Why Does Single-Slit Diffraction Create a Pattern of Maxima and Minima?

[Theo1]

When waves diffract through one slit why does it form a series of maxima and minima when there is no interference?...our teacher won't tell us and its really annoying me...and i have no idea why it should.
please help!
~sorry if this is in he wrong place

 

[Andy Resnick]

Loosely speaking, the wavefront interferes with itself- it has finite extent, and so as the wavefront propagates and spreads (diffraction), the various parts interfere.

 

[Theinvoker]

When waves diffract through one slit why does it form a series of maxima and minima when there is no interference?...our teacher won't tell us and its really annoying me...and i have no idea why it should.
please help!
~sorry if this is in he wrong place

Short answer is, it interferes with itself. It only really applies when the slit is larger than the wavelength and is a superposition of sets of waves diffracting at various points along the length of the slit.

 

[Dr Lots-o'watts]

A good intro:
http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/sinslit.html