Diffraction pattern

[UIUCstudent]

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Diffraction pattern is said to be most noticeable when the opening is smaller or has comparable length to the wavelength. BR gives the example of diffraction of sound vs light through a window. Light has a much smaller wavelength than the window opening so less diffraction is seen, whereas sound has a comparable wavelength so diffraction is more noticeable.

But in single slit experiment sin(theta)=m(lambda)/w so the width must be bigger than the wavelength for a diffraction pattern to be seen.

Am I missing something here? They seem contradictory.

 

[Isoprop]

Diffraction pattern is said to be most noticeable when the opening is smaller or has comparable length to the wavelength. BR gives the example of diffraction of sound vs light through a window. Light has a much smaller wavelength than the window opening so less diffraction is seen, whereas sound has a comparable wavelength so diffraction is more noticeable.

But in single slit experiment sin(theta)=m(lambda)/w so the width must be bigger than the wavelength for a diffraction pattern to be seen.

Am I missing something here? They seem contradictory.

The opening doesn't have to be smaller. Like you said, it can be bigger than the wavelength. The important point is that diffraction is most pronounced when the opening is on the same order of magnitude (more or less).