Cosmic Apprentice: Dispatches from the Edges of Science (15 page)

It has been suggested that the continuous presence of water on the Earth’s surface for the last four billion years is not an accident but the result of life, which is made mostly of water and continues to maintain itself in (and as) this planet’s surface. Plate tectonics, too, which requires limestone—made by marine microbes—to lubricate the continental plates, may also be dependent on life. Because a continuous marine rain of algal skeletons ultimately forms a layer of calcium carbonate that lubricates Earth’s giant continental plates, life seems involved in plate tectonics. Crashing plates also open up expanses from which ocean water can evaporate, leaving behind salt and thus removing it from the ocean where it can, in too high concentrations, become deadly to most marine life-forms.

Without the continental plates, which move on life-made limestone and require life-recycled water, there might be no Himalayan or Andean mountain ranges. Microbes really do move mountains, and life and the environment are connected with a depth and intimacy that may surpass the imagination of even the boldest scientists.

Convolutedly, the wet recursive chemical system of waterlogged life seen from space as our turquoise blue beauty of an aqua planet might not be here without life. Water is made of hydrogen, but hydrogen, the lightest element, tends to escape into space, where it has gathered again around the giant outer planets. As Stephan Harding of Schumacher College points out, one of the escape routes for hydrogen ever since the Archean eon has been a chemical reaction between water and basalt, which is the major rock type at the bottom of the oceans. Basalt contains ferrous oxide and in the presence of carbon dioxide strongly captures oxygen atoms from seawater, letting hydrogen molecules escape to space. Life is moist and damp, and we live on a happily wet planet, but this natural process could have dried Earth up in two billion years. Bacteria again saved the day: photosynthetic life at the sea’s surface liberates free oxygen, which binds to the escaping hydrogen making new water molecules. Other bacteria, such as chemautotrophic anaerobes dwelling in ocean bottom ooze, combine escaping hydrogen with carbonated seawater, creating water in the ocean and liberating methane gas.

Life’s alteration of this planetary “rock” is so complete that Earth would look to us to be barren and alien beyond the most hopeless desert if it were not for life and its naturally intelligent, highly evolved metabolic ways. The intuition that Earth looks alive from space has some basis in fact.

Nature is not just red in tooth and claw but quite exuberantly white with apatite, golden with chrysophyte algae, purple with photosynthetic plastids, and peachy orange with carotenoids eaten by long-legged filter-feeding flamingos, whose diet of shrimp and algae and cyanobacteria shows up under their skin. It is butterscotch gold with naturally archiving, insect-preserving amber, beige with
Beggiatoa
bacteria, and black with the magnetic teeth of chitons. It is green with
Chlorobium
sulfur bacteria and red with
Chromatium,
a purple sulfur bacterium that, like its ancient metabolic brethren, oxidizes sulfide rather than water, excreting yellow sulfur rather than oxygen as its photosynthetic waste. Nature is not just dog-eat-dog but bacteria-inside-archaeon, protist mingling with protist, quorum-sensing swarm-sensing crowd-controlling human-making swarm. There is more in it than we dreamed; it comes in colors and keeps on coming, psychedelically without pause or apology.

The night is black and the sky is blue. The sky is blue because of life. It is blue because of oxygen atoms released billions of years ago by green cyanobacteria. Exuberant and dangerous, they spread, poisoning the planet with their toxic oxic pollution. They were the first to be victimized and among the first to be transformed, forced as they were to evolve ways to tolerate and eventually make use of the life-produced reactive gas.

Why is the sky blue, no-longer-jumping Jack asks. A correct answer would be cyanobacteria, the mean lean greens that give summer its verdant sheen. The sky would not be its beautiful aqua or azure, the oceans would not reflect the sky’s blue kiss without these frisky germs. For the sky’s blueness, its tranquil aerial fields, comes from a surfeit of atoms of oxygen. Their minuteness is a right size to catch a light wavelength and send it spinning and scattering all directions every day. The short, blue-wavelength light reflected by atoms hits our eyes. The early world may have seemed pale and ruddy, and smelled sulfurous and foul by comparison. Inhaling oxygen first released in any meaningful way into our atmosphere by slimy cyanobacteria, we can only say that life on Earth is, if it is, a gas, because these photosynthetic bacteria spread, about two billion years ago, like green wildfire. They directed the energy of light to break the molecular bonds of water, getting a metabolic pathway up on the purple sulfur bacteria that are otherwise much like them. They incorporated hydrogen into their cells and released reactive oxygen into the atmosphere, giving us something to think about, and breathe.

