We humans live in a water world. Our bodies are about 60% water. We and all the other animals cannot go long without drinking it. Earth’s surface area is 71% liquid water. Earth’s atmosphere soaks up moisture like a sponge. Clouds move it from place to place, condense into rain and snowfall, and wet the land surface. Soil soaks up this life-giving water used by microbes, algae, lichen, fungi, worms, beetles, plants, and tree roots.
Liquid water that does not infiltrate the soil runs off into streams, arteries of the land, pulled by gravity, joining into larger rivers, driven relentlessly to the oceans. This water is heavy, a gallon weighing eight pounds, a cubic foot weighing 62 pounds. With big rivers flowing at a typical 4 feet per second, the weight of water passing a given point every second is many tons. No wonder water erodes the land. Even single raindrops splash soil particles into the air.
All life on Earth requires water. Liquid water on the early Earth provided the crucial medium for life to burst forth. Yet, the water molecule is wonderfully uncomplicated at the microscopic level: one positively charged oxygen atom and two negatively charged hydrogen ions. Deceptive in its simplicity, the water molecule gains surprising power through what seems like a trick: the hydrogen atoms attach to the oxygen at an angle, giving the molecule a polarity, like a magnet. This subtle power has numerous ramifications and has made life on Earth possible. Otherwise, we would be a frozen planet. The molecular polarity makes water ice float, preventing Earth’s oceans from freezing from surface to seabed.
Without any of the scientific details, early humans were awed by water. Its overwhelming power was evident. A man cannot cross even a small stream if its flow is moderately deep and fast. It would sweep him away downstream. He would have to wait until the flow receded or find a better place to cross. Maybe a large tree would have fallen across to provide a natural bridge. Humans eventually built ships to cross seas and lakes, only to find that the water surfaces would sometimes get rough, swamp, and sink them. Humans learned to swim, but we only have the stamina to stay afloat for so long. And the salty oceans could not slake our incessant thirst.
Early humans also noticed that the seas were home to monstrous animals, so large that people could only imagine what other dangers might lurk in the deep. Of course, they also saw many small creatures and waves endlessly pounding the shores. No matter how far back the humans probed their oral histories, waves hit the same coastlines in the same relentless ways, generation upon generation.
And why would the seawater flood far into the beach each day but a few hours later fall back, leaving broad stretches of sand?
Standing on a beach, watching wave after wave, we feel their pounding in our chests, hearts perhaps recognizing a common bond. Salty seawater—salty blood. Are these signs of a common origin? Yet, we should consider the entire atmosphere an ocean of air, all plants and animals steeped in a fluid world, whether above or below the ocean surface.
To keep from destroying Earth’s habitability for ourselves, perhaps our best hope as humans is to stand on the beach, open our senses, and feel the unity that water provides. All life and even non-biological processes on Earth are water-infused. But the planet can accommodate conditions that humans cannot tolerate. After we are gone, Earth will stabilize itself and bring forth life again. That life will be new and different but still dependent on water. And its evolution will take time.