Polarized Light Explained + Experiments
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- čas přidán 20. 07. 2024
- I discuss and experiment with polarizers and polarized light. First though, I try to explain light itself, and the basic equations that govern its behavior. Some of this is down to my own interpretation, so please feel free to discuss and debate in the comments.
=SUPPLIES=
Polarizing Film Sheet - set of 10: www.amazon.com/gp/product/B004...
Tiffen 77mm Circular Polarizer: www.amazon.com/gp/product/B000...
I think the plastic wrap was Gladwrap, but I don't think that matters.
=IMAGES=
"Sphere wireframe" licensed under CC BY-SA 3.0 via Wikimedia Commons - commons.wikimedia.org/wiki/Ima...
"View of paddy fields from Bojjannakonda hilllock, Sankaram" by Adityamadhav83 - Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons - commons.wikimedia.org/wiki/Fil...
"Double-slit". Licensed under CC BY-SA 3.0 via Wikimedia Commons - commons.wikimedia.org/wiki/Fil...
"Double-slit experiment results Tanamura 2" by user:Belsazar - Provided with kind permission of Dr. Tonomura. Licensed under CC BY-SA 3.0 via Wikimedia Commons - commons.wikimedia.org/wiki/Fil...
"Electromagnetic wave" by P.wormer - Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons - commons.wikimedia.org/wiki/Fil...
"Ray optics diagram incidence reflection and refraction" by Nilock - Own work. Licensed under Public Domain via Wikimedia Commons - commons.wikimedia.org/wiki/Fil...
"Brewster window" by ChrisHodgesUK - Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons - commons.wikimedia.org/wiki/Fil...
"Brewster cigar box" by Chasles Stutz Co., New York - [2]. Licensed under Public Domain via Wikimedia Commons - commons.wikimedia.org/wiki/Fil...
"Wire-grid-polarizer". Licensed under CC BY-SA 3.0 via Wikimedia Commons - commons.wikimedia.org/wiki/Fil...
"Circular.Polarization.Circularly.Polarized.Light Homogenous Circular.Polarizer Left.Handed" by Dave3457 - Own work. Licensed under Public Domain via Wikimedia Commons - commons.wikimedia.org/wiki/Fil...
"Rising circular" by de:Benutzer:Averse - www.radartutorial.eu/06.antenn... via de.wikipedia.org. Licensed under CC BY-SA 2.0 via Wikimedia Commons - commons.wikimedia.org/wiki/Fil...
Some images used without attribution in the public domain. www.pixabay.com openclipart.org
Plots generated with www.fooplot.com
=MUSIC=
"Mell's Parade" by Broke for Free / CC BY 3.0
"The Theatrical Poster for Poltergeist III" by Chris Zabriskie / CC BY 4.0
"Day Bird" by Broke for Free / CC BY 3.0
"My Luck" by Broke for Free / CC BY 3.0 - Věda a technologie
ur video is not just physics, but mentally soothing
blows my mind that people are even able to figure this out.
Methodological naturalism
you are an wonderful presenter.
I'm a phone tech, and change polarizing film on lcds regularly.... I don't have a strong physics or science background but you do an excellent job of both explaining and entertaining. Thanks again.
i seen a lot of videos on CZcams and i think that was the best vid explaining such a difficult subject that I've ever scene.
next to the animated series physics videos by eugene
but yours didn't put me to sleep
I agree. very well presented.
I saw a video that talked about circular polarized light, and had no idea what that was. Thanks for breaking it down in a way I can understand! Hope to see more vids!!
Nice video, weird and fantastic this is still new information 30 years after 👍👍. In 1992 my physics project (6th year) involved the design and invention of a hand held optical polarimeter. Had to build it too. Captured my fascination deeply. The rotational dependence of your 3rd filter on color pertains to the relationship its thickness has on light wavelength. A. If the thickness is just right such that multiple odd quarter wavelengths of light (λ/4, 3λ/4, 5λ/4, etc) fit between its faces, then that light will pass through. Multiple half wavelengths will cancel. B. Remember that a quarter wave (λ/4) is also 90° which determines how circular polarization manifests. Rotating a third polarizer in between two others (a linear polarizer and an analyzer) will also change the transmitted color. The trick is to first begin with linearly polarized light.
