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## Main Question or Discussion Point

**Negative Changes in Entropy??**

Perhaps this is not the right forum location, but I would like to ask some of the more experienced physicists here about the notion of negative changes in entropy in the universe. According to the text I am currently reviewing by Hill, the probability that a thermodynamical system will have ΔS<0 is:

[itex] P(\Delta S <0) = {1/(10^{10}}^{20}) [/itex]

Obviously this is an extremely small number and in our everyday lives we can approximate this as 0. However, on the scale of the universe, are there enough processes that are occurring (or rather, different thermodynamical systems) such that this special case cannot be ignored?

Now assuming such a location in the universe exists where negative changes in entropy can occur, would we see the equivalent of reverse reactions. An example of a reverse reaction would be striking a match in "rewind". This leads me to question several things about physics and our interpretation of the universe (or universes), but I will hold off on those questions for now.

If we assume that no place exists in the universe where negative changes in entopy can occur, does this mean that there is a finite amount of processes that are taking place in the universe, IE are there less than 10

^{10}

^{20}processes in our universe? Alternatively, is the extremely small value mentioned above simply a mathematical singularity?

Please, share your insight! I am curious.