Haha! Meet infinity - where parallel lines converge. They are certainly parallel and they do keep going, but infinity is a LONG way away. You can get a sense of this by looking at railroad tracks.
There's a little chromatic separation in person, but it's just a slight hazing of color at the edges. What is really cool is when you put water on the ridged side! I'll make a video of that.
Awesome. I have taken apart another 20 monitors since this video and can confirm that they are prism sheets, and diffusers are behind them. I'll check for diffraction in the spring.
oh yes this just saved me over 40 points in my assignment i missed my online class and they offer no video recording just slides and the experiment with no commentary. definitely gonna watch more of his videos very interesting and despite my terrible attention span I was listening intensely which really surprised me :)
dude u made physics way more fun!! I was laughing the whole time lol , and most importantly I understood everything cuz u have a great way of teaching and delivering the information so thanks a lot Doc Schuster !
YES! I don't know! It has the most bizarre optical properties, as you can see. I found it in a flat-screen monitor. There's all kinds of cool sheet goods (polarization filter, light diffuser, etc.) in there. I hope someone who knows will be able to answer us, as I am as interested as you are.
Nice work! Thanks! It's so cool, and I hope every kid and physics teacher takes apart an LCD panel to get one. Careful, though. The thin glass in the screen breaks easily.
Sure. There are a lot of variables here, and it's too easy to become confused. Delta l is path-length difference from the two sources. d is separation of the slits. Neither of these is the separation between the fringes, which depends on how far the screen is. You are most interested in theta, which is how I am measuring [angular] fringe separation. To increase theta, either decrease d or increase lambda. I hope this is also conceptually consistent.
This is lovely!! I have physics exam on this monday and this really helped! actually this is the first time I'm understanding physics instead of learning it algebraic.
You are simply an Awesome teacher, I've tried understanding this on my own from the notes I've wrote in my lecture and i couldn't understand them but then you just saved me, Thank you so much Doc!
I AM IN LOVE WITH YOU AFTER BEARING THAT STUPID PHYSICS TEACHER FOR TWO LOOOOONG YEARS AND UNDERSTANDING NOTHING ABOUT WAVE OPTICS! You're a SAVIOUR and I SCREAM that!
Fun way of teaching man!!I wish all teachers would adopt yours way of teaching then learning could really be fun making.And I wanted to know bright and dark fringes have certain length or they are just points??You havent talked about that!
Hi, thanks for the video. You are a great educator. Around 6:58 you mention that the angle between the normal to the first slit and the diffracted ray from the first slit is equal to the angle between the normal to the first diffracted ray and the line containing the slits. We can see this intuitively, but is there a specific name or term for the argument which proves this equality?
Coming from a mathematical background, I loved your set notation. Very useful explanation, thank you. One question, if both rays have an angle theta, how come they will converge as they are parallel?
+inteusproductions They will converge where all parallel lines meet, at infinity. This is embodied in our assumption that the screen is very far away compared to the slit spacing.
I feel confused about 7:17. Why, if they have same angle (and they both would hit a wall parallel to the line that separate the slits) have different lengths? that initial difference would be compensated with the adittional distance that the above ray would travel before hitting the parallel wall
Am I the only one who thinks he sounds like Barney Stinson from How I Met Your Mother? Thanks for the upload, easy to understand, now I can finish my physics hw.
I disagree, but see where you're coming from. When I say half-integer, I don't mean half of an integer. I mean an integer plus a half. So, 6/2 is "half-an-integer" but not "a half-integer." I totally agree that if I were just dividing an integer by 2, I'd need that integer to be odd. All semantics, of course. Thanks for pointing this out!
To be more precise , for destructive interference , we dont need an half integer of the wavelenght but instead an ODD half integer of wavelength. Its logical but makes a difference
Wonderfully explained doctor... but i am confused with the formula of destructive interference , you have written it something like this (m-1/2)lambda ,but as i have studied it seems like this (m-1/2)lambda. please sir make me correct..
amazing explanation. I just want to ask why did he not pass the filtered light from the double slits from the beginning?why did he pass it from a single slit first?
