Still coming back to watch it once more because I can't sleep and want to calm my mind 💫
@HaitaoWang2684 жыл бұрын
I am a 9 year old boy in Grade 4 in Melbourne Australia. I am writing to thank you for the lecture you gave. I am a fan of maths and physics. I am learning quantum physics on my own through Wikipedia and books. My teachers saw me doing this and they didn’t want me to get bored on my maths lessons so they gave me a task to explain the mathematics of a rainbow. I was having trouble at first in finding a good video until I saw your lecture. After seeing your video, I was really excited because I fully understand this topic now and I was also blown away by how you taught and summarized so well that even a 9 year old can understand. Cannot thank you enough!!! My dream is to solve the Navier Strokes equation and win the one million dollar prize! Anbo
@lecturesbywalterlewin.they92594 жыл бұрын
Thanx for your kind words
@Phymacss10 ай бұрын
I hope you are keeping up the good work! Great job!
@FabstaPizza9 күн бұрын
great job!!
@giuseppe3010 Жыл бұрын
As a child I saw lots of rainbow because it rained all the time in my native country!! But only now I understand HOW rainbows are formed. THANK YOU !!!Grazie mile !!
@caseylocke44744 жыл бұрын
I never thought a mathematics lecture would bring a tear to my eye. I don't know what to say so I will say the only thing I can: thank you, Professor Lewin. God bless you.
@dabanfarad87567 жыл бұрын
can't wait to see a rainbow again to make sure that knowledge only adds, thanks for showing the hidden beauty
@lecturesbywalterlewin.they92597 жыл бұрын
YESSSS if you remember the many features of a rainbow that you were NEVER aware of, you will confirm that knowledge only adds. Knowledge is the hidden beauty of the rainbow.
@mohitswami77295 жыл бұрын
Sir can you explain me that when we make a rainbow by the water then why the rainbow is make like a full round path
@burutatung2 жыл бұрын
@@mohitswami7729 because you are seeing it from the above where it can occur in 360,but if you made rainbow while laying then you will see 180
@ShivanshTrisal4 жыл бұрын
Rainbows are beautiful, whenever i water my plants, I will try to create them and it makes me happy and admire the beauty of nature. Thankyou professor, for such brilliant lecture and book
@lecturesbywalterlewin.they92594 жыл бұрын
My pleasure 😊
@VeganSemihCyprus337 жыл бұрын
Prof Lewin You are one of the first lecturers I have watched online, and when I watched one of your lectures, I had to watch all of them :D If only we had more teachers like you who loves what he/she is doing. Wish you the best :)
@lecturesbywalterlewin.they92597 жыл бұрын
:)
@7thHanuman2 жыл бұрын
@@lecturesbywalterlewin.they9259 thank you for your presentation on SEEING a rainbow. My question for Professor Lewis, WHAT is a rainbow? There are missing links on understanding of rainbows. Thank you for sharing.
@MattLaubhan128 ай бұрын
Dr. Lewin: A bonus question for a public lecture should be, "Can you ever reach the end of a rainbow?" Like the leprechaun. Can you reach that pot of gold? ;) Forgive me if somebody already thought of that question. Likely I suppose... Of course, MIT students wouldn't be stumped. Most of us know the answer. Thank you for all your wonderful MIT OpenCourseWare--over several prior decades. I am an R&D engineer in electrical and computer engineering. I love physics and electro-mechanical systems (the latter of which is waning these days). And thank you for continuing to present this knowledge via KZbin since then--re-publishing and your constant physics challenge questions. Colorful outfits and colorful personality! I also taught university for ~16 years (many of which while working full-time in industry). I learned a lot from your teaching techniques! Much love!
@MattLaubhan128 ай бұрын
An introductory question at the beginning of the lecture of course. A question before the first 6.