Instead of using cellophane tape an excellent multiple quarter-wavelength polarizer (near yellow light) can be found using scotch tape. Thicknesses is around 2.3 mil or 2300 nm which is happily about four wavelengths at yellow.
You will also notice that the diatomic molecules in the upper atmosphere are linearly polarized (in blue) when looking toward the north sky. Works very well when the sun is near meridian (south in the northern hemisphere, so about noon) such that the light experiences a 90° reflection upon traveling to your eyes. So the sun is at your back while you're looking toward the north and the upward angle of view is dependent on your latitude. Not sure where the angle of maximum linear polarization occurs but it likely has something to do with Brewsters angle. 🙂🙂
You definitely deserve more subs! Thanks for the great video, passionated and easy to understand while it covers the topic and explains it well. You have earned one more sub
If only you were my physics professor, I might actually loved the subject back in college itself. Awesome explanation man!
Heyyy, your video and explanation should have more views^^ I loved it, specially because it inspired me to make design ideas for my Thesis 🤩
You are changing the perceived wavelengths of light when you spin the polarizers and that is why you see the colors changing.
how, polarizers only change orientation,,, i wonder if it has to do with a time effect, like fermats principle of least time
This is so wrong. Polarizers are not capable of changing the wavelengths of EM waves and no color change is happening. As the polarizer is being rotated, some components of waves are being filtered by the polarizer (that's why also called polarizing filter), and therefore reducing the intensity of surface reflected light as it pass through the polarizer.
@@bryanfuentes1452 it just changes the angular orientation, no?
@@bryanfuentes1452 he never said that the polarizer was changing the wavelength... He just said that it is canceling out the other wavelengths of light and thus polarizing.
Hey Eric, great video. We just referenced it in our video on removing reflections. Instead of going into the details and a deep dive of how polarizers work for video, we just said hey, go watch Eric's awesome explanation.
Thats bad. Cause there is more simple and at the same time more wide explanation of polarized light on youtube.
One of the best science episodes on youtube, ever!!! thanks Eric. You made my day. Love&light!
Thanks for this video! Do you have any insight of what is going on with the polarizing filters in the end of your video? Any sources that could be of some use?
LunaNympha I honestly don't have any sources for that, but if you found one, I would love to read it!
You will get color effects whenever different wavelengths are affected differently. You found that rotating the polarizer changed the color of light passing through the glasses. That means that the light emitted by the source is polarized differently for different wavelength ranges.
I watched the Minute Physics video on this subject like 10 times but it just made no sense
Your video is so good! Offering an intuitive explanation of whats actually happening, instead of just leaving it at "unexplainable quantum effects that break the laws of the universe"
I was studying mantis shrimp and didn't understand anything about the polarized light and when I looked at CZcams you were the first to pop up. Thanks for the help!
At the end of the video reminds me of the reflections on my GShock Aviator watch. If I hold the reflection just right, I can turn my hand and it will change color like that.
This very helpful and entertaining at the same time. We need more people like you! Thanks
Circular polarizes twist the polarization angle depending on its wavelength. If you start out with linear polarized white light and pass it through a circular polarizer, each color (wavelength) will exit at a different polarization angle. Now use a another linear polarizer after that to dial in the color you want to pass. I think this is done on stage lights instead of color filters and permits smooth transitions from one color to another.
sweet! i think the aforementioned principle is used to modulate the warmth in the picture. or the scenery choice.
Thank you so much. I know nothing about physics, yet you make this so easy to get. Keep it coming!
if we stacked enough translucent polarization layers to form a cube, could we theoretically not precisely create the location in 3D space, for a photon to light up, e.g. a volumetric display? if you stopped or polarized the light in the middle of the cube, and then used the light blocking property of the now electrically visible screen there, to light up there locally in the middle of the cube, and had enough images to fool the eye of course.
The color separation change with the angle of the 3rd polarizer.
One of the 3 is a circular polarizer filter? Since these filters introduce a delay of a quarter wavelength, and the speed change in transparent material with wavelength, .... Am I getting close to the answer?
This is actually the best video explaining polarizers on youtube.
Lately I started wondering about polarized light. So I did a little research and a few experiments.
+vril ya Yes, they are exactly 90 degrees out of phase.
***** I hope they aren't. Do you have an example?
It's generally easier to think about just electrical potential if you can. The magnetic component is equal to the rate of change in the electrical component.