Can someone help me please. In some notebooks for destructive interference it says that delta l=(2m-1)*lambda/2 and in other there is plus sign after m. Help!
Hey Doc, amazing video. I definitely learned a lot in these 17 minutes. I just have this one doubt. See,you said that the light waves(let's call them waves) coming out of the slits were spherical. But shouldn't they be forming a cylindrical wavefront according to Huygen's Principle? Please just explain this. Loved the video. Instant subscribe!
I had been reading many books about this topic for a weeks, but after I saw this vidieo it is just simple. I want to ask you one question on this vidieo. My qustion is I know we start the order of maxima with m=0. What about for dark fringe, can I start with 0 which is the first dark?And then the formula for distractive =((m+1/2)lamda) =(0+1/2)lamda=lamda/2 For the second dark, =(1+1/2)lamda=3/2lamda....and so on.
They’re both destructive since they only differ by some integer. In other words, m-1/2 and m+1/2 are still half integers (and since any half integer multiple of wavelength is destructive), so both are destructive. Which one u want to use is up to u as both are correct
Man. This is awesome. I'm subscribing. Question:I'm trying make a video, an Elegant way to describe gravity, dark energy, black holes and quantum fluctuations all in one: Take a rubber membrane and suck on it using a vacuum cleaner. It creates balloon. From the outside, the membrane mimics gravity sucking space time to form a black hole. From the surface inside the balloon, the membrane mimics the expansion of universe due to a mysterious dark energy. Obviously both gravity and dark energy are the same thing looked from different angle. They are both caused by the energy differential on each side of the membrane. The energy differential is, at small scale, called quantum fluctuations. At large-scale it is called a black hole or a white hole/big bang Then i go in quantum gravity. When energy of quantum fluctuations are locally not equal and thus generates a flow. Same principle as Hawking radiation. It separates virtual particles like the waves separates the sand in the beach according to size and weight. Is that a good illustration of all of the topics in one? Thank you for your time. And have a great day.
Your title is misleading. There exists another experiment known as Double slit diffraction, where screen is nearby so you can observe interference phenomenon AND diffraction phenomenon.
I've watched at least dozen of videos on the double slit experiment, this is the first video that regard the fact that two parallel light beams are met at infinity. All the other explanations simply connect two parallel beams at the screen without telling why.
Doc Schuster I've seen other people only using positive numbers for m. That doesn't really matter right? Appart from the fact that using negative numbers for the fringes under the 0th fringe makes it easy to tell them appart from the fringes above the 0th central fringe. Right?
Maybe the grating isn't very fine. I mean, the spacing between the two slits in that huge sheet is large? That's why the bright fringes are very close to each other and it forms a line.
+sachi codo Well, keep watching the next videos for a surprise. But two slits were the first ones explained and they're easiest to understand, I think.
Amazing how much I can absorb when the lecture is not boring. Thanks!
the colors help too
Best video on Young's double slit experiment I've seen.
First physics tutorial I have ever witnessed where the narrator isn't talking in endless monotone. For that, you have my unwavering respect, sir.
I went through 3 physics textbooks and this still didn't make sense! I see your video once and it finally clicks!! Thank you! This helped a lot.
Never thought optics could be so interesting.
Thanks a ton Sir.
A legendary teacher with such a sweet personality !!
I just love how you explain stuff with a empty paper :). Thank you very much for this contribution to help me study :)
we need more teacher like you!
Haha! Meet infinity - where parallel lines converge. They are certainly parallel and they do keep going, but infinity is a LONG way away.
You can get a sense of this by looking at railroad tracks.
That's EXACTLY my goal here! Thanks so much for your support.
There's a little chromatic separation in person, but it's just a slight hazing of color at the edges.
What is really cool is when you put water on the ridged side! I'll make a video of that.
You explained this so much better than most other videos I’ve seen, thanks man.
