After Illusions Come the Impossible

Last week's focus was a contest involving the creation of visual illusions, many of which create an aura of the mathematically impossible. Thus, it is only fitting to continue on this theme with a recommendation of a neat web site that focuses on impossible figures, which are closely connected to geometrical thinking.

The Impossible World is run by Vlad Alexeev as a hobby, and offers both an English and a Russian version. Without question, it is a great resource for mathematics teachers and students.

Consider these options:

• Art of the Impossible World, including the work of Escher, Reutersvard, Del-Prete, Orosz, de May, Segui, Nikolayeva, et al
• Animations of the Impossible World such as Escher's "Waterfall" and others such as the Impossible Triangle shown above
• Visual Library of Impossible Figures
• Collection of Articles about Impossible Figures, which is a great resource for mathematics teachers all by itself
• Impossible Puzzle is a computer program that lets you create your own impossible figures
• Great set of links to other web sites about impossible figures
• News about Impossible Figures...believe it or not!