Cosmic complexity does not rise smoothly; it jumps in steps, and each step opens only once a narrow set of conditions is met, what David Christian calls Goldilocks conditions. Gravity must squeeze gas hot enough for a star to ignite; stars must die before heavy elements exist; a rocky planet needs liquid water before the chemistry of life can run. Eight such thresholds string into one continuous account, from the Big Bang 13.8 billion years ago to the language and collective learning of humans about 300,000 years ago.
Cosmic complexity does not rise smoothly; it jumps in steps, and each step opens only once a narrow set of conditions is met, what David Christian calls Goldilocks conditions. Gravity must squeeze gas hot enough for a star to ignite; stars must die before heavy elements exist; a rocky planet needs liquid water before the chemistry of life can run. Eight such thresholds string into one continuous account, from the Big Bang 13.8 billion years ago to the language and collective learning of humans about 300,000 years ago.
Related topics in Cosmic Timeline