@navroopkaur37373 жыл бұрын
I had seen rainbow a few months ago and took some photographs. Now that I have learned so much about them , when I see those photos again ,I can't resist watching all the things which I have learned here. The Alexander's dark band ,the colour sequence of both the rainbows , the white light and no light area everything! It feels so good to know more. I don't want to resist seeing the things I have learned here. This lecture is amazing. I have surely fallen in love with physics of rainbow. THANK YOU VERY MUCH!
@natarshawiseone54814 жыл бұрын
Came here to learn about a Rainbow and fell in love with this Teacher. His passion and love of Knowledge will keep me watching more of his lectures. This was so gratifying, thank you!
@JmSantos784 жыл бұрын
He really is an amazing teacher. Imagine if all teachers had the passion on their subject as he does.
@Mukta4102 жыл бұрын
Absolutely right.
@thecoasterman1002 жыл бұрын
Prof. Lewin, This rainbow lecture has 100% changed my life. I come back and watch it again from time to time. Every time I see a rainbow, I tell all that are around me all about rainbows. It has been a wonderful thing to not only observe, but to share with others, and I thank you! Sincerely, Brandon Johnson Sandusky, Ohio
@lecturesbywalterlewin.they9259 Жыл бұрын
you are most welcome
@ashokkumarsheram60373 жыл бұрын
I saw this lecture last week, since than I was waiting for rainbow to see. And finally I have seen today, 3 bows at a same time. Primary bow was so bright that I could see its full semicircular arc and one of its leg was seen as it was about 200m away from me. Felt like I can go and touch it.
@Bangalibabu954 жыл бұрын
So much of energy, dedication and power you have in this age. Thank you much for sharing knowledge !!
@firozkhan_20023 жыл бұрын
Best explaination I have ever heard... Rainbow would be proud of you Sir! ❤️ Huge love and respect from India 🇮🇳
@Ibrahim_090004 ай бұрын
❤❤
@sahilKumar-lf7ir5 жыл бұрын
Outstanding I m greatful to Mr lewin for such a wonderful lecture that clears every doubt I have been fan of this genius professor since I watched his first lecture he never let his lecture to be boring .Every time I watch the lecture I learn something new and interesting . Thank you sir
@pierluigiugolotti6 жыл бұрын
This is pure poetry!
@lecturesbywalterlewin.they92596 жыл бұрын
:)
@b.physicist-photonic12017 жыл бұрын
He is a wonderful lecturer. I have watched almost all his lectures. They are really useful. I have learned Physics by his lectures. Thank you professor Lewin for making Physics lovely, beautiful, and simple.
@prakashgupta38234 жыл бұрын
Now, here is a teacher whom i can admire ..throughout my jounry i.e from my school to the college i have never seen a single teacher who is this much passionate about their work... i want to be an astrophysicist and i wish i get a teacher like you who make understand the fact and make me fall deeper and deeper in love with the subject ,just as like u did.. :-) a great respect to ur work sir.
@neal30825 жыл бұрын
Indeed it answered my question.. And now I know the reason for my confusion.. I always thought that rainbow is caused by single drop of water.. And I think prism experiment that I did during my school days was the reason to think so .. but your lecture not only cleared my doubt.. but give me insightful knowledge which will remain with me to eternity.. thank you
@1000Zebedee3 жыл бұрын
Tremendous explanations and mesmerising. This is the 4th or 5th time I have watched your lecture on rainbows Mr. Lewin. Full marks for your presentation.😀
@divyanshichauhan44083 жыл бұрын
Left speechless after being taught by such a great teacher.. 🙏🏻🙏🏻 Respect and prayer for your well being sir from India..
@jerryfrugoli33395 жыл бұрын
Although I’m already familiar with this material I so enjoy your lectures, and strongly recommend your lectures over mine any day of the week. You sir are a treasure, thank you for sharing your work.
