Tuesday, July 5, 2016

As Interesting as Watching Grass Grow

“As interesting as watching grass grow” is a cliché. It is also indicative of the ignorance that most people have of the fascinating world of plants.

Granted, it is not very interesting to watch plants grow in real time. But if their growth is compressed into the time span of human perception, as in the superlative films of Sir David Attenborough, or if you measure their growth over time, you can discover some very interesting things about them. While plants do not have intelligence, they adjust their growth to their environments in ways that look intelligent to us. Plants have to make a living, like everyone else, and their growth patterns allow them to do this. As a seedling grows, its stem may actually do a little circular dance (circumnutation) in search of light. As its leaves expand, their anatomical structure adjusts to the amount of light: thinner leaves with more chlorophyll in shade, thicker leaves with less chlorophyll in bright sun. Meanwhile the roots penetrate the soil and proliferate their growth in patches that are rich in nutrients. Plants have a limited amount of food stored in their cells, and they invest this food in growth that is appropriate to their conditions: they invest more in roots if the soil is dry, and more in leaves if the soil is moist. Plants also prepare for the future, producing next spring’s buds the previous autumn. When the leaves burst open from buds in the spring, you are seeing merely the expansion of tissues that were built the previous year.

Perhaps watching grass grow in real time is not very interesting, but to envision its growth over the course of days and weeks in the real and complex world can be astonishing.


Originally published on http://www.stanleyrice.com in March, 2008.

Sunday, June 26, 2016

Rediscovering Jules Verne


I just finished reading Jules Verne’s Voyage au Centre de la Terre, in French. No, I did not enter it word for word into Google Translate. I’m now quite good at reading French, but still very bad at understanding spoken French and creating my own sentences. I am trying to get used to the abundance of silent letters in French. (For example, the last seven letters of appartiennent are silent.) I will be in France for a couple of weeks, so if I do not post anything for a while in July, that is the reason.

In 1969, I read Twenty Thousand Leagues under the Sea (Vingt Mille Lieues sous les Mers) in English translation. It was the first book I read that was not a little-kid book. It was just the right book for a budding scientist and lover of words. Back then, I thought that good writing consisted of using complex words, many of which (like prodigious, lugubrious, lucubrations, and peregrinations) I learned from Verne. But it was not just a book about science nerds exploring the bottom of the sea (it was that, but more). Captain Nemo (the original man, not the fish) was such a captivating and mysterious character—one who wanted to take revenge against humankind for something, we did not find out what until the sequel (the much less interesting Myserious Island). Verne had a way of putting in exciting endings; in Twenty Thousand Leagues, it was swirling into the maelstrøm in the North Atlantic, and in Journey to the Center of the Earth it was getting spewed out of a volcano in Sicily.


Of course nobody could write a novel today after the fashion of Jules Verne. But he was creating a new kind of novel and was writing the rules for himself. And if he wanted to have a chapter that consisted of scholarly discussion, he could do so. I wish I could do so in my novels, but if I did, nobody would publish it. (Of course, nobody publishes them anyway…)

Verne had some interesting comments about scientists. In chapter XXXVIII of Journey, Professor Liedenbrock, who led the expedition, was normally very heroic and efficient. But when, in the vast underground vault, he and his team found not just a skeleton (ossements) but the actual desiccated corpse of an ape-man, he held it in his arms and knew that he was holding proof not only of human evolution but of a particular theory of human evolution that was being argued among scholars at the time. And the professor, holding the body, gave a lecture as if he were at a meeting of the top scientists of his day. (Liedenbrock also rejoiced in the evidence that the first humans were white. Yes, racism infected scientists, too, but at least we are trying to emerge from it.) This made me realize that we scientists are not merely dispassionate explorers of truth; we are members of a culture, a society, which consists of other scientists, and we feel their admiration or their disapproval very acutely. A scientist at an AAAS plenary session feels more or less like the Speaker of the House or an artist receiving a Grammy. I further realized that we scientists need to make sure that our passion is to open the eyes of non-scientists to the truth about the world, rather than just talking to ourselves and admiring one another.

