Deep Simplicity - Chapter 7

Life Beyond

• Jim Lovelock - developed idea that living and nonliving components of terrestrial environemnt interact in network that maintains conditions suitable for life on Earth (Gaia)
• Suggest that the best way to search for life was 'entropy reduction'
• Life creates islands of order in the midst of chaos
• Search for non-equilibrium gases in atmosphere
• Search for 1/f noise (information giving)

•  Gaia - idea of Earth as a self-regulating system

• NOT synonymous with idea of Gaia as God or Mother Earth
• Simply states idea of living & nonliving processes working together in self-organizing matter to create and preserve order
• Evolutionarily speaking, change in biological species not only affect other species, but the entire planetary system

• Daisyworld (Faint Young Sun Paradox)
• Paradox - During earlier periods, the Sun existed at only 70% of present heat levels.  Around 4.5B years ago, the Sun settled down to present temperature.  However liquid water (and life) existed prior to the rise in temperature, and persisted throughout the ordeal.  How??
• Life manipulated the physical environment for its own benefit
• Simulation - Phase 1
• Initially - Sun is weak, surface is barren and gray
• As Sun increases, black daisies grow and thrive
• Absorb radiant energy
• As heat increases, white daisies also grow
• Two population eventually reaches equilibirium and work together to regulate surface temperature (black/white surface to absorbe/reflect light)
• Simulation - Phase 2
• If temperature increases, white daisies gain advantage
• Increase in white daisies will cause decrease in temperature
• Equilibrium is restored
• Vice versa
• Simulation - Phase 3
• Temperature increases to the point where even white daisies can no longer survive
• Surface becomes barren
• Key - Feedback allows life to manipulate the larger environment

• Real world examples of Daisyworld-type scenarios exist
• Dimethyl sulfide (DMS)
• Microscopic life in oceans regulate Earth's climate
• If algae become active, cloud cover increases
• Less sunlight available for photosynthesis
• Biological activity declines