Kinetic Theory
(a) The ordinary state of gas in a container is a disorderly, random distribution of atoms or molecules with a Maxwell-Boltzmann distribution of speeds. It is so unlikely that these atoms or molecules would ever end up in one corner of the container that it might as well be impossible. (b) With energy transfer, the gas can be forced into one corner and its entropy greatly reduced. But left alone, it will spontaneously increase its entropy and return to the normal conditions, because they are immensely more likely.
Source
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"OpenStax College, College Physics. February 13, 2013."
http://cnx.org/content/m42238/latest/?collection=col11406/latest
OpenStax CNX
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