A
ball in motion - sliding diagonally across a table top -
appears rolling, rising in the air, or bouncing, depending
on the relative position of its shadow (although the original
path of the ball remains unchanged!)
Original
animation
Rolling
marble
Floating
bubble
Bouncing
rubber ball
Strange
triacontadohedrons
The green cylinder is placed on top or inside the polyhedron?
(see also kickboxer illusion)
Concave?
Solid?
Hollow?
Discovering
the Shadow
"La scoperta dell'ombra" written by Roberto
Casati
is an excellent book about shadows...
We recommend it!