I happen to believe it is impossible to settle the existence of God conclusively by any achievable observation, experiment, or chain of reasoning. The reasons have nothing to do with whether one side or the other has a stiff-necked refusal to believe or a childish inability to abandon a mental security blanket. My reasons are based on the inability to perform controlled experiments or gather convincing observational data, plus, as problems become more complex, there are multiple competing ways to explain observations that explain the data equally well. Some of those explanations may simultaneously be part of the answer, others may be irreconcilable, but they may all explain the data equally well.
Case in point is the infamous YouTube video of a creationist showing the way a banana fits the human hand perfectly, therefore showing that bananas and human hands must have been designed to fit together. Of course, the fact that bananas equally well fit gorilla and chimpanzee hands argues equally forcefully that humans, gorillas and chimps are close relatives. (There are very rude people who have posted far less polite parodies of the banana argument. We shall not go there.) And, even if we accept the hypothesis of a designer, an omnipotent deity, a finite deity and a very advanced alien bioengineer all explain the data equally well.
So there is no way you can point to order in nature as conclusive proof of the existence of God. It may be suggestive or persuasive, but those are a long way from being conclusive. There's are other explanations that fit the data equally well. On the other hand, it's equally improper to argue that naturalistic explanations disprove the existence of God. They are an explanation, but that doesn't mean they are the explanation.
But as the banana explanation shows, the arguments put forth by some intelligent design advocates barely even rise to the level of being wrong. Many of them are so childish, naive and ill-informed they are merely irrelevant. They're on the level of saying we should vote for John McCain in 2008 because otherwise the government will relocate the Grand Canyon to Mexico. Not only is the argument absurd in its own right, it's completely irrelevant to what it's supposed to be supporting.
On the other hand, I could respect an Intelligent Design advocate who advanced the arguments below. They'd at least have to demonstrate a fairly high level of scientific literacy. None of these, of course, prove the existence of a Designer, but they're far more respectable than pointing out how a hummingbird's bill fits a particular flower (or a banana fits a human hand).
And no, I will not explain this stuff to you in more detail. Don't even ask. I'm normally happy to answer questions, but not in this case. Get some science books and take some courses. You have no business even getting involved in issues of science and religion without being scientifically literate. If you're going to talk about religion and science, you have a moral obligation to be literate in both subjects.
We're so used to seeing ice float, we think it's normal. But as soon as you see other systems of solids and melt liquids, it becomes obvious that ice is a very abnormal material. Most solids sink in their melt liquids. A common example is melting wax to make candles or to seal preserves; the wax sinks to the bottom of the liquid rather than floating on top.
Imagine what would happen if ice sank. Pack ice in the Arctic and Antarctic would sink to the bottom and stay there. Glaciers flowing off of Greenland and Antarctica, instead of floating as ice shelves and breaking off icebergs, would simply continue flowing on the sea floor. Very quickly most of the oceans would be frozen. The Titanic would never have sunk but plodded majestically through the slush to arrive safely in port.
Water has so many fantastic properties that Intelligent Design advocates, instead of fixating on the complexity of DNA, would do far better to focus on the properties of simple water. It's an asymmetrical, or polar molecule, with positive charge on the hydrogen atoms and negative charge on the oxygen. That makes it very effective at latching onto ions and dissolving them, so ionically bonded materials, like table salt, generally dissolve in water to a greater or lesser extent. So water is very useful for moving ions around in the human body. On the other hand, water is very ineffective at dissolving things with covalent bonds, like most organic molecules. That's why oil and water don't mix. So even though we're about 2/3 water, we don't dissolve in our own cell fluids. I think that's a nifty design feature.
Water molecules attract each other. The hydrogens of one molecule are attracted to the oxygens of another. This tendency of hydrogen atoms on molecules to be attracted to neighboring molecules is called hydrogen bonding. Since water molecules are attracted to each other, it takes quite a bit of energy to break them apart. For a simple, light molecule, water has remarkably high melting and boiling points and a wide liquid range.
