Apollonius and Harmonic Conjugates - Universal Hyperbolic Geometry 2 - NJ Wildberger

Explore the concept of harmonic conjugates in Universal Hyperbolic Geometry through this 38-minute lecture. Delve into Apollonius' introduction of harmonic conjugates and their relationship to four points on a line. Discover how pole polar duality associated with a circle produces families of harmonic ranges. Examine the occurrence of harmonic ranges in vertex bisectors, vector combinations, and quadrangle sides. Learn about polarity in general conics, find the polar of a null point, and understand various types of geometry. Investigate examples of harmonic ranges, harmonic pencils, and related theorems. Gain insights into harmonic vector combinations and the Harmonic Quadrangle Theorem.