Order from Disorder: “The Second Arrow of Time” Could Challenge Scientific Orthodoxy

A proposed theory called “The Second Arrow of Time” argues that the universe may contain a process that increases order, challenging the usual emphasis on rising entropy. Mineralogist Robert Hazen and planetary scientist Michael Wong say simple structures can develop into increasingly complex and organized systems.

The proposal extends evolutionary selection beyond living organisms. It suggests that nonliving processes, including the formation of elements through nuclear fusion, the development of chemical compounds and the growth of crystal structures, can face selection pressures. Order, the researchers argue, emerges when a system offers many possible structures, can produce new forms and has a mechanism that filters among them.

The theory measures this increase in organization through the idea of “functional information.” Its proponents say mass extinctions and environmental crises can intensify selection pressures, increasing functional information in a system. They also point to Earth’s geological record and the history of life, which show long periods of stability followed by sudden bursts of evolutionary diversification.

The proposal has prompted objections because the second law of thermodynamics states that total disorder in the universe should increase. Critics say a new universal physical law must apply under every condition, while functional information that develops according to context may be difficult to measure objectively. Mathematical and experimental tests will determine whether the theory becomes an accepted law.