Verne also shared the optimism of nineteenth-century science. The resources of the world were infinite and just waiting for science and technology to put them to use. “Ainsi se formèrent ces immenses couches de charbon que la consommation de tous les peuples, pendant de longs siècles encore, ne parviendra pas à épuiser” (Thus formed the immense layers of coal which consumption by all people during long centuries will not succeed in exhausting) right up to “la dernière  heure du monde.” We can now see how wrong he was, but he shared the opinion of all scientists at the time.

We scientists do our best to be objective, and in doing so we can experience the thrill of discovery. But we are also members of a social group, with its power plays, and we are also victims of bias. It is easy for us to see the power plays and biases of nineteenth-century scientists. It is harder for us to see our own.

Tuesday, June 21, 2016

A Young Scientist and a Solstice

June 21 is typically considered to be the summer solstice (for some reason this year it was June 20). And 50 years ago on this day, this budding young scientist (age 9) decided he wanted to calculate the latitude of Lindsay, California, where he was growing up.

It was quite simple, really. On this day each year the sun is directly overhead at the Tropic of Cancer, about 23 and a half degrees north latitude. Therefore all I had to do was measure the length of a shadow cast by a vertical stick and do some simple trigonometry, and I was able to calculate how many degrees north of the Tropic we were. In order to get the vertical stick, I used a broken arrow embedded in mud, and used a protractor to make sure it was vertical. I had to do this precisely at midday, of course. I seem to recall my answer was pretty close to the latitude shown on the map.

This was an exciting thing for a nine-year-old boy. It was one of my earliest moments as a scientist. I was putting my faith into action: faith that the universe followed natural laws, and faith that humans could learn truths about the universe by measurement and calculation. This is exactly the kind of faith, and the kind of curiosity, we should encourage in children.


By the way, “solstice” comes from “sol,” the sun, and “stasis,” unmoving. The solstice is the day on which the sun appears to stop moving and reverse its direction, as viewed from the Earth.

Thursday, June 16, 2016

Some more thoughts on Thoreau

Robert Sullivan wrote a book called The Thoreau You Don’t Know. In this book, Sullivan explains that the image that most people have of Henry David Thoreau is wrong. I happened to not learn much from this book, because I got my knowledge of Thoreau from reading introductions to his work written by competent historians, but I’ll bet there are many people who have very inaccurate views of what kind of person Thoreau was and what he did and for whom this book would be quite valuable.

Many people think that Thoreau went to Walden to be out in the wilderness, because he saw human society as something separate from Nature. This image is reinforced by the misquotation often associated with Thoreau, “In wilderness is the salvation of the world.” Thoreau said preservation, not salvation; and he said wildness, not wilderness. He meant, as Sullivan tells us, not wilderness away from man but wildness even within a human landscape. But when Thoreau built his shack near Walden Pond, he was not “in the wild.” The forest was actually an actively-harvested woodlot, harvested not the least by Thoreau’s mentor Ralph Waldo Emerson. In the winter, ice-cutters harvested big blocks of ice. A railroad passed nearby, and railroad workers lived there. Thoreau did not project an attitude of “Just leave me alone already.” He left a second chair by the door of his shack to invite people to come and talk with him. He wrote not just about the wild things he saw, but also about the things he noticed in the railroad cut. When he wrote about his walk to Wachusett, he noted not only the plants and animals but also the gunshots and the “kine” (cattle) that he heard and saw, as they were part of the whole world around him. Thoreau was in favor of preserving some of the woods intact—but sustainably harvesting lumber from the rest. As ecologist Richard Primack points out, Thoreau wanted us to see nature even in a human-dominated landscape. Most days, Thoreau walked into town to visit his family or the Emersons. When he was in New York City, he enjoyed taking walks with Walt Whitman through the streets. He was not alone in a cabin in the woods.

