Saturday, August 4, 2012

Prometheus and the Scientist


This entry was originally published in Spanish in ¿Cómo ves? magazine, August 2012.

At the foot of the Cerro del Chapulín in Chapultepec Forest there is a fragrant and beautiful park smack in the middle of Mexico City. The park is home to a very Mexican tree species, the ahuehuete, known for its longevity. Some of the ahuehuetes in Chapultepec have their age marked with red paint on the trunk —400 years, 500, 600… The most ancient of these trees were there before the founding of the Aztec city of Tenochtitlan.
I discovered the labels on the trees a few years ago, while strolling in the shade of the old ahuehuetes. I knew that the age of some tree species is determined by counting the growth rings in a cross section of the tree trunk. How could the age of the Chapultepec trees be calculated without cutting them down? I didn’t know it then, but this is the way it is done: you plug a special drill into the trunk and turn a crank until the drill reaches the core of the tree; out of the drill comes a thin, striped cilinder; the stripes are sections of growth rings. You then head back to your laboratory and count stripes under a microscope. The number of stripes gives the approximate age of the tree. To me it was a revelation --and a relief-- to learn that it could be done without killing the tree.

In Search of Time Accumulated
Actually taking the samples, however, can be complicated, as Donald Currey, a graduate student from the University of North Carolina, discovered in 1964. Currey was conducting research on climate change during the period paleoclimatologists call the Little Ice Age, which runs from about 1300 to 1850. During this period world temperatures dipped several degrees. The Little Ice Age had consequences ranging from the biological to the social, but that’s a different story.
Donald Currey needed samples from ancient individuals of the species Pinus aristata, known as brisltecone pine, a tree that dwells in the highest mountains of the southwestern United States. He wanted to do a statistical study of the relationship between the age of the trees and the altitude at which they grow. This would help him tell whether climate changes during the Little Ice Age had modified the altitude of the tree line. If he found very old bristlecones close to the present-day tree line, then Little Ice Age changes could not have been too severe.
Since the 1950s, when Edmund Schulman discovered that bristlecone pines keep very precise and readable registers of climes past in their growth rings, ecologists were convinced that the oldest individuals grew in the White Mountains of California, on the western limit of the species’ habitat. There Schulman found bristlecones more that 4000 years old, which he made famous in an article that appeared in the January, 1958 issue of National Geographic. Schulman died weeks before the article was published.
Schulman’s pines became famous for their eerie beauty. When they reach millennial ages, the gnarled branches of these trees stretch to the sky like pleading arms, and their convoluted trunks of dead, barkless wood seem to fly in the wind like the robes of a Biblical patriarch. The bristlecones of California were also celebrated as the oldest known living organisms.
Donald Currey did not go to California, however, but to Nevada, at the center of the bristlecone habitat. There the young scientist found what he was looking for in a grove of wondrously old-looking pine trees growing at the edge of a deep valley carved out by an ancient glacier in Wheeler Peak. The trees looked as aged as Schulman’s, notwithstanding the dogma that the species only reached extreme ages in California. The young man chose the oldest-looking tree, sank his drill into the trunk, and began to turn the crank. Crick, crick, crick went the drilll as it bit deeper and deeper into the wood of the Methuselah of trees. Crick, crick… CRACK! The crank snapped in Currey’s hand. The device had broken its teeth in the rock-hard wood. Without a spare drill and with the academic calendar against him (he had to turn in a report to the National Science Foundation before the end of the summer), Currey went to the Forest Service for help.

