Sunlight from wall into dark chamber
Book I, Chapter 3, Paragraph 25
This experiment considers sunlight shining through an opening onto a back wall. This light then illuminates a darkened chamber. As the sun rises in the morning sky the amount of light reaching the chamber will increase and get more intense.
Sunlight shines through the hole in the wall on the right hand side, illuminating a circular portion of the wall on the left. This light then bounces into the dark chamber on the right.
The entrance to the dark chamber on the right with the reflected spot of light ontop of it. The roof above the setup is to ensure the chamber entrance has no direct view of the sky.
A closer view of the chamber entrance.
From this angle the inside illumination of the dark chamber can be seen.
Now the rising sun is simulated and the illumination of the dark chamber is observed.
The light moves from not illuminating the chamber, to fully illuminating it, and then back to no illumination.
Copyright © Tom Bickley and Tom Lancaster, Durham University.