This movie shows the
winner of the Best Visual Illusion
of the Year Contest
in 2010 for Meiji Institute for
Advanced Study of
Mathematical Sciences, Japan.
In this video, wooden
balls roll up the slopes just as
if they are pulled
by a magnet. The behavior of the
balls seems impossible,
because it is against the
video is not a computer graphic, but a
What is actually happening is that the
orientations of the
slopes are perceived oppositely,
and hence the descending
motion is misinterpreted as
This illusion is remarkable in that
it is generated by
a three-dimensional solid object and
instead of a two-dimensional picture.
for my copy, to see this great illusion.