Is diffraction through 2 slits same as interference through 2 slits? I think that they are the same ,and when we observe interference pattern, we just focus on th first order of diffraction.

Question

anonymous · Answer

No they're not the same.
Diffraction is the spreading of a wave that results when it encounters an edge or opening.
Interference occurs when two or more wave disturbances reach the same location.
In the two slit experiment, waves from a primary source are diffracted at the slits, which thereby act as two secondary sources. The waves spreading out from the slits due to diffraction can then interfere.