Yesterday I helped Sheri & Stephane move. Ahhhhh invigorating.
I learned about camera obscura in school. Here’s a neat application of it:
Abelardo Morell blackens out all but a half-inch circle of a rooms window. As
light rays are forced through the small opening, they criss-cross and turn
the image of the outside world upside-down as the rays pass into the room.
He then records this optical phenomenon in an eight-hour exposure with a
large-format camera, and the resulting image shows the outside world
upside-down over the rooms interior. (thanks to Palle)