@lecturesbywalterlewin.they92595 жыл бұрын
:)
@desireew77007 жыл бұрын
After watching this past summer, I produced a complete circular rainbow about 5 ft in front of me, while watering my garden one early morning. The Sun behind me rising in the East, as I faced the West observing this complete revolutionary rainbow!! The knowledge passed on by such a brilliant mind has ignited a passion and deep desire to learn and understand the mathematical phenomenon which surrounds us. Forever I am thankful for you, Walter Lewin :)
@kshitijsharma-jd7hr6 жыл бұрын
What an amazing lecture! Everything is so crystal clear now in my mind.
@lecturesbywalterlewin.they92596 жыл бұрын
:)
@joblessalex4 жыл бұрын
Thank you so much for this. Any time I'm with someone and there's a rainbow, I point out all these features and get "wow!" and "I never knew!" Even some "Daddy, come look!" I'm keeping this with me till I die. Every idol I've had is gone now except you.
@lecturesbywalterlewin.they92594 жыл бұрын
:)
@steffenleo59972 жыл бұрын
Great Lecturer Prof Lewin.... I will expressed it this Way... The hidden beauty of your Lecturer is science.... Thank you Prof.... 👍👍
@aaqidmasoodi6 жыл бұрын
I am Sooo Damn Lucky that I am able to experience Professor Lewin's Lectures... and pause them and rewind them... Oh Boy! :)
@pauloleandro75662 жыл бұрын
Amazing class. I watch almost every year before my refraction\ prism class. Thank you so much Mr Lewin.
@lecturesbywalterlewin.they92592 жыл бұрын
You are very welcome
@mrmomb6 жыл бұрын
Fantastic presentation! I will never look at another rainbow but from here forward I will clearly see them. You had this retired man on the edge of my seat for the last hour plus. K2LED
@user-kc4mk9hp1m7 ай бұрын
Sir I am 14 years old. And I am from India. Respected sir you are teaching and way of explaining the information ℹ️ is very good 👍 . Sir this topic is in our school textbooks I can't able to understand in my school 🏫 when my teacher was teaching. But now my all concepts are cleared . Thank you sir for teaching free of cost in very easy language. Thanks sir very much. ❤
@Protegit6 жыл бұрын
This is amazing! Thank you professor for sharing your knowledge with us
@lecturesbywalterlewin.they92596 жыл бұрын
:)
@visualflights45738 жыл бұрын
Awesome! Enjoyed it.
@monsieurmitosis6 жыл бұрын
Holy shit, how does he draw those dotted lines so quickly!?!?
@MK-mt7yf6 жыл бұрын
vibration. Holds the chalk more at the other end which results in the chalk "hopping or jumping" as unstable.
@billglaser6 жыл бұрын
Friction basically, the chalk skips across the board and depending on pressure and grip on the chalk, that determines the length and distance between the dots.
@CocktaiLMolotovX3 жыл бұрын
Parkinson can help you to do that.
@hseverins3 жыл бұрын
@@CocktaiLMolotovX professor Lewin has not got Parkinson
@MrU4theChillWind3 жыл бұрын
He's a Wizard, Harry!
@xrisku6 жыл бұрын
wow, AMAZING lecture. in calculus, we are skipping the rainbow (boo hiss) due to too many snow days. so I decided to explore on my own. i am SO GLAD I DID! now I have the disease too. thank you so much. :)
@wiegervanderburgt7 жыл бұрын
Thank you for uploading and thank you for the epic lectures Walter Lewin. finally someone that is able to explain properly such a beautiful thing:)
@lecturesbywalterlewin.they92597 жыл бұрын
Thank you Wieger
@manojmakal16065 жыл бұрын
Thank you professor.
@debmalyasen14 жыл бұрын
woww spellbound. Thanks for such a beautiful lecture. You made my day.
@lecturesbywalterlewin.they92594 жыл бұрын
I'm so glad!
@odysseashlap7 жыл бұрын
What an outstanding performance!
