Huygen's theory of light & wavefronts | Wave optics | Physics | Khan Academy

[@Eternal_stardust]

Wow ! Never had an idea that learning can be so fun. Animation is at next level . Thanks for such videos .

[@m.c.4674]

don't worry it will be even more fun when aether theory take back it place from relativity .

[@extreme4180]

@@m.c.4674 Yeah

[@ariebaudoin4824]

As i dutch person i can tell you that your dutch pronounciation is verry good sir, also, a lot of dutch people dont really know how to pronounce huygens

[@AbhayJaiswal-tf9iu]

Hooligans Am I correct?

[@NobS019]

​@@AbhayJaiswal-tf9iu that's crazyy

[@purityvsprofanity2962]

WAIT WHAT???!!! Ive been watching other videos that made wavefronts so complicated i thought it's a very fancy thing... and they're just ripples! thanks Khan Academy for making things easy and yet concrete!

[@marvhartigan3677]

beautiful explanation my man, made me appreciate science, thankyou thanks a lot.

[@rizzmechanics]

You're carrying my whole study at this point. thank you for the easiest explanations🙏

[@GlennGoossens]

It could be helpful to emphasize that the animation at min 2:05 is NOT how light actually propagates. This would be how light propagates if it was a longitudinal wave like sound and if there was something like aether in the universe (as Huygens etc. first imagined) so that the particles of the medium would get pushed closer together (compression) and then farther apart (decompression) again as a way to transport energy. In actuality, light is a transversal wave and the particles (photons) are in constant movement away from the source.

[@arunimachakraborty4596]

I have a confusion. Please help me out. Does Huygens theory have some limitations then? As aether medium or aether particle doesn't exist, then is the principal of wavefront correct? Since the wavefront principal is based on aether medium, should it be correct? And if it's not correct, then is there any alternative theory? A theory which can explain light's interference, diffraction as well? Because we know that the wavefront principal was able to explain these natures of light. If that principal is wrong, is there any alternative/supplementary theory to describe these natures?

[@utkarsh7225]

​@@arunimachakraborty4596 no, this theory is sufficient but the one thing that has been corrected is the type of wave. Hugens had assumed it as longitudinal wave while it is a transverse wave because it is electromagnetic radiation which propagates three dimensionally so the comment on the medium " Aether " get meaningless.

[@HimanshuKumar-kz8rx]

Well I really can't go into the transverse wave thing because I don't fully understand it or even a little bit but I just wanna say light isn't made of photons. We don't know what is it made of. There is a famous notion which is a popular joke which goes like light behaves as a particle on Mondays, Wednesdays and fridays and as wave on Tuesday, Thursdays and Saturdays and on Sundays we don't talk about light.

[@droshumbaloch5850]

your voice is so smoothing😍❤

[@fequalsmalol]

newton and huygens staring at each other at start 😆

[@AnantKesarwani-dw4rz]

0:26 i like how both newton and huygen started looking each others as rivals 😂😂

[@marybiswas6445]

These animations are my saviour

[@icarus3797]

Bro, I'm watching from Bangladesh. You're the best

[@varshithakv9765]

You made it sooo simple thankyou

[@Shukla.sanskar]

I can't believe that concepts can be made this much easier by animation

[@Noone-wz1ys]

Thank u Khan academy. It was really helpful

[@ryostyles9904]

Thank you very much. Those technical terms didn't give me much of an idea about a wavefront, but your video did.

[@VG__]

3:09, 4:56 wavefronts 7:05

[@ChiragSonne]

This teacher is smart and awesome!

[@adityaparanjape3827]

Thanks a lot

[@asciencestudent]

reeeallly reeeaally good explanation! thanku so much :)

[@marvhartigan3677]

i agree its a very beautiful explanation, you are a woman of culture Shrutika!

[@asciencestudent]

@@marvhartigan3677 woman of culture lol thanks ❤️😂

[@jondeere5638]

Newton at different times of his life thought they were both particles and light, and changed his mind.

[@Ethiohope]

Thanks I understand its concept

[@OkusoluboOluwabusayomi]

This is so beautiful.. thank you very much sir.

[@snowflake______]

Thank you

[@inshaalish2]

Thank you so much😊

[@prakash.r8059]

Realllllly reallllly good explanation !

[@sashwatyo1293]

So sir, what is it that vibrates when a light propagates........for water ,it was water particle itself, but what is it for light?

[@harrypanthero4858]

Electro-magnetic waves,he said it at the end of the video,Khan academy also has videos on that.

