Our Amazing World: Water
by Joe Selzler
Think of yourself on a hot, sunny day going to the park to have a picnic. You bring with you, among other things, some water, ice and perhaps a nice, juicy beef steak. After you have set up your picnic area with a blanket and have the fire going you put some ice in a glass and pour in the water. Next you throw the steak on the grill and then kick back with your glass of water and proceed to cook your meal. Did you know that in this one event you will be observing water in its three different states? Those states are 1. liquid water, 2. solid water in the form of the ice cubes, and 3. gaseous water in the form of the steam that rises from your steak as the fire heats the water in the meat to its boiling point. (It is important to note that not all of the smoke or steam that you see rise is water vapor.)
What is water? Most of us take it for granted and give very little thought to its properties and makeup. We use water in many ways in our lives that we just couldn't be without. We use water to wash our cars, sustain our gardens, cool our power plants, run our generators, cook our food, wash our clothes and many other things. We skate on it, sail on it, and swim in it. Over 70% of the earth's surface is covered with it. That's about 326 million cubic miles. 1 However, with all of that water, only about 1% of it is fresh water. 2 Without water the earth would be like our moon, desolate and lifeless.
For all of the water we see around us and the important part it plays in our lives, many of us don't realize what water really is or know anything about its very unique properties. As I studied water I was amazed by the things I learned. If we follow the water cycle for just one day we can see the water at work. The heat from the sun turns water from the earth's surface, mainly the oceans, into water vapor. This water vapor rises from the surface of the oceans and forms clouds in the air, which are moved along by prevailing winds and taken over land masses. As these clouds are moved over the warmer land masses they rise even further until they reach the colder air of the higher altitudes. There the water vapor begins to condense and join with other droplets to form drops that are too big to stay up because of the gravitational pull of the earth. So they begin to fall as rain.
As the water falls it picks up carbon dioxide which is dissolved by the water to form carbonic acid, a substance which is vital to the life of plants. When the rain hits the ground some of it will fall on dry ground and soak in, working its way deep down into the soil. Other portions of the rain will pool on the surface and will even begin to run along the ground and eventually into the rivers. In both cases the water will begin to pick up chemicals and nutrients, all vital to the plants, animals and humans who depend on them for life. We don't notice how much we depend on these chemicals that water soaks up because we get our nourishment in several ways, but we all understand how much plants depend on water for their main source of food. There is a vital property of water, which we will study in a moment, that allows plants to draw the water up from the ground into their roots and up into their leaves.
Finally the water makes its way back into the seas where the whole process can begin again. As I said earlier, we take it so much for granted. However, water is one of the most unique molecules on our planet. Let's take a moment to study its unique structure.
Diagram of a water molecule
The water molecule is made up of just two elements, hydrogen and oxygen. These two elements are combined in the water molecule in just the right way for it to have all of its unique properties. Each molecule of water has two hydrogen and one oxygen atom that is why we see the water molecule represented with the symbol H20. All the pictures I see of a water molecule remind me of drawings of a mouse's head, two round ears stuck on a round head. You may notice from the image that the two hydrogen atoms, which are gray, are positively charged while the oxygen atom, which is shown as blue, is negatively charged. This is because the hydrogen atoms are set at 105 degrees from each other. Therefore the molecule becomes what is known as dipolar. In any amount of water it is this property of the water molecule which causes it to "stick" to other water molecules and gives water its cohesiveness. This gives water the highest surface tension of any of the common liquids, aside from Mercury.
Water is known as a universal solvent, meaning it can dissolve just about anything. It can dissolve more substances than even acid. You may be thinking to yourself, "That's interesting, but what's important about being a universal solvent?" You will see in the next paragraph why this is an important property for water to have, because it goes hand in hand with that other important property of water, its cohesiveness.
The high surface tension of water causes it to form drops or rises in a glass where it touches the sides. What significance does this have apart from being a curiosity for us to observe? Our trees, flowers, grasses and indeed all of our plant life are dependant on this property of water. Because of this cohesiveness of water, plants can use capillary action to draw water from the ground up into their leaves. As the water molecules touch the sides of the tubes which run up through the stem of a plant other molecules cling to them and begin to "rise", so to speak on the molecules below them. This process is what helps get water from the roots up to the leaves. (Recent studies have found another contributing factor in this process to be a sort of vacuum that is formed when moisture begins to evaporate from the bottom of the leaves. This vacuum is thought to be quite considerable. A vacuum pump cannot pull water to a height of more that 10 meters (about 33 feet). However, the tallest trees can draw water to their crowns which are about 100 meters high, (or about 330 feet).3 ) So you see, combining this surface tension property of water and its ability to dissolve almost any substance makes plant life on our Earth as we know it possible.
When I was growing up I was always fascinated by Big Red Fire trucks. I would dream of riding one to a fire. However, there was a secret about the water that the firemen poured onto the fire that I never knew. Do you remember the Hindenburg, that great German Airship that exploded over Lakehurst, New Jersey in the 1930's? It was full of Hydrogen, one of the most flammable gases on the planet. Hydrogen is lighter than air and able to lift such vast aircraft as the Hindenburg quite easily. But one spark and that gas explodes with catastrophic consequences. Do you know what it is that all fires need to burn? Oxygen! In pure oxygen even steel will burn. But these two elements combined in water is the main substance used by fire fighters to extinguish the flames of a fire.
Here is one more property of water to consider. Have you ever noticed that as ice melts in a glass full of water that the water doesn't overflow the top of the glass? Give it a try sometime. Put some ice in a glass, fill it to the top with water and leave it to melt. I guarantee you will not have to mop up spilled water. Why? It's because water is the only liquid that becomes less dense when it freezes. When other liquids freeze they become more dense and so will appear to shrink when they freeze. Water, however, does the opposite. It becomes less dense and so will appear to grow or rise as it gets closer to the freezing point. Why is this so important for our planet and its life? Consider a lake full of fish. If water were to become more dense as it froze it would sink to the bottom of the lake instead of float. As it sinks the water above it would freeze and sink behind the first freeze and the process would continue until the lake had frozen solid, along with all of the fish in it. Because it becomes less dense, however, it floats and acts as insulation for the water and the life below the surface, protecting it from the cold above.
As you can see, our world is a truly amazing place. It really is hard to believe that it came about by pure chance, without a designer. It seems that in every way it was designed just right and for a specific purpose. Each and every molecule in it has properties that makes chance a far more unbelievable cause for their existence than that they were designed by a Creator. If that Creator has taken great care to ensure that everything in nature, including our own bodies, operates perfectly, can we not also believe that he has seen all that we have and will face in our lives? Can we not believe that he will ensure that the cash flow will be there when we need it? Can we not trust that he will ensure we have enough customers this week, even though the weather is lousy? This is why I believe it is worth our time to stop and look at the world around us. It will help to give us the confidence that there is someone who does look after us. It may appear at times to be the opposite by our circumstances. But take a look at a mountain or a star and think of how long it has been there. Compared to that, our circumstances will only last for a brief moment and we will come to the end of our lives under the watchful eyes of our Creator.
Follow a drip through the water cycle
What is the Triple Point of Water?
Transpiration: Transfer of water from plants to the atmosphere
Bad Meteorology: The reason clouds form when air cools is because cold air cannot hold as much water vapor as warm air.
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