@lecturesbywalterlewin.they92597 жыл бұрын
:)
@Zeyadhany Жыл бұрын
Wow! physics is a real enjoyment.. Thanks alot from Egypt 🇪🇬👍
@aarzoosrivastava11022 жыл бұрын
I saw two rainbows yesterday in some distance. I related these with this lecture
@sh4m4npi7ot96 жыл бұрын
Whatever this Lecturer has got... it's definitely contagious :D
@PhilTaylorPhotog2 жыл бұрын
Thank you Prof Lewin. I have a degree in scientific photography, did assignments on rainbows back in the day, but even though I understood the physics, I never saw it quite like this. Fantastic.
@lecturesbywalterlewin.they92592 жыл бұрын
Wonderful!
@Paul-ph7zb9 ай бұрын
I just had a textbook example rainbow right in front of me outside the window, even the secondary rainbow was bright and clear. Ever since I watched that lesson of yours many years ago I`m always thinking of you when I see a rainbow and hope you are well.
@ivanyesidguzman6 жыл бұрын
Profesor, estoy leyendo su libro y es maravilloso como muestra de forma clara las maravillas que nos rodean además de su sencilla y a la vez intrincada belleza.
@lecturesbywalterlewin.they92596 жыл бұрын
Estoy encantado de que te guste mi libro
@heetmalani31776 жыл бұрын
Sir i was reading your book for the love of physics, i didn't understood the white circular rainbow, that was happening due to fog and created beautiful background rings behind the body. sometimes it is hard to imagine while reading but by this lecture video is imagination got better to understand this type of topic.
@baijnathkumar83623 жыл бұрын
Your every lecture make me love physics. You are like a god for me now. In india in my city there is no teachers teaching physics as physics. they teach math. They are using language of equation not the hidden beauty of physics. After watching many of your lecture i have decided that i have to study physics. By the way i don't know english very well. i am trying to learn. But i can understand your lectures easily. I think may be it is because there is pure physics in your lecture not Language. Thank U very much.
@kana13722 жыл бұрын
His connecting lines is always a legend for me.
@sadececns002 ай бұрын
"Knowledge always adds, knowledge never subtracts..." ❤❤❤❤❤🌈🌈
@sameer261219807 жыл бұрын
Nice rainbow shirt Sir Walter :)
@alistiqamat70664 жыл бұрын
Thanks again and again...... 😎
@uthpakhi5 жыл бұрын
Just saw an full rainbow. Sir you cam in my mind. ❤️❤️
@lecturesbywalterlewin.they92595 жыл бұрын
:)
@alessandrolima42664 жыл бұрын
For sure I've never saw a rainbow before. Amazing
@CarlosDuarte20074 жыл бұрын
This is sooo cool!! Now I know that to find the gold at the end of rainbow I only need to walk 42 degrees out of the line of my shadow!!
@lecturesbywalterlewin.they92594 жыл бұрын
you got it!!!!
@CarlosDuarte20074 жыл бұрын
=) Great lecture!
@prasantpanda56804 жыл бұрын
@@CarlosDuarte2007 Will you please explain how is that so? I didn't understand...
@GPCTM6 жыл бұрын
One don't say "the famous physicist Newton". No. We say "Newton". And we bow.
@David-km2ie5 жыл бұрын
true
@CarlosDuarte20074 жыл бұрын
He had to say ... "The Physicist"... we should know refers to Newton. =)))
@timmy181354 жыл бұрын
One doesn't say "the famous philosopher Plato" We say "the philosopher" And we bow
@ankurbakshi5 жыл бұрын
Hello sir... You are a genius... The simplicity with which you explain is amazing.....
@lecturesbywalterlewin.they92595 жыл бұрын
:)
@susansutton17126 жыл бұрын
amazing. thank you x
@lecturesbywalterlewin.they92596 жыл бұрын
:)
@FabstaPizza3 күн бұрын
this is amazing, ever since I was little I wondered how rainbows are so perfect, so circlular Im 13 and dont know much in physics or maths but u made it easy to understand, thank you alot!
