The Importance of Water

Even though scientists often point to Mars and tell us that the discovery of water on the red planet makes the possibility of the existence of life significantly greater, water is often overlooked as important right here on Earth. Water exists on Earth in great abundance on the surface and it exists in three forms: as water vapor, as a liquid, and as a solid.

It was in water, quite possibly, where life first formed on the Earth. Our cells and the cells of most animals and plants have a great amount of water inside them. The movement of water through a cell membrane is so important that it has been given its own term "osmosis". Water is the "universal solvent" being able to dissolve many substances. Water can be salty or fresh, it can hold heat or cold for long periods of time, it provides many ecologically unique environments for plants and animals, it can be broken into oxygen and hydrogen and it expands as it nears freezing.

The fact that water expands slightly as it freezes is extremely important to life in the water environment. As ice becomes less dense its density is lowered and it hardens into ice at the surface. This forms a protective layer, holding heat in the water below the ice and keeps animals and plants in a liquid water environment under the ice rather than in a solid block of ice.

As water freezes in cracks of rocks and soil on the earth, the expansion can crack rock and soil into smaller pieces. Water cause erosion all around the world and water is affected by the pull of the moon. Our tides, set a rhythm for life on the Earth and along with the cycles of day and night and lunar cycles water helps to maintain a global balance.

Our skin cells have water and salt, so when we sweat, if we were to taste the sweat it would taste salty. If we sit in a bathtub with regular tap water, the salt in our cells will try to move from the higher concentration in our skin, into an area of lower concentration, the bath water. As this happens water will be pulled out of our skin cells along with the salt. This will cause our skin cells to loose enough water to shrivel somewhat. To counter this "bath salts" are sometimes added to the bath water thus increasing the concentration of salt in the bath water and thus keeping the water and salt from being pulled out of our skin cells.

We can live longer without food than we can live without water, but we have also found that excessive rapid intake of water can be deadly. A recent contest where participants were asked to drink large quantities of water, resulted in the death of one participant. This is not like drowning where water fills the lungs, but excessive rapid intake of water can cause excessive swelling in the brain.

When we talk about the importance of water, its value for our health is vital, but water has so many important points of consideration it may well prove not only the most important substance on Earth, but perhaps on many worlds.