Most
of our planet is covered with water. Oceans and seas make up three
fourths of the earth's surface while the land itself contains countless
numbers of rivers and lakes. The snow and ice on the summits of lofty
mountains is water in its frozen form. A substantial part of the
earth's water is in the sky: every cloud contains thousands--sometimes
millions-of tons of water in the form of vapor. From time to time, some
of this water vapor turns into drops of liquid and falls to the ground:
in other words, it rains. Even the air you're breathing now contains a
certain amount of water vapor.
In
short, no matter where you may look on the surface of the earth, you're
certain to see water around somewhere. Indeed, the place you're sitting
in at this moment probably contains about forty to fifty liters of
water in it. Look around. You can't see it? Look again, more carefully,
this time raising your eyes from these words and look at your hands,
arms, legs, and body. That 40-50 liter mass of water is you!
It's you because about 70% of the human body is water. Your body's cells contain many things but nothing so much or so important as water.
The biggest part of the blood that circulates everywhere in your body
is of course water. This is true not just of yourself or of other
people however: the bulk of the bodies of all living things is water.
Without water it seems, life is impossible.
Water is a substance that was specially designed so as to be the basis of life. Each and every one of its physical and chemical properties was specially created for life.
Other
liquids freeze from the bottom up; water freezes from the top down.
This is one of the most unusual properties of water and it is crucial
for the existence of water on the surface of the earth. Were it not for
this property, that is, if ice didn't float, much of our planet's water
would be locked up in ice and life would be impossible in its seas,
lakes, ponds, and rivers.
Let's
examine this in detail to see why. There are many places in the world
where the temperature falls below 0°C in winter, often considerably
below that. Such cold will of course affect the water in seas, lakes,
etc. These bodies of water grow colder and colder and parts of them
begin to freeze. If ice didn't behave the way it does (if it didn't
float in other words) this ice would sink to the bottom while the
warmer bits of water would rise to the surface and be exposed to the
air. But the temperature of that air is still below freezing so these
will freeze too and sink to the bottom. This process would continue
until there was no liquid water left at all. But this isn't what
happens. What happens instead is this: As it gets colder, water grows
heavier until it reaches 4°C at which point everything suddenly
changes. After this, the water begins to expand and it becomes lighter
as the temperature drops. As a result, the 4°C water remains on the
bottom, the 3°C water above it, the 2°C water above that and so on.
Only at the surface does the temperature of the water actually reach
0°C and there it freezes. But only the surface has frozen: the
4°C layer of water beneath the ice remains liquid and that is enough
for underwater creatures and plants to continue to live.
We
should note here that another property of water-the low thermal
conductivity of ice and snow-is also crucial in this process. Because
they are such poor conductors of heat, the layers of ice and snow keep
the heat in the water below from escaping into the atmosphere. As a
result of all this, even if the air temperature falls to -50°C, the
layer of sea ice will never be more than a meter or two thick and there
will be many fractures in it. Creatures such as seals and penguins that
dwell in polar regions can take advantage of this to reach the water
beneath the ice.
Again
let us recall what would happen if water didn't behave this way and
acted "normally" instead. Suppose water continued to become denser the
lower its temperature became like all other liquids and ice sank to the
bottom. What then?
Well
in that case, the freezing process in the oceans and seas would start
from the bottom and continue all the way to the top because there would
be no layer of ice on the surface to prevent the remaining heat from
escaping. In other words, most of earth's lakes, seas, and oceans would
become solid ice with a layer of water perhaps a few meters deep on top
of it. Even when the air temperature increased, the ice at the bottom
would never melt completely. In the seas of such a world, no life could
exist and in an ecological system with dead seas, life on land would
also be impossible. In other words, if water didn't "misbehave" and
acted normally, our planet would be a dead world.
Why doesn't water act normally? Why does it suddenly begin to expand at 4°C after having contracted the way it should?
That is a question that nobody has ever been able to answer.
Water is "just right" for life to a degree that cannot be compared with any other liquid.
The larger part of this planet, a world whose other attributes
(temperature, light, electromagnetic spectrum, atmosphere, surface,
etc) are all suitable for life, has been filled with just the right
amount of water necessary for life. It should be obvious that this
cannot all be accidental and that there must instead be intentional
design.
To put it another way, all the physical and chemical properties of water show us that it is created especially for life. The
earth, purposefully created for mankind to live in, was brought to life
with this water that was specially created to form the basis of human
life. In water, God has given us life and with it He causes the food by which we are nourished to spring from the soil.
But
the most important aspect of all this is that this truth, which has
been discovered by modern science, was revealed in the Qur'an, bestowed
upon humanity as a guide fourteen centuries ago. Concerning water and
mankind, God's word is revealed in the Qur'an thus:
It
is He who sends down water from the sky. From it you drink and from it
come the shrubs among which you graze your herds. And by it He makes
crops grow for you and olives and dates and grapes and fruit of every
kind. There is certainly a Sign in that for people who reflect. (Surat
an-Nahl: 10-11)
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