Monday, August 29, 2011

Inciting Brownian motion at the macro-scale

Entropy is the process of moving from order to disorder, for example one’s desk becoming cluttered after being cleaned. In many cases, lower entropy states are desirable as they connote greater order. Without doing work to decrease entropy, it generally increases at the macro level (the spacetime of objects that humans encounter on a daily basis). Entropy increases and time appears to move only forward.

At the micro scale of atoms, Brownian motion occurs (the constant jiggling of atoms), and creates an important case where the Second Law of Thermodynamics (heat eventually dissipates; systems move from being warm to cold) does not hold. Brownian motion at the micro scale also allows fluctuations in the arrow of time and in entropy, e.g.; time may flow forwards and backwards, and there may be fluctuations towards lower and higher states of entropy. This can be seen not just at the very-very small Planck scale and the atomic scale of statistical mechanics (for example, atoms jiggling in a gas), but also at the level of cells in the body, and in another example, pollen cells suspended just the right way in water.

That Brownian motion can occur at the comparatively larger scale of cells suggests that it may occur, or be induced to occur at even more macro levels too. For example, in complex adaptive systems, an economy has phases of Brownian motion, when rational agents are jiggling constantly to make the invisible hand of supply and demand meet. Perhaps incentive structures including policy may be used to facilitate the persistence of Brownian motion and devolution of entropy in macro-level systems.

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