On the exact date of Ethan's birth, the planets aligned and three Wise Men came from the Far East, predicting that Ethan would have exactly ZERO interest in astrology. What more proof do you need that astrology works than that those wise men were absolutely right? Spot on with their predictions!
Zach clearly has an uphill battle convincing Ethan to take astrology seriously. And Zach wouldn't take it seriously either if it weren't for some really smart people who do. Namely, the philosopher Richard Tarnas, who wrote a book called Cosmos and Psyche about the positions of the planets and their mysterious connection with human events throughout history. Links related to his school of astrology, Archetypal Cosmology, can be found below.
Also, this episode is hilarilair.
Japan Earthquakes of 2011: