Why does diffraction occur?

Question

Specifically, how does it work for light? Does it need an aperture (small slit) to work?

Answer 1

No. Check out Huygen's principle. Every point on a wavefront acts as a source of disturbance( or a new wave) . An aperture just makes it easy to see. The aperture becomes a source of new waves so that the energy spreads out instead of just going in a straight line

Answer 2

It is an interference effect due to the wave nature of light. If two light waves arrive at a location 180 degrees out of phase, they cancel each other out. If light is shining through an aperture, and a point is exactly half a wavelength of light farther away from one edge than from the other, that spot will be less bright because of the interference of light waves from each edge of the aperture.

It is all about light being a wave and how many wavelengths different various paths are.

Answer 3

Diffraction works because it is the nature of subatomic particles to move from an area of higher concentration to an area of lower concentration. It is a different notion for light and is dependent on the energy within the photon components within a certain area of light. Light propagate in waves and the wavelength and amplitude of the wave increases until it covers a given space with the energy displacement posible governed by the energy quantity of the photons that make up the light.A photon with 200J of light and an area of light consisting of 4 photon will diffract a greater length and have waves that are of greater wavelength and amplitude that a photon with 100J and an area of light consisting of the same 4 photons.