Diffraction Diffraction occurs when a light wave passes by a corner or through an opening or slit that is physically the approximate size of, or even smaller than, that light's wavelength. In the real world most objects are very complex in shape and should be considered to be composed of many individual diffraction features that can collectively produce a random scattering of light. Polarization Natural sunlight and most forms of artificial illumination transmit light waves whose electric field vectors vibrate in all perpendicular planes with respect to the direction of propagation. When the electric field vectors are restricted to a single plane by filtration then the light is said to be polarized with respect to the direction of propagation and all waves vibrate in the same plane. In either case, it carries energy through a vacuum at a velocity which is a universal physical constant, and is the same for all observers and for all colors.
Light frequently behaves as a particle.
Light is a complex phenomenon that is classically explained with a simple model based on rays and wave fronts. Light also behaves like a wave in many contexts. All colors propagate with the same velocity c in vacuo. Wavelength, frequency and photon energy are all interrelated. Our Way Light has been both an elusive and necessary driving force in our biotic world since life began.