echi wrote:
Are you saying that satellites maintain equilibrium and that this is supported by the Second Law? The way I understand it is that orbits of any kind are not stable; the speed is always changing, and eventually the satellite will either collide with the center or it will escape and fly away.
Think about the human body. Osmosis is one process by which our body maintains homeostasis (which is a state of equilibrium). Homeostasis is the opposite of disease, so to speak. Disease occurs as a result of imbalance. Therefore, we know that balance is health and it will maintain stability if it given appropriate nutrition and as little chemical enhancement as possible (preferably none). The mind has more to do with it than the physiological processes, themselves, but I won't confuse that into this explanation.
Now, the healthy body is stable and balanced. Yet it is in motion, even when we are still, our innards are busy. Osmosis is the exchange of fluids between that which flows in the circulatory system, interstitial (in and among the cells) and I think there is one more but my memory fails me...
Anyway, electrolytes, such as sodium and all those, are what determines the specific gravity of any given liquid, think about a glass full of dissolved salt in water compared to a glass of just water. If these where in a container that had a permeable divider between them, the salty water would exchange with the plain until there were solutions of equal concentration on both sides of the divider. That kind of thing is constantly taking place in our bodies.
That is just one example. But maybe it helps to explain equilibrium as a balanced state yet not an 'at rest' state.