@lecturesbywalterlewin.they92593 күн бұрын
Wonderful!
@tiantianchen25563 жыл бұрын
Thank you professor
@mahendiran475 жыл бұрын
All of your lectures really remind me of einstein explaining the theory of relativity which I saw in national geographic channel...All of your explanation are like "hey i am the inventor of physics". And With no doubt you are the Another genius of this Planet
@kamalansari14175 жыл бұрын
OMG. Understood rainbow for the first time. amezing
@evanjoshychittilappilly79596 жыл бұрын
Nice teacher for a good university. I love physics and I want to enrolled to MIT, just to hear your amazing lectures. To know how to make excitement out of boring subjects. Sadly In studying on 9th
@lecturesbywalterlewin.they92596 жыл бұрын
:)
@FinBoyXD2 жыл бұрын
Good explanation!
@lecturesbywalterlewin.they92592 жыл бұрын
Thanks!
@abhaypal51554 жыл бұрын
Hello sir I recently snapped a few picture of rainbows and I would like to share it with you. How can I do that? Thank you.
@trevorkearney30884 жыл бұрын
Absolutely brilliant. Thankyou. I'm puzzled by one of your comments - Is the speed of light in water 33% less than that in air or 25% less? If v in water is 0.75c, then n[water]=c/v=1.3333..
@carultch2 жыл бұрын
The reciprocal of "33% more" is "25% less". Percent differences aren't a simple reversal, when taking a reciprocal. They are close to a simple reversal, when it is a single digit percent change we are talking about, but not for percent changes as high as 25% and 33%. X% more is 100 - 10000/(100 + X) percent less. Since the index of refraction of water is about 1.33, the speed of light in water is 25% less.
@Jirayu.Kaewprateep3 жыл бұрын
What if seeing rainbows from inside room or other medium⁉️ They remain all color or fews of identical since the yield value change even using windows.
@emnabensallem39305 жыл бұрын
hello sir lewin! I want first of all to thank you because through your lectures i am learning to see and notice the wonderful natural world around me ! that being said , allow me sir to ask you a question about light diffraction : what the condition on the width aperture that should be fulfilled in order to obtain this phenomenon?
@lecturesbywalterlewin.they92595 жыл бұрын
question unclear. I cover light diffraction in my 8.03 lectures
@ranadas38702 жыл бұрын
Prof. can we see only a secondary rainbow without a primary one?
@varunahlawat90133 жыл бұрын
OH DAMN! those are millions of diffused light cones, now I know it I already love physics and I love it more now!
@iamthealgorithm31907 жыл бұрын
I'm not sure how to word this question, I will try my best. Why is it that the primary rainbow does not have two reflections and a phi minimum instead of one reflection and phi maximum? Or, what determines the amount of reflections made in a single water droplet?
@lecturesbywalterlewin.they92597 жыл бұрын
Watch my lecture. It's all explained there. You can also watch kzbin.info/www/bejne/l3eZkqind6iDpLs which is a little bit more advanced.
@cbbarh3 жыл бұрын
🙏🙏🙏🙏🙏⚘⚘ no words to say.
@imdadkhambatikhambaty41422 жыл бұрын
I had previledge of seeing circular rainbow. One afternoon on rainy cloudy day I happened to look upward in sky. The sun was hidden by a patch of cloud and rainbow was formed on peripheral of cloud
@lecturesbywalterlewin.they92592 жыл бұрын
that was not a rainbow. That was the 23 degree halo. use google
@JarekKordalewski2 жыл бұрын
After that lecture I never look at the rainbow in the same way as before
@TheaDragonSpirit7 жыл бұрын
Line of sight is not a straight line, so one can see multiple angles at the the same time. Unless one specifically focuses on a point, but even then one can see multiple lines of sight. If you squint your eyes you can see less lines of sight.