Well, non-polarized or incoherent or broad spectrum light is really hard to depict. It has quantum mechanical weirdness. The relationship between the e and m components is well defined, but hard to visualize unless you simplify to polarized, coherent light, single-wavelength light. Except for lasers, light is generally not even in a particular phase in the first place.
@Eric Mickelsen. Excellent video and very instructive. Thank you.
this channel is underrated. U should have more subscribers. Keep doing good job. All the best
Please use this to talk about the famous slit experiment about Quantum Mechanics. I would like to hear your perspective of how light changes its behavior depending on whether you're observing it or not. TY.
Ha I was just looking at those polarizing films before I came here. Noticed the size, the quality, and thought "sounds like the ones." Great video!
I would like to see the colourful filter rotated to cover the entire camera lens view while filming something. I would like to see the effect of moving through the rainbow filter for the entire screen. You may have a very cool video effect there when expanded to full screen.
about the last experiment, the wavelight varies accord to the angle of inclination with the secondary filter, more open is more wavelenghts passing through (all the range between 800-400nm as example), the less is the angle the less is the wavelenght allowed to pass (420-400nm as example). Please correct me if i'm wrong
+ignacio carrasco I think you're on the right track.
Can all of the wavelengths on the electromagnetic spectrum be polarized? Thanks
Tis is the best explanation video I have ever watched on you tube. Are you a Professor? Well done you. Thank you with deep gratitude and appreciation. Excellent presentation.
Just a brilliant, and entertaining presentation on a subject that students have issues with. Thank you!
This was a very fun way to look at this, it was awesome
and apperently im not the only one that thinks that.
you got something good working for you mister.
i hope you all the best
This was amazing and you're a legend!!
This is a great explanation - thank-you for posting! :)
Hi, I have a problem with my LCD display. The display was monochrome. After removing the polarizing film and rotating it by 90 degrees, the colors have changed. The black has changed to white and white to black. After removing the next filter (transparent, which was under the polarizing filter) and re-applying the polarizing filter, the colors change - yellow, purple, green ..... and I can not use black. I am asking for a hint of what's stuck under the polarizing filter, what should I look for to "fix" my display. On my channel there are videos that show the problem :( Thank you in advance for a thank you.
Hey +Eric Mickelsen ! I was wondering if the lights of different wavelengths undergo polarization differently (as in the case of difference in refractive index from red to blue thereby different polarizing angles), that might be the reason for obtaining single color only for a certain configuration at the end of the vid.
I am really intrigued by polarization, and your video was cool!
Here's another neat trick that I discovered after watching this video:
1. Put on a pair of 3D Glasses.
2. Look at your phone. (It might help to turn your screen timeout to 1min or more. Also, I looked at mine when there was no other light in the room.)
3. Rotate your phone. You should be able to see different shades of color. (Also, the glasses I used were for an IMAX 3D movie.)
4. Try closing one eye at a time while rotating your phone. (I discovered that the left lense blocked most of the light while my phone was horizontal; while the right lense blocked out most of the light while my phone was vertical.)
POLARIZATION!
Kim Bayer that's right. The lenses are circularly polarized, in opposite directions.
Because it combines 2 difference image to 3D
that was a great question right at the end. i'm a physics student but have no clue about the colors changing due to respective angle of the polarizer.
Ok. i seem to have an idea. maybe is due to the way the lighting is set up. somehow the white light reflecting off of the white background is polarized in a way where each light color is polarized at different angles so that when the polarizer is rotated it only lets that specific wavelength go through. the more interesting question would be what is polarizing the light in that specific pattern. is it the light bulb itself or some material that is reflecting it. in either case the polarization is wavelength bias.
Brilliant video, thanks Eric!
Can you tell that how the polarized light is related to transverse wave?
how does it works with 3d polorised glasses and is one glass different from other....
Shubham Patil the lenses in most modern 3D glasses are out of phase.
Can we DIY polarized lenses?
Does a circular polarized guitar string sound different than linear? Maybe this is a way to make a unique sound. Or maybe this is what violinists are doing with their strings as they change the angle of their strokes? Or maybe it doesn't sound different at all? Do musicians know?
different frequency light gets bent by different amounts , turning the filter changes the incident angle and thus changes which light is reflected or refracted . probably more to it .