Witness
As the first civilization was inventing the plow in Mesopotamia, in a different continent a sapling was growing at the edge of a glacial valley. With the first snows of the alpine winter, at close to 10,000 feet, the little tree entered a phase of lethargic growth as it waited for better times. When the brief summer came, it grew in a desperate spurt to profit from the sunlight and rain. The wood it made during this accelerated growth phase was less dense than the wood produced in the severe conditions of winter. The cycle was repeated through the ages, and the yearly ebb and flow of growth and dormancy was recorded in the stuff of the trunk.
Tree rings represent alternate phases of rapid wood production, when the tree has plentiful sunlight and rain, and slow growth, when sun and nutrients are scarce. Generally, one would expect this cycle to match the cycle of the seasons —in which case each ring would represent a year’s growth—, but if drought strikes in midsummer followed by abundant rains in the fall, the tree will produce two rings. On the other hand, if the whole year is bad —with unseasonable cold, drought and insufficient sunlight—, there simply won’t be a measurable ring to speak of.
Tree rings, then, are not only a proxy for the tree’s age. In their width and other characteristics, nature has written a detailed, year-by-year history of varying weather. Growth rings are like the personal diaries of the tree world. Matching ring sequences from many different trees to average out errors due to double or missing rings, climatologists can build chronologies of past climates. The tecnniques of dendrochronology (dendros means “tree” in Greek), help scientists recognize patterns of climate change with periods as short as one year or as long as several centuries.
Our tree grew old as humanity went from the Bronze Age to the Space Age. Its environment didn’t change much, except for the weather. The land on which it grew remained stable, but for occasional avalanches that deposited two feet of rubble on top of the original ground. The glacier that carved the valley was already long-gone when the tree was a sapling.
But one day in August, 1964…

The Truth and Nothing But?
What happened when Donald Currey went to the Forest Service for help is not clear. One version has it that the scientist asked permission to cut down the tree and take a slab of trunk, which would be more cumbersome than the thin cilinder from the drill, but would certainly simplify the actual counting of the rings. According to another version, it was Donald Cox, from the Forest Service, who suggested that Currey cut the tree, which was, after all, one of many ancient bristlecones in the area. However it happened, Currey went back up the mountain with pack horses and Forest Service personnel armed with chainsaws. The men brought down the ancient tree.
Very satisfied —or perhaps not—, the young researcher took a large wooden slab more than two meters in diameter down the mountain to his hotel in Baker, Nevada. The next day he set the slab on a table outdoors, took out a magnifying glass and some sandpaper to bring out the grain in the wood, and started counting. By the end of the first day he had counted back to the Middle Ages. This did not surprise him, because he already had core samples from 113 trees from Wheeler Peak. He knew they were really old. Currey counted on. The following day he had reached back to the time of the Roman Empire —and he was not even halfway through the counting.
In 1965 Donald Currey published a paper in the journal Ecology. By that time his goal had changed from building a chronology of the Little Ice Age to proving that Schulman had been wrong to believe that the oldest individuals of the species Pinus aristata were to be found only in California. Here is what Currey writes regarding the tree he named WPN-114 (the 114th tree from Wheeler Peak, Nevada): “The tree-ring series contains both distinctively thin (microscopic) rings and difficult-to-count incomplete (locally absent) rings.” This did not daunt the scientist. He went on counting rings for one week. The article continues: “The derived radius measures 2,280 mm to the pith, 100 inches above the original base, and encompasses 4,844 counted rings.” Then, in the same serene, unfathomable monotone, he adds: “Allowing for the likelihood of missing rings and for the 100-inch height of the innermost counted ring, it may be tentatively concluded that WPN-114 began growing about 4,900 years ago.”
The impersonal drone typical of scientific papers conceals what the author must have felt when he discovered that his tree began life before the birth of Greek civilization, and even before the Ancient Empire in Egypt. Schulman’s oldest specimen was 4,600 years old. Currey had found one that was even older… and he had cut it down.

