This animation reproduces an experiment that you can carry out at home or in the classroom.
We place a light source inside a cardboard box in which all interior walls are painted black (to limit light diffusion), except for the one at the bottom of the box which will be painted white to serve as a screen.
When the light source is lit in front of an opaque object, we can define various zones of shadow. In all cases, the shadow corresponds to the region that is not reached directly by the source’s light.