Specular and diffuse reflection | Geometric optics | Physics | Khan Academy
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- čas přidán 26. 08. 2024
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Specular and Diffuse Reflection. Created by Sal Khan.
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"were going to reflect on reflection"... Sal slays me.
Did anyone else's college just link them to this video in its class materials? Not that I'm not happy to hear Sal Khan again, I had like immediate homeschooling nostalgia. Thank you for all that you do, Mr. Khan! You've made the world a lot smarter.
Fun fact: That picture is of Mt. Hood over Mirror Lake! I used to live about fifteen minutes down the road from where the trail to the lake starts, it's a really beautiful area.
6:14 "it's a pretty interesting thing to do if you are looking for things to do in the bathroom" LOL
Not everybody can get that joke, LMAO
@@metastag Can u tell me the meaning
Got it! I love doing interesting and new things in the bathroom.
what are you talking about
@@bbbfizzy4175 bathroom, mirror, reflection
"It's a great thing to do, for those of you looking for something to do in the bathroom" 😂😂
Awesome video! i just finished my optics course :)
just a small suggestion- Law of reflection holds even in Diffuse reflection.In Diffuse Reflection, the light scatters in different orientations because the surface of the underlying object will be not uniform.Pls correct me if im wrong. "Law of relection" holds for any light ray!
Weird question, if you surrounded a perfect chrome ball with a 1 way mirror that was sided to only let light in and not let it escape, would the chrome ball look uni formally black with no form?
Strange thought that started with thinking how the predator displacement camouflage might would work. :p
@ 6:20 "if you're thinking of things to do in the bathroom" ...
( ͡° ͜ʖ ͡°)
serio, muito bom a explicação, choquei em saber que é conteúdo estrangeira, e dublado que vi no site, muito bom, entendi muito bem neste video, o que nao encontrei informações de outras pessoas!! SHOWW!!
"Reflect on reflection"... Jesus Christ
Jesus said that?
@Jørgen Raun Boné we can’t know he’s not
A ray of light strikes a mirror at an angle of 60 to the normal. the mirror is then rotated 18 clockwise. what is the angle that the reflected ray makes with the mirror ?
would some explain please :3
no doctor... still u have to analyze this curd ,my chemistry mam asked us to avoid packet curd
"It's a pretty interesting thing to do if you're looking for things to do in the bathroom"! haha :)
Lets get it BASIS only videos for physics
Hi Nick
I was wondering, and my question is quite general, how can different lenses with different focal lengths, or a zoomlens, produce an image of the same dimensions? After all, the field of view represents how wide the scene is that we capture, and a smaller part takes less space than a larger part? So, how do they do it?
By moving the camera relative to change in focal length (step forward or backward) you can preserve the same dimensions of the subject, but you will also have a different depth of field
@@LiamCShepherd Your reply is of course obviously correct. But, it has been so lang ago I honestly have no idea what I meant with my question. I know that I already knew then about the relationship distance/field of view/focal length. If it comes back to me, what I meant exactly, I will let you know.
edit: I think I meant the image dimensions, not the content of the image. But the question still does not really make sense to me I'm afraid. Our retina does not change dimensions either after all, whatever we look at.
Very nice video. It's great to get the terminology down.
I want 3rd and 4th questions
Nice
@blackroze1000
An angle of 78. If the ray of light is stationary, but the surface it is reflecting off of is moving clockwise, then the angle it forms with the normal (the line 90 to the surface) is getting larger, in this case by 18. So the angle of incidence is 60+18=78. Since the angle of incidence is equal to the angle of reflection, it reflects at an angle of 78.
I know you asked a month ago and probably don't need the answer, it's still good to know.
It’s been 11 years how are you?
@@disas22 I’m going great, how are you?
@@hedonism13 I’m doing great too :) Hope you have a great day
It seems to me you described specular reflections from a smooth surface vs specular reflections from a rough surface.
