Chapter 10
(continued)
EVERYWHERE
In the metric system of temperature measurement, Celsius, 00 is the temperature at which water freezes at Earth sea-level and 100o is the temperature at which water boils at Earth sea-level. Celsius is aligned, as a tool of measurement, according to one of the very special characteristics of water.48 Liquid water is required to support life. And H2O is liquid at normal Earth temperatures! Yes! Everywhere on Earth has enough time above freezing and below boiling temperatures to support life! Even in Antarctica, where temperatures above freezing can be minimal, ocean water is abundant above freezing around Antarctica, if only beneath the sheets of sea ice. Therefore, most life in Antarctica is found on its fringes... where there is access to water!
Liquid water is vital to life. And liquid water exists in a narrow temperature band, which narrows further when pressure is reduced! Martian atmospheric pressure, for example, is very low compared to the Earth’s because it’s a much smaller planet with less gravitational attraction to gas molecules (atmosphere). Under lower pressure, liquid H2O converts to gas (boils away) more easily and thus at a lower temperature. The point? The temperature band for liquid water, required for life, is smaller on Mars than on Earth.
On Earth the temperature band for liquid water is perfect
in 3 ways:
(1) It’s range of temperature is enough (liquid water at sea-level
exists between 320 and 2120 F... 00 - 1000 C) to allow for a vast variety
of life forms.
(2) The temperature range (of liquid H2O) is limited, thus allowing
super-hot water which is harmful to life to evaporate away!
(3) This is my favorite way (that liquid H2O is perfect on Earth): The
vast majority of the Earth exists continually within the temperature
band of liquid water! Every part of Earth, including the polar regions,
have some time within the temperature band perfect for liquid water.
Now this may seem insignificant. Water, after all, is liquid when it is! Surely there’s nothing mysterious about this. But few (if any) other substances exist in a liquid state at normal Earth temperatures. What’s the temperature of liquid iron, for example? Hot, that’s what! Different substances exist as liquid only at circumstances of extreme heat or cold or under great pressure. H2O is liquid at normal Earth temperatures and pressure.
Ain’t it great?
A quick disclaimer as we take a look at another amazing property of
water. Physicists do not understand why water is as it is. They have
theories, but not scientific knowledge of everything regarding water’s
wonderful mysteries. My point is not that science won’t ever learn
these points of fact. With continued research it’s likely that
details of understanding will unfold. Rather, my point is that the unique
characteristics of water are NECESSARY for life to exist in the abundance
that it does and that those characteristics are extremely specific and
highly adapted to conditions on Earth, rather than elsewhere. So, let’s
speed on!
Another property of water that you take for granted daily has to do with density. Density of matter refers to how close molecules join together. Nearly all things in nature are densest when coolest. This is because heat is a result of the vibration of atoms. As atomic vibrations increase, matter expands... the atoms want to get away from the slam dance of the atoms surrounding them! When temperatures cool, atoms mellow out. The same as you would do in a crowded room with no cooling in the summertime. As you get hot and uncomfortable and agitated you’re likely to seek an escape route. That’s what atoms do!
If 100 people are in a room designed for 10, their agitation will increase in a collective search for the door. Quickly the density (# of people per room) will reduce as people exit! Now, what if it’s a cold winter in the Arctic and you have no heating? In order to survive you may increase density in the room by joining with as many others as possible in order to share body heat and keep from freezing! Atoms aren’t stupid! That’s what they do! Density increases with cooling and decreases with heat. The solid state of matter is the coolest, mellowest, most stable. The gaseous state of matter is the least dense. The liquid state of matter is the middlest in terms of density.
But ‘tisn’t so with water!
Despite the fact that H2O atoms, just like any other atoms, are moving slower at temperatures below freezing, H2O doesn’t shrink (increase density) into its calmer, gentler, solid, frozen state. Instead, H2O expands into its calmer, gentler, solid, frozen state! What other substance does this? None that I’m aware of!
Physicists like to discuss this issue, sometimes with exuberance. Perhaps it’s the crystalline structure of ice that explains the non-compliance of H2O with the accepted pattern of nature. But why? Whatever the explanation, however, H2O does not reach maximum density in it’s solid state. H2O reaches maximum density at 40 Celsius (39.20 Fahrenheit). Liquid water, therefore, is denser than ice!
So what? Your life would be incapacitated if it were otherwise, that’s what! And worse! Think about it. You’re opening a warm can of Dr. Pepper. You’re hot and weary and need a cold drink. So you pour your soft drink into a glass with ice in it... but the ice stays at the bottom of the glass! OH, NO! Because heat rises in nature and cold subsides, the warm Dr. Pepper remains at the top and your life is ruined!
But, of course, ice floats. Good for Dr. Pepper, bad for the Titanic. And the ramifications of this are far reaching, indeed.
Why does ice float? Because H2O reaches it’s highest
density above the freezing temperature. Thus, when water freezes it
expands, becoming lighter per volume. You do know that H2O expands into
its solid state, don’t you? If you’re not sure, fill a bottle
to the top with water and seal it and place it in the freezer overnight!
