Young's double slit introduction | Light waves | Physics

Young's double slit introduction | Light waves | Physics | Khan Academy

Рет қаралды 971,716

10 жыл бұрын

We can see interference in action if we shine laser light through two slits onto a screen. Created by David SantoPietro.
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Пікірлер: 356

@ThatDudeEddiee0 6 жыл бұрын

I spent 1 hour in lecture and 1 hour in lab and was so confused as to understanding the constructive/destructive interference, the first minute at 40 seconds answered just that. BIG THANKS.

@tamilachirajeshwari701 2 жыл бұрын

Can u tell me definition of constructive nd destructive interference...🙄

@IdunDied 2 жыл бұрын

@@tamilachirajeshwari701 When waves of same kind in cross they combine to make one wave at that point. Like if a high water wave went into another higher one it would be higher at the point they cross because the water is being lifted up by both. Constructive is when the waves add together to make a bigger wave. [aka when they cross you add amplitude together]. However if one wave was in the other direction (negative) to the other (positive), if they were at same height (amplitude) but in those opposite directions they cancel out so there is effectively no wave at that point. That's why it's destructive. Constructive and destructive usually mean where the waves are either crossing at max height in same direction (constructive) to make new one double the height, or they are same but opposite direction so completely cancel (destructive).

@KibyNykraft 2 жыл бұрын

Everyone seems confused... Why is there no interference pattern on the first wall? How do we know the photons pass gently uniformly through the next wall slits in the same manner as through the first? Let's follow the classical mechanics here of early Einstein and of the the classical physics, assuming that the photons are discrete pieces of matter : Once they enter through the first slit from the candle or lamp, there is a second wall with another slit. It is only needed a small discrepancy from the light path to create an interference pattern on the wall number 2. What the case was in Young's early experiments inspired by Huygens who of course understood that there had to be an interference pattern, was just that he assumed that photon rays would pass uniformly through all slits. But that we don't know just out of nothing; it only takes a small variation of the light path to hit the sides of the slit in the next wall, meaning there will be small pattern of interference. Some of the photons would reflect from off the back of the first wall, already having a changed path while or if going through slit 2. And so forth and so forth. Aggregated with the already discrepant variation from the main ray. Thus it has to be a wider and wider pattern of interference.

@muhammadtouhid998 5 жыл бұрын

first time in my life, i have realized what the circular form of wave representation means, all after passing everything, huh

@sahilyadav3783 4 жыл бұрын

@akshayjagtap9338 3 жыл бұрын

Exactly bro

@nisha1180 2 жыл бұрын

True

@majsterektv7528 6 жыл бұрын

I just relized my teacher is useless as I always heave to learn from the internet

@96mohormukherjee56 6 жыл бұрын

Hahahaha same @majsterektv

@e0413836 6 жыл бұрын

Not sure it's the teacher's fault - realized and have! Oh there is only so much that can be built from the basic lego kit.

@praharshsingh2095 5 жыл бұрын

i dont even call my teacher a teacher

@cnu9948 4 жыл бұрын

Its your fault first did you ask the teacher or not

@litinggoh1169 3 жыл бұрын

@@cnu9948 Maybe he asked his teacher, but his teacher doesn't even know how to explain / explain in a way that's to difficult to understand / repeat the same thing that's mentioned in the textbook. Because that's what my teacher does. KZfaq is much better than some of my teachers to be honest.

@amartyachoudhury8991 8 жыл бұрын

Beautiful explanation.... especially that part where you explain how the wavefronts from the two slits interfere constructively or destructively; and finally on the screen... very helpful; thanks a lot

@CorisWorld404 4 жыл бұрын

Beyond incredible instructor!! He not only explains the right way but also shows you common misconceptions to avoid.

@TheGatoroberto 7 жыл бұрын

Thanks ,good video and made very clear ... probably the easiest and most understandable explanation that I have ever found about this experiment

@johntindell9591 6 жыл бұрын

i never had an intuitive understanding until i watched this video. The impact you are having on the world is deeply profound.

@AlonePlaying 4 жыл бұрын

Dude, i'm from Brazil and I'm really thankful for this video. I wasn't understanding a bit of what my college's teacher was saying, you'll save my exercises. Keep doing a great job!

@annearts5 4 ай бұрын

U learn that in college?? We have this is 12th grade in India.

