If you want to make a spooky house : Fraunhofer diffraction

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May 11, 2008
For those of you faint at heart. Do not try this.
But it is a most interesting optical illusion. It is called Fraunhofer diffraction.

Long ago, it was very easy to scare anybody. Now we have the advances of science to explain strange happenings and remove the superstitious believes. Imagine that this would have happened 300 years ago. People would have been burned for sure. Highly possible that furniture, curtains or window dressing creating a similar effect as vertical blinds would have caused quite a stir.

Fraunhofer diffraction is a type of optical wave diffraction that occurs when field waves are passed through an aperture or slit, causing the size of an observed aperture image to change due to the far-field location of observation. This image shows how the slits of vertical blinds in a window bend the rays of the sun and influence the shapes of the shadows projected on the wall. As the ears approach the shadows of the vertical blinds, the shadow of the ears stretches toward the shadow of the vertical blind to produce elongated ear shadows. The shadow of the head seems to grow horns at the points where the shadows of the blinds intersect the head.


Fun visual effects :

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