When the water freezes it will expand and break the bottle! Another
idea. Remove the coolant from your car’s radiator, fill it with
water, drive to Minnesota in January and park your car overnight! The
water will expand into the solid state (ice) and you will be privileged
to support the local economy!
Think about this: no American history! That’s right! If it weren’t
for the Boston Tea Party, there would never have been an Independence
Day... right? And there would never have been a Boston Tea Party if
H2O did not expand into its solid state, because Boston would not have
had a harbor! In fact most of the world’s great harbors would
be iced over all year, if H2O did not expand into its solid state. In
summer the warmer harbors might reach a melt-depth of a few yards (meters),
then re-freezing.
If H2O did not expand into its solid state, ice around the world would sink to its ocean and lake floor wherever winters experience freezing temperatures. That’s most of the world north of the 300 parallel in the northern hemisphere and south of the same in the southern hemisphere! In summer the ice at the sea floor would be insulated by the water above it, and that sea-floor ice would gradually build upward each winter.
In a few thousand years most of the world’s harbors would be iced in. The busiest port in the world? Rotterdam, Netherlands would be iced in forever! New York harbor, London, San Francisco, Seattle, Sydney, Capetown, Los Angeles, Valparaiso, Buenos Aires would be iced in all or much of the year... and the list goes on! The St. Lawrence Seaway would never have been!
Why is that?... after all, Los Angeles doesn’t freeze! But it would if ice sank! If H2O did not expand into its solid state, the Polar regions would never thaw and the reduced solar insolation resulting from the increased reflection of solar heat, as surface ice worked its way equator-ward, would cause the Earth to cool. Furthermore, one of the most important mechanisms of heat circulation on Earth is the system of great ocean currents. But they would never exist if H2O did not expand into its solid state! Why? Because the currents don’t flow through ice! The result? Further cooling of the Earth’s surface temperature. And, yes, Los Angeles and Sydney and Capetown and Buenos Aires winters would be icy! And their harbors useless.
There is still more to this. The cooler world would produce less agricultural goods which would be unable to move down the world’s mid-latitude rivers (which would also be frozen more of the year) to the world’s frozen mid-latitude ports and across the world’s frozen mid-latitude oceans.
Got time to read about 3 more characteristics of H2O (for a total of 5)? I’ll make them really short. Capillarity of liquid water. High specific heat index of water. Solvency of water.
Capillarity means that liquid water clings to solid surfaces. Without that fact (and few other liquids display capillarity) life could not exist. Not because the Earth would be colder, instead because nutrients necessary to support life could not be distributed within life forms. Unless all life forms were fitted with little electric water pumps to move water around inside the stems of plants and the limbs of creatures!
In the photo below you see a drop of water between my
wife’s thumb and index finger (in front of our refrigerator).
The water sticks to Phyllis’ index finger in magnificent resistance
of gravity! Capillarity is the propensity of liquid water not merely
to adhere to a solid... even resisting gravity... but to climb upward
in a wild craving for ever more solid, dry stuff! And water will resist
gravity, rising in channels of the proper shape and size, thereby carrying
necessary nutrients from the soil all the way to the top of a redwood
tree!
Capillarity of water must exist, but please note that the setting must be correct for capillarity to work. If the vertical channels in a redwood tree are too tiny or too big (or if it had none), then capillarity of water would not function! These two (and a million or so other) features must work together for life ever to come to be.
The fourth characteristic of water is that it holds heat so exceptionally well. In fact, it has a higher specific heat index (which measures ability to absorb and retain heat) than any other known substance except ammonia. Again, the effect of this is the extraordinary way that currents of water distribute heat from the tropics to the polar regions.
Finally, 49 water may be called the universal solvent because it so effectively dissolves Earth material. Remember that water resists gravity, carrying necessary nutrients from the soil all the way to the top of a redwood tree? How does water carry those nutrients? In solution... because water is the universal solvent.
On a larger scale, rivers dissolve away the land as they race for the sea, creating a natural access to treasures within the Earth’s crust. Thus shaping land surfaces into a magnificent variety of beauty.
The magnificent beauty.
48 - 320 Fahrenheit is the sea-level temperature
that water freezes and 2120 is the boiling temperature. I love the Fahrenheit
system. It makes no sense, which makes it delightful! Fahrenheit is
English, a language filled with random pronunciation and spelling idiosyncracies.
And the English system of weights and measurements is, likewise, a gloriously
irrelevant standard. The metric system is far too logical!
It is good to know, however, that you still buy beer in the United Kingdom
by the pint (although most of the English world, except the USA, has
gone metric). The beer may be better in Germany, but half-liter is a
boring size.
The statement above is an opinion. Please do not mistake it for science.
49 - The 5 characteristics of water:
(1) H2O is liquid at normal Earth temperature!
(2) H2O expand into its solid state (ice floats)!
(3) Capillarity!
(4) High specific heat index of water!
(5) Solvency of water!