Hi all. Just some moments ago I've experimented the diffraction phenomenon at home, in a situation I would have considered impossible. I did this because a guy that I know had experienced that too and I wanted to reproduce the experience: the diffraction from circular aperture. As far as I know the aperture must be as the order of magnitude of the wavelength, and the light should be coherent, but I was able to reproduce the interference pattern by simply using a normal incandescence lamp and a hole of about 1 mm of diameter. Now, visible light lies between 380 and 780 nm, while the aperture is 1 mm. Even in the worst case is more than one thousand times bigger. Moreover this light is produced by a incoherent source, so I cannot just figure you how this is possible. The circle was either pretty large but very undefined with the screen far from the aperture, or pretty small but more clear with the screen close to it. Can somebody please explain me why?