A chick hatching from an egg. The chicken or the egg causality dilemma is commonly stated as which came first: the chicken or the egg?. The dilemma stems from the observation that all chickens hatch from eggs and all chicken eggs are laid by chickens.
Unpolarized light can also become polarized when it is scattered in air (also known as Rayleigh scattering). This occurs due to the fact that the EM waves cause the electron in air to vibrate, producing radiation and causing polarization of the light.
Rayleigh scattered produces blue sky and the color the clouds receives. Mei scattering is responsible for the color we see. Even with Rayleigh scattering taking place in the atmosphere, over one-half of the sun's 'white' light continues through the atmosphere reaching the earth's surface. Next, blue light waves scatter at a rate about four times stronger than red light waves.