See Quantum Mechanics in Action with 3 pairs of Sunglasses

Here's a rather nice summertime experiment you can do one the beach or anywhere else if you have or can borrow three sets of polarized sunglasses.

With just two pairs of sunglasses, you can see the typical effects of polarized light, but add a third at a diagonal angle and you can see light getting though two oppositely polarized filters which shouldn't be possible.

Classical electromagnetic theory does not predict this, but quantum theory does. Its one of the few cases were you can easily see the direct effects of the probabilistic nature of quanta and particles in contrasting to the effects of EM waves. We also see how this is relates to the Schrödinger's cat thought experiment and the universe possibly splitting at every such "choice".

[ElectromagneticVideos]

I garbled the classicall em discussion when trying show how the diagonal light partially gets though a 45 degree rotated polarizing filters. Simply put, in classic theory, once one polarization is selected by the first filter, that is the only polarization that can continue though to the end. The following filters all reduce the level of that polarization further based on how more or less misaligned it is with each of the subsequent filters. Sorry about the confusion!

[WOFFY-qcte]

In the 70's I found some polarised film and had the idea of fitting it to car head lamps in the vertical plane and using un-tinted polarised glasses at night. It worked very well and I was surprised that car makers did not install polarised windscreens and headlights. Interesting video thanks. I will have a play after I have found Schrodinger the cat.

[ThriftyToolShed]

That's very surprising. I know a little bit about the 2 layers and only learned about the polarized films difference on LCD screens while working on a friend's jetski display a couple of years ago in a video. I thought it was very interesting the effect turning the polarized layer 90⁰ had. I had no idea about the 3rd lens. I always learn something. Thanks!

[Scott-sun]

You can check if sunglasses are polarized before you buy them with your phone...turn the phone while looking at the screen through the glasses. If the brightness changes, it's polarized. Fishing glasses are usually polarized.
Now, I gotta try this! I have two pairs of polarized glasses...just gotta go get a third pair...

[SoundsLikeOdie]

I am not a rf expert by any means but I recall seeing various types of antenna. Some were vertically polarised others horizontally and others in a spiral manner.
I wonder if the science is similar here. The radio waves travel in rotating fashion and you can see it by looking at the antenna design. I wonder if the middle lenses somehow manages to twist the light so it begins to rotate and have screw type waveforms

[EgonSorensen]

I wonder if this also work with the 3D glasses from a movie theater. The ones used here (Denmark) uses circular polarization, and I have a few pairs.. Will have to try this out at some point - thanks

[RetiredEE]

I now have a use for all those broken polarized sunglasses that i threw into a box! (I have saved a few by combining parts)

Can quantum theory explain why breaking a left vs right eyeglass temple seems random? Or why a right sock vs left sock disappears?

Thanks for the interesting and nicely demonstrated video!

[cyndi]

Enjoyed the video! LCDs have a polarizing filter as well. Then the liquid crystal arranges to make a “twist” and blocks the light. I wonder if I look through my one pair of known polarized glasses at a black digit on my clock and rotate would the digit get lighter. I’m wanting to go try!

[cyndi]

Well, in my experiment just now i didn’t get the result I thought but I learned something; my LCD clock is diagonally polarized 45°. I assume like in a car you don’t want to have your display blocked by your sunglasses so they compromised. Anyway the part that didn’t work as expected was that the glasses rotated clockwise 45° in front of the LCD clock display made the display completely black and at no point were the digits lighter than the background. I suspect it’s because I’m looking at the light going through the glass twice both into and reflected back out of the polarized glass.

[Uterr]

Soo, I huv a queston. Why do we need a third set of glasses to show this effect? Because if after first set of glasses we have perfectly polarized light, than if this effect not exists then alredy after second set of glaases we are going to see black image at any angle, except of when second set of glasses oriented exactly like first, and thus to show this effect its enough to have 2 set of glasses and we dont need 3rd set.

[mahmoudmohammad]

Your videos are great but better thumbnails could do magic in terms of views.