Creationists claim that the Second Law of Thermodynamics makes evolution impossible.
Complex living organizms could not arise by natural processes because their structure is highly ordered.
Law only applies to processes close to equilibrium.
The argument is based on classical thermodynamics which only apply to closed systems which are near thermodynamic equilibrium. If you look at the entire system, energy goes from a form able to do work to low-temperature thermal energy unable to do work. This is very loosely associated with the idea that a closed system becomes more disorderly as time goes on. If this argument were true, life would be impossible! Consider an egg, which starts out as a simple mixture of liquid yolk and white, but which organizes itself into a chicken if kept at 100 degrees F for three weeks! The Second Law is obeyed throughout, and the chicken contains less useful (chemical) energy than did the yolk - the difference being the heat produced by the metabolism of the developing chick. The secret is that the egg is far from thermodynamic equilibrium, and only part of the system becomes organized -- the part not converted to chick becomes very simple carbon dioxide gas and water vapor.
Similarly, open thermodynamic systems can be organized by importing energy. Your bedroom tends to get messy, but may become more organized if you import your energy and clean it up. The entropy in the room is decreased by your efforts, but by far less than the amount associated with the energy your body used during the cleanup. The Earth imports vast amounts of energy from the Sun, and a minuscule amount of this is used to produce biological order.
Ilya Prigogine received the 1977 Nobel Prize in Physics for showing that a thermodynamic system that can import energy, or one that is far from equilibrium (i.e. with lots of available energy) not only can, but often must, form organized structures. Only the usual laws of chemistry and physics are needed. Consider a drop of salt water evaporating due to imported heat. The salt changes from a liquid to a more-orderly solid. The net result is increased entropy, but the salt part has nevertheless become more organized. This is a direct consequence of the Second Law (Prigogine et al., Physics Today, Nov. 1972, p. 23ff, Dec. 1972, p. 38ff). The Second Law of Thermodynamics thus appears to be an instrument of creation. ecently, it has been shown that a system that is far from equlibrium