@sachinagashe63523 жыл бұрын
Interesting....
@salmanashfaq8448 Жыл бұрын
When you consider a drop of water and a ray of light entering at A the ray then refracted toward below in drop why does ray not refracted above from the original ray?
@meikejune40092 жыл бұрын
Walter, in this playlist I miss your video :20th century Art in the eyes of a Physicist. That is one of my favourite. Please take it into your list.
@lecturesbywalterlewin.they92592 жыл бұрын
my art lecture is in the same playlist. Look more closely. It's the first video in this playlist.
@meikejune40092 жыл бұрын
@@lecturesbywalterlewin.they9259 Yes, I looked more closely. You meant Pl.: "Special Talks" But I asked to add the video in your list: " Best of Walter Lewin" . It is one of your best lecture, we both know that, Walter.
@lecturesbywalterlewin.they92592 жыл бұрын
@@meikejune4009 OK will do
@meikejune40092 жыл бұрын
@@lecturesbywalterlewin.they9259 That makes me happy, because I love this lecture the most.
@meikejune4009 Жыл бұрын
@@lecturesbywalterlewin.they9259 Do you remember the white rainbow? Look at them: kzbin.info/www/bejne/f5XVYZ6tpsqUr6c
@firebird21863 жыл бұрын
Sir Lewin , last night it was full moon in where I live . When I looked at the moon behind the transparent thin layer of cloud I saw a circular rainbow (moonbow) surrounding the moon. This phenomena was observed only when a thin layer of cloud was present. Unlike regular rainbows, the source of light was behind the rainbow rather than being on the opposite side. I tried to figure it out and did some research on the web but found nothing fruitful. Would you be kind enough to explain this phenomenon Sir.
@lecturesbywalterlewin.they92593 жыл бұрын
If it wasa circle around the moon then it was probably the 22 degree halo. use google for more pictures.
@hseverins5 жыл бұрын
Beste Walter , nogmaals bedankt voor je boek en leuke slingerfoto ....... ik heb in de tijd dat ik jou volg ,wat foto’s gemaakt van regenbogen! Ik heb er inderdaad heel veel naar gekeken, maar nog nooit een gezien 😏😏😏! Tot je optreden bij DWDD . Tevens heb ik een foto gemaakt van mij en mijn dochter mét jouw slinger foto! Zou ik jou die toe mogen sturen ??? Groeten uit Oosterhout
@sciencetadiumofficial7 ай бұрын
Too good 💖
@lecturesbywalterlewin.they92597 ай бұрын
Thanks a lot 😊
@merveozyalin4 жыл бұрын
Dear Dr. Lewin, I have to choose a background color for a rainbow project. I heard the darker background, the more visible the rainbow is. Is it true? If so, should I choose the background black? Or is there an optimal color for that? And what is the scientifistic reason of darker background makes the rainbow that is in front of it more visible?
@lecturesbywalterlewin.they92594 жыл бұрын
Merve there is no such thing as one background. Watch my lecture. I explain why the sky inside of the primary bow is quite bright (white light). Why the area between the primary bow and the secondary is very dark (Alexander's Dark Band) and why the sky outside the secondary is not very dark, but nowhere nearly as bright as inside the primary. I suggest you google "rainbows" and click on "images". You will see more rainbows than you may have ever seen in your young life. You can then decide which *backgrounds* please you the most.
@schang_lh4 жыл бұрын
@27:05 if the red light is anywhere within the 42 degree, does that mean all the colours beneath (yellow, green, blue...) consist of some element of the colour red? And the centre consist of all colour, thus resulted in white?
@lecturesbywalterlewin.they92594 жыл бұрын
"white" sunlight consists of many different colors. Due to dispersion, the different colors emerge from water drops in different directions. Just like in a prism.
