It occurs to me that this balance pertains as well to the world of weather, and particularly to water. There is just so much of it (ignoring additions from cosmic snowballs). Some is locked up in solid form at the poles. A vast amount fills the ocean basins, and lakes. A third vast amount exists in invisible gaseous form in the lower atmosphere (troposphere).

For the purpose of this essay, let us focus on the liquid and gaseous water.

Let your eye sweep across the sky. On an average day you will see regions of cloud interspersed by regions of noncloud. Granted, in winter days there are days of overcast, but many summer days are clear.

If you look in the same direction for an extensive period of time you will see an alternation between cloudy sky and clear sky. Visible water (cloud) becomes invisible becomes visible becomes invisible. There is continual change. There is no beginning nor end.

Visible and invisible are not always in balance. Sometimes, in certain places, cloudiness prevails for days on end, while at the same time in other places, noncloud is the name of the game. There may be flood in one place and drought in another. But the global amount of water remains the same; only the form changes.

There is another give and take at work. It takes a certain very large amount of energy to wrest water molecules free from the confining surface of liquid water. But the same amount of energy is released when gaseous molecules cluster about a condensation nucleus of salt or soil, first in a cage-like configuration growing to a tiny sphere of liquid water -- a cloud droplet.

What lies behind this mystery of the visible becoming invisible? The answer is a criticality factor in Nature's laws.

The atmosphere is in a continual state of motion as it transports excess heat energy to regions of deficit, i.e. from low latitudes to high latitudes. It accomplishes this by lateral motion. But the atmosphere is also quivering up and down like a living thing, in a state of oscillation on a continuum of scales from microscopic to global.

Go back to the Yin/Yang symbol and visualize a membrane separated by the S shaped divider. Think of a state of oscillation as though it were a soap bubble film -- one side rising while the other subsides, and vice versa. Now, remember the sequence of events described in the Precipitation Ladder. Rising air produces visible water; sinking air produces invisible water. Cloud equates to rising; noncloud equates to sinking.

The process goes on and on and on without end, all over the Planet. It is the Yin and Yang of water.