We live on a psychedelic planet where partners triumph, the chemistry of the early solar system lives on in our bodies, individuality appears at higher levels, and evolution evolves. Once upon a time, billions of years ago, Earth’s sky was not yet blue. This is because life liberated such oxygen atoms from the hydrogen molecules to which they were molecularly bonded. The size of oxygen atoms is such as to scatter light of a blue wavelength. The life-form responsible for this release of oxygen atoms was cyanobacteria. Their forerunners were purple sulfur bacteria that had thrived on hydrogen sulfide. The new water-using cyanobacteria took their hydrogen directly from the liquid medium in which they lived. Breaking water’s molecular bonds was difficult, but it saved early life from perishing and led to a life-form—a very successful life-form—that is arguably the dominant form of life on Earth today. And they were nicely named, considering what they did: cyanobacteria, cyan denoting any of a range of colors in the blue-green range of the spectrum. These blue-green sunlovers became trapped in the ancestors of plant cells, inaugurating the eternal salad days land plants still enjoy. Language itself contains fossils, and thus it is that these beings are still more often referred to by their old name—“blue-green algae”—which tends to obscure what they are: bacteria, symbiotic aquatic oxygenators of a planet that, once upon a time, was a whiter shade of pale. It is an amazing story, all the more powerful for being both mythic and true:

Life gave Earth the blues.

CHAPTER 10

MOUSETRAP

WHY ARE WE HERE?
Might this all just be a big fluke? Even if evolution is, as Arthur Koestler said, like an “epic recited by a stutterer,”
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what is the plot? It seemed like God had a good idea, but then he got sidetracked. Where is he going with this thing?

I believe the writer Kurt Vonnegut touched on the heart of this question. Before a full house of mostly women at Smith College, he first drew a chart that graphed stories. On the X axis he drew time, on the Y happiness. By making a line, he showed, he could map any human story. Goldilocks and the Three Bears started off with a jump when she found the house in the woods, it moved higher like a stock as she saw the table place set for her, then higher again as she found her warm bed, before plummeting when the bears came home. The Garden of Eden started off very high, plummeted down, and then flatlined. Vonnegut used a big sheet of paper to mock scientific reductionism and social science in particular. Most stories weren’t so clear-cut or geometric; they were more squiggly.

Then he told about his own days. They often started, he said, despite protests from his wife, who thought he could use his time more wisely, in taking a leisurely walk to the post office to mail a single letter. At the post office he bought a single stamp from the pretty teller. They smiled and he slid her the envelope. Nothing would ever happen, he admitted. But still, that was not his point.

What was it?

“I tell you, we are here on Earth to fart around, and don’t let anybody tell you different.”

OF COURSE, Vonnegut’s is not the last word on the subject. “We are here,” writes the paleontologist Stephen Jay Gould, “because one odd group of fishes had a peculiar fin anatomy that could transform into legs for terrestrial creatures; because comets struck the earth and wiped out dinosaurs, thereby giving mammals a chance not otherwise available.” Vonnegut’s son, the physician Mark Vonnegut, takes a more ethical slant, emphasizing our emotional and physical interconnectedness. “We are here to help each other get through this thing.” The poet W. H. Auden was mystifyingly succinct: “We were put here on earth to help others. I’m not sure what others were put here for.”

I had a teacher, Don Levine, who taught Avant-Garde Cinema, Madness in Literature, and other fun subjects. One day he informed the class that meaning and moaning share the same root. Although we should be dubious of what Jacques Derrida calls “fabulous etymologies”—words evolve much faster than organisms and are thus even more apt to erase traces of their origins in transit—I would not be surprised. It seems to me that the impulse to do something comes before even the discrete task to be done and is also implicit in the thermodynamic equilibrating of nature, especially the elaborate actions, sometimes including planning, of far-from-equilibrium systems that perish if they lose access to the energy gradients that sustain them. A “forness” or “towardness” blankets life at all levels: physiological, unconscious, and conscious. A couple of days ago, for example, I awoke knowing I had to do something. The unusual part was I did not know which of three things. One, I had jammed my finger while playing basketball two days before and it was throbbing with pain that could be addressed. Two, my bladder was full. Three, I had a sleep mask on, it was Sunday, I had taken melatonin the night before, the mask had fallen off, and I wanted to get it back on before the morning light stung my eyes. What I noticed was that these three desires—treating the pain in my swollen finger, going to the bathroom, and not having light on my eyes—all vied equally for my attention. None was so strong that it obliterated the others, and I initially was not aware of any of them but only of a general desire that something needed to be done. We might call them “telons,” from the Greek
telos,
“end” or “goal.”