“Murderer”
It was Currey’s misfortune that the people of Baker had grown fond of the trees in the old grove on Wheeler Peak. Darwin Lambert, an official with the Forest Service, had formed an association to promote the creation of a national park in the area to protect them. To make things more poignant, Lambert had even named every individual tree. Currey’s was called Prometheus.
In 1966 Darwin Lambert, who by then had nourished the park project for years, heard that a researcher from North Carolina had found in Wheeler Peak the oldest living tree in record. Lambert felt a jolt of excitement at the possibility that it was one of his trees. He procured a copy of the journal where the researcher had published his paper and his heart sank when he understood that the tree in question had been destroyed. Understandably, Lambert flew into a rage and wrote an article in a local newspaper. The media and the public went after Currey, accusing him of killing “the oldest living organism in the world.” Overwhelmed, the young man hid in his university and tried to keep a low profile, as scientists will after a clash with the media.
Now, Currey killed (the term may be too strong in its overtones) the oldest living organism known at the time, which does not necessarily mean that Prometheus was the oldest tree in the world. We do not know the age of every tree in existence. There may be others that are even more ancient. It is misleading to call Prometheus the oldest living organism in the world. And exactly what is an individual organism? Many plants reproduce by a kind of natural cloning mechanism consisting in throwing offshoots that are genetically identical to the original plant. The offshoots form a clonal colony. One can argue that the clonal colony is an organism that lives on even if the individual plants die. There is a clonal colony of creosote bushes which we know for certain to be 11,700 years old. In the state of Utah there is a colony of quaking aspen trees linked by an enormous root system that has lived for some 80,000 years (though not one of the individual trees is more than a couple of centuries old). Prometheus was the oldest living non-clonal organism known in 1965, not simply the longest-lived being on the planet.
One more detail: Currey found on Wheeler Peak the remains of pines of the same species scattered all over the place. The trees had been cut down without consideration by surveying expeditions in the 19th century. Some of those trees were probably older than Prometheus. Currey was “appalled by the destruction.” This was not contrition enough. In the eyes of the public he remained a heartless murderer.

Two Martyrs
Today bristlecone pines are recognized as useful to science. In 1970 a researcher by the name of D. K. Bailey found variations in the form of the pine cones and needles of bristlecones from different regions. Bailey proposed dividing the species in two: Pinus aristata and Pinus longaeva. Climate chronologies based on the growth rings of this species as well as on pieces of deadwood (dated by radiocarbon) reach almost 9,000 years into the past. The oldest living non-clonal organism known today is one of Schulman’s bristlecones. Named Methuselah, it is 4,844 years old as of 2012 and its location is kept secret.
There is another turn of the screw in the story of Donald Currey and the Prometheus tree. Darwin Lambert, the national park advocate, and his group never could get the US National Park System to approve the recommendation to create a park in the mountains of Nevada. The area’s resources (mining, hunting, pastures) were too rich to give up in the name of tourism and the environment. Powerful lobbies opposed the park. The death of Prometheus gave the project a new edge by focusing attention on the need to protect bristlecone pines. Currey’s error contributed at least a little to tilt the balance and finally, in 1986, the Great Basin National Park was created.
Donald Currey endured as best he could the grief that his mistake caused him. At the time of his death, in 2004, he still was not over it. As for Prometheus, all that remains of the once proud ancient is an inglorious stump.

Saturday, June 16, 2012

Found!

You are locked in. Outwardly, you are dead -no movement, no reactions, no emotions, just bodily functions driven by machinery.
    But you are conscious, only there is no way you can tell the world. You listen to conversations around you -it's an election year, it appears-, you agree, you disagree, you strongly disagree.
   You know your family is grieving. You'd like to let them know you are there, but you are locked in, as if in a different plane of existence, in a parallel universe.
   One day one of the voices you spend your life listening to to pass the...time?... addresses you.
   "Can you  hear me?" it says, incongruously. The owner of the voice knows that, whatever the answer is, you will not answer. However, it is clear that the owner of the voice thinks that the answer is yes.
   The voice says something odd.
    "Imagine you are playing tennis."
    You do. You have never played, but you have no trouble imagining the sequence of movements needed to hit the ball. You imagine the sun on your face while you're at it and just for the heck of it.
    "Now imagine you are walking around your house. Show us around."
    You go upstairs to your room. "This is my room," you'd say. Then down to the yard.
    Elation in the other universe.
    They make you repeat the tasks. It has been so long since anyone last asked you to do things. Your family talks to you, but they never ask you to perform tasks. They do not really believe you can hear them. Now someone is requiring you, the locked-up patient, to actually do things. How do they know you are responding? You tell yourself they probably have you in some kind of brain scanning machine.
    You wait for more instructions, but the voice just wants you to perform these two tasks over and over. Might you be dreaming? What does dreaming mean in your universe?
    Then you understand.
    "I'm going to ask you some questions", the voice says. "I want you to imagine you're playing tennis if the answer is yes and imagine you're walking around your house if the answer is no, ok?"
    Clever, you think (how does that thought show on the brain scanner?)
    "Is your father's name Thomas?"
    You go around your house.
    No.
    "Is it Alexander?"
    Tennis. Yes!
    "Do you have brothers?"
    Whack! You hit the tennis ball with all your might and mark a point. Yes! Yes!
    "Do you have sisters?"
    A quiet walk from the yard to the living room. You don't have sisters.
   "That is correct," says the voice, barely containing its elation after several more questions. You are elated too.
    They have found you.
    Time passes, you don't know how much. Time means little to you in your locked-up universe. The voice comes back. You can sense the hesitation when it says:
    "This is something your family wants to know. I don't know how else to put it. Should we discontinue life support?"