[@arunimachakraborty4596]

Later it was discovered that light is a electromagnetic wave. As a result, light doesn't need any medium to flow through (electromagnetic waves don't need mediums to travel). Nothing vibrates. Electromagnetic waves occur when there's a electric field and magnetic field perpendicular to each other. The waves are too at a 90° angle with electric and magnetic field. Imagine a 3 dimensional graph, where all the three axis are at 90° angle with each other. That's how the setting is between the electric field, the magnetic field and the electromagnetic wave. The creation of those waves are simultaneous with how those electric and magnetic field are acting. I believe KhanAcademy has videos about this topic too. You can check those out.

[@Wilayat1]

​@@arunimachakraborty4596changing electric and magnetic fields btw nice explanation

[@sweetchilli9014]

Thankyou into 100

[@adityashinde6197]

0:23 what's up with those eyes? By the way, enjoyed learning wave optics through this video.

[@niranjan7457]

Sir 🙏At 03:12, can we say that simply put, a wavefront is a sphere/circle/plane (depends on 2D or 3D)?

[@vaibhavnegi9273]

Best explanation 👌

[@arunimachakraborty4596]

Thank you sir for the video. I have a confusion...does Huygens theory have some limitations then? As aether medium or aether particle doesn't exist, then is the principal of wavefront correct? Since the wavefront principal is based on aether medium, should it be correct? And if it's not correct, then is there any alternative theory? A theory which can explain light's interference, diffraction as well? Because we know that the wavefront principal was able to explain these natures of light. If that principal is wrong, is there any alternative/supplementary theory to describe these natures?

[@m.c.4674]

well their is special relativity which says their is a pocket of measurements (energy is a measurement) moving through space . this is what replaced the aether , a pocket of nothing. also don't make them confuse you ,they like to call the pocket of measurement a particle sometimes . but we know it is not a particle because particles scatter and doesn't produce any interference pattern . special relativity Believes , that a wave is waving it self through space , well that's just crazy ,because we know that a wave is what something does and is not an actual object . that's is why I say that it is a pocket of measurement . well you probably wont believe me and think I'm crazy , but if you are interested in science what i just said with repeat in your head over and over , until you are force to conclude their is countless flaws in special relativity or deny it and move on just like must people .

[@georgestanciu5466]

Brilliant video. I guess that light propagate in 3d because is massless? also my guess is that the photon moves in spiral...

[@anishaghosh101]

Higgs field is everywhere but u can't see it

[@a.pal_yt2018]

UR GODFATHER! HELP ME CLEAR IITJEE THIS YEAR ITSELF!! SIR

[@harshvardhanrajput4730]

Congrats man

[@harshvardhanrajput4730]

I'm a 2024 aspirant, any tips

[@natte431]

Why is it vibrating = Whybrating 📈📈📈

[@physicslab5787]

Nice explanation

[@induvr131]

Waittt.. flat earth mentioned😂 6:58

[@roshaans7129]

plane wavefront

[@pandurangnaik9291]

huygens thought that light travels like a shock wave from a big boom explosion like in nuclear boom

[@TusharDhiman-dr8ei]

point source

[@poonamnagar3512]

It's ether

[@tejikachoudhary6340]

: )very nice: )

[@zarmeenaajmal5773]

I am friom pakistan thanks for uploading thease video s

[@siyaramsingh7915]

I did not hear about aether medium

[@anishaghosh101]

Well it is because it's not in our course ,,, it's just an hypothesis or theory and it doesn't end up making sense so it's out of context now

[@divyanshushankar8134]

@@anishaghosh101 earlier scientist used to think that light cannot travel in vacuum ...so they hypothesised an imaginary medium called ether.

[@anishaghosh101]

@@divyanshushankar8134 you know I like the fact that so many of us gettt knowledge from the Khan academy. I love you people who supports Khan academy

[@Manishasgamingturbo]

👍🏻

[@Junaidhoque-]

sir ur accent is very dangerous........

[@nisha-rx4uo]

Can you pin me that animation please

[@MinarulAfrin]

Plz sir translate in Hindi

[@Mahiaxeous]

69 comments lemme fix it😎

[@zayan5128]

U ruined it lil bro

[@harshvardhanmankotia6492]

This video is has a jojo reference

[@ayshakhatun00]

Yal where is the genshin impact community??! AETHER MEDIUM

[@induvr131]

Waittt.. flat earth mentioned😂 6:58