What happens on the molecular level? I'm a molecule struck by a photon. I would have to know the angle of the light relative to the surface I'm part of and shoot off a photon in a corresponding direction. How do I know all that? What's my motivation for following this scientific rule?
The law of reflection is actually a special case of the laws of conservation of momentum and conservation of energy. In any elastic collision, if one object collides with another object but the other object is so large that it doesn't really move, then the reflected object will have its incident angle equal to its reflected angle.
This is because we can break the motion down into two pieces; a portion that is moving normal to the large object (at the point of contact), and a portion that is perpendicular to the normal. The motion perpendicular to the normal is not affected by the collision, but the motion in the direction of the normal is reversed by the collision.
Importantly, the molecule in question in your example is not absorbing and reemitting a photon. Instead, because the molecule has charges, those charges respond to the electromagnetic field of the photon and reverse the portion of the electric field which is normal to the orientation of the molecule at the location where the photon hits the surface. Reversing the direction of the electric field reverses the direction that the light is moving; reversing only the normal component will reverse only the normal direction, meaning photons (or electromagnetic waves) obey the same rules for conservation of momentum and energy, and so they obey the law of reflection. The only thing the molecule has to do is (1) be in the way and (2) interact with the electromagnetic field.
@ElisHong
A reading, from the book of Physics, Chapter 135, verses 6:14 - 6:18.
"It's a pretty interesting thing to do if you're looking for things to do in the bathroom."
This gets diffuse reflection wrong! Diffuse reflection (technically speaking) is what happens when incident light is reflected in all directions from one location. This can't be explained by specular reflection off of a rough surface. While surface roughness does play a role in diffuse reflection, subsurface scattering also plays a role. This is what is responsible for light reflecting in all directions from a single spot. Surface roughness only gets you light scattering in one direction from a spot.
After watching this video I just went to the bathroom and hanged their little bit while observing the mirror :D. Nice video really nice.
Is it necessary that at least 2 light rays should meet for formation of image by plane mirror or even in the retina, if yes then why is it so
now i can multi task in the bathroom. finalleh
Small correction: for the double reflection, the first point of reflection is not the same as for the single reflection. Because if it were, it would hit our eyes directly and could not go to the paddle.
Is Scattered Reflection the same as Diffuse Reflection? What about Back Scattering (Diffuse Scattering) is that something else?
the middle line is called a normal
gud explanation
good vid.. 9:39 plugs photosynthesis vid lol
It’s not a mirror, you had forgotten to silver the plane.
Hi. O.k. so, are the white light rays that are hitting those trees to the left also bouncing off said trees, going down, hitting the water and bouncing off just like the light rays from the mountain?? And when you say the light is bouncing off the water to our eyes you must also mean to our chest and waste and knees ect. Because as I stand at 6 ft my friend is much shorter and yet also sees the reflection. So saying (which everyone does) the light bounces off and up to our eyes is misleading. That same reflection can be seen from many many places and there fore must be bouncing to all those spots. And that doesn't sound so specular and starts sounding a little more like a reflection in many directions. I don't know. Just thought I'd speak up.
does diffuse reflection follow the law of reflection?
YES IT DO follow the law of reflection but cuz of reflected on different directions it's a diffuse reflection
Im always looking for new things to do in the bathroom.
yea me tooo
6:15 lmao
Khan comes on, pants come off.
한국어 맨처음 번역을 못했네. reflect는 반사뿐만 아니라 깊이 생각해보다 라는 의미도 있음. 물론 나는 그걸 어떻게 한국어에 녹여낼지 방법을 제시하는 건 아니고 걍 훈수만 둠
@hedonism13 lol thanx !!!! my teacher explained that twice and no one really got it xD ur way is much much easier O.O
hehe
....sorry..but i slept while i ws watching the Vid. LMAO !!
Why do you repeat things?
Do you like crash course or khan academy better?
blu-ray :P
Got here from a Between the Buried and Me song... Lol
where is the math part? +1 dislike
I am looking for boy friend