Consider, by contrast, methane (CH4), something often touted as a possible replacement for water in alternative biologies. Methane consists of a central carbon molecule with four hydrogen atoms symmetrically arranged in a tetrahedron. Basically the outer surface of a methane molecule is positively charged and there's very little space for a hydrogen of one molecule to be attracted to the carbon of a neighbor. So it doesn't take much energy to pull methane molecules apart. Methane melts at -182.5 C. It takes very little energy to pull the molecules in the liquid apart, so methane boils at -161.6 C, only 21 degrees higher. Water, on the other hand, has a very similar molecular weight (18 versus 16 for methane) and melts at 0 C and boils at 100 C, a liquid range of 100 C.
The energy required to break apart molecules (heat of fusion) can be measured. For methane, the heat of fusion, or the energy it takes to melt solid methane, is 58,000 Joules per kilogram. It takes a lot more energy to vaporize the liquid, some 510,000 Joules per kilogram. But check the figures for water. To melt ice takes 333,000 Joules per kilogram, over five times what it takes to melt methane. To vaporize water takes a whopping 2.26 million Joules per kilogram, over four times the energy it takes to vaporize methane. Since water molecules are attracted strongly, it takes more energy to get them moving. It takes 4200 Joules per kilogram to warm water by one degree C, versus only about 1000 Joules per kilogram for liquid methane.
The huge amounts of energy it takes to melt, heat, and vaporize water make the oceans the great storehouse of heat on the earth. It's the reason why you'd much rather be in Vancouver or London in January than Winnipeg or Irkutsk, even though all are at about the same latitude. And though it takes a lot of heat to raise the temperature of water, huge amounts of heat are locked up in phase changes: from ice to water or water to vapor. It takes 4200 joules of energy to warm a kilogram of water by one degree C - it takes 80 times that to melt a kilogram of ice and 600 times as much to evaporate a kilogram of water to vapor.
It turns out that the chemical bond arrangement in water is remarkably similar to methane. In both molecules, the outer orbitals of the central atom merge, or hybridize, into a tetrahedral arrangement. The difference is that methane has hydrogen atoms attached to all the orbitals of the carbon atom whereas the oxygen in water has only two hydrogens attached. To make a three dimensional crystal of water ice, the tetrahedral orbitals all line up so that the hydrogens of one water molecule are attracted to the oxygens of a neighbor. There's no way to do this and pack the molecules tightly, so solid ice actually takes up more space than its parent liquid. If ice were denser than water, it would sink and the oceans would be mostly frozen. Things at the atomic level have planetary implications.
So why don't Intelligent Designers say much about the remarkable properties of water? Well, the fact that water not only organizes into a structure when it freezes, but actually does so strongly enough to force things to give it room, sort of blows a large hole in their claim that order can't arise from natural processes. And if mere water, with only three atoms, can do all the remarkable things it does, what's to prevent nucleic acids from spontaneously organizing into DNA?
It's a lot more fun making arm-waving claims about the "irreducibly complex" nature of DNA. Actually, if anything points to Intelligent Design, it's the simplicity of DNA. A mere four pairs of nucleotides code protein synthesis, height, hair color, and a lot more of behavior than many social scientists like to admit. An unintelligent designer would decide each trait was so unique it required its own coding system (like a lot of computer software, but don't get me started). Geniuses make simple things that achieve complex results. Clods and incompetents make complex things when simpler things would do.
When carbon dioxide dissolves in water, it forms a weak acid called carbonic acid with the formula H2CO3 (1). Acids like nitric and hydrochloric acid are strong acids. In water, they break down completely to ions. Nitric acid (HNO3) breaks down to H+ and NO3- and hydrochloric acid breaks down to H+ and Cl-. On the other hand, H2CO3 mostly stays in that form in solution. Only a very small fraction of carbonic acid molecules break down to H+ and HCO3- (the latter is referred to as the bicarbonate ion). Acetic acid in vinegar is another familiar weak acid. Being a weak acid doesn't make an acid harmless - hydrogen cyanide and hydrofluoric acid are also weak acids. One will make you dead and the other will make you wish you were dead (hydrofluoric acid produces severe skin burns and the vapors do serious lung damage).
