Changes

Information is in the eye of the beholder.  The first ten million digits of pi can be considerd to be a very precise and detailed piece of information, or they can be considered to be ten million digits of random garbage.<ref>The digits of pi are believed to be truly random.  They have passed every statistical test for randomness.  No patterns are known.</ref>  In the former case, the digits have an entropy of zero; in the latter case the entropy is 3.2 x 10^-21 Joules per Kelvin.

Information is in the eye of the beholder.  The first ten million digits of pi can be considerd to be a very precise and detailed piece of information, or they can be considered to be ten million digits of random garbage.<ref>The digits of pi are believed to be truly random.  They have passed every statistical test for randomness.  No patterns are known.</ref>  In the former case, the digits have an entropy of zero; in the latter case the entropy is 3.2 x 10^-21 Joules per Kelvin.

The entropy of the human genome, in each cell, is 6 x 10^-14 Joules per Kelvin when the base pairs are considered to be random, and zero when the base pairs are in a given human's specific genetic configuration.  The metabolism of 2.5 x 10^-22 grams of sugar can provide the "entropy budget" to copy a cell's genome.  That is, to turn the random base pairs floating in the intracellular fluid into a copy of an existing set of chromosomes.  This is done every time a cell divides.  Of course the process is far from 100% efficient.  10^-8 grams of sugar are sufficient, under 100% thermodynamic efficiency, to copy the DNA of all the cells in one's body.  Avogadro's number really is very large.

The entropy of the human genome, in each cell, is 6 x 10^-14 Joules per Kelvin when the base pairs are considered to be random, and zero when the base pairs are in a given human's specific genetic configuration.  The metabolism of 2.5 x 10^-22 grams of sugar, or one nanosecond of sunlight falling on one square centimeter, can provide the "entropy budget" to copy a cell's genome.  That is, it can turn the random base pairs floating in the intracellular fluid into a copy of an existing set of chromosomes.  This is done every time a cell divides.  Of course the process is far from 100% efficient.  10^-8 grams of sugar, or 4 seconds of sunlight falling on one square meter, are sufficient, under 100% thermodynamic efficiency, to copy the DNA of all the cells in one's body.  Avogadro's number really is very large.

==Reversibility and irreversibility==

==Reversibility and irreversibility==