Why, then, did Thoreau go out to Walden Pond and live in a shack for two years? He was conducting an experiment in how to live. What do you really need in order to be happy? A big house? Fancy furniture? In this experiment, Thoreau removed one item of civilized comfort after another; against which the life of a homeowner in Concord was the control. He compared his frugal use of firewood to the enormous amount that Emerson used. That’s why Thoreau kept track, down to the nearest half cent, how much it cost him to do this. And, even though he may not have actually been planning to write a book about his experience, he was thinking continually about publication. In this way, I believe (although Sullivan did not actually say this) you could think of Walden as the equivalent of Colin Beavan’s No Impact Man or A. J. Jacobs’s A Year of Living Biblically: to see if it could be done. At the very least, Thoreau was no misanthrope; his writing is full of humor, and some people today take it far too seriously. Thoreau was the kind of guy who today would hang out his clothes to dry and tell his too-serious environmentalist buddies that he was using a solar-powered clothes dryer. As Sullivan points out, if someone today wonders what kind of car would Thoreau drive, he would probably answer their question with a question: How do you know that your car isn’t driving you? Thoreau’s stuff is sometimes hard to make sense out of—which is perhaps the effect Thoreau intended. To make you think, rather than to give you clear instruction. In wildness is the preservation of the world? What? However you interpret this statement, you will probably be the wiser for the effort.

Sullivan also points out that we should consider that Thoreau’s time was one of social disruption in the United States. During a period of economic prosperity, people thought the banks were the ultimate pragmatic security; but the severe recessions of 1837 and 1857 (which most readers of Thoreau never heard of) disrupted this idea. Thousands of people went west. Thoreau’s friend Horace Greeley said, “Go west, young man!” Why? Because there aren’t any jobs in the east. Sullivan says the Oregon Trail was, in effect, a long unemployment line. When Thoreau said that most people were leading “lives of quiet desperation,” he might have been referring specifically to the fact that they lived from one mortgage payment to the next. Or not. Well, if the purpose of life is not to build a bank account, then what is it? This is what Thoreau wanted to find out. We need to think about this today.


Sunday, June 12, 2016

Henry David Thoreau, the scientist

This is the second essay I am posting about Henry David Thoreau, recycled from my encyclopedias. In this essay, I concentrate on Thoreau’s oft-forgotten contributions as a scientist.

Thoreau was also a scientist, though without formal training. His observations of nature suggested hypotheses to him, which he (however imperfectly) investigated. He was passionate about making observations (for example, the colors of Walden Pond ice and the stages by which it thawed) and measurement (the depths of Walden Pond). Scholars puzzle that his last writings were all mere observations of seed dispersal and spring budburst dates of plants. But his observations were the basis upon which important aspects of ecological science was later based, such as the following:

  • Seed dispersal. In his long essays “The Dispersion of Seeds” and “The Succession of Forest Trees,” Thoreau presented many detailed observations to prove that trees grew only where their seeds had been planted by wind, water, or animals. As unbelievable as it may sound today, some intellectuals (none of them scientists) believed that trees just sprang up from the ground. Thoreau demonstrated that wild cherry trees grew where birds had carried their seeds, and that cherry seeds would not grow unless they had passed through a bird’s digestive system. He tested a hypothesis that mice dispersed hazelnut seeds by microscopically comparing tooth marks on a hazel nut with the teeth of a mouse skull.
  • Forest succession. He also systematically surveyed tree stumps, counting the rings to reconstruct forest history by determining when each tree had begun to grow. He applied his observations to an understanding of the successional processes by which forests changed over time: oaks grew up underneath pines, not underneath oaks, not only because oak forests cast too much shade upon the seedlings and oak leaf litter contained toxins, but also because animals such as squirrels and jays carried acorns preferentially into pine forests. Thoreau also knew about natural disturbances, as well as human disturbances (he noted that Native Americans deliberately set fire to forests).
  • Stochastic processes. Thoreau recognized what scientists today call stochastic processes. Ecological succession is not a deterministic process, always occurring in the same way, but by stochastic chance depended upon which species of plants as a seed source might happen to be near the disturbance.
  • Spatial patterns of plants. Thoreau also studied spatial patterns in plants, noting that species whose seeds were dispersed by wind tended to grow in clumps, while animal-dispersed plants were more evenly spread on the landscape.
  • Seasonal patterns. Thoreau also kept copious notes about the dates on which trees burst their buds in the spring, on which birds migrated, on which the ice thawed, and on which wild fruits matured. Modern scientists, such as botanist A. J. Miller-Rushing, have used Thoreau’s data to document that springtime comes earlier, and winter comes later, in New England today than in Thoreau’s day. Thus Thoreau started the science of phenology, which is the study of seasonal adaptations of the life cycles of plants and animals.

Tuesday, June 7, 2016

Henry David Thoreau, the man

