perceive yellow. An ordinary person cannot tell the difference between that, and monochromatic yellow light. A tetrachromat person might be able to tell the difference, but that is a rare genetic condition.

[@dainispolis3550]

Hi professor Dave! Question: We have a material , whooes lambda zero (on which materials electrons not emitted) is yelou, lambda - therefore this light not emits electrons, but look, let the this yelou light go trough green filter, then this light will be green? But in that case as wavelength diagram shows lambda on green is shorter and electrons must be emmited. What interesting this green filter does with light energy?

[@saschagrusche1573]

A yellow body usually reflects all colors except its complementary, blue. Therefore, the yellow body not only reflects yellow, but also red and green. The green filter then absorbs the red and yellow, but transmits the green.

[@dainispolis3550]

@@saschagrusche1573 For me question about yellou is already solved. There is a "two" yellows for a human - one where human receives red and green , another where is one wave length - yellow equivalent - it is what rainbow shows as yellow

[@saschagrusche1573]

@@dainispolis3550 Exactly.

[@physicslab5787]

Amazing video

[@EricPham-gr8pg]

Light spreading out as it travel and prism had different lenght so it spread out at different rate at shorter distance had higher intensity with less spreading than the longer lenght at other part of the prism it travel and spread more so lower intensity with different color appear

[@esrasaleh3020]

Please tell me what will happen if I shone white light into blue filter and then green filter. Would any light pass through?

[@TylerSimonds]

I’m sure some would! Beats me what that would look like tho

[@TylerSimonds]

Actually yeah-apparently blue and green combine to absorb all the visible light. This is so interesting

[@peeledblackpotato]

What decides whether an object reflects certain colours and absorb others?

[@scptime1188]

Where did you find the diagram for 3:31?

hey, lovely vid

[@LifeologyEducationProgram]

If an object like a mirror or clean water is reflecting all the light that hits it, what then is the principle behind white objects? Since black objects absorb all the wavelengths, shouldn't white objects reflect all wavelengths? Another way of saying this: What is the difference between a mirror and a white object in terms of how they play with light?

[@krishbisht6095]

Tumne to bahut Achcha padhaayaa hai aapka padhaayaa Hua Hamen samajh mein a Gaya

[@tkhaiku2401]

mr professor can you please explain the topic of astronomy 🤗

[@ProfessorDaveExplains]

check my astronomy playlist

[@tkhaiku2401]

@@ProfessorDaveExplains thankyou very much 🥰

[@thegameryt4779]

Professor Dave is fantastic ^w^

[@zeyroxlb6885]

ESTEZ YOUSEF🔥🔥💪🙏

[@alishamagotra6099]

Best Teacher of Physics though ur source is also book but ur explaination n ur understanding is outstanding Hatsoff to Professor Dave like God himself through u explained ng it soo well all His laws n phenomenons God's grace on uh Professor Dave 🌈🌈🌈

[@crocock3483]

This helped me win a debate against my friends. They said primary colors were red blue and yellow not green

[@SidheKnight]

Your friends were kinda right.. when talking about subtractive primary colors (the kind kids learn in school when combining paint pigments in art class). RGB are the additive primary colors, used for adding light sources.

[@sanjaygandotra644]

So light consists of three colors ? Red, Blue and yellow. And the other colors are secondary and show up as transition between two primary colors.

[@sanjaygandotra644]

@Tilz xxx If that's the case, then I have a billion dollar patent in mind. Who can sponsor my idea, can you help.

[@derrickckt8024]

@@sanjaygandotra644 ?

[@sanjaygandotra644]

@@derrickckt8024 [e-mail]

[@DANGJOS]

@@sanjaygandotra644 Not quite. Light is made up of a range of wavelengths, but there are only three light sensitive cones in our eyes, which respond most strongly to different wavelengths. The comparison of those responses yield the colors we can see.

[@sanjaygandotra644]

@@DANGJOS , thanks, that is the most relevant and logical input.