@lecturesbywalterlewin.they92594 жыл бұрын
en.wikipedia.org/wiki/Dispersion_(optics)
@sebastianfrohlich75056 жыл бұрын
Where does those Intenstity Peaks come from? (Minute 31:00). Couldn't find anything about that. :(
@lecturesbywalterlewin.they92596 жыл бұрын
It's due to the geometry. Do some ray tracings it will then show up. Or even better write a program that does the ray tracing for you.
@pawelbjanowski4 жыл бұрын
Dear Mr Lewin, I was also curious about that so I've done some Excel calculations and I have such maxima but they are nothing like those on the blackboard... I used Fresnel equations for calculating two transmission and one reflection coefficients... I haven't included "area density', or simply the flux of the rays... The max intensity of rainbow rays is approx 29 deg, but there are as you mentioned above many more rays for the 40 deg angle... IT works :) I have added intensities in one degree steps manually. Thanks to you, Mr Lewin :)
@lecturesbywalterlewin.they92594 жыл бұрын
@@pawelbjanowski max intensity is at phi_max which is 42 degrees for red light. watch kzbin.info/www/bejne/n3y4hIqAjLKGoZY
@TheaDragonSpirit7 жыл бұрын
Get a glass, look at the very bottom of it, you will see light sort of refracting away. Can't see your finger thought it. Same in water, this is how to make an invisible suit by the use of refracting light, so that all in front is behind. 11:47 You could also use a strobe light effect but most people would notice that, even if they could not see you.
@astropredo4 жыл бұрын
Professor, you said that would be *no light* after 42º. But what about Mie Scattering?
@lecturesbywalterlewin.they92594 жыл бұрын
rainbow is not due to Mie scattering.
@astropredo4 жыл бұрын
Lectures by Walter Lewin. They will make you ♥ Physics. Yes, professor. I understood your class, and for the first time I do understand the rainbow, and I really thank you. Im amazed. And I am using this knowledge to make a scicomm video in portuguese to explain it to brazilians! Its an entire series called “colors of the sky”! Its on the channel AstroTubers, that I create videos along with other 31 brazilian astronomers and physicists! Im really engaged. And I read your book, and more than that: I participated here on Who Wants to Be a Millionaire, that will be aired in a saturday afternoon in the biggest TV company in Brazil - the second in the world - and guess what: I spoke about your book. So maybe, september 21st I think it will be aired, your book sellings over here will have a spike. Well, about my question: you said that there is no light after 42º, ok, but, while the light interacts with the drop of water, doesnt it also scatter? Like Mie Scattering? If so, wouldnt it also go after 42º? And make a white color - however maybe even impossible to notice for 1 drop? Or maybe the scattering will also have a maximum angle and that indeed will be *no light* there. Thank you. You inspire me to be an edutainer for portuguese speakers!
@lecturesbywalterlewin.they92594 жыл бұрын
:)
@Zak_Bone5 жыл бұрын
My inspiration.
@astropredo4 жыл бұрын
Professor, are these lectures creative commons? I would like to use the laser demonstration to illustrate reflection + refraction on another video explaining rainbows in portuguese. Is it possible?
@lecturesbywalterlewin.they92594 жыл бұрын
go ahead
@merveozyalin4 жыл бұрын
Dear Dr. Lewin, I was outside looking at 42 degrees up from my shadow, making my friend spray water. Yet, I just saw only a little bit of specturum. So, I was wondering how does size of water drops or heat effect rainbows? How do I get a better rainbow? with a more powerful sun? with a spray that creates bigger water drops? What is the optimum way of doing it and how can I calculate it? Thank you!
@lecturesbywalterlewin.they92594 жыл бұрын
Merve I have a water hose for my plants in my garden. When I choose the option of very wide beam, if there are no clouds I always see a wonderful rainbow, over an angle of at least 30 degrees. Of coz the bow is everywhere 42 degrees off the line from my head to the anti sun (which is below the horizon).
