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polarization a level physics confusedddd

sorryyy for the amount of threads im making abt qs i have today aha i hv a test on this coming up and i dont understand it

when two filters are at 90* to each other, is the transmission 0, or is just minimum? a guy in his videos showed that it's minimum' cuz some light still transmitted through when the two filters were at right angles to each other, but my teacher said that it is zero? whos correct lol
thanks so much
also, as you rotate a filter, why does the magnitude decrease?? cuz surely its juts cutting out one plane of oscillation or something...
Original post by vix.xvi
also, as you rotate a filter, why does the magnitude decrease?? cuz surely its juts cutting out one plane of oscillation or something...

It is definitely a minimum but can be and often is zero. (Best be on the sake side.) It will depend on the quality of the two filters. In the ideal case it would be zero.

The reason why it would be zero is that the 1st filter (say) cuts out all the light (in the ideal case) except the light oscillating in the vertical direction.
The second filter cuts out all light except that in the horizontal direction. But there is none in that direction, because it was cut out by the 1st filter.
Result: the 2nd filter lets through no light.
Original post by Stonebridge
It is definitely a minimum but can be and often is zero. (Best be on the sake side.) It will depend on the quality of the two filters. In the ideal case it would be zero.

The reason why it would be zero is that the 1st filter (say) cuts out all the light (in the ideal case) except the light oscillating in the vertical direction.
The second filter cuts out all light except that in the horizontal direction. But there is none in that direction, because it was cut out by the 1st filter.
Result: the 2nd filter lets through no light.

thanks so much

sorry one more q- as you rotate it, say 0 to 90*, why does the magnitude of the light decrease and then become 0?
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Avatar for β0b
β0b
21
Original post by vix.xvi
thanks so much

sorry one more q- as you rotate it, say 0 to 90*, why does the magnitude of the light decrease and then become 0?

I had this same question a while back and I think I understand it now. you know how people say particles are waves of probability more so than actual waves sometimes? this is partly why. say the filter is 60 degrees to the waves' oscillation where 0 is parallel. oscillations can be seen as vectors. and all vectors are made of components. an x and a y. that means that some of the components are able to pass. but saying that some of a light wave passes is not right. hence the probability. in this case, 2/3 of the light will be blocked because of this. I hope I explained this well, my dad never understands me when I try to teach him what I learn 😅 I also hope I am correct because it would be awkward if I was wrong. here are some sources for my reasoning. they aren't 100% related to your question if at all, but it influenced my thought process so it is good I guess.

https://www.thestudentroom.co.uk/showthread.php?t=2657815
there is also a physics teacher, but I can't really link him.
this video however is made by a real scientist with a degree if that helps validate.
Also feel free to ask questions. that is partly the reason for the student room anyway as far as I know :smile:
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Avatar for β0b
β0b
21
Oh! one other thing. https://ptable.com/#Properties this may be a website for chemists, but the community also has biologists and physicists so it is a pretty good place to ask questions. scroll down on the page to see if you can/want to join any of the groups.
Original post by β0b
Oh! one other thing. https://ptable.com/#Properties this may be a website for chemists, but the community also has biologists and physicists so it is a pretty good place to ask questions. scroll down on the page to see if you can/want to join any of the groups.

thank you! ill check it out
Original post by β0b
I had this same question a while back and I think I understand it now. you know how people say particles are waves of probability more so than actual waves sometimes? this is partly why. say the filter is 60 degrees to the waves' oscillation where 0 is parallel. oscillations can be seen as vectors. and all vectors are made of components. an x and a y. that means that some of the components are able to pass. but saying that some of a light wave passes is not right. hence the probability. in this case, 2/3 of the light will be blocked because of this. I hope I explained this well, my dad never understands me when I try to teach him what I learn 😅 I also hope I am correct because it would be awkward if I was wrong. here are some sources for my reasoning. they aren't 100% related to your question if at all, but it influenced my thought process so it is good I guess.

https://www.thestudentroom.co.uk/showthread.php?t=2657815
there is also a physics teacher, but I can't really link him.
this video however is made by a real scientist with a degree if that helps validate.
Also feel free to ask questions. that is partly the reason for the student room anyway as far as I know :smile:

thanks so much!!
i think ur correct...its the component of the wave. thats why the magnitude decreases :smile:

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