Q.How is polarisation of light obtained by scattering of light?

Step 1. The electric field of incident (unpolarised) sunlight drives the electrons in an air molecule to oscillate in the plane perpendicular to the sunlight's own direction of travel.

Step 2. An observer at $90°$ to the original sunlight direction can only receive scattered radiation whose oscillation has a component transverse to the observer's own line of sight, since an accelerating charge radiates no energy along its own axis of oscillation. …

Explain the electron-oscillation and no-radiation-along-own-axis argument for pol …

• Claiming ALL scattered skylight is fully polarised -- only light scattered at exactly 90 degrees is completely pola …