I just came across the 3D glasses example kinda by accident, and the more I experimented the more confused and perplexed I got. After watching a bunch of videos and still feeling slightly disappointed by their explanations I came across this one. This was expertly explained and your demonstrations helped a ton. I love youtube videos from the earlier days, always the purest content.
That is a very beautiful demonstration involving day to day experience making it comparatively easier to understand the whole polarization concept. Good job Kevin..!
YOU NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOB BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
The colours in the Petri dish arise because the plastic is birefringent, meaning that it has not one but two polarisation axes each with their own index of refraction. The polarised light is resolved into two perpendicular waves which travel at different speeds through the plastic. The parts of these two waves that are parallel to the analyser interfere, producing interference colours much like those seen in a slick of oil on the surface of a puddle or in soap films.
Good job Kevin! Thanks for making this Video. I am having a problem with my progressive prescription polarized sunglasses. While I am driving, each time I look at the navigation screen, I tend to tilt my head slightly to the right to look at the screen, and when I do the light from the screen is blocked and I can't see it. I didn't have this problem with my old clip-on sunglasses that I used to clip on to my old progressive prescription glasses.
Videonun bilgiyi aktarım kalitesine bayıldım. Thank you for this much effective way delivering this concept at this much of ease. Demonstrations are so valuable
Best demonstration of polarization I've seen! Thanks for taking the time to demonstrate it. Also, I've read that there is a theory that turtles are able to find new bodies of water to migrate to by being able to see the polarized light reflecting off the water. Can you explain how this is possible? Thanks
sweet. I was wondering about those 3D glasses for a long while now. I used to have tons of fun popping the lens out and watching it change colour as I turned them in front of each other. So since it lets light come in differently from each side, that makes sense why it's not recommended to wear them as sunglasses. XD
awesome explanation . amazing. Before watching this video I thought polarisation as topic I could never be able to understand but now I am curious about it. thanks 😘
Thanks so much for this ! Do you think that polarised light therapy (500-2500nm) can be more effective than regular red light therapy due to a wider spectrum of light combined with polarisation ? Does polarisation of light increase its capacity to permeate the skin ??
perfect explanation, but i think that the expression for the sun light polarization is due to the difference between the plane of polarization of the aye and that of polarizer
That's incorrect. The human eye is not sensitive to the polarization of light. This is why we need eg, the analyzer to view the polarized stress in the plastic cup. Bee eyes are another matter.
Hi Kevin, great video! Thanks a lot for sharing how to show this effect. Just to be sure, you now place the polarization filter in front of your cameralens. But do you also see the colors when you just look with your eyes through the polarization filter? And is the petri dish you are using a glass or plastic one? Can I use it to see the stress in a glass of wine for example?
so it's like a slope and movement? going forward with a wall in front of you gets you stopped, but if you put a gradual slop to change directions it'll change the direction to up? (no gravity etc)
That's a neat explanation! (a) So how are these polarizing filters made. How do they work? Are there millions of tiny slits? Is it made of some chemical or crystal? (b) Why is the interaction so consistent all over the filter? Are there materials man made or otherwise where polarization is not consistent? (c) Do diamonds show polarization?
a) In a way they are - they're typically polymer chains, such as PVA, that are pulled during manufacturing. When they're pulled, all of the chains line up in one direction. The electrons are then free to move along the polymer, but not transverse (90-degrees) to it. This allows the polymers to absorb the light that is polarized along the direction of the polymer, and let the other polarization pass through. There are some other ways of making polarizers - metal wires can be used for lower frequencies (the spacing of the wires has to be less than the wavelength. This is really close for red, 800nm, light, but not so bad for microwaves). Some of the most efficient polarizers use two pieces of glass precisely joined together. These only work for a certain 'viewing angle' though. b) Our eyes can be pretty sometimes - they're capable of detecting single photons in very low-light situations. But they're also not always the best relative detectors. I'm not sure what the relative consistency over the filter is, but it's probably less than 5%. Also, I'm sure the manufacturer has experimented in the best ways of making consistent filters, and have implemented quality control measures to make sure that they're mostly consistent. If not, they can always re-melt and re-stretch the polymers for another batch. c) I'm not aware of any bulk optical polarization in diamonds. This doesn't surprise me much, as the crystal structure is a tetrahedron and is fairly isotropic - unlike the clearly directional pulled polymer filter. Of course, the faces of the diamond do reflect light, and you can get polarization when viewing reflections (from any surface, glass, water, diamond) at the Brewster angle. Unfortunately, I forgot to touch on this topic in the video.
