Assertion 1.3: Big Bang theory violates the second law of thermodynamics.
Analysis
The creationist contention is that because the second law of thermodynamics states that all systems tend to become more disordered over time, but the Big Bang posits a state of high order at the beginning of the universe, Big Bang theory violates the second law of thermodynamics.
(i) The second law of thermodynamics does not, in fact, state that all systems tend to become more disordered over time, but only that no closed system (a system into which new sources of energy cannot enter) can become less disordered over time.
Some creationists insist that the only open systems that are able to become more ordered with time require some kind of sophisticated conversion mechanism in place. However, their claim is neither stipulated nor entailed by the second law of thermodynamics. Moreover, their claim is known empirically to be false, as the examples of crystallization and endothermic reactions make clear.
(ii) A violation of the second law of thermodynamics requires that there be two times T and T* in the history of the universe, with T prior to T*, and for which the universe is more disordered at T than it is at T*. But if we go by general relativity alone, the origin of the universe is the origin of time itself (see 1.1), which means there cannot have been a time prior to the origin of the universe when it was more disordered. Likewise for scenarios employing quantum gravity in which there was a first moment of time: for any cosmological model in which there is a first moment in time, the initial state of the universe can be ordered to any degree without violating the second law of thermodynamics.
Theories of quantum gravity that allow the universe to continue existing infinitely into the past are a different matter. If such a theory has the universe maximally ordered at some point in time, and also at every moment prior to that point in time, then there is no conflict with the second law of thermodynamics. Remember, the second law of thermodynamics does not require disorder in a closed system to increase, but only forbids it from decreasing: a system that maintains a constant level of disorder over time is consistent with the second law of thermodynamics.
Theories of quantum gravity that have time breaking down in the early universe are difficult to assess, but since the second law of thermodynamics makes essential reference to time, it would seem that the second law of thermodynamics could not apply to such cosmological models at all.
(iii) If the universe came into existence from something preexisting, then the origin of an ordered universe still would not necessarily have violated the second law of thermodynamics: in these kinds of scenarios, the universe would not always have been a closed system, and could have purchased its initial order at the expense of more disorder in the wider system of which it was a part.