Walter Alvarez

A Most Improbable Journey

A Big History of Our Planet and Ourselves

Multco St Johns, 550 A4739m 2016

Big History is traditional human history expanded into evolution, paleontology, and cosmology.


The impact zone was shallow ocean. Would a different impact longitude (onto land, or into deeper oceans) cause different results? Follow the impact latitude east or west, and imagine...

The book reminds us of the contingent nature of our existence. Tiny chances times 10²³ stars? Assuming some very old technological civilizations expand to fill their stellar neighborhoods, that suggests the "tiny chances" of civilization per star range from 1 in 10²³ to perhaps 1 in a thousand. We do not have nearly enough data to narrow that range, and philosophical attempts to bypass our ignorance are ignorance on stilts.

WalterAlvarez (last edited 2019-11-13 22:41:16 by KeithLofstrom)