Awesome. I have taken apart another 20 monitors since this video and can confirm that they are prism sheets, and diffusers are behind them. I'll check for diffraction in the spring.
oh yes this just saved me over 40 points in my assignment i missed my online class and they offer no video recording just slides and the experiment with no commentary. definitely gonna watch more of his videos very interesting and despite my terrible attention span I was listening intensely which really surprised me :)
This was an EPIC explanation and I feel like I understand how the entire world works!! Thank you so much for your help!
dude u made physics way more fun!! I was laughing the whole time lol , and most importantly I understood everything cuz u have a great way of teaching and delivering the information so thanks a lot Doc Schuster !
you are the best teacher for college physics courses .
You taught physics like a story in jungle book..amazing explanation with such humour.
You are an amazing teacher :')
thank you for this video. I hate studying for physic test but the way you talk about it is refreshing xD
So much easier to understand now.. Finally! Thank you.
now that was some great narration!!!
Sir you just nailed the YDSE
YES! I don't know! It has the most bizarre optical properties, as you can see. I found it in a flat-screen monitor. There's all kinds of cool sheet goods (polarization filter, light diffuser, etc.) in there. I hope someone who knows will be able to answer us, as I am as interested as you are.
best physics videos on youtube
yeah
I'm so glad that I found this channel ....with that laser exp I could understand even more better...we need more physics tr like him :) ^.^
Nice work! Thanks!
It's so cool, and I hope every kid and physics teacher takes apart an LCD panel to get one. Careful, though. The thin glass in the screen breaks easily.
These are the best physics vids out there!
Sure. There are a lot of variables here, and it's too easy to become confused. Delta l is path-length difference from the two sources. d is separation of the slits. Neither of these is the separation between the fringes, which depends on how far the screen is. You are most interested in theta, which is how I am measuring [angular] fringe separation. To increase theta, either decrease d or increase lambda. I hope this is also conceptually consistent.
This is lovely!! I have physics exam on this monday and this really helped! actually this is the first time I'm understanding physics instead of learning it algebraic.
The Greatest teacher ever 😍
Oh my god, you are amazing !!!!! Best teacher ever ! :)
You are simply an Awesome teacher, I've tried understanding this on my own from the notes I've wrote in my lecture and i couldn't understand them but then you just saved me, Thank you so much Doc!
Happy to help! This is really a new age in learning. You will be able to understand anything you have a desire to understand!
Really really really really really really really really really really really really really really really really really really really really really really really really helpful as well as entertaining. Thanks.
Amazing teacher, extremely useful! Thank you
I AM IN LOVE WITH YOU AFTER BEARING THAT STUPID PHYSICS TEACHER FOR TWO LOOOOONG YEARS AND UNDERSTANDING NOTHING ABOUT WAVE OPTICS! You're a SAVIOUR and I SCREAM that!
Holy Holy, mind blowing lesson.
This was amazing. thank you so much for your time and effort!
Wow!
Physics is beautiful!
This was awesome! I absorbed the information very well!
this may sound totally crazy but i am so touched. i found all this so interesting n i always feel like sleeping in my actual physics class.
15:54 That's what she said...
wow! you make physics so much fun! keep up the good work, thanks!
Are you Neil Patrick Harrison??? Wow, same voice! Thanks for the videos and the enthusiasm, it helps a lot!!
Awesome!! Thanks to you, I shall pass my physics exams!!
This is so awesome!! Thanks for breaking it down piece by piece. Physics is fun with your teaching :)
Fun way of teaching man!!I wish all teachers would adopt yours way of teaching then learning could really be fun making.And I wanted to know bright and dark fringes have certain length or they are just points??You havent talked about that!
Hi, thanks for the video. You are a great educator.
Around 6:58 you mention that the angle between the normal to the first slit and the diffracted ray from the first slit is equal to the angle between the normal to the first diffracted ray and the line containing the slits.
We can see this intuitively, but is there a specific name or term for the argument which proves this equality?
hey man thank you very much! i've learn so much your teaching style is just awesome! stay cool!
Thank you! You stay cool, too!
thanku so much.....most nyc explaination ever.........
in the 11:49th minute
I think that the m value must be -1 for the dark fringe and not 0
'cos there can only be one central maxima/minima(m=0).
Coming from a mathematical background, I loved your set notation. Very useful explanation, thank you. One question, if both rays have an angle theta, how come they will converge as they are parallel?
+inteusproductions They will converge where all parallel lines meet, at infinity. This is embodied in our assumption that the screen is very far away compared to the slit spacing.
Maaan are you amazing!!
That was great Doc. Can I please know what that plastic thing is called? Also the second one? Can I get them online? :)
I feel confused about 7:17. Why, if they have same angle (and they both would hit a wall parallel to the line that separate the slits) have different lengths? that initial difference would be compensated with the adittional distance that the above ray would travel before hitting the parallel wall
...and thanks to YOU! I'm not the guy who's going to pass his physics exam - you are! Go get 'em.
Am I the only one who thinks he sounds like Barney Stinson from How I Met Your Mother? Thanks for the upload, easy to understand, now I can finish my physics hw.
was just about to say that.
Sounds more like Phil from Modern Family! Great vid btw!
was about to say that lmao...the comment is 5 years old....hey hope your doing great now
I disagree, but see where you're coming from. When I say half-integer, I don't mean half of an integer. I mean an integer plus a half. So, 6/2 is "half-an-integer" but not "a half-integer." I totally agree that if I were just dividing an integer by 2, I'd need that integer to be odd. All semantics, of course. Thanks for pointing this out!
this was a great explanation :) thanks!!
I freakin love this doc.
Thanks for your wisdom.
I have already learned many of the things you teach but you just make it click!
D Berks I'm so glad to hear it! Keep rocking.
To be more precise , for destructive interference , we dont need an half integer of the wavelenght but instead an ODD half integer of wavelength.
Its logical but makes a difference
Your videos are so good! I wanna study physics at uni and I find all this stuff so interesting :):)
Wonderfully explained doctor...
but i am confused with the formula of destructive interference , you have written it something like this (m-1/2)lambda ,but as i have studied it seems like this (m-1/2)lambda. please sir make me correct..
Damn! You are great teacher! Loved it!!!
I think that those green circles are the wavefronts and the dots in the circle is the point source of secondary wavelets...
amazing explanation. I just want to ask why did he not pass the filtered light from the double slits from the beginning?why did he pass it from a single slit first?
I love this guy. Fun to learn.
I think you can get to my google plus account from youtube. I don't have another page per se.
Can someone help me please. In some notebooks for destructive interference it says that delta l=(2m-1)*lambda/2 and in other there is plus sign after m. Help!
This guy is just too cool to be a Physics teacher😤
Super helpful!! And fun. Bravo!
Awesome tutorial sir!!!One Question During laser tricks session if we use white light what do we expect rainbow fringes or no interference?
well i dont think rainbow fringes will b observed bec its not dispersion
What is the explanation for the formation of circular pattern when the incident light is not at right angle to the gratings?
Hey Doc, amazing video. I definitely learned a lot in these 17 minutes.
I just have this one doubt.
See,you said that the light waves(let's call them waves) coming out of the slits were spherical. But shouldn't they be forming a cylindrical wavefront according to Huygen's Principle?
Please just explain this.
Loved the video. Instant subscribe!
Rãčhït Ãgárwáł YES! I'm surprised I was so sloppy. I'll fix that.
+Doc Schuster why should it be cylindrical?? I don't get it, could you please explain or direct me to the video which has the explanation!
I guess it is spherical only!
I had been reading many books about this topic for a weeks, but after I saw this vidieo it is just simple.
I want to ask you one question on this vidieo.
