the borromean rings

These three rings taken together are inseparable, but if you remove any one of them then the other two fall apart. It has been proven that the borromean rings cannot be constructed with flat circles.

The borromean rings have been and are still used as symbols and emblems; they appear in many logos.
3 rings

rings built on golden ellipses rectangular rings (golden rectangles) locked rectangular rings

3 sculptures

Intuition - Genesis - Creation  (John Robinson - Isaac Newton Institute - Cambridge)
references:   The Borromean Rings

  summary   August 2005
updated 29-07-2006