Wow, I actually understood that! Thank you, and awesome video!!
Hi!
I'd like to see if I can find a way to filter laser light through glass. the end result would be to be able to see a red laser image on one side of the glass it's projected on but NOT see it on the other side. Is this possible?
thanks!
Danny
+danny white Definitely possible, but it might be tricky. I think the easiest way might be to put a polarizing filter on the glass. Otherwise, even if you completely polarize the light and hit the glass at Brewster's angle, some light will pass through.
+Eric Mickelsen it works! Red laser and green filter. filter not only stops the light, you can't see the laser fro the other side of the filter!
Next question, how many laser colors are there and if there a corresponding filter for them? Theoretically there should be based on my findings?
very well done and explained.. this channel should have far more subscribers!
I think you cannot see the colors because the light is bouncing off the squares as the spectrum traveling into the camera, while the light that passes through is not and travels to your eye. Two sources of input in different locations.
A very good and simple explanation for something that's a pretty complex subject :)
Gosh, your video helped me understand quite a few things about light. I've been on a quest to understand more about quantum mechanics and entanglement and they brought me here. Hey, make more videos! ;-)
I wanna know how u actually make the lense polarized like How could u make it yourself
I think the wave length is changing by turning the linier polarizer .
Maybe what happens is that the nearest electron gets the "signal" and once that happens what we see as light is just the fields updating. But the electron has already got the signal.
The Universe works in pairs (dualism) and circulair motion (half circle is a wave. A circle is the most efficient way for Energy). With a circle it doesn’t matter at which position it begins. It will always be the fastest path from point A to point B. (brachistochrone curve)
Please make vedio on how can we make a polarizer
Thank you very much for the video. Very good explanation. Please do more!
Your Photo is so wonderful and give me dreams.I feel that I had meet you before ❤
I think particles like photons are in orbit likely with dark matter particles giving them an apparent axial wave as travel, or an apparent helical wave (circular polarization), depending on the orientation of the orbit. And I think light has the ability to travel faster, it's the dark matter interaction that's the limiting factor.
+sanjuansteve Anything a photon orbits is a black hole, and if light interacted with dark matter, it wouldn't be dark.
The different colors we can see because it passes only one wavelength of light and blocks all other!!!? May be color depends on which type of polariser is it, as the experiment shown here in oven?
I am not an "expert" but here is my guess: The linear polarizer is simply refracting light from the full spectra along a single axis. Ambient light is is all colors/wavelengths. As you rotate the polarizer is is polarizing different wavelengths based on their phase angle.
could polarisation be used to make windows that can block light or let it pass depending of the alignment of the materials?
+ThePapino134 certainly
*****
You obviously pulled that out of the air. The simplest polarizers are just doped transparent plastic that are stretched. Anyway even 500 USD isn't that much for something which is supposed to be used for decades.
*****
Oh yeah, the real issue is that you need to rotate them to continously change transparency, so you need circular windows.
(Huh, my first comment here was removed without a squeak. It didn't have anything objectionable in it. How "nice"...)
Can't remember if I saw it first on NextStep or Beyond2000 - yeah! back in those days.
I need help figuring out the proper way to reinstall the film in my home projector
That is so cool!
Can someone explain to me what he meant about microwaves being 1 cm? Is he talking about waivlength or the hight of the waves?
+EE Ehrenberg - wavelength
Height (or amplitude) would reflect the intensity or saturation of the signal, whereas wavelength would be the actual horizontal length of each sinusoid. Wavelength is what he is referring to. :)
@Eric Mickelsen. Excellent video and very instructive. Thank you.
Excellent explanation, really helpful
Amazing my brain just waking up with your explaination
Could this mysterious phenomena possibly the IR sensor in the camera lense?
Right, and the higgs boson met the quaternium isotope in a bar somewhere, Wi-Phy.
So, I only saw one demonstration of a polarizer, and it was pretty cool.
But you didn't really explain how it works, you only explained how the physics behind light works.
Could you demonstrate what a polarizer IS?
Like...what does it look like, up close?
A bunch of lines across a film?
Isn't that more like, a dimmer?
That's exactly what it is. They will look different up close depending how they are made. But they are literally just microscopic, parallel wires. goo.gl/images/YcDcxW
@@EricMickelsen Wow. A poster that actually responds. That, is truly new to me. Thank you.
