Second Law of Thermodynamics

This was actually an essay that I had to do for one of my physics classes. I am a christian, but I wasn't about to turn in a paper to my atheist teacher, cos y'know, I'd quite like a good grade :-)

The basic laws of science are meant to be fundamental, unchanging, and can be applied anywhere within our universe, however the second law of thermodynamics appears to go against common scientific belief concerning evolution. The second law of thermodynamics states that “In all energy changes, if no energy enters or leaves the system the potential energy of the state will always be less than that of the initial state ”, generally referred to as an increase in entropy of a system and therefore an increase in the measure of disorder. This is in conflict with evolution as evolution leads to increasingly complex yet more beneficial systems, which are less disordered, which suggests a decrease in entropy, which goes against the second law. There are numerous arguments discussing whether evolution breaks the second law or not, such as open versus closed systems, and is there a greater force at work in the universe.

The second law of thermodynamics is very important to science, and it governs all that scientists know of the universe. There is no currant way to beat this basic law, as the flow of energy is what maintains order and life throughout the universe, and is evident when organisms die naturally, as they have ceased to take in energy, therefore entropy wins.

Creationists argue that evolution is not possible, as “There is no recorded experiment in the history of science that contradicts the second law or its corollaries .” Naturalistic evolution requires that physical laws and atoms always arrange themselves into increasingly more complex but ordered arrangements. This implies that things are supposed to develop upward becoming more complex and orderly; evidence for this can be seen by looking at how humans have developed from apes to homosapiens. However, the basic law of science says the opposite should happen, and that over time, complex arrangements should become simpler, making evolution appear impossible in the real world, as the second law affects everything in the universe.

There is an argument which says that chemical compounds ultimately break apart into simpler ones, and do not become more complex in the long run. Outside forces can increase order for some time through large amounts of energy, but this is not permanent, and once energy stops being provided, processes return to natural disorder . Therefore all complex ordered systems will eventually become simpler and disorderly with time, thus increasing the entropy of the universe. Either evolution will get to a point where it stops and reverses, which would be in agreement with the second law, or continue on the trend it does, going against the second law.
For the second law to be broken, and evolution to forever work by continuing on the upward trend, creationists believe that there must be an extremely powerful force at work within the universe, such as a god, but no such force in nature has been found yet. Creationists believe that this force is bigger than nature and therefore can’t be measured.

The second law of thermodynamics allows for local pockets or systems where entropy can decrease (thus an increase in order), as long as there is an expenditure of energy somewhere else . For example, a refrigerator is able to produce order (such as crystals in ice), from disorder (random water molecules), as long as energy is used. Therefore it is possible for evolution to happen, as energy is being used to maintain this, such as by an embryo is able to produce order (a more complex system as it develops), by receiving energy from an outside source (the mother).
A number of scientists argue that evolution is possible through the use of open systems. By considering the earth as an open system , it is able to receive light energy from the sun, which “powers” evolution . Therefore, if we stop receiving energy from the sun, it would suggest that things return to simpler less complex systems, in agreement with the second law as energy would have to be spread more thinly. There is an argument which suggests that an open sun-earth system is not enough to sustain life. For example, when a plant dies, supplying it with energy, and other needs, would suggest that it would become alive again, thus breaking the second law. However, it is shown that supplying light energy speeds up the disorganization process of decay, which is when an organism is returning to its simpler compounds, even though energy is being supplied, which seems contradictory. Also by considering the entire universe as a closed system, suggests that there will come a time when all the energy is used up, and decay across the universe will set in due to lack of new energy being spread throughout the universe.


In contrast, by considering the conservation of energy it is possible for positive evolution based on how evolution is not a perfect system. Positive evolution tends towards complexity, but sometimes organisms de-evolve or become extinct as they are not able to adapt successfully to their surroundings, and die out due to entropy. Therefore it can be argued that life is just battling entropy, and the ones that aren’t good at this die out first, and they return to simpler systems/compounds. Therefore, other organisms are able to take this energy, which they can then use themselves to evolve and grow. This is an ongoing cycle, where organisms die out; their energy is broken down into simpler forms and then used again, which does not violate the second law, as order is being created from disorder, but that order will eventually be returned and reused, thus not violating the conservation of energy or the second law. This is all due to random adaptation, not a notable effort to evolve. Bad adaptations just collapse to entropy quicker, but ultimately each one dies out.

You could also argue that you could treat every organism or species as a separate closed system and within those they all die as entropy increases. The only thing different about treating the entirety of life as a closed system is the assumption that something has directly happened between species A and slightly improved species B. The only reason there is an improvement is because adaptation is random. They will still all die as entropy increases, hence extinction.

By not looking at the importance of closed/open systems and conservation of energy, it is easy to see why a number of scientists and people believe that evolution violates the second law of thermodynamics, as the idea of increasing complexity and therefore order, goes against the idea that organisms should become simpler to increase entropy. It is also argued that energy can’t be continuously added to a system to increase order, and once this stops, to comply with the second law, everything will return to a state of disorder, therefore the idea of a god is brought in to prevent this from happening.

However, by considering the idea of open and closed systems where energy is merely moved around continuously, and neither added nor destroyed then the second law is not at all violated . Order is created from disorder, but that has been an expenditure of energy, and this new order will eventually become disorder again in an ongoing cycle, so again the law is not violated. Therefore organisms can become more and more complex, and thus evolve positively, as long as energy has been expended, but ultimately they will die due to entropy. Therefore in a closed system there is always energy, and no new energy needs to be added due to the conservation of energy, although some of the energy will become less useful. However, in an open system, less energy needs to be expended as new energy is constantly being added.

In conclusion, evolution is possible, as although everything is still tending towards disorder, the complexity of an organism can still increase, as there would have been energy expenditure at some point, and eventually the organism itself will die, releasing energy which is then used again to create something more complex in an ongoing process. Therefore the second law of thermodynamics is not violated.