irrationality

In a TED talk, behavioral economist Dan Ariely uses visual illusions and his research to show that people are less rational in their decisions than they think. He covers defaults, such as organ donation rates, and how choice framing steers decisions.

Numberphile's Ben Sparks shows why the golden ratio is the most irrational number, using seeds, continued fractions and rational approximations. He also explains why plants use it for spacing leaves and seeds.