Imagine what the world would be like if carbonic acid were a strong acid. It would break down completely to carbonate ion (CO3=) and hydrogen ions (H+). We wouldn't be worried about global warming because the oceans would be a perpetual carbon dioxide sink, since carbon dioxide would form carbonate ions as soon as it dissolved. On the other hand, the oceans would be extremely acidic.
Let's say we had H2CO3 = 2H+ + CO3= and its equilibrium constant equals 1:
(H+)2(CO3=)/(H2CO3) = 1 (A good value for a very strong acid. If anything, it's generous, since it allows for some carbonic acid.)
Since there are two hydrogen ions for every carbonate, (H+) = 2(CO3=)
If we assume we have (H2CO3) = 10-5, the present value in water exposed to the air, we'd have
(H+)2(H+/2)/(10-5) = 1 or (H+)3 = 2 x 10-5 and (H+) = .027, meaning we'd have a pH of 1.6. We'd have oceans like battery acid. It would be a wonderful place for extremophiles but probably not very good for us. Paradoxically, in this extremely acid world, limestone wouldn't dissolve easily, since the solution of limestone involves combining hydrogen ions with carbonate ions to make bicarbonate. But so much carbon dioxide would be in the oceans, we probably wouldn't have much limestone anyway.
One of the things the bicarbonate ion does is help to maintain the pH of solutions. Add some acid to a weak carbonic acid solution, and the hydrogen ions combine with carbonate ions to make bicarbonate. Add some carbon dioxide, and it breaks down to bicarbonate and hydrogen ions. This mechanism helps maintain the pH in our blood at a steady value. Handy stuff, this weak acid thing.
(1) For the benefit of the chemistry purists, most dissolved carbon dioxide remains in the form of carbon dioxide molecules and only a couple of percent combine with water to make carbonic acid. We normally don't discuss this in speaking of the effects of dissolved carbon dioxide because it merely adds another step to calculations and makes no difference to the final result.
Atoms bond by sharing electrons in various ways. Atoms also have a preferred arrangement of electrons, so that some arrangements are more stable than others. In many substances, bonding is achieved when some atoms lose electrons and others gain them, either by sharing or by more or less complete transfer. Atoms that lose electrons have a positive charge and are called cations, those that gain electrons have a negative charge and are called anions. The charge an atom has in a given situation is called its valence.
Elements can be made to combine in all sorts of weird and wonderful ways in the laboratory, but out in the real world only the most stable valence states tend to occur. Many elements occur in nature in only one valence state. Sodium and potassium occur pretty much exclusively in the +1 state, chlorine and fluorine in the -1 state, oxygen in the -2 state, boron and aluminum as +3, and so on.
But not all. One of the most stable configurations is for elements to gain or lose enough electrons to have eight electrons in the outermost shell. Elements that are close enough to both ends of the Periodic Table can go either way. The most important element by far in nature to do this is sulfur, which can either have a -2 valence, as in sulfides, or a +6 valence, as when combined with oxygen and other elements to form sulfates. Sulfur can also have a +4 charge, as in the gas sulfur dioxide. Carbon can lose four electrons to assume a +4 charge, as it does in virtually all natural materials, but it can also gain four electrons to take on a -4 charge. An industrially important example is silicon carbide, used as an abrasive. Nitrogen can have a -3 charge, as in ammonia, or a +5 charge, as in nitrates.
Once an element has a large enough number of electrons, it may not be practical for it to complete its outer shell of eight electrons, so it settles for "good enough." The transition metals across the middle of the Periodic Table are in this situation, and most of them have several kinds of "good enough." Far and away the most important is iron, which can assume valence states of +2 or +3.
