Talk:Dissipation

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[edit] Dissipative systems and boundaries

The conservation of energy requries that in a closed system (where there is no energy crossing the boundary, either in or out) the total amount remains exactly constant, so adding up all the energies, potential, kinetic, heat gives a constant, measured in joules. Most systems are not closed, and it's a matter of choice where we draw a system boundary. I think it's important to be clear about the thermodynamic manifestation of energy - the generation of heat is not, of course, loss, it is just a movement of the system towards a more entropic state. The heat and noise created by waves may transfer energy to the atmosphere and coastal matter, but in the overall system there is no energy loss. Looking at the sea as a system means there is energy leaving it, but at the same time the sun and wind add energy to it, so it's a dynamic system with flux in and out. Overall I'd say there is conservation in a closed system, but closed systems can consist of many interacting dissipative systems, all exchanging energy. I'm sure someone could express this ina neater form, it's early in the day for me.

Jas 11:50, 12 January 2007 (UTC)