[@renanmonteiro5261]

that was awesome

[@mrmexicano64]

so I had have this question for a while already and can't get an answer I know computer's monitors use the additive primary colors yet it seems like you can't create black out from it. I been wondering how are monitors able to produce black since turning of a pixel (to me) seem like an ineffective way to produce the black color.

[@ProfessorDaveExplains]

hmm, i assume that a black pixel is just one where all the light is blocked? i dunno really! maybe one day i will do a playlist all about computer technology.

[@mrmexicano64]

Professor Dave Explains lol well thank you anyways. Your channel is the best BTW! and wish you the best!!! :D

[@byjonathan_]

That's great! I'm loving your channel. I'm brazilian. :)

[@hesha13]

Jonathan Augusto and i am juneollie

[@derrickckt8024]

No on asked where you came from...

[@jlpsinde]

Thanks Dave!

[@benas664]

Why the light is reflected? And what laws or properties determines it? Basicly whats is the reason leaves reflect green? Sorry if it's a dumb question.

[@ProfessorDaveExplains]

has to do with atomic structure! check out my tutorial on the bohr model of the hydrogen atom to see how atoms interact with light

[@coreycheng9926]

thank you buddy

[@kugaththeplaguefather6332]

why is Yellow+Blue= White? Can anyone please explain?

[@caw8635]

Yellow= Green + Red Green + Red + Blue = White Yellow + Blue = Green + Red + Blue

[@shantonoyona5687]

I had a question that; when the rest colors are absorbed, electrons chnage shells and returning back to their previous shell emit electromagnetic wave; so if that wave is in the visible wavelengnth will that gonna effect the color of the object?

[@intrpolfan1]

Can you please explain why a red rose appears black under blue light?

[@ThePoodle]

Blue and red are on opposite ends of the 'subtractive color wheel' like when you mix red and green paint you get brown. but with the subtractive colors of light, opposite colors make black

[@darcyoqueef2176]

Since there is no red light to refract from the rose it appears colorless

[@DANGJOS]

@intrpolfan1 Because the pigment in red roses (mostly anthocyanins) absorb blue light, but they don't absorb red light.

[@intrpolfan1]

DANG JOS thank you! I passed my test

[@DANGJOS]

@@intrpolfan1 Glad to hear

[@cajonbilly]

I like this

[@Vagdebrume]

I have a strange question ^^ : Why we have Red Orange Yellow, Green Blue INDIGO and Violet ? Why indigo and not other intermediate colors ?

[@ProfessorDaveExplains]

pretty dumb huh? i really don't know, i agree that there are other intermediate colors that occupy more bandwidth. i think it stems from newton's time, he may have been trying to make a correlation with musical scales or something. such is life!

[@zainabmehdi6380]

great video...

[@mytestimonychanneltv6981]

Intro: so kiddish During lesson:super serious

[@encyclopediaofvideoseov.2902]

i know that but atleast the teaching is good.

[@rohansachdeva3724]

I became happy after seeing Taj Mahal of my country.

[@Lia_0906]

How can i know the color of an objeft if it is illuminated by a blue light?

[@Carrot-ks7lb]

You can't. If you only see a red object under blue light, you'll never know it's red, because there is no red light to be reflected or seen anywhere Unless that object just blue, you may just never know what color it really is (I hope that all i said was correct and helpful in some way)

[@marialuisaassuncao8929]

shoutout to all the secret colors out there

[@wunky5591]

This is so pog

[@kennethpadecio4311]

Thnx Dave to understand me

[@prithvipanicker]

you da best

[@carultch]

Could a material exist in theory, that has a uniform refractive index across all colors of light? Could a material also exist in theory (or in practice), that has the opposite relationship between frequency and refractive index? I.e. lower refractive index in high frequency blue, and high refractive index in low frequency red?

[@airsmellnice4133]

No

[@rileytavares4087]

I did my own digging on lights as a child by opening the tv’s and other electronics.

[@supremeleader9579]

Colours of the rainbow hell yes!

[@suemiller9506]

This video is 5 years old, so you might not see my question. But I'm wondering why shadows on snow are blue. This occurs mostly - but not exclusively - when the sun is low in the sky.

