| The
Müller-Lyer Illusion Here
are two
vertical lines of identical length. One has reversed arrowheads ('fins')
while the other's look
normal. One of the lines looks longer!
Something about the arrowheads distorts
our perception. It may be our "built-in" sense of
perspective.
Adjust the
vertical line on the left by pulling the top, or bottom
end.
When both lines appear to be the
same length,
Press show
measure.
Press reset to do
another measure (starting with a
randomly selected line length).
Credits:
Illusion by Franz Müller-Lyer, 1889.
Java Applet:
©1997 Tony Azevedo
modified for instuctional usage
(changing variables and quantitative measurements),
Eugene Switkes, CfAO/COSMOS Program 2001
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