@swapnilthorat37426 жыл бұрын
Hello professor, Sometimes we see a distinctly bright circle around moon. What is it called? How is formed?Is it result of same phenomenon that causes rainbow? I see no rain drops there causing it.
@lecturesbywalterlewin.they92596 жыл бұрын
google 20 degree halo
@TheaDragonSpirit7 жыл бұрын
Knowledge only adds when you can reproduce it in reality, this way you get a sense of creating art or experimenting. So like a child you can be in awe, the first time you see something beautiful and then later knowing you can replicate it on demand is a wonderful feeling.
@alleneverhart41416 жыл бұрын
i once saw a 360 double rainbow from Mt Washington. this is called a 'glory'. the sun was high in the sky and shining down on clouds in the valley. glories are commonly seen from airplanes flying above clouds.
@lecturesbywalterlewin.they92596 жыл бұрын
yes, glories are very common. I have seen many.They are not rainbows as they are not caused by rain.
@alleneverhart41416 жыл бұрын
yes, but it just doesn't sound right to call them cloudbows.
@lecturesbywalterlewin.they92596 жыл бұрын
they are cold glories - plain and simple
@alleneverhart41416 жыл бұрын
yes, to the cognoscenti it is glory, but, if i'm describing what i saw to my mom - it was a rainbow.
@lecturesbywalterlewin.they92596 жыл бұрын
Excellent When I describe it to my kids or wife, I call it a glory.
@santkumarhooda327611 ай бұрын
Thanks
@abhishekagrahari12194 жыл бұрын
Sir, then position of the same rainbow is different for people at different positions.
@tapendrabc9048 жыл бұрын
good morning professor. I also love physics and I always had a quest for knowledge in physics. I want to aquire a lot of knowledge in my life. I want a favor from you....
@lecturesbywalterlewin.they92598 жыл бұрын
+Tapendra Bc ????
@Paravetje6 жыл бұрын
I saw (part of) a red rainbow once at sunset, because there was only red light hitting the raindrops, it was beautiful. Edit: I posted this just before he talked about rainbows at sunset or sunrise, I'm so smart.
@subhankarpaira86623 жыл бұрын
Sir , the change in angle is (180 - phi)
@giovannigrassi27078 жыл бұрын
I KNEW WHY YOU DON'T SEE de Withe bit blue!!!i tought and tought stopping the video ,and at the end i arrived myself! I fell soo smart! p.s.sry for Any mistake
@tomy14557 жыл бұрын
Is refraction the reason why the sky is red in the afternoon?
@lecturesbywalterlewin.they92597 жыл бұрын
not refraction Rayleigh Scattering in the atmosphere
@tomy14556 жыл бұрын
I see. Thank you for the reply! :)
@shadowmedow40283 жыл бұрын
why fi = 4r-2i can u explain its derivation please
@bpark100016 жыл бұрын
The red cone drawn at 33:42 in video is not properly oriented. Its axis should be parallel to the incident sunlight, not parallel to the direction the observer is viewing.
@ibrahimamezyane90426 жыл бұрын
Brian Park you are right, yet I think it's just a mistake and the cone would cover the observer's view anyway. But you are right.
@ibrahimamezyane90426 жыл бұрын
Brian Park he actually corrected that a minute after
@firebird21863 жыл бұрын
You made me fall in love with Physics sir.
@lecturesbywalterlewin.they92593 жыл бұрын
8.01 Physics Hans C. Ohanian Physics 2nd edition W.W. Norton & Company ISBN 0-393-95748-9 8.02 Physics for Scientists & Engineers by Douglas C. Giancoli. Prentice Hall Third Edition ISBN 0-13-021517-18 8.03 Vibrations and Waves by Anthony French CRC Press ISBN 9780748744473 8.03 Electromagnetic Vibrations, Waves and Radiation by Bekefi and Barrett. The MIT Press ISBN 0-262-52047-8