Desarrollo del pilar de Mantenimiento Planificado

An example of apparent design is found in the element carbon. Talk about designer jeans, carbon is a designer element! Simply stated; if carbon did not have the properties it has, there would be no life. The properties of carbon show clear evidence of design, and therefore of a creator. Why is that? To evaluate this claim, one must consider the unique properties of carbon, and why it is the only element available which can support the existence of life.

Living things are made up out of molecules. As has already been described, the molecules out of which living things are made are large and complex. For example, proteins, the molecules which control everything which occurs in cells, are made up of tens of thousands of atoms all joined together to form a complex, three-dimensional shape. The backbone of all these molecules is composed of carbon atoms. Why carbon? Of the ninety or so naturally occurring elements, carbon is the only one that has the properties which allow large, complex, three-dimensional molecules to be synthesized. The properties of carbon allow for strings of dozens and even hundreds of atoms to form. No other element has the property that long strings of the atoms of that element can form into stable molecules. Carbon can form ringed structures. It can form three-dimensional structures as well. Carbon can form single and double and triple bonds with itself and with a number of other atoms. All of these properties are unique to carbon, and all these properties are absolutely necessary for life to exist. In the words of Spock, we truly are “carbon based units.”

Speaking of Star Trek, one of the original episodes of that series had Kirk and the gang coming upon a monster whose molecular structure was based on silicon. Spock said that this was very logical. The reason silicon is a “logical” alternative to carbon is that it is the only element, other than carbon, which can form a total of four bonds, and which can therefore, in principle, be used to build three- dimensional structures. Nevertheless, Spock’s claim that a silicon monster is logical does not work. Silicon-silicon chemical bonds are very weak. It is impossible to build a large molecule joined together by silicon atoms. The author is sorry if the reader’s faith in Star Trek is diminished, but there never has been, nor will there ever be a silicon-based life form.

Returning to the subject, if carbon did not have the properties it has, there would be no life. If you do not believe this point, please

Could This All Just Be a Coincidence? 155 find you nearest biochemist, biologist or chemist and ask them if this claim is true. It is indisputable. There is exactly one element with the properties that allow for life to exist. Not two, one! Not zero, luckily for us. But is it luck? If some intelligent being were designing the properties of electrons, protons and neutrons, and therefore the properties of the atoms to allow for there to be living things, this being would have to create at least one element capable to making large, complex, flexible molecules. Recognizing the problem, God created carbon. Good going, God!

WATER. THE MIRACLE SOLVENT

Life requires a solvent. It requires a solvent with just exactly the properties that water happens to have. In fact, if it were not for the existence of water and its unique properties, there would be no life anywhere in the universe. This is a strong statement, but it will hold up to the strictest scrutiny. The existence of water is further evidence that there is an intelligent creator behind the scenes intent on creating life.

So, what is so special about water? I am trained as a chemist. When I teach introductory chemistry, I spend a great deal of time listing and describing all the ways in which water is a unique substance. There are so many things which are unique about water, the thought almost inevitably emerges that this really neat molecule must have been specifically designed in order to support life.

One of the special properties of water is that for a molecular substance, it is very sticky. Individual water molecules are strongly attracted to one another. Water molecules consist of two hydrogen atoms bonded to a central carbon atom. The molecule is bent at an angle of 105o_{. This bent shape (as opposed to linear, 180}o_{) is essential}

to the unique properties of water. In fact, if water were a linear molecule, there would not be life anywhere in the universe. More will be said on this later. The reason water is “sticky” is that the hydrogen- oxygen bond is highly polarized. In other words, the electrons which are shared between the hydrogen and the oxygen atom in the water molecule are not shared equally. Oxygen atoms attract electrons strongly, compared to hydrogen, lending a partial negative charge to the oxygen atom and a partial positive charge to the hydrogen atom in the water molecule. See the picture below for an illustration of the polarized structure of water.

Another factor in water’s stickiness is its shape. If water had a linear structure, rather than bent, its symmetry would make it non- polarized, despite the oxygen-hydrogen bonds in the molecule. As an example of this principle, the molecule carbon dioxide, although it has fairly polarized carbon oxygen atoms, is linear and symmetric, and therefore not polar. This non-polar molecule is therefore not sticky. Even though carbon dioxide molecules have more than twice the mass of water molecules, CO2 becomes a gas at over one hundred

degrees below zero Fahrenheit. Carbon dioxide is definitely not a molecule which could act as a solvent to support life.

When water molecules approach one another, the positively charged hydrogen atom on one molecule sticks to the negatively charged oxygen atom on the other. Due to factors beyond the discussion here, the O-H bond in molecules is the most effective of all chemical bonds at creating this stickiness. The reader may be saying to themselves ‘so what’ at this point. This unique stickiness of water is what results in its amazing properties as a life supporting solvent.

For example, because water molecules are so sticky, water has a very high boiling point for such a small molecule. If it were not for the stickiness of the molecules, water would boil at something like – 200o_{F, way too low to support life. Besides, the stickiness of water}

allows it to be a liquid over an unusually large temperature range, an important factor in water’s ability to control climate.

Figure 10.1 The structure of water molecules and why