#1 Müller-Lyer
#2 Poggendorf

#5 Ebbinghaus

#7 Zöllner
#8 Hering

#9 Sander

#13 Poggendorf

#14 Kmunicek

Note to #14:

Author of #14 is Vilem Kmunicek. He sent me animated gif 27.7.2003. His commentary follows:

How to do it
What is a square?

Commentary on an optical illusion

Usually, we have two things: the truth that we wish to improve, cover, render impossible or unreliable, and the lie that, on the other hand, we want to make seemingly truthful. In such a case, the easiest way is to use the opposing statements for creating chaos (in this picture suggested by a number of lines), where the truth will appear as lie and the other way round.


V o c i l k a  J., B i l y  J.: Zrakove klamy. Epocha, r. XI, 1906, p. 107, 138, 174, 205, 222.

T h i e l e  R.: Matematicke dukazy. SNTL Praha, 1986.


main page rexx page apple 
snails identification and authentication mail ceska verze

last modified 8th August 2003
Copyright 1998-2003 Vladimir Zabrodsky
Czech Republic