The dual valences of iron create something that seems, from our standpoint, to be the exact opposite of intelligent design. Why is it that a thin film of aluminum oxide keeps highly reactive aluminum from corroding, but iron oxide, with exactly the same atomic arrangement as aluminum oxide, doesn't protect iron? In fact, rust accelerates the corrosion of iron, which is why it has to be removed when refinishing a car. The answer is that iron has two valence states in nature but aluminum doesn't. Once iron rusts, it oxidizes to the +3 state. It can then grab electrons off the intact iron, dropping back down to the +2 state but also converting formerly intact iron to the +2 state as well. The reaction goes: 2Fe+3 + Fe = 3Fe+2. Of course, the real unintelligence is us for using steel to build cars instead of something rustproof like stainless steel.
Lots of other elements have multiple valences as well. Manganese, copper, tungsten and uranium are important examples.
Carbon (and a few other elements) have another trick. They share not just one, but multiple electrons with a neighbor. These bonds are called multiple bonds. Oxygen atoms in an oxygen molecule are joined by a double bond and nitrogen atoms in a nitrogen molecule are joined by a triple bond. But easily the most important multiple bonding is that of carbon.
Multiple valences and multiple bonds perform two vital functions in nature. First of all, they store energy. Many micro-organisms use this energy storage capability, and the most common cases use the two most abundant multiple valence elements: sulfur and iron. Thus some bacteria oxidize sulfur, others reduce it. Iron oxidizing bacteria were probably responsible for creating most of the world's iron deposits. Changes in the valence of iron also allow hemoglobin to absorb oxygen in the blood, with one very cool twist. Since a +3 iron ion has a surplus of positive charge in its nucleus, it pulls the electrons in tighter and the ion shrinks in radius. So when an oxygen atom binds to an iron atom in hemoglobin, the iron shrinks, pulls the oxygen in tighter, deforms the hemoglobin molecule and makes it easier for oxygen atoms to bind to the other iron atoms. Pretty tricky, no? Isn't this way more fun than babbling about the way a banana fits the human hand?
Second, they store information.
Where did atoms come from, and how did there come to be so many different kinds? We can answer this question in quite a bit of detail, thanks to what we know about nuclear reactions in particle accelerators, reactors, and nuclear bombs.
The sun gets its energy by fusing four hydrogen nuclei (protons) to make a helium nucleus. This process is actually fairly complicated and proceeds in several steps. The final nucleus contains four particles, or nucleons: two protons and two neutrons.
Beyond helium we encounter a bottleneck. If we try to add a neutron or proton to a helium nucleus, the new nucleus disintegrates almost instantly. There is no nucleus with five nucleons that lasts long enough to be a basis for heavier elements. Perhaps we can fuse two helium nuclei together? But it turns out that there are no long-lasting nuclei with eight nucleons either. It looks like there is no way to make anything heavier than helium.
However, there is a way around this bottleneck. When stars collapse to form red giants, the temperatures and pressures inside the star become high enough for three-way collisions of helium nuclei to occur. Actually, two helium nuclei collide, but they remain together long enough for an occasional third helium nucleus to collide as well because conditions are so crowded in the cores of red giant stars. These collisions are rare, to be sure, but they occur often enough to form heavier elements in the quantities we observe. The product of these collisions has 12 nucleons: 6 protons and 6 neutrons, and is a carbon nucleus.
Actually, it is probably a good thing that it is so hard to form heavy atoms. I sometimes refer to the mass 5-8 bottleneck as the Universe's Great Fuel Conservation System. If it were much easier to make heavy nuclei, stars might long ago have fused all their hydrogen to heavy atoms and there would be no available energy left in the universe.
What about lithium, beryllium, and boron, the elements between helium and carbon? These atoms form only when collisions knock nucleons off of heavier nuclei, a process called spallation, and they tend to be destroyed in the interiors of stars. Compared to carbon, they are rare in the universe.
Once carbon forms, it serves as a base for building heavier atoms. Nucleons can be added one-by-one, or by fusing more helium nuclei to an existing nucleus. Building elements by fusing helium nuclei is a common process, and elements with even numbers of protons in their nuclei are more abundant than atoms with odd numbers. But each heavier nucleus takes more energy to make and gives less energy back, until at iron, with 26 protons, the process ends. Beyond iron, it takes more energy to make a nucleus than the nuclear reaction gives back. Random collisions build some heavier nuclei, but the abundance of elements drops off sharply after iron.
