Grab two pairs of polarizing sunglasses
Line them up and look directly above you into the sky when the sun is at 10 o clock relative to your position

Rayleigh scattering predicts light will be polarized linearly when traveling through a spherical medium i.e. the atmosphere because of nitrogen/oxygen dipole transmittance. A jones vector matrix reduction can quickly show this

Tell me what happens when you rotate the sunglasses perpendicular to each other.

Come back here with your results..