Franz Carl Müller-Lyer [SEP] date of death
Franz Carl Müller-Lyer
Franz Carl Müller-Lyer, born Francis Xavier Hermann Müller (5 February 1857 - 29 October 1916) was a German psychologist and sociologist. The Müller-Lyer illusion is named after him.
Life.
Müller-Lyer was born in Baden-Baden. He studied medicine at the Universities of Strasbourg, Bonn, and Leipzig. He also studied psychology and sociology at the Universities of Berlin, Vienna, Paris and London.
In 1888 he entered into private practice in Munich.
Müller-Lyer illusion
The Müller-Lyer illusion is an optical illusion consisting of three stylized arrows. When viewers are asked to place a mark on the figure at the midpoint, they invariably place it more towards the "tail" end. The illusion was devised by Franz Carl Müller-Lyer (1857–1916), a German sociologist, in 1889.
A variation of the same effect (and the most common form in which it is seen today) consists of a set of arrow-like figures. Straight line