One way or another some members of life have successfully taken care of their goals for the last 3.8 billion years. In a little-known book that has been considered a
Principia
for biology, Robert Rosen identifies anticipation as a key property of life.
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He argues that its ends and means are entailed, that life is noncomputable and naturally purposeful. Rosen points out that when causes and effects are nested together, purposes become real. I, too, would argue that life’s forwardness and towardness comes before any discrete task—any, that is, except for gradient reduction. Life is a cyclical system, so its ends and means must be entailed, but organisms can become their own purposes only within the larger context of gradient destruction in which they are already always engaged.

Try to be completely still. You can’t do it. Your heart beats, you breathe, you continue to metabolize. Even sleeping you produce more entropy than a corpse. This, not reproduction, is the essence of life. It is the essence in that it explains not only what we are, aggregates of cosmically abundant matter like hydrogen and carbon, or how we are, but
why
we are, to spread energy more rapidly, more long lastingly than would be the case if we were not here. We are manifestations of the second law, as one of my coauthors, Eric Schneider, has said.

In one of his early books,
The Cosmic Connection,
my father had written words to the effect that the best evidence extraterrestrials might find that Earth has life would be the spectroscopically measurable excess of atmospheric methane, a product of “bovine flatulence.”
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Although there are more important biospheric sources of atmospheric methane than the methanogenic archaea in the rumens of cattle, my father’s throwaway phrase is a memorable bit of rhetoric. Whether belching or farting, passing gas lets loose thermodynamic wastes. Compared with the oxygen and food we take in, the carbon dioxide and methane and other carbon compounds we put out are in a less energetic state. They are not completely energetically stable, however, as the microbially aided breakdown products of food include tiny amounts of hydrogen, carbon dioxide, and methane that combine in the large intestine with hydrogen sulfide and ammonia to make a redolent, combustible mixture: Relatively stable, if smelly, these compounds can, if provided activation energy, be caused to burn, as the psycho rockabilly crooner Angry Johnny, the lead singer of the Killbillies, demonstrated one night by nonchalantly taking a lighter to his rear end in Hell, his name for his studio in Easthampton. This created an invisible torch at some distance from his pants.

Methane, although a waste produced by cows, termites, swamps, and others, is still highly unstable in the presence of oxygen, which is why intelligent aliens might notice it, this cosmic, spectroscopic equivalent of a fart. Indeed, here is a solution to the Fermi paradox: the aliens have detected us but don’t want to come close for fear of Earth’s smell.

The entire genesis of the Gaian idea is that Earth’s atmosphere is out of thermodynamic equilibrium, more complex than it should be, given the rules of chemical mixing. But this persistent admixture is explained by the fact that the living organisms of Earth are open systems. Their complexity bleeds over into the environment, even as they produce more entropy (molecular chaos), mostly as heat, farther out. Life is one of a class of thermodynamic systems that naturally organize themselves as they grow by tapping into, and sometimes depleting, local energy stores.

But excess can be bad. It can be fatal, as in death by drug overdose of a Jimi Hendrix, or worse, it can be speciescidal, as in the overpopulation of a species that uses up all its resources and dies of famine or becomes prey to an epidemic. Flatulence and laughter represent “human” aspects of any number of processes that naturally arise to perpetuate the universally observed energy-spreading mandate codified by the second law. Moreover, laughter and farting, although they seem to represent more or less random examples of gradient breakdown, are not really. Unlike, say, spontaneous combustion, or world war, or genocide, they represent
moderate
gradient breakdown; they are examples of stable processes, processes in beings letting out steam, as it were,
gradually,
and thus not, in all likelihood, endangering themselves or the external gradients that sustain them and around which, quite necessarily, their activities are organized.

It is indeed an amusing astrobiological irony that through a smorgasbord of sphincters comes in the aggregate such gas that it provides, within our atmosphere one-fifth oxygen, with which such gases should react, a kind of chemical signature indicating the presence of intelligent life on Earth. Compounds such as the butyl mercaptan released by skunks, methane released by archaea and belching cows and wetlands, and butyric acid released from mammal skin all react strongly with oxygen but linger in our atmosphere—because life keeps farting them around in the shared ether of its collective home.

