physics thermodynamics entropy
Definition
Second Law of Thermodynamics
The Second Law of Thermodynamics states that the total entropy of an isolated system can never decrease over time; it can only remain constant or increase. In other words, such a system will naturally progress toward a state of maximum disorder or equilibrium.
Implications for Life
The Second Law gives time its “arrow” by distinguishing between past and future through the statistics of molecular motion. While the fundamental laws of physics are time-reversible, the macroscopic world is not, due to the statistical inevitability of disorder.
Obs
Life appears to locally violate the Second Law by growing, reproducing, and increasing in complexity. However, this is only a local phenomenon made possible by the continuous input of free energy (typically from the sun), which increases entropy elsewhere in the universe.
Thermodynamic Stability vs. Dynamic Stability
- Thermodynamic Stability: The state of maximum entropy or “heat death” (e.g., a pile of rust).
- Dynamic Stability: A state maintained far from equilibrium through continuous activity and replication, allowing complex patterns to endure.