Daisyworld

Daisyworld is a deliberately simple planetary model: a world orbiting a star that grows steadily brighter, populated by two species of daisy — one dark, one light. Dark daisies absorb sunlight and warm their local environment; light daisies reflect sunlight and cool theirs. When the star is dim, dark daisies have a competitive advantage and their proliferation warms the planet. When the star is bright, light daisies dominate and cool it. The result: a planet whose surface temperature remains remarkably stable across a wide range of stellar luminosity, not because any daisy intends regulation but because competitive dynamics between species with different physical properties produce a feedback loop that stabilizes the system. Daisyworld did not prove Earth works this way. It proved Earth could work this way — that self-regulation at planetary scale was not logically impossible, not a violation of physical law, not mysticism in scientific clothing. It was the mathematical demonstration that dissolved the strongest early objection to the Gaia hypothesis.