My qustion is I know we start the order of maxima with m=0. What about for dark fringe, can I start with 0 which is the first dark?And then the formula for distractive =((m+1/2)lamda)
=(0+1/2)lamda=lamda/2
For the second dark, =(1+1/2)lamda=3/2lamda....and so on.
I have my Optics exam in 2 days...thanks for making this fun :P!
Susie Robertson Go get 'em!
Thanks!
yo boss! Great video! Great humour! Keep it up!
3:53 Why did he use two Card pieces. I think this experiment would go fine if we eliminate the first card (one with a single slit in it).
what material was the sheet at last? it looked so cool
honestly this made me laugh and I understood it all- that's a breakthrough
you lowkey sounds like Ryan Reynolds, I love it! Great vid!
Lovely tutorials! But, why the title says ''diffraction''? Isn't it an Interference phenomenon?
+ED Project (ProjectED) yes, but the fact that the waves don't go straight (i.e., that they interfere at all) is due to diffraction.
Doc Schuster Got it! Thanks a lot from Italy!
Equation for destructive wave is it [(m-1/2)*wavelength] or is it [(m+1/2)*wavelength]?
They’re both destructive since they only differ by some integer. In other words, m-1/2 and m+1/2 are still half integers (and since any half integer multiple of wavelength is destructive), so both are destructive. Which one u want to use is up to u as both are correct
you are a very very very good tutor!!!!!
aand ive got unit 2 tomorrow too good!!!
Suddenly a wild marker pen appears at 11:40....
asemnafiz XD
Hehe
Yay! I'm glad you like physics!
Man. This is awesome. I'm subscribing.
Question:I'm trying make a video, an
Elegant way to describe gravity, dark energy, black holes and quantum fluctuations all in one:
Take a rubber membrane and suck on it using a vacuum cleaner. It creates balloon.
From the outside, the membrane mimics gravity sucking space time to form a black hole.
From the surface inside the balloon, the membrane mimics the expansion of universe due to a mysterious dark energy.
Obviously both gravity and dark energy are the same thing looked from different angle. They are both caused by the energy differential on each side of the membrane.
The energy differential is, at small scale, called quantum fluctuations.
At large-scale it is called a black hole or a white hole/big bang
Then i go in quantum gravity. When energy of quantum fluctuations are locally not equal and thus generates a flow.
Same principle as Hawking radiation. It separates virtual particles like the waves separates the sand in the beach according to size and weight.
Is that a good illustration of all of the topics in one?
Thank you for your time.
And have a great day.
Lengths are different only if the screen is angled perpendicular to the direction of the light rays.
Better than my physics teacher , much obliged =V=
Where have you got that plastic sheet (as slit (s))?
And laser light too.......
Best explanation, thanks!
Your title is misleading. There exists another experiment known as Double slit diffraction, where screen is nearby so you can observe interference phenomenon AND diffraction phenomenon.
I've watched at least dozen of videos on the double slit experiment, this is the first video that regard the fact that two parallel light beams are met at infinity.
All the other explanations simply connect two parallel beams at the screen without telling why.
It is insane to think about how early Young came up with this experiment.
Doc Schuster
I've seen other people only using positive numbers for m. That doesn't really matter right? Appart from the fact that using negative numbers for the fringes under the 0th fringe makes it easy to tell them appart from the fringes above the 0th central fringe. Right?
Maybe the grating isn't very fine. I mean, the spacing between the two slits in that huge sheet is large? That's why the bright fringes are very close to each other and it forms a line.
I have a question why it should be double slit ?
and Thank you so much for your awesome explaining :)
+sachi codo Well, keep watching the next videos for a surprise. But two slits were the first ones explained and they're easiest to understand, I think.
In the video you mentioned the rays would be in line, they could also be in phase.
Also, for the destructive interference equation, it should be (m+(1/2)) x wavelegth
subscribed after watching just 5 mins of the video
I thought wave idea was put forward by Hugyens during Newton year?
It was, and Newton used it, but he didn't believe light was a wave, just its refraction and reflection could be described with waves