Timeline for Why can adding more polarization filters increase the amount of light that goes through them?
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 27, 2016 at 2:35 | vote | accept | psitae | ||
| Oct 24, 2016 at 16:28 | comment | added | knzhou | However, "adding waves" is still, to me, the more natural picture, even for a non-absorptive polarizer which appears to split a wave instead. As an even more extreme case, consider a mirror. It feels much more natural to say that it "bounces" a wave off, but there's no term anywhere in Maxwell's equations that describes this. If you compute what the electrons are doing, they're simply spawning a canceling wave in the forward direction and a new wave in the backward direction. We can look at the result and call it reflection, or beam splitting, but this is a secondary interpretation. | |
| Oct 24, 2016 at 16:25 | comment | added | knzhou | @Emil If the initial and final polarizations are $A$ and $B$, all my answer is saying is that you can think of $B$ as $A + (B-A)$. There's strictly speaking no physics there, it's purely to aid intuition. | |
| Oct 24, 2016 at 9:07 | comment | added | Emil | I'm having a hard time to apply your microscopic picture to the case of non-absorptive thin film polarizers. Can you elaborate how added light is still a good picture there? | |
| Oct 24, 2016 at 4:53 | comment | added | bright-star | This is the most important answer, because it mentions that electromagnetic waves induce new electromagnetic waves. For similar reasons, radar doesn't "bounce" waves off of metallic objects, it induces currents that cause the emission of waves in the opposite direction. | |
| Oct 23, 2016 at 23:08 | history | answered | knzhou | CC BY-SA 3.0 |