# Could the Big Bang be the result of a decrease in entropy?

In my freshman engineering physics class I learned that a decrease in entropy, though hypothetically possible, is less statistically likely than either any or almost any other possible single phenomenon. I was taught that the likelihood of a decrease in entropy was of an order inversely proportional to many, many times the quantity of elementary particles in the entire universe, and that even given all of the interactions between particles since the Big Bang, it could be mathematically shown that it is almost impossible there was ever any decrease in entropy.

Given all that, is it possible that the Big Bang itself was simply a decrease in entropy? Perhaps entropy decreases, there is an explosion of energy and matter (I differentiate because the delineation thereof is a conversation I lack the expertise to get into), and then the universe steadily increases in entropy until it reaches total stasis, at which point it somehow collapses and the cycle repeats? Were this to be true, could it in any way relate to or explain the existence of the major forces in the universe?

EDIT: It was suggested this might be a duplicate of this question. I disagree; that question regards the necessity of any explanation for there having been less entropy, whereas my question asks if an actual sudden decrease in entropy might have caused the big bang. In other words, that question asks if it is wrongheaded to assume any correlation, whereas my question asks if there might be causation.

• Book recommendation: Sean Carroll, "From Eternity to Here," 2009. – rob Jan 10 '16 at 22:27
• Why would the big bang be an unlikely event in the first place? It happened, didn't it? That makes its "likelihood" exactly 1. They need to teach statistics better over there in engineering. – CuriousOne Jan 10 '16 at 23:28
• – Muze the good Troll. Jan 11 '16 at 3:12
• @CuriousOne to me the Big Bang constitutes an "unlikely event" because at least within our reference frame it does not appear to occur all the time, the way events such as the death of a mosquito or the splitting of a perchlorate compound do. That said, ours is a relatively arbitrary reference frame and possibly Big Bangs do occur very often in a significantly more 'zoomed out' reference frame. – Max von Hippel Jan 11 '16 at 3:19
• Indeed this is not all a duplicate. – user10851 Jan 11 '16 at 9:04