Physics – Optics: Polarization (3 of 5) Three Polarizers

28 thoughts on “Physics – Optics: Polarization (3 of 5) Three Polarizers”

1. Should really talk to Bells theorem here.

2. Hello, thanks so much for the explanation, I'm incredibly grateful.
   I have a question; this thing has really stumped me…
   I have two polarizers at an angle of 90°. I'm supposed to put a polarizer in between at such angle so that the final light intensity is 1/4 of the initial.
   I have been calculating this for a few hours now and I came to a conclusion, that there is no solution to this… (the highest intensity I could reach was at 45° angle and was equal to 1/8). Thank you so much for your answer and videos — like I said I'm really grateful.

3. So if we would rearange those filters: first, third, second, then no light would pass?

4. Why is I1=0.5 I0? Cos 0=1 so I1=I0

5. How many molecules are there in 1m^3 gas in the standard state? (Pressure is 1.013•10^5 Pa, Temperature is 273 K)

6. Unpolarized light falls on two polarizing filters so oriented that no light is transmitted. If a third polarizing filter is placed between them, light still cannot be transmitted.is it right or wrong?

7. why?

8. Hello, I am trying to replace a poliriser on a device, but the colours are inverted, any thoughts?

9. Amazing explanation sir 🙏👆

10. 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.

11. Thank you! Good explanation.

12. Nice presentation. Please reply, can we say 0-degree polarised image is a non-polarised image?

13. For anyone wondering, Malus' law works only for polarized light.

14. Amazing Thanks Sir!!!!

15. Thank you for the video. It helped me a lot 🙂
    The math checks and the experiment confirms it… but it's so counterintuitive it still bothers me a bit 😛

16. it's not working in real life

17. I don't think this is correct. There should be a mention of the change in theta for each equation and he simply just plugs in the angle instead of delta theta…

18. I know all this must hold up for a the photon (quantum) explanation?

19. What if the third polarizer is moved in place of second. The intensity of light is 0, but in application if you put the third polarizer at an angle of 45 degrees it becomes bright again. 0*cos^2(45). (i2 = 0.)

20. Hello and thanks for the explanation, I got a question, If the light is already polarized (vertically for example)and it goes through a first polarizer with and angle, does the intensity would be half? or in that case we have use the angle formed between the vertical polarized light and the polarizer?.

21. what if the first polarizer is tilted through an angle theta then what will be the intensity of light is it half of the given intensity or not?

22. Thank you sir, keep the videos coming, it helps students like me. May God bless you!!!

23. The third polariser is at 90' to the first polariser though shouldn't the end result/intensity be 0?

24. How come there is a factor of 1/2 for intensity I_1 but not for I_2?

    Oh and thanks for these videos! These helped me with engineering dynamics last semester and now this is helping with E&M 🙂

25. This was indeed pretty interesting! My intuition definitely led me to believe there would be 0 light.

26. wow wow ammmazing 

27. Counter-intuitive resoult to me. I especially like this stuff in science. Thanks for the video!

28. Why/how does this happen?

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