IN 1948 the Dutch artist M. C. Escher made a famous lithograph. Two hands emerge out of sleeves on a piece of paper to draw each other. Ends and means become beguilingly intercalated in highly entangled complex systems, tending to obscure the basic operations of those systems, especially when they themselves possess semiotic and interpretive abilities. In the 1790s Immanuel Kant said that the difference between an organism and a watch was that an organism creates all its own parts. An organism, unlike a watch, is “both cause and effect of itself.” Kant, who meditated on the difference between a watch, a mechanism that is made, and an organism, a being that grows, was one of the first to think about self-organization. But he was, I think, a little off, as are those who follow on that train, because the organism is connected to an environment and, indeed, dependent on it and the continuous telic reduction of its energy gradient for its own continued sustenance. The internal nesting of causes and effects obscures a function, or purpose, which becomes far more clear when one takes into account the environment. Kant also described an organism as its own purpose. But there is no self disconnected from the material substrate and energetic flows on which it depends. It only ever cycles in order to reduce ambient gradients.

Kant, aware that religious humanity tended to think of itself as made, like a machine, for a higher being, also focused our attention on the difficulty we have determining purpose. The nestedness of cause and effect in cyclical systems disturbs linear logic in interesting ways. For example, as a cyclical system I may be hungry. Therefore I eat a cupcake. Therefore I am not hungry. If we remove the intermediary behavior, we end up with the logical contradiction, “I am hungry . . . therefore I am not hungry.” Still, it makes perfect sense within the cyclical system of which it is a part.

The cells responsible for clotting blood near a paper cut on your finger, if they were conscious, would not necessarily have a clue what they were up to participating in a cascade of enzymes that stops blood flow and heals the damaged tissue, repairing the wound. The purpose becomes evident only as we move outward to see how the organism functions, not only in terms of itself, which it does do, but also in terms of the environment.

Without knowing, or being familiar with, certain details of the cyclical operation of a complex system, we may completely misrecognize or overanalyze its simple natural function. A story by the great French writer Denis Diderot (1713–1784) beautifully illustrates the point. This story is of a wayward horse ridden by the servant Jacques in the novel
Jacques le fataliste et son maître
(Jacques the fatalist and his master). Jacques, who behaves rebelliously, willfully, even though he believes in fate, as if everything were already written above in the stars, takes orders from his nobleman, who, ironically, although he believes in free will, is more happy-go-lucky, rarely taking any initiative. In any case, Jacques one day is on a horse that appears quite willful and takes him, Jacques, off the beaten path and certainly not where Jacques has been telling him to go. And where he ends up is indeed fateful. The horse, moreover, as if making sure Jacques understands, leads him there not once but twice.

And where does he lead him? The gallows.

Naturally, Jacques believes that the horse is sending some kind of message. And the message is clear; it is one of impending doom. For whom, Jacques doesn’t know. But he cannot help but think that the horse’s repeated purposeful behavior is a sign that the grim reaper may be on Jacques’s tail.

The third time the horse goes off course, Jacques arrives at the property of its previous owner, the executioner. There was nothing sinister in the horse’s purposeful movements: it was simply returning to places it knew well, places where it was used to being cared for and fed.

If Diderot is arguing that the horse’s true purpose is not as ornate as Jacques superstitiously imagined, I am arguing that neither may be ours. We have our little purposes and indeed big purposes, such as finding meaning in life, a purpose that gives us the will to live. But there may be bigger purposes. Indeed, if our immediate purpose is to get a bite to eat or a date, to make money or a baby, or even to raise a family or win a war, if we step back we may be able to see that these take place in a larger frame. They take place in the cosmic context of a naturally telic, purposive universe.

MY LIMITED RESEARCH SUGGESTS that Vonnegut’s humorous and partial nonanswer to why we’re here was not just a throwaway line. He gave it some thought. It was the highlight not just of his lecture but, in a more extended way, of the plot of his novel
Galapagos.
Here he tells the story of rich tourists stranded on an island after the rest of humanity has perished from world war and epidemic. The narrator, the ghost of a shipwrecked sailor who drowned but now speaks from the pink tunnel of the afterlife, tells of how the last old man, feeling responsible for humanity’s future, among other things, takes matters into his own hands, literally, introducing semen into the young women in their slumber to preserve the species. The result is healthy young who possess some odd traits. They evolve hairless and develop an extra layer of blubber. After a few generations, their heads are so pointy that they enter the water without a splash. In a few more, none of them remember their mothers after the age of three. Finally, their only trait that ties them to the species from which they came is that whenever they lie about in the sun and one of them farts, the rest laugh.