But, I do then, Mr Know-It-All, have a few more questions.
What's the distance between these lines? I can't help but visualize them as microscopic "shades" or "blinds."
Does this matter? How does it affect the EM wave? Too short in blocks all the light, not short enough, it doesn't do much of anything in terms of ensuring "uniform orientation of the waveform."
That doesn't explain the phenomena czcams.com/video/gP751qpm4n4/video.html @ 4:30.
I'm really trying to figure out the "quantum physics" here.
I don't know the precise relationship, but the distance between lines needs to be in the same ballpark as the wavelength of the light. Thickness may also matter a bit, but barely. Think of it this way: electrons can move on these "wires" in one axis, so they can make an electromagnetic wave in that polarization. The motion of the electrons is induced by the light itself, and the electromagnetic wave produced by that election motion gets added into the light. The wires need to constrain the electrons to move in that one axis, and they need to be able to move roughly a wavelength in that axis, but not the other axes.
The weird brightening quantum effect comes in because the electrons in multiple filters and the light itself have quantum properties that interact and form a wave function that is not observed or collapsed until the photon is absorbed by the camera or eye.
To answer the final question, one really needs to think about the standard model of light in the first place. If anyone's interested in adding to this discussion...: physics.stackexchange.com/questions/195941/concerning-the-dark-bands-in-the-light-wave-interference-pattern
...then, please do so.
It asks basically "is light really a transverse (up/down) wave?" while providing evidence for the contrary.
good job!!! really innovative project.. pls do more of it
Hey Mr. Owl, how many licks does it take to get to the center of a tootsie pop?
+Josh Krisko 1, 2, 3... 3.
superb video!!! Great work!!
Really great video! I enjoyed watching
Great video! Thank you for the explanation.
the dielectric constant change with the frequency this is why you are able to filter the white light, i guess
Best physics teaching with practical
Homeschoolers here!! Great video for basic understanding of polarization for my grade 5 and grade 7 boys. Well done!! You may want to reach out to homeschool companies and put together a video series. God Bless
For avoid reflect from water when shoting on camera circle polarized need or linear
Second follow up. It's possible the reason why experimental and secret aircraft (mistaken for alien UFOs ) are suddenly visible with certain cameras is due to the effects of polarimetry.
I study B.S physics and you sure know a lot more than I do!
Thanks
"Im not a physicist" but I can tell your a mathematician and a good teacher
YES!! FINALLY!! THANK YOU!!
Can I use these polarized sheet to make 3d glasses ?
I guess, but you'd have to make a cling wrap sandwich like I did, and they'd be pretty bad.
Excellent video on many levels.
The talk is nicely is nicely accompanied by demo. But circular polarization with stretching is not clear. There are only patches of light passing here and there. But I am impressed. The sheet polaroid are not perfect linealy polarizers, I hope.
Sooooo, Light wave is 2 dimensions?
This video was amazing!
I would like someone to tellme what the lines on the filter are, in terms of chemistry/magnetic fields. Why do they interfere with the light? Are those lines just long and plain magnets all stright?
+martiarenax3 They are conductive lines - just metal acting as a wire. They interfere with the light because the light wave interacts with elections that can flow freely in the metal along those lines: a metallic reflection.
Thank you very much. Now i get it. Is a faraday jail in just linear pattern.
Right?
mmm.. What is the size of a light wave? May be i can construct my homemade filter out of simple copper wire.
+martiarenax3 that's right
great video..my physics teacher showed it in the class.
@4:32 actually the frequency of light determines the color, not the wavelength.....
whats the brand name and model of the Bass guitar ? :D
Epiphone Thunderbird
Please make more video about anything thank you!
great effort really enjoyed it
@11:22 shameless plug; a similar effect can be developed using a waveguide before the linear polarization layer, mica works. www.tindie.com/products/wallfacerdesign/psychedelic-mica-wave-plate-camera-filter-52mm/
nice video using this for help for my physics class
Hi there. There is an interesting yet little known about model of light that explains the nature of impossible colours. en.wikipedia.org/wiki/Impossible_color
The two light waves are thus organised through the nature of the musical octave (1/2) and musical 5th (3/2). I think what you have stumbled upon is explained by this nature. Great video by the way.
Very Good Explanation