@benisman 4 жыл бұрын

This has been really helpful for my A-Level studies, thank you so much. I finally understood how to implement the constructive and destructive interference pattern formula w=λD/s

@bardotons 7 жыл бұрын

thank you for speaking quickly and getting to the point!!!! great video.

@maazali9456 8 жыл бұрын

seriously i just understand the whole concept thank you very much.GOD bless you

@johnparks6936 8 жыл бұрын

I went through so many videos... And this one finally did it for me!! Thank you so much. Here's what I couldn't understand: why were they showing waves as propagating lines when, in reality, they were like the sine and cosine waves with peaks and troughs? This videos answered that question and even explained where they would interfere constructively and where deconstructively, Beautifully explained!

@MrWolfchamp-xi3cu 7 жыл бұрын

Didn't work for me. Still don't know what destructive interference is. Can't even find any real life examples of it. Just never see it happen. Waves don't cancel, PERIOD. If i turn on two flashlights i just get more light. If i turn on two radios i just get more sound. NOTHING EVER gets CANCELLED!!!!!

@OmriToren 7 жыл бұрын

you're doing it wrong! you need one source of light (1 flashlight, radio, sun,...) and a screen with 2 slits on it (hence the name Double Slit experiment!) if you display that light onto a blank screen you'll see interference patterns! this wikipedia picture shows it animated upload.wikimedia.org/wikipedia/commons/3/33/Doubleslit3Dspectrum.gif -- if you don't understand the physics of it, look at the philosophy behind it! i find that easier to understand!

@MrWolfchamp-xi3cu 7 жыл бұрын

The interference is those blue dots on in the green of the pic right? plus what is the philosophy behind this?

@OmriToren 7 жыл бұрын

yes! the blue would be the perfectly destructive interference (two troughs) the yellow would be the interference of one peak and one trough (+1 + (-1) = 0) and the green would be the positive peaks of light! the philosophy behind this experiment is thomas young trying to prove that light is a wave based on his experimental results. his argument is as follows: if my theory is true (A), then when i set up my experiment i will see the results that I expect (B). he does see the results of (B), therefore (A) must be true! this is a philosophical fallacy that results in his theory being confirmed (not proven) and is called affirming the consequent

@MrWolfchamp-xi3cu 7 жыл бұрын

One peak and one trough? No idea what that means. If the blue is the destructive then that means that yellow is constructive right since its brighter that green and blue?

@ydkathy5771 4 жыл бұрын

ur ten minutes have covered the content that my teacher spent classes talking about with clearer explanation. Thanks a lot :)

@zahrashahabinezhad 4 жыл бұрын

Absolutely fantastic videos on this topic. I finally understand this. Thank you!

@HM-rc7nn 8 жыл бұрын

A great explanation, for which I was looking for!! Thanks for such videos:)

@geniusm3521 2 жыл бұрын

The person, who understands best, explains best! perfect lecture about double slit experience. thank you

@ishantripathi9707 8 ай бұрын

Oh boy! Oh boy! Oh boy! Man you explained the concepts so clearly and simply. Hats off!

@PeaceboneGotFound Жыл бұрын

THANK YOU for explaining this so well!!!

@melynx1159 Ай бұрын

This helped me trillions! I learnt in roughly 10 minutes what I struggled to understand in hours of lectures. Thank you so much! ❤

@DeuceBoots 5 жыл бұрын

"How 'bout the destructive points?...shoooot, you know how to do that. These are gonna be the half wavelengths." Love it. Thanks again Khan.

@barbros2023 9 ай бұрын

Already 2 mins in and I've learnt more than weeks of school. This teacher also doesn't sound boring and monotone. 10/10

@bluecloud3059 6 жыл бұрын

Thank you so much. The best video for explaining Young's double slit experiment.

@mannykhan7752 2 жыл бұрын

I love this guys " tough love" approach to reaching. Would love him to explain human conception.

@Taqsunis 7 жыл бұрын

This is absolutely amazing!!! Ty

@Inovb 9 жыл бұрын

That's explained very well thank you.

@-fish-3316 3 жыл бұрын

Very clear explanation! Thank you!

@aishwaryagorti8412 4 ай бұрын

This really helped me to understand what actually happens in the experiment... This was so helpful. Thanx a lot

@andypritchard8017 3 жыл бұрын

Wonderful explanation. Thank you!