Wednesday, July 28, 2010

Two Musicians

Watch this video of two musicians playing a two-violin arrangement of Mozart's sonata in C major K 296. They reach for their instruments, grab their arches. One look and they're off --the voices of the instruments mingle, each answering the other. One suggests a new direction, the other takes the challenge and ups the ante, and down the new path they go, frolicking in the cascades of sound. Together they weave a web of pure, exhilarating structure. The mathematics of Mozart!


One of these players is a professional violinist, the other a particle physicist. Can you tell which is which? How can you tell?


Friday, July 2, 2010

Venus, a "Pulquería", and an Observatory

People strolling around downtown Mexico City in 1875 might have come across countless “pulquerías” with odd names (pulque is a beverage made from the fermented sap of the maguey plant, Wikipedia dixit). But for weirdness of denomination none beat the latest addition to the long list of hangouts for the brothers in pulque: ”El tránsito de Venus.” The name was no allusion to Roman mythology, but the pulque fraternity´s way of celebrating a major scientific event that took place in 1874.

That was the year a Mexican expedition traveled to Japan to observe the transit of the planet Venus across the sun´s disk. Venus transits occur in pairs, the second transit in a pair coming eight years after the first. Consecutive pairs of transits happen at intervals of more than one hundred years. The transit of 1874 was the first in a pair, the previous one having taken place on June 3, 1769.

Venus transits are interesting because they allow scientists to measure “solar parallax” --a quantity from which the earth-sun distance can be accurately computed. The Mexican team was part of an international effort to determine solar parallax. Enthusiastic about the project, President Sebastián Lerdo de Tejada chose Francisco Díaz Covarrubias, a geographer from the Colegio de Minería, as head of the expedition. There were, at the time, no secure roads between Mexico City and the Pacific, so Díaz Covarrubias and his team took a train to Veracruz, stopping in Orizaba for several days after learning that an epidemic of black vomit was ravaging the port. From Veracruz they traveled to Havana and Philadelphia, then on to New York, where they inquired about ships leaving San Francisco for Japan. (No, I don´t know why they took such a roundabout route.) They then crossed the United States, arrived in San Francisco, and on October 19, sailed aboard the steamer Vasco de Gama. The Mexican expedition made landfall in Yokohama on November 9, 1874, precisely one month before the transit.

Díaz Covarrubias intended to build two observation stations on Japanese soil, but he needed permits. Unfortunately, they had reached Japan at the time of a national holiday, and Díaz Covarrubias had to wait for several days before he got an answer from the Japanese government. During this time he hired a Chinese carpenter who understood some English to assemble the stations. When the government finally responded, it did so handsomely. They even provided a special telegraph line for the Mexicans to communicate with their American and French counterparts, in Kobe and Nagasaki. The transit was duly observed on December 8-9, 1874.

