Earth science lab radiometric dating answers
So, if you hold up a horizontal polarizer below the Sun it’ll appear clear, but if you hold it up by the side of the Sun it’ll appear dark (bottom).
Because of the way light scatters in air, if you point your hand at any point in the sky (other than the Sun), and turn your palm toward the Sun, then the flat of your hand will be aligned with the polarization of the light coming from that part of the sky.
It’s a long way from obvious (there’s It looks like the sunlight is made of particles moving in straight lines, but in reality you don’t need “particleness” to describe what’s happening here. With enough elbow room, waves will proceed in a straight line due to interference effects., absolutely everything is fundamentally quantum mechanical. The De Broglie wavelength decreases with increasing mass, and while even the lightest particles have fantastically small wavelengths (electrons typically have wavelengths on the order of trillionths of a meter), light can have wavelengths ranging up to miles long (radio waves).
Which of the incoming and outgoing angles experiences constructive interference depends on the thickness of the film, the material of the film, and the color of the light. It’s sometimes hard to see, but you can see thin-film effects in soap bubbles as well.
There’s an optical device called a “Fabry–Pérot interferometer” which uses wave interference to separate out light of very, very nearly equal frequencies, and it’s basically just two mirrors.
As it happens, thin films of transparent material mimic the F-P interferometer.
Some light will bounce off of the surface of the film, and some will go through.
If the extra length between paths (red dotted line) is a multiple of the light’s wavelength, then you get “constructive interference”.