@FelisChow 4 ай бұрын

Thanks for the lecture. Got me to viusalize the phenomenon .

@somnathganapa5789 8 жыл бұрын

Thank you for explaining the shape of the light waves before it enters the two slits! My textbook completely ignored how strange it looked!

@lordepixz6364 6 жыл бұрын

This video was really helpful! thank you

@Aliens797 7 жыл бұрын

amazing explanation! thank you for the review!

@raghavpathania016 7 жыл бұрын

Best of luck for tomorrow hueheuheu

@MJ-hq1ie 5 жыл бұрын

Raghav Pathania thanks bro

@savewater2840 4 жыл бұрын

It's greatly explained. Thanks for this video

@HoussamBenhallam 7 жыл бұрын

You made my day ! Thank's a lot

@MRAXELGRINDER 7 жыл бұрын

This is a really great video, thank you so much, it helped a lot,I am grateful for the time you took to explain this, please keep it up :)

@k95channel 7 жыл бұрын

thanks for your helpful explanation!

@effectbest7532 7 жыл бұрын

Thanks man this cleared all my doubts ....Well explained

@muhammadabdullahae2480 5 жыл бұрын

Brilliant superb I could not understand it from many teachers but this let me understood

@made_in_Khaos 7 ай бұрын

Relearning this after half a decade, amazing video!

@saisevithaa1772 6 жыл бұрын

Thanks Sal! Love your vids!

@huanganan700 2 жыл бұрын

Thanks so much for perfectly visualizing the process of light diffraction. Always love Khan Academy😄

@sarmad1645 Жыл бұрын

this is so good im speechless!

@niveyoga3242 6 жыл бұрын

Best explanation I've ever heard!

@yoanch0 Ай бұрын

Bro, you have no idea how much this video helped me understand those things

@unknown-ku4ri 4 жыл бұрын

oh its so easy before watching this video every time i thought about this topic my mind was liking bursting Thank you so much.

@sreyasthejas4715 7 жыл бұрын

thank u soo much for the video . one of the very best videos on interference out there.

@fajarprasetya_jamulogi 6 жыл бұрын

wonderful. . it's made me so relief. . thank You very much bud

@Rubi747HVY 9 ай бұрын

Thanks for clarifying so well.

@RealEverythingComputers 6 ай бұрын

Thank you so much! This video was very helpful

@sheriff5109 6 жыл бұрын

Just take a minute and praise how satisfying the drawing on 4:32 is. Thank you sir.

@shreyajindal3871 6 жыл бұрын

This video was really awesome !

@premedmelody Ай бұрын

This just blew my mind

@KashafNaeem. 4 жыл бұрын

Thanks this was first video i saw in this chanel and was good not boring

@sharmass3756 8 жыл бұрын

super explanation I got all my doubts cleared excellent

@sycamour5654 6 жыл бұрын

Thank you! I understand now

@bettercallbhanu 2 жыл бұрын

Best lecture on YDSE on YT. Thank you sir :)

@MysticMD 9 жыл бұрын

Wow i understand now. Thanks !

@adamdangelo7644 6 жыл бұрын

You saved my life. Thanks

@guillaume6373 Жыл бұрын

amazing!! thank you very much

@hashirkhattak9180 4 жыл бұрын

You are the wizard of physics... Damn bro wow... Such an inspiration you are... 🔥... Lots of respect Love you

@nicotean8376 4 жыл бұрын

anyone in 2020? 🙋‍♂️🙋‍♀️

@keme_004 3 ай бұрын

2024😂✊🏻

@mugdhorozario4785 4 жыл бұрын

Sir , The explanation enhanced my understanding. If I didnt watch this video , I would have lived under a rock with thousands of confusions So sir, I would like to thank you and would encourage you to keep up the good work for us , students.

@fluffzxx9615 3 жыл бұрын

Sar, full support sar

@ihaveagoal4665 2 жыл бұрын

@@fluffzxx9615 wow how funny, what a subtle racist remark to a student who is just appreciating a teacher for teaching him a concept

@fluffzxx9615 2 жыл бұрын

@@ihaveagoal4665 seethe harder

@delusionalplatonist6077 2 жыл бұрын

@@fluffzxx9615 you're sooooo funny bro 🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣

@veerp2865 4 жыл бұрын

THANK YOU SOOOOOOOO MUCHHH! THIS HELPED A LOT

@christianpungo5210 3 жыл бұрын

Now that all my college classes are virtual I can finally say (with evidence) youtube is just as good, or better than some teachers. Watching these instead of my prerecorded lectures from now on.

