Volcanic ash is forming little piles on our roof, and the sky has been gray from dawn to dusk. Although mindful of the cows killed by toxic volcanic ash on their skins after the eruption we saw of Tungurahua in 2006, I tasted some. This ash, from Puyehue/Cordón Caulle, has no flavor, but it has that intense grittiness of volcanic ash between my teeth; its grains have not been weathered for generations, as all other soil has, and so they are twisted into sharp microscopic contortions.
There is an early MODIS photo of the eruption at <http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=50862&src=nhrss>. These grains have floated 1400 kilometers from the volcano to my teeth and my laundry, five milliseconds for light, but five days for volcanic ash. As a small child, I often imagined vaporizing solid objects such as rocks, but I always imagined that when the vapor cooled, it would coalesce into rocks again and fall from the sky. It didn't occur to me that when you boil water in the air, the steam mixes with air before condensing, and so forms a kind of fine mist of water. It seems that the same thing happens to rocks. You don't even have to vaporize the whole rock; you can melt some of it while vaporizing the rest and squirt the mixture out of a hole in the ground, and if the phases are well mixed, the effect is like an aerosol can. Whether you get hairspray or whipped cream depends on how much gas there is in the liquid rock. So, here I am on the receiving end of a 1400-kilometer-long plume of razor-edged stone hairspray, and as it settles on my laundry and grinds between my teeth, I wonder if its toxicity explains why so many people I know here are reporting nausea today. Tonight, friends will arrive to share vegetarian sushi with us, if they are not too nauseated. The most serious consequence of breathing volcanic ash is usually silicosis, sometimes know in these cases as pneumonoultramicroscopicsilicovolcanoconiosis, a word that fascinated me as a small child, long before I had any idea what it could mean. In silicosis, tiny grains of the normally benign and inert mineral quartz settle in your lungs, causing inflammation, shortness of breath, and sometimes lung cancer. Quartz is the second most common mineral, and in the form of flint, was a crucial early tool material. Thus, in our modern wisdom, we have classified almost all soil as a carcinogen, and it turns out that human technological development has been dependent on handling of carcinogens since the Paleolithic. This ash, though, is low in silica, so silicosis is no danger from this volcano. And although flint is a carcinogen, you don't normally powder and inhale it when you participate in flintknapping, which continues today as a tradition unbroken since the Paleolithic, although today it is practiced almost entirely as an art form rather than a practical craft. I myself am still cut off from this most ancient of human traditions; I have never made so much as a useful stone knife. Infected cuts on my hands would be a more likely danger of flintknapping than silicosis. Pottery is another Paleolithic technology, and one in which I *have* occasionally participated; and it *does* cause silicosis, because grains of clay are small enough to inhale, and, like flintknapping, this technology depends crucially on skilled artisans handling carcinogens, day in and day out. Volcanic ash is one of the sources for clay, although volcanic ash by itself does not make a clay that is good for pottery. For fifteen hundred generations my ancestors have been creating works of art in this way, specifically statues of naked chicks with huge tits; some time later they began to use the same technology to carry the water that sustains life. <http://en.wikipedia.org/wiki/Venus_of_Doln%C3%AD_V%C4%9Bstonice> Perhaps four hundred generations back, in what we now call the Neolithic, my ancestors in Africa invented a biotechnological substitute for pottery: they domesticated the wild calabash gourd (which, like the clay used in pottery, is poisonous) and bred it to have a thick, waterproof husk. This was probably the very earliest agriculture, long before any cultivation of food plants. When my earliest American ancestors crossed the Bering land bridge from Asia, they brought these bottle gourds with them, and today I am sitting now in front of my computer, drinking yerba mate from such a gourd, known here as a "mate". It is far superior to clay cups — it's lightweight and resilient like plastic, although its continued use here for yerba mate probably owes more to stimulant-induced operant conditioning than to instrumental considerations. Many generations after its initial domestication, my ancestors used selective breeding to genetically modify the poisonous calabash gourd into a plant they could eat safely, and they began to breed other food plants as well, to the point that they could get more food by farming in one place than by traveling with the seasons. One effect of this has been that the unique technological advantages of the husk of the poisonous calabash over lung-destroying carcinogenic pottery were less prized, so the technology of calabash cultivation for containers, the wellspring of agriculture, was lost to much of the world. The pointless heaviness of clay became a symbol of prosperity, while the lightness of plastic or gourd became a symbol of poverty. So it goes. Agriculture may not have been a good idea. It was advantageous for the individuals who adopted it within a group, and for the groups that adopted it, but not for individuals who belonged to a group that adopted it: the paradox of the prisoner's dilemma. The skeletons of the first generations of settled farmers are shorter than those of their latest nomadic ancestors, worn from overwork, and their teeth are ground down as if they'd spent their lives chewing on volcanic ash. Nevertheless, by artificially increasing the biological production efficiency of land, it enabled dramatically higher population densities, and these denser populations of my farmer ancestors could usually exterminate or drive off my nomad ancestors — and those nomads who failed to become my ancestors. Today we continue to face population density problems with prisoner's-dilemma situations. Just as agriculture increased the production efficiency of land, with the natural consequence that much more land came under cultivation, modern engineering has increased the production efficiency of burning coal, and so we are burning much more coal today than ever before, a phenomenon dubbed Jevons's Paradox, after the Englishman who documented it most clearly. And just as agriculture made everyone worse off in the long run, but benefited those who adopt it, any country today that stops burning coal will be quickly overrun by its richer neighbors — but if we don't stop burning coal, we will all perish from climate change. Now I must go to burn some fossil fuels with my wife as we prepare sushi on ceramic plates from cultivated genetically-modified plants, hoping our guests will not be suffering too much from inhaling volcanic ash, and will arrive despite the government advice to stay indoors unless necessary. -- To unsubscribe: http://lists.canonical.org/mailman/listinfo/kragen-journal