What does it get darker when the two filters are place together with the axis aligned ? Shouldn't intensity be the same since the polarized light is already blocked by the first filter ?
Good question, let me explain in words and then try a diagram as well. After the, say, left-circular (LC) polarized light is reflected from the mirror and becomes right-circular (RC) polarized. The 'circular' polarizer, isn't actually just a circular polarizer. It's a quater-wave plate (1/4-wave plate). This transforms the RC light to linear polarized. But it's polarized 90-degrees to the linear polarizer it encounters next. So the linear polarizer ultimately blocks the light. Here's an attempt at a diagram: Incoming light (arrows show direction of light - read from right to left): | No light out ^mirror
Thanks a lot for this video. I find myself coming back to it occasionally. I am now curious about this behaviour at 4:35 . 1) Why does this behaviour occur at all? 2) Is there any name for this behaviour that I can lookup on the net?
Re-radiation. It's "re-radiation" of the light energy (EM wave) at a new polarization angle. Take a look at the vid below- the metal grate is re-radiating the microwave energy in the direction that the grate is positioned, having intercepted the RF from the transmitting end at 45 degrees. So, re-radiation of the RF then takes place at the new 45 deg angle AND is picked up at the far end receiver. ruclips.net/video/KM2TkM0hzW8/видео.html&t=116 Also, this MIT demo goes into a little more detail: ruclips.net/video/AVn49LbYoB8/видео.html
5:25 I still don't understand how did the intensity increased ? I mean in polarisation, I2 = I1 (cosx)^2 So intensity should have decreased But it increased ? I don't think it should have been possible in an isolated system
Saw a video where the two opposing lenses nothing gets through light changed the look of certain gems to lots of colors and different geometric patterns. I think quartz was one. (Edited) Found it. I don't know how to paste a link but the video is called 12 foundation stones of new jerusalem. It's 2 yrs old only has about 6k views. I forgot this video says some gems like diamonds look black in different light. Why have i never heard of this? Wife and daughter are into rocks, me too. This is interesting.
***** I had the same question. The key to understanding this is that a diagonal vector has horizontal and vertical components! So what the middle filter does isn't bending the light but rather allowing the horizontal or vertical components (according to the middle filter's direction of axes) through. The sunglasses at the end do the same thing.
I think it's not a linear wave like people demonstrate, it's a three dimensional field. I believe that all fields pass through even if we don't see the light. I think the polarized glass change the shape of the field making it invisible through our eyes and the other glasses reshape back to normal somehow.
still doesn't explain why my room projecting outside building with colours and movement. I just wanted to know why I see the building with its original colours on my wall. I know it somehow being projected from my window but I'm just curious.
3 minutes in and anyone paying some amount of attention would understand polarization, great contribution, the internet is pleased.
4:30, understanding destroyed
@@skaramicke 🤣🤣🤣
Better than my 1 hr physics class
I just came across the 3D glasses example kinda by accident, and the more I experimented the more confused and perplexed I got. After watching a bunch of videos and still feeling slightly disappointed by their explanations I came across this one. This was expertly explained and your demonstrations helped a ton. I love youtube videos from the earlier days, always the purest content.
How people dare to dislike such a video when that much effort is put in. Thanks a lot !!
That's is RUclips's fuckin algorithm
Less than 0.03% of views disliked this. What are you even on a tiff about?
Your practical examples really quenched the trust.....!