@virtualgirl7697 4 жыл бұрын

Now its very easy to visualise and reason.thanks😊

@bhruseantv3461 7 жыл бұрын

it was really helpful...thank u for such a great vedio...

@vamshikrishna323 7 жыл бұрын

Iam a bit confused about this experiment..but with this vid my confusions just got rid off....thank u very much 😃 for uploading this video...

@cmdrriotz5283 5 жыл бұрын

Thanks for explaining this! I am curious...what about the observation part of it? I watched a video talking about when the light was measured/observed during this experiment, it behaves differently than when it's not. Do you know anything about that?

@001khokhar 8 жыл бұрын

Excellent explanation of a very conceptual topic

@Telest0 5 жыл бұрын

I wish I had a teacher like him...

@rakinhasan3833 Жыл бұрын

I couldn’t understand this experiment... But now I can understand this.. Thanks khan Academy 🖤

@kiranrq9387 5 жыл бұрын

Wow!!!! You are a hero! I just woke up and stressed about how these wave interfere, but you made it like a piece of cake 😊 thank you very much. I still have a question about diffraction. Say the slit gap is exactly same as one wavelength of that particular length. After it is diffracted it spreads out, so does that mean that same wave’s wavelength increases as it moves forward ? And the same amount of waves go through that slit each time? As I have seen water pressure increases through holes. Does pressure make the amount of water flow increase too? Or again it is just as it spreads out it’s wavelength increases? Pleaseeeeeeeee help

@ardopalanjian3998 9 жыл бұрын

Excellent. .thank u alot.

@gboyawesome1159 4 жыл бұрын

Thank you so much I understand it now

@Medusaogre 6 жыл бұрын

Best explanation I've seen.

@jayashree378 7 жыл бұрын

thanks . very good explanation

@martintnguyen0916 6 жыл бұрын

you're the best. love ALL your videos :)

@095-anamaykashyap2 7 жыл бұрын

well explained ... definetly helpful for boards and jee

@marwaebrahiem7485 4 жыл бұрын

Thanks allot for the exaplenation

@AbdulMajeed-fo9lv 7 жыл бұрын

well explained man....

@paryaolfati6451 7 жыл бұрын

wonderful ☺ thanks a lot

@MihenHighroad 7 жыл бұрын

when he says "shoooooooot" , get's me every time lmao

@marshchow3093 8 жыл бұрын

thank you very much!

@IsrarKhan-kb9hs 11 ай бұрын

Really helpful Jazakallah Sir👌

@johanchime6063 5 жыл бұрын

thank you so much, helped me understand and I had a laugh with you haha xd

@32kirby32 2 жыл бұрын

Perfectly done

@qiuk5988 6 жыл бұрын

Thank god, someone is able to explain this properly since my prof is hella horrible

@zed6213 7 жыл бұрын

Great...👍

@LawGTSenpaiLaw 4 жыл бұрын

My teacher’s name: Leci Things she’s good at: being useless and bragging thanks lol I’ve a test in 20 mins and I finally understand the experiment

@beigeboi_7714 4 жыл бұрын

Poor Leci :(

@beyondemotionsvibe2408 Жыл бұрын

Bro, thank GOODNESS YOU EXIST!

@ahmedabotaleb7584 6 жыл бұрын

could you please make a video about intensity distribution of the pattern ?

@shreyasmiliger1751 4 жыл бұрын

I am from India and I love this Please keep continuing this...

@akashneelsaha8300 3 жыл бұрын

This is so amazing

@abhisheklate6906 5 жыл бұрын

A perfect explanation

@_boss_baby_ 3 жыл бұрын

Awosome video, Sir can you please make a video on plane wave and circular wave with diagram ,or if possible with some simulation

@DinaHelmy Жыл бұрын

Thank you!

@qammarabbasturi3477 7 жыл бұрын

Great ...

@theflyingkingkong1469 6 жыл бұрын

Awesome explanation

@pratiksaha2592 5 жыл бұрын

Thank god Sal didn't taught this topic or else I don't think I could have understood so well..............Thank you so much Khan Academy for uploading this video.