[@bforbittoo8001]

what determines color of light frequency or wavelength?

[@ProfessorDaveExplains]

both, frequency and wavelength depend on each other and both describe the wave

[@bforbittoo8001]

But when light ray moves from one medium to another its wavelength changes because speed of light changes.Frequency remains constant in this case.Further more color also remains unchanged so shouldnt we say that color is a property of frequency?

[@DANGJOS]

@@bforbittoo8001 Correct. Frequency is the more fundamental property. In fact, the wavelength of light is always smaller inside our eyes. The color we perceive depends on how it interacts with the cones in our eyes of course.

[@carultch]

@@bforbittoo8001 Frequency is the more fundamental property that directly determines color, since if you change the frequency (e.g. Doppler effect), you change the identity of the color you see. Whereas if you change the wavelength (e.g. via refraction), the frequency and color both remain the same. The only reason we commonly identify colors by wavelength instead of frequency, is that above a certain frequency, it is no longer practical to measure frequency directly. You can measure a 547 nm wavelength a lot easier than you can measure a 547 THz frequency, even though they are the same color. The Terahertz frequency is simply calculated from the known speed of light. Implicit in the nanometers that define color, is that it is the free space wavelength.

[@DiamantitoOtaku_]

Wow

[@helium73]

So all the electrons in a leaf move to higher orbitals and stay there forever? The light never runs out of electrons at lower orbitals that it can raise to higher orbitals? What happens to the light of the other colors when all the orbitals in the leaf get filled up?

[@ProfessorDaveExplains]

no no, the electrons relax back down to a lower state and emit more photons, those are the ones that interact with our eyes! when we see an object, we are receiving photons that it is emitting. check out my tutorial on the Bohr model of the atom!

[@itsscience8115]

0:18 Professor Dave how about vib-gyor

[@whysegaming3212]

white black reflect

[@kathryntrn]

Why is green a primary colour in this video, isn't it yellow?

[@randomperson1714]

You mixed the two up. Yellow,magenta and cyan are secondary colours. Red,green and blue are primary are primary colours. Yellow can’t be a primary colour because it is made up from other colours.

[@carultch]

@@randomperson1714 Yellow/magenta/cyan are called subtractive primaries, because you mix the pigments together, and pigments "eat" color. These are primary colors, since they each absorb just one primary color of light. The trio of red/green/blue are called additive primaries, where if you mix light sources instead of pigments, mixing red/green/blue is what you'd mix to make white light, and two of these colors to make any of the subtractive primaries..

[@user-mu8cv2de3y]

❤

[@danielnaylor9069]

Hi to my science lesson

[@happydeath1575]

I always loved color science

[@EgyptsLost]

You're definitely gonna have to show me how all the colors combined give you white because I'm getting black with my experiments

[@SidheKnight]

The additive primary colors (RGB) give white when adding light sources (you can see this in screen pixels and RGB lighting). When mixing paint, you're combining substances that absorb light as opposed to emit it, so you'll never get white by combining other colors.

[@sanjeetkumarsharma3160]

Very nice

[@jessnopeniss561]

When we talk about pain, cyan + magenta + yellow = black. What about light? CYAN + MAGENTA + YELLOW = ????

[@lurelexilore1587]

You are bald

[@happilyevernever4289]

We know from *additive color mixing* that we start off with no colors (absence of light), so we basically start off with the *Black* color and we get the *White* color by overlapping or adding *Red, Blue* and *Green* lights together. For pigments, think of it as already beginning with the *White* color. You get the primary colors *(Cyan, Magenta and Yellow)* when you subtract one of the *RGB* colors from the *White.* Subtracting a color here means it actually gets absorbed into the material/object. While the other two colors are reflected and catches our eyes. For example, if we subtract *Green* from the *White* color, we are left with *Red* and *Blue,* which we perceive as the color *Magenta.* The secondary colors *(Red, Blue and Green)* happen when further subtracting occurs, where you subtract one of the *RGB* colors from the primary ones. For example, if we subtract *Blue* from the color *Magenta,* we are left with the color *Red.* Lastly, if you subtract the secondary colors from the material, there would be no light. Therefore, no color left for the material or object to reflect, so it would appear *Black.* Hence, why it's known as *subtractive color mixing.*

[@mariamrajput1443]

Can you plz tell me why we see blue color of sky instead of violet because violet has shorter wavelength than blue?