No theory can clear the things in such a intresting way ☺
That is a very beautiful demonstration involving day to day experience making it comparatively easier to understand the whole polarization concept. Good job Kevin..!
YOU NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOB
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So many presenters on YT get the 3-polarizer explanation wrong, but, you got it right!!
Congrats.
~one of the most coolest way to understand polarized light~
Thanks a bunch, im in Electricity,Magnetism & Optics right now and next monday is my final. This is a great explanation of Malus Law!
splendid teaching...........thanx a lot!
Very lucid elegant explanation. Thanks a lot Mr. Kevin.
Fate. Hirata, Pillars of light, Eyes of Wisdom, Fate. Crow and Declaration, Between front and back, Imaginary Technique, Hollow Purple
Best demonstration of polarization I've seen!
Wonderful way to express the idea of polarisation. I like your practical approach, thank you.
The colours in the Petri dish arise because the plastic is birefringent, meaning that it has not one but two polarisation axes each with their own index of refraction. The polarised light is resolved into two perpendicular waves which travel at different speeds through the plastic. The parts of these two waves that are parallel to the analyser interfere, producing interference colours much like those seen in a slick of oil on the surface of a puddle or in soap films.
Sir we were just to take off our heads to put this topic into our head. U just showed us what exactly it is....thank you...
You have the mind of a teacher. Good job.
Thanks so much, Kevin. Greetings from Spain.
Nice vid! Why exactly are different parts of the sky reflecting a variety of polarisations?
Good job Kevin! Thanks for making this Video.
I am having a problem with my progressive prescription polarized sunglasses. While I am driving, each time I look at the navigation screen, I tend to tilt my head slightly to the right to look at the screen, and when I do the light from the screen is blocked and I can't see it. I didn't have this problem with my old clip-on sunglasses that I used to clip on to my old progressive prescription glasses.
Videonun bilgiyi aktarım kalitesine bayıldım. Thank you for this much effective way delivering this concept at this much of ease. Demonstrations are so valuable
awesome explanation.👌
Best demonstration of polarization I've seen! Thanks for taking the time to demonstrate it. Also, I've read that there is a theory that turtles are able to find new bodies of water to migrate to by being able to see the polarized light reflecting off the water. Can you explain how this is possible? Thanks
Wow really thanks for the video. Very useful and informative video.
I just wonder how amazing nature is
Best video on polarisers. Thanks a lot.
Thanks for clearing my concepts on this topic, From India
Really made the topic more intresting! Loved it!!
Thank you for these awesome demonstrations👏👏💖
Great video man you explained every concept of polorization with examples in one video.
You made polarization so much more fun for me! Thankyou!
100 times better than my Indian rote learning education system
Real life explanation wow..simple but powerful
Thank you very much!!! I only wanted to see an animation but a real life experiment is more helpful :D
sweet. I was wondering about those 3D glasses for a long while now. I used to have tons of fun popping the lens out and watching it change colour as I turned them in front of each other.
So since it lets light come in differently from each side, that makes sense why it's not recommended to wear them as sunglasses. XD
fantastic explanation of applications ...keep it up bro
That was so helpful to understand the polarization in an interesting way thanks
That was great! I wish I had found it before. Thank you very much Kevin.
what a brilliant demonstration
nice, thank you for the enlightening ^^ I was looking for that exact simple explanation
awesome explanation . amazing. Before watching this video I thought polarisation as topic I could never be able to understand but now I am curious about it. thanks 😘
Man this explains so much things, bro I gotta thanks you what an amazing video
that was a smooth learning curve.. gr8 video.. Thank you :)
Thanks so much for this ! Do you think that polarised light therapy (500-2500nm) can be more effective than regular red light therapy due to a wider spectrum of light combined with polarisation ? Does polarisation of light increase its capacity to permeate the skin ??
My mind was blown, thank you for that
Great explanation, thanks for upload this kind of useful videos. It helped me a lot to learn about this subject matter.
very good job! this will hopefully help me with the understanding for my electromagnetics exam next week :)
We're in 2020,i wanna ask u, did u pass the exam?? ☺️☺️
Fabulous vedio !!!