Díaz Covarrubias and his men sailed home via the Indian Ocean, the Red Sea, the Suez canal, the Mediterranean, and Paris, where they published their results. They then crossed the Atlantic to Veracruz. On November 19, 1875, the train carrying the Mexican expedition rolled into the Buenavista station. The men were given a hero’s welcome, recounted the following day in the daily El siglo diecinueve .

I wonder if the event stirred the patrons of “El tránsito de Venus.” Did they discuss it? Did the pulquería take pride in making the news that day? Did a chorus of pulque-besotted voices toast the men who had sailed around the world to witness the event celebrated in their saloon´s strange name?

Whatever the reaction of the pulquería´s clients, the following year Porfirio Díaz, the new president (and future dictator), signed a decree whereby Mexico was officially given a National Observatory.

Monday, April 12, 2010

A Message from the Future

I'm strolling leisurely along the darkest corridors of the web in search of nuggets of information for my radio program tomorrow. Newscaster Pedro Ferriz asked me to talk about the Large Hadron Collider, the largest particle accelerator in the world, which has made headlines now for 14 months, since it's opening -and subsequent failure- in September, 2008.

I come across a blog in portuguese (from Portugal? from Brazil? I'm guessing Brazil...). A post in that blog reports that a few days ago a strange young man was arrested by Swiss police after he tried to sabotage the LHC. Sabotaging the LHC is not easy. The thing lies hundreds of meters underground, and the facilities are protected by heavy security, but the blogger does not go into details. The would-be saboteur may have tried to tamper with the power grid in the region (though I don't know how he might manage even that...). When questioned, the strange-looking young man -who was decked in even stranger-looking clothes- claimed he was a visitor from the future. His mission was to stop the LHC from creating the Higgs boson, a particle expected to appear after protons and antiprotons collide at great speed, sometime between today and 2012. Apparently, if the chronotraveler is not wrong, the Higgs boson will bring forth great destruction ("and gnashing of teeth," one is tempted to add, like in the Bible).

It would be great if we could believe this young man from the future. Indeed, if he is right, that means that the Higgs boson really does exist! The LHC was built to answer that question. Now we can all relax and maybe even break out the champagne.

Or maybe not. Scientists don't plan multibillion-dollar experiments just to be proven right. They will be happy if nature presents them with the Higgs, which was predicted theoretically more than 40 years ago, but what would really give them a champagne-worthy thrill is to be proven wrong. Nothing makes for more exciting times in science than the discovery that everything we thought we knew is not so. If, after 20 years of work on the collider, not to mention the billions of dollars it cost, the thing only tells the scientists they were right, and nothing more, it will actually be a catastrophe. A confirmed prediction is a sort of dead end. No new roads to take, no different outlooks to pursue. No new scientific work to do. Scientists like surprises. And they thrive on challenge. If the Higgs turns out not to exist, the discovery will immediately suggest new paths and it will open wide vistas of possibility. That means a lot of work for a lot of people, young and old. Even Peter Higgs -who is pushing 81- might join in on the action (though he would probably miss his shot at the Nobel Prize).

So, even if the saboteur from the future is correct, we should not stash the LHC in the closet. Let's go looking for new lands. Let's risk being awfully wrong after 40 years. That's what science is about.

Monday, September 21, 2009

Talking the Talk of Science

Common sense, as discussed here some time ago, is a tool we use in everyday life to sort out our surroundings. But it evolved to solve certain problems arising in the everyday experience of cavemen, or hunter-gatherers. Science takes us far from that realm of experience and so, common sense is not to be trusted if one wants to understand the world scientifically.

Scientists have common sense too, but they learn not to rely too much on it.

Speaking of which I am reminded of another tool for everyday life that cannot be applied unchanged to science --language. Languages, like common sense, developed in the “normal” world of everyday experience. Guided by our limited perception, we invented concepts like “light” and “sound,” and gave them special names We created words for everything we could see, hear, or otherwise perceive. We named what we could imagine. But our imagination rarely creates something new. It only puts together existing conceptual elements, however artfully. Our mental constructs are not unlike Frankenstein’s monster.