[@ProfessorDaveExplains]

it's just about the way that particles in the atmosphere scatter light, they happen to scatter blue wavelengths best

[@mariamrajput1443]

Professor Dave Explains thanku

[@DANGJOS]

@@mariamrajput1443 That answer isn't actually correct. Violet is actually scattered more, but there is also less violet light coming from the sun than blue light. Also, other colors are scattered as well, and they desaturate the final color a bit. Over all, the sky will range from a very light blue, to a dark blue 90 degrees across the sky from the sun (if it's low on the horizon).

[@lbfernandez257]

One historically misguided issue. If you were to mix a true Yellow pigment that reflects even quantities of red and green light at a greater value than blue light with a true BLUE pigment that reflects a higher value of blue light than an even quantities of red and green light then you would in fact make a neutral grey. i can prove it.. look me up if you have questions, Lino Bernabe

[@Dycdom]

OMG ..im sorry but this is like 20th of video which say the same...but no one actually explained what makes that somethings bounce specific wavelength .. what in my blue cup makes that its absorbing all the "colours" but not the blue? The lack of answer for that drives me nuts ! sorry.

[@ProfessorDaveExplains]

Check out my tutorial on the Bohr model in the general chemistry series to learn about why an atom would absorb a photon of a particular wavelength.

[@platano8893]

Dave my G

[@shiroluoibienglam0758]

Hi i have my test tmr and now i’m stupid

[@alabbascell8407]

Thx

[@spooksiscool]

No

[@ProfessorDaveExplains]

Yeah, bro.

[@bandarmohammed3175]

الجاي من مدرسة روابي الربيع لايك

[@Ahtohallan.]

لا

[@mandihyatt]

Can't help but notice orange doesn't exist?!

[@karhukivi]

Thar's true! Pigments are subtractive colours, not like light which is additive, so you can have an orange pigment but not orange light. The orange colour of the pigment is because it is reflecting red and yellow while absorbing green and blue.

[@sxntandave]

Thank you Jesus 🤗🤗

[@lolhelp6170]

Does anyone else click on almost all his videos just for the theme song?

[@malayapaul458]

hey you did not answer my Gmail question!

[@ProfessorDaveExplains]

patience! wait at least a day before getting antsy. i'm a busy fellow.

[@ffly.7947]

@@ProfessorDaveExplains you are trash

[@wgliam]

@@ffly.7947 Why? He takes hours and hours out of his days to make these videos, along with being a teacher. His videos are so informative and I suspect you don’t even have a reason.

[@lurelexilore1587]

@@ffly.7947 you are a trash too

[@leejoon2862]

MMMM, I WENT TO OHIO OF SCIENCE

[@dlon8899]

Therefore why is black classified as a color?

[@ProfessorDaveExplains]

well in science it's not, but we refer to it as a color in other areas, like art and stuff, as we do perceive black and experience something that can be thought of as blackness.

[@nickgentile6770]

Dollar store brand cr1tikal

[@Warcrimes-lw8qt]

Shout out to Choi

[@ophiolatreia93]

Indigo isnt a colour. Newton made it up so there'd be the magic 7

[@thebestofallworlds187]

can you talk about the major role the Jews played in the Russian Revolution please?

[@punkrock7906]

This most definitely proves how God's intelligence is so far more superior than humans He created can fathom!!

[@lumin10]

Why are you bringing god into a physics lesson

[@Thug_shaker445]

Open na noor

[@karasunull]

Where is thé orange light

[@ChopperKlNG]

roses are red violets are blue i leik chiken and so do u

[@periyasamypalanisamy1105]

this gave me nothing