Thanks kevin sir
For doing this experiment.
Cool video, thanks for the explanation and demonstrations!
perfect explanation, but i think that the expression for the sun light polarization is due to the difference between the plane of polarization of the aye and that of polarizer
That's incorrect. The human eye is not sensitive to the polarization of light. This is why we need eg, the analyzer to view the polarized stress in the plastic cup.
Bee eyes are another matter.
You nailed it in our understanding. Thanks 😊
Thanks a lot Mr. Kevin.
I notice that with some phones polarized sunglasses will often block the light.
Hi Kevin, great video! Thanks a lot for sharing how to show this effect. Just to be sure, you now place the polarization filter in front of your cameralens. But do you also see the colors when you just look with your eyes through the polarization filter?
And is the petri dish you are using a glass or plastic one? Can I use it to see the stress in a glass of wine for example?
The BEST video ever
Wow 👍
Where can i get those linear polarising filters?
Thank you so much Kevin 👏👏👏👏
Quick Question: Is there a difference between an Analyzer and polarizer?
very much thank u . I was reading stress analysis and in photoelasticity it helped me a lot
that was a really nice demonstration ! tysm
Great explanation, Now I can apply my 3D glasses to microscopy.Thanks.
Thank you very much for making this video. It was pretty easier for me to understand than other videos. Keep it :D
no words can express my appreciation than I love you hhh
one of the best on this topic, thanks!
Truly fascinating!
Nice experiments, can you tell me what kind of flashlight is that?
Excellent explanation.
Please teach us about ND filters, this is something amazing.
so it's like a slope and movement? going forward with a wall in front of you gets you stopped, but if you put a gradual slop to change directions it'll change the direction to up? (no gravity etc)
That's a neat explanation!
(a) So how are these polarizing filters made. How do they work? Are there millions of tiny slits? Is it made of some chemical or crystal?
(b) Why is the interaction so consistent all over the filter? Are there materials man made or otherwise where polarization is not consistent?
(c) Do diamonds show polarization?
(a) they are made in molecular level.
a) In a way they are - they're typically polymer chains, such as PVA, that are pulled during manufacturing. When they're pulled, all of the chains line up in one direction. The electrons are then free to move along the polymer, but not transverse (90-degrees) to it. This allows the polymers to absorb the light that is polarized along the direction of the polymer, and let the other polarization pass through.
There are some other ways of making polarizers - metal wires can be used for lower frequencies (the spacing of the wires has to be less than the wavelength. This is really close for red, 800nm, light, but not so bad for microwaves). Some of the most efficient polarizers use two pieces of glass precisely joined together. These only work for a certain 'viewing angle' though.
b) Our eyes can be pretty sometimes - they're capable of detecting single photons in very low-light situations. But they're also not always the best relative detectors. I'm not sure what the relative consistency over the filter is, but it's probably less than 5%. Also, I'm sure the manufacturer has experimented in the best ways of making consistent filters, and have implemented quality control measures to make sure that they're mostly consistent. If not, they can always re-melt and re-stretch the polymers for another batch.
c) I'm not aware of any bulk optical polarization in diamonds. This doesn't surprise me much, as the crystal structure is a tetrahedron and is fairly isotropic - unlike the clearly directional pulled polymer filter. Of course, the faces of the diamond do reflect light, and you can get polarization when viewing reflections (from any surface, glass, water, diamond) at the Brewster angle. Unfortunately, I forgot to touch on this topic in the video.
What does it get darker when the two filters are place together with the axis aligned ? Shouldn't intensity be the same since the polarized light is already blocked by the first filter ?
excellent examples ! i commend you
Glow array of spherical photons get pole arrayed or polarized via certain crystals. Tensors.
Self Tinting car windows with a push of a button
Very well explained, thank you! At the very end when the light is reflected off the mirror, is it blocked by the linear polarizer or the circular one?