Very heavy atoms like gold are extremely rare in the universe, and seem to form only in the fierce environment in the core of a supernova. Much of the light given off by a supernova turns out to be due to the decay of radioactive nickel. In a supernova, there is so much energy available that particles can pile onto nuclei at a tremendous rate. Atoms at least as heavy as plutonium form this way, and probably atoms far heavier than that. These atoms require more energy to form than our most powerful particle accelerators can produce, but nuclear physics predicts that nuclei with about 110 protons might have very long lifetimes, possibly long enough to be left over from the formation of the earth. Some physicists have attempted to find such super-heavy elements in rocks, so far without success.
In normal stars, the process of building elements ends with iron because you can't get energy out of iron nuclei. So how do we get to thorium and uranium?
Well, you could just add a proton at a time. After all, in stars there will be lots of protons whizzing around. The problem is the electrical repulsion between nuclei. The repulsive force is proportional to the product of the two nuclear charges. So in a star fusing helium and carbon to make oxygen, the repulsive force would be 2 (He) x 6 (C) = 12. But adding a single proton to an iron nucleus would result in a repulsive force of 1 (p) x 26 (Fe) = 26. In other words, in a massive star fairly far along in its giant phase, it still takes way more force to fuse a single proton to iron than to fuse helium and carbon.
On the other hand, there is no repulsion involved in adding neutrons. So you could add neutrons to normal Fe-56 to get Fe-57, Fe-58, and so on. Of course, too many neutrons make the nucleus unstable, so logically the nucleus should just spit the excess neutron out. In such a universe we could make iron nuclei until they got so neutron heavy that they couldn't hold any more, but that would be all.
But that's not what happens. Instead, one of the excess neutrons breaks down into a proton plus an electron, then spits out the electron. The nucleus doesn't gain or lose mass (the mass of the electron is negligible) but it does decrease by one neutron and increase by one proton. A chart of all atomic nuclei shows a zigzag chain of stable and long-lived radioactive nuclei in the center of a broad swath of highly unstable nuclei. You add neutrons to some elements for a while, hit the limits of stability, climb upward a few elements by neutron capture and beta decay, hit another horizontal step, and so on.
That process is called the s-process (for slow) and it happens in giant stars. But there are some nuclei that can't be made this way. In supernova explosions, the r-process (r for rapid) builds atoms. In a supernova, neutrons are flying around ten billion times faster than in a typical giant star. These slam into nuclei faster than the nuclei decay. When these nuclei do decay, it may take a bunch of beta decays for them to settle into something stable, crossing even wide gaps in the stable nucleus zone.
So we have the apparent paradox that in stars, the decay of radioactive atoms creates more complex atoms. I can really see why creationists don't want to touch this. Here they go arguing that it's impossible to create order without violating the laws of physics, and that things have been going downhill since the Fall, and it turns out that radioactive decay plays a role in creating complex nuclei. How embarrassing.
If there were no friction, machines would run perfectly smoothly, never need lubrication, and probably never wear out. And things would also slide down the tiniest slope. Brakes wouldn't work. It would be impossible to walk, fly, or swim. You couldn't grip any smooth surface. You couldn't turn a doorknob or stand up in the bathtub. A quarterback wouldn't be able to hold a football. When we talk about physics, we say things like "objects in motion would remain in motion, except for friction," as if friction were some sort of imperfection or flaw in nature. But it isn't. You might just as truly say "friction would hold everything in place, if it weren't for momentum."
If materials were perfectly rigid, beams and bridges wouldn't bend. On the other hand, nails wouldn't penetrate wood and nuts and bolts wouldn't work. In fact, it would be impossible to shape metal. Nuts and bolts hold because tension stretches the bolt slightly, causing it to pull the nut tightly against what it's holding. Meanwhile friction keeps the nut from simply unwinding. Far from being flaws in the universe, friction and deformation permit a host of otherwise impossible beneficial phenomena.