In the relatively recent past science and technology have revealed that what we call light is only a tiny part of the electromagnetic spectrum, the part that our eyes can see; and what we call sound is only the range of pressure wave frequencies that our ears can detect. We now use these words for light that cannot be seen and sound that cannot be heard. When confronted with new scientific developments, everyday language is forced to either stretch the meaning of extant words, or create new words by agglutination. The term electromagnetic is a case in point. Like the concept it labels, it is the result of putting together “electric” and “magnetic.” Now elektron is Greek for amber. When rubbed with a piece of cloth, amber has the strange property of attracting small objects placed nearby. This property we call electricity. Magnetism is the property of the lodestone, a material also known as magnetite after the ancient Greek city of Magnesia. The word electromagnetic is a Frankenstein monster assembled with parts of other Frankenstein monsters.

There is yet another typical reaction of language to new developments, and that is not to react at all. We have known that the earth spins on its axis these four hundred years. Yet we still say that the sun rises and that the sun sets.

So, not surprisingly, scientific language sometimes clashes with the rules of “good” English (or “good” Spanish). A scientist friend of mine was recently asked by a Spanish teacher to write a short text as an example of scientific language for a book she was writing. My friend complied, and soon got back a “corrected” version (corrupted is more like it) of his text from the teacher. She objected to his use of the phrase “almost constant.” She argued that being constant is not a matter of degree --either you are or you’re not. She is right, of course, but as my friend points out, the meaning of this phrase is self-explanatory, and to say the same thing in pristine Castillian Spanish would require a lengthy circumlocution. Scientists often don’t have time or space for such niceties. (Which is not to say, I hasten to add, that they should not try to write good Spanish or good English whenever possible.)

Tuesday, September 15, 2009

Tempted into Censorship

I remember once doing a reprehensible thing. I remember doing many reprehensible things, but this one is related to my being a scientist and priding myself, perhaps in a self-congratulatory and delusional way, in being a lover of the “truth,” whatever that may mean.

I was browsing around in the science section of a bookstore in Mexico City. The science section of Mexico City bookstores can be quite bewildering because bookstore owners have a very dim idea of what the term “science” means (witness the book department in any Sanborn’s store, where bona fide science consorts promiscuously with astrology, UFO-abductee accounts, and New Age self-help pap.) Next to some physics textbooks I found a little tome. I don´t remember the title or who the author was. I just remember that it was an enraged accusation of physicists and their strange ideas about relativity. The author, obviously a crank, was not comfortable with the notion that someone might know for a fact something he did not understand. A little training in math and physics shows relativity to be a logical necessity despite its weird predictions (which, by the way, are perfectly established by experiment), but this the author did not know and did not bother to find out. Too much trouble. Instead, he just ranted and raved and argued nonsensically against the special theory of relativity --whithout a single equation.

Now, this is what I did: I pushed the little volume all the way back in its shelf, effectively hiding it from view for the rest of time.

Later it dawned on me what I had really done. I had tried to suppress an idea --an act of censorship. Censorship, of course, is what people do who are not sure they are right. Totalitarian states do it, and the Inquisition did it. It is the weapon of the liar and the usurper, the corrupt and the power-hungry. Censorship, as opposed to argument, is contrary to the search for truth. I don´t mean to say that censorship is unheard-of in science, because it most certainly is not. Scientists are human and subject to human passions. But science has an advantage over political or religious systems of belief, where censorship is common --that its criteria for truth or falseness are clear, and shared by most scientists (the criteria include reproducibility of results and consistency of explanations, among others). The best way to challenge ideas is with ideas. My deed, although inspired by the noblest sentiments (as I’m sure the author of the little book is convinced his own deeds are), was reprehensible and childish.

And then again... The author wasn´t there for me to argue with. With the mass media gone over to the cranks, scientists are reduced to guerrilla tactics. We can´t speak out as they can, and most scientists will not upset their schedules to take part in the war effort. What could I do? I was feeling frustrated. (And please don´t go telling me that maybe so were Hitler, Stalin and Torquemada.)