Posted by Scott Ellis (65.193.194.199) on June 11, 2002 at 12:02:13:
In Reply to: Second law + evolution posted by Davis Landstrom on June 11, 2002 at 06:39:24:
Here's a great link related to this discussion:
http://www.nous.org.uk/entropy.html
-Scott
: As an evolutionary biologist by profession, I feel that I must clear up one thing Scott.
: The process of evolution is not a violation of the second law of thermodynamics at all.
: The second law of thermodynamics deals with the model concept of a closed system at time (lets say) 1, possesing a quantity of energy in isolation made to do work, the entropy of that system will increase to the point where the initial quantity of energy will be unable to perform the same work at time (lets say) 8.
: This is because of an increase in 'dissorder' in the system, but more specifically because that system is irreversable, despight the fact that it is closed and isolated, it is still coupled with time and the universe, hence the closed system (at time 8) could never restore (regenerate) its self to the same entropic state that it was at time 1.
: The initial and final states of the system are different entropically, hence the Second law of thermodynamics joke: 'You can never break even'
: HOWEVER, if we were to take this system and energetically couple it to another system (make it open), then we could use the output of the coupled energy source to create a local reduction in entropy by performing work on the system, the entropy in the system that was orrigionally colsed will decrease and will remain decreased (depending on the amount of work being done on that system by the coupled source system) HOWEVER this entropy reduction comes at a cost, there HAS to be a pay off of entropy somewhere along the line, that pay off is either to the systems evironment (depending on the degree of 'openness') or it occures in what ever process is driving the coupled source system.
: I shall give two examples to illustrate the above:
: 1.The evolution of life - some evolutionary lineages since the precambrian have indeed increased in complexity. If we take a life form to be a system, we immediately see that it is by no means isolated, it is energetically coupled to the system of earth's environment, which in turn is energetically coupled to the sun, the decrease in entropy on earth that allows for increasing complexity evolution, is 'paid off' with an increase of entropy of the sun. I suggest that you look up Ilya Prigogine, who won a Nobel prize in 1977 for a mathmatical description of this very process.
: 2.A fridge 'violates' the second law about as much as evolution does. The third law of thermodynamics informs us that 'colder' systems (sinks) are less entropic that 'hotter' systems (sources), a fridge can maintain it's low entropy internal environment because it is a pumper of heat, by doing work on a heat engine you can make it take thermal energy from one system and deposit it into the environment, the end result is a low entropy internal environment which is sustained because the system (fridge) is coupled to the mains, the entropic pay off is two fold, in the combustion of the oil that fired the power station that produced the electricity, and in the form of the energy paid off to the environment by the heat pump.
: I have never heard of this Steve Wolfram chap, (I have heard of and know MANY evolutionists, both contraversial and orthadox)
: If he is claiming that evolution is a violation of the second law of thermodynamics then I strongly urge you to take his claims with scepticism as it sounds to me like he is basing his argument on this flawed basis.
: One more thing, in my profession I frequently hear the claim that evolution violates the second law of thermodynamics, however not from evolutionists, but from creationists and we all know about their pseudoscience!
-Scott