The 2nd Law of Thermodynamics

Themodynamics

• "Evolution violates the 2nd law of thermodynamics."
  
  You get this sort of statement: "One of the most basic laws in the universe is the Second Law of Thermodynamics. This states that as time goes by, entropy in an environment will increase. Evolution argues differently against a law that is accepted EVERYWHERE BY EVERYONE. Evolution says that we started out simple, and over time became more complex. That just isn't possible: UNLESS there is a giant outside source of energy supplying the Earth with huge amounts of energy. If there were such a source, scientists would certainly know about it."
  
  Gee I wonder what would fit that description?
  
  
  
  This shows more a misconception about thermodynamics than about evolution. The second law of thermodynamics says, "No process is possible in which the sole result is the transfer of energy from a cooler to a hotter body." [Atkins, 1984, The Second Law, pg. 25] Now you may be scratching your head wondering what this has to do with evolution. The confusion arises when the 2nd law is phrased in another equivalent way, "The entropy of a closed system cannot decrease." Entropy is an indication of unusable energy and often (but not always!) corresponds to intuitive notions of disorder or randomness. Creationists thus misinterpret the 2nd law to say that things invariably progress from order to disorder.
  
  However, they neglect the fact that life is not a closed system. The sun provides more than enough energy to drive things. If a mature tomato plant can have more usable energy than the seed it grew from, why should anyone expect that the next generation of tomatoes can't have more usable energy still? Creationists sometimes try to get around this by claiming that the information carried by living things lets them create order. However, not only is life irrelevant to the 2nd law, but order from disorder is common in nonliving systems, too. Snowflakes, sand dunes, tornadoes, stalactites, graded river beds, and lightning are just a few examples of order coming from disorder in nature; none require an intelligent program to achieve that order. In any nontrivial system with lots of energy flowing through it, you are almost certain to find order arising somewhere in the system. If order from disorder is supposed to violate the 2nd law of thermodynamics, why is it ubiquitous in nature?
  
  

The second law of thermodynamics states that there is no reverse entropy in any isolated system. The available energy in a closed system will stay the same or decrease over time, and the overall entropy of such a system can only increase or stay the same. This is an immutable physical law, and it's true. Young Earth Creationists argue that this means a complex system, like a living organism, cannot form on its own, as that would be a decrease of entropy. Order from disorder, they argue, is physically impossible without divine intervention. This argument is easy to make if you oversimplify the law to the point of ignoring its principal qualification: that it only applies to a closed, isolated system. If you attempt to apply it to any system, such as a plant, animal, or deck of cards, you've just proven that photosynthesis, growth, and unshuffling are impossible too. Organisms are open systems (as was the proverbial primordial goo), since they exchange material and energy with their surroundings, and so the second law of thermodynamics is not relevant to them. Innumerable natural and artificial processes produce order from disorder in open systems using external energy and material.

The thermodynamics argument against evolution displays a misconception about evolution as well as about thermodynamics, since a clear understanding of how evolution works should reveal major flaws in the argument. Evolution says that organisms reproduce with only small changes between generations (after their own kind, so to speak). For example, animals might have appendages which are longer or shorter, thicker or flatter, lighter or darker than their parents. Occasionally, a change might be on the order of having four or six fingers instead of five. Once the differences appear, the theory of evolution calls for differential reproductive success. For example, maybe the animals with longer appendages survive to have more offspring than short-appendaged ones. All of these processes can be observed today. They obviously don't violate any physical laws.