If materials were unbreakable, windows would be safe from errant baseballs, and you'd be safe from fractures if you fell down. And seeds would be unable to split their casings. A saw wouldn't cut wood because it would be impossible for the teeth to break the cellulose fibers. In fact it would be virtually impossible to manufacture anything. Finite strength, far from being a flaw in nature, is a blessing. Materials are strong enough to be useful, but not too strong.
A perfect meritocracy would probably be a truly nasty place. It's bad enough that many people suspect that homeless people did something to deserve their situation (and to be brutally honest, some did). Imagine what society could be like if you knew beyond doubt that people who were down and out deserved it, and that people who were low on the salary scale or the social pecking order were there because they deserved to be. Nobody would lift a finger to help them; in fact people would likely compound their misery by rubbing their lowliness in their faces. (In fact, that's actually the vision British sociologist Michael Young had when he coined the term "meritocracy" in 1958. He pictured a dystopian future ruled by a callous and complacent elite of technically competent people lording it over the untalented masses.) On the other hand, societies ruled excessively by fatalism or chance, like hereditary aristocracies or clan societies, where family status takes precedence over individual achievement, tend to encourage the delusion that people have earned something when they have merely been lucky. Also, people who didn't get lucky may get the idea that striving for improvement is pointless. But a mixture of causality and chance mitigates both extremes. A visible linkage of effort and outcome encourages people to try to improve their lives, but a healthy dose of chance reminds people that they can't afford to be too smug; that with a different set of circumstances their lives could have been quite different. While chance creates some injustices - talented people often don't get the breaks and far less qualified people do - it's not hard to see that a society with perfect meritocracy might end up being far more unjust than what we have now.
A world where natural selection operated with perfect efficiency would probably be a dull and not very diverse place. There would be one kind of organism for each ecological niche. In fact, there might well be one kind of plant. Period. Predators couldn't evolve because prey animals would evolve foolproof ways of escaping, and herbivores couldn't evolve because plants would evolve perfect defenses against being eaten. And whatever plant was most successful would displace all others. Chances are the planet would be covered in green goo as one micro-organism proved dominant. It would all have the same, optimal DNA. But if conditions ever change drastically....
But in our inefficient world, some of the best adapted individuals get eaten anyway or die from disease or accident, and some of the substandard ones pass on their genes. And even perfect individuals mate and produce less than perfect offspring because they're carrying less than perfect genes. Some seeds are eaten and digested, but some - and not necessarily those with the optimal genes - are excreted or transported, so plants evolve ways of cooperating with herbivores. And just when it looks like a system is evolving toward real stability, a fire or storm or drought or epidemic or ice age or meteor impact comes along and shakes up the snow globe. All of a sudden the first become last and the last become first (Neat concept. It ought to be in the Bible). Species that were marginalized under the old system flourish under the newer one. Sometimes, if the perturbation is big enough, former rulers become extinct and the world is wide open for new variations that could never have appeared in a world of constant stability. But even with smaller disturbances, organisms and ecosystems are constantly knocked out of equilibrium, constantly facing new opportunities, new threats, new competitors, and new changes.
If we ever succeed in suppressing all natural extremes in the world we will probably regret it. We have already learned that small ground fires prevent catastrophic wildfires in forests. We will probably discover that severe storms are essential for proper redistribution of earth's heat, as well as for maintaining the variability in ecosystems that keeps them healthy, that torrential rains flush debris and contaminants out of rivers in a way that moderate rains cannot, that coastal floods are bad for condominiums but renew coastal wetlands.
For thousands of years, humanity's picture of an ideal world was a cultivated garden. Biblical images of paradise are invariably cultivated landscapes under human control, and images of destruction are wilderness and wild animals. That was natural enough in a world where humans were at the mercy of the natural environment, and where safety and security were hard won and precarious. But we now know enough about the workings of the natural world to realize that the simplistic picture of Eden as changeless and static is a better image of Hell than Heaven.
Created 12 March 2007; Last Update 13 April, 2013
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