Question

If entropy can only increase in a closed system, then how can life grow more complex over time on Earth? Doesn't this violate the 2^nd Law of Thermodynamics? Explain

Answer 1

The second law of thermodynamics is sometimes used as an argument against evolution. Evolution is a decrease of entropy because it involves things getting more organized over time, while the second law says that things get more disordered over time. So evolution violates the second law.

It is important to note that the Earth is not an isolated system : it receives energy from the sun and radiates energy back into space. The second law doesn't claim that the entropy of any part of a system increases : if it did, ice would never form and vapour would never condense, since both the processes involve a decrease of entropy. Rather, the second law says that the total entropy of the whole system must increase. Any decrease of entropy must be compensated by an increase in entropy.