I saw something quite odd this morning and I can’t quite explain it. When I woke up, there was what appeared to be a diffraction pattern projected on my wall, resulting from a small gap between the curtains (a single-slit diffraction pattern). But as far as I understand, single slit diffraction only occurs when the slit width is roughly the same order of magnitude as the wavelength of light.
In addition to that:
- the light source is reflected sunlight (which should consist of lots of different wavelengths) from the building opposite
- it was hard to see a whether the different bands had different intensities
- there were two bands which were red (why?)
- too many bands to be a diffraction pattern? Given the wall is probably ~5m from the window, the angle between each “slit” is actually tiny.
Here’s the curtain & slit:
If anyone could shed any light on this, it’d be appreciated 