Good question, let me explain in words and then try a diagram as well. After the, say, left-circular (LC) polarized light is reflected from the mirror and becomes right-circular (RC) polarized. The 'circular' polarizer, isn't actually just a circular polarizer. It's a quater-wave plate (1/4-wave plate). This transforms the RC light to linear polarized. But it's polarized 90-degrees to the linear polarizer it encounters next. So the linear polarizer ultimately blocks the light. Here's an attempt at a diagram:
Incoming light (arrows show direction of light - read from right to left):
| No light out
^mirror
thank you so much for your explanation. very helpful!
Thank you!! That was very interesting and very informative!
Just an aswm explanation.....Very clear concept.....Just amazing......😍😍😍❤Aswm job brh!!!....Keep making videos like this.....I reaply love it.....
Its really not reaply😂
Thanks a lot for this video. I find myself coming back to it occasionally. I am now curious about this behaviour at 4:35 .
1) Why does this behaviour occur at all?
2) Is there any name for this behaviour that I can lookup on the net?
Re-radiation. It's "re-radiation" of the light energy (EM wave) at a new polarization angle. Take a look at the vid below- the metal grate is re-radiating the microwave energy in the direction that the grate is positioned, having intercepted the RF from the transmitting end at 45 degrees. So, re-radiation of the RF then takes place at the new 45 deg angle AND is picked up at the far end receiver.
ruclips.net/video/KM2TkM0hzW8/видео.html&t=116
Also, this MIT demo goes into a little more detail:
ruclips.net/video/AVn49LbYoB8/видео.html
wonderful explanation...
5:25
I still don't understand how did the intensity increased ?
I mean in polarisation, I2 = I1 (cosx)^2
So intensity should have decreased
But it increased ?
I don't think it should have been possible in an isolated system
It became polarised at a diff. angle that's why it regained the intensity, as it no longer made 90° with the sunglasses & the 2nd polariser.
Thanks a lot, learned a lot in 15 minutes
Saw a video where the two opposing lenses nothing gets through light changed the look of certain gems to lots of colors and different geometric patterns. I think quartz was one. (Edited) Found it. I don't know how to paste a link but the video is called 12 foundation stones of new jerusalem. It's 2 yrs old only has about 6k views. I forgot this video says some gems like diamonds look black in different light. Why have i never heard of this? Wife and daughter are into rocks, me too. This is interesting.
Awesome!! Keep it up ❤️
How come when you overlap the second polarizer with the same axis as the first one, it dimmed the light slightly?
Great explanation
repolarized? I see it, but I don't buy it. You're saying that the sandwiched filter is 'changing' the polarity of the light wave?
Yes, it does - but in the case of the sandwiched filter it comes at a cost. The filter blocks some of the light, reducing the overall brightness.
***** I had the same question. The key to understanding this is that a diagonal vector has horizontal and vertical components! So what the middle filter does isn't bending the light but rather allowing the horizontal or vertical components (according to the middle filter's direction of axes) through. The sunglasses at the end do the same thing.
I think it's not a linear wave like people demonstrate, it's a three dimensional field. I believe that all fields pass through even if we don't see the light. I think the polarized glass change the shape of the field making it invisible through our eyes and the other glasses reshape back to normal somehow.
great job,now a will be able to tell if sun glasses genuine or not
This was very cool!!!
Awesome video
Perfect
Satisfied 🎉
how do you explain polarization in terms of photons? We're told light is a particle. Can a particle/photon be polarized?
How does the “repolarization” alluded to at ~6.00 because to that point i see polarization filters are removing photons in proportion to sine theta…
Why the 3D glasses change the colour of the light apart from its polarisation?
Great work👍
still doesn't explain why my room projecting outside building with colours and movement. I just wanted to know why I see the building with its original colours on my wall. I know it somehow being projected from my window but I'm just curious.
This is high quality ASMR
excellent explanation
You are amazing.....❤️❤️
How does polarization support the model that light is an electromagnetic wave?
Like a boss!!!! Thank you!!! Greetings from Argentina.
Viviana V k🍧