Dymanic said:
I get a little confused while flipping back and forth between considering entropy as a property of a system as a whole and as a property of an organism. Taking your advice and, rather than taking a strictly biological approach, including physics, it gets worse: is entropy a property which can even be meaningfully attributed to a single particle?
Yes, entropy is "... a property which can even be meaningfully attributed to a single particle."
When a hydrogen atom absorbs a photon (heat or light), the electron jumps to a higher "orbit" or "shell." The natural law says that the hydrogen proton likes to remain "cuddly" with its electron. Too much energy, and the electron will be torn from its "arms." So the atom sheds the higher energy state by re-emitting the photon. In doing so, the hydrogen atom attains a lower energy state and hangs onto the electron. This nuclear "game of hot potato" keeps the photons flying outward everywhere. This is the core of entropy: atoms seek a low energy state by shedding energy as photons (
http://theory.uwinnipeg.ca/mod_tech/node151.html). As a result, energy is shared. High energy gets thrown out; high energy travels from high energy sources to low ones, and equilibrium is the eventual result.
On a macro level, this directly relates to the Sun shedding light which the Earth, being directly in the path of the radiation, is forced to absorb. Since the Earth also sheds this extra energy, convective thunderstorms and low pressure systems develop as heat is transferred to the upper atmosphere and into outer space.
Higher energy, bombarding the atom, may also kick out the electon "teddy bear" leaving the atom ionized. This is another form of entropy at the particle level. The loose electrons and ions form the basis of electricity as well as ionic and covalent bonding.
The mechanical form of entropy, such as beating an egg until the yolk and egg white are no longer distinguishable, is still based upon the lower forms. If we muster energy to beat the egg, it is born of energy created in the mitochondria of our muscle and brain cells where the Krebs cycle pumps energy out of ADP and ATP translations (
http://www.bmb.leeds.ac.uk/illingworth/oxphos/).
Without entropy at the particle level, atoms would absorb energy - like tiny "black holes." Without entropy, energy would never be shared, and the universe would freeze in place. The Sun would not shine, there would be no rain, and life, as we know it, could not exist.
The Big Bang was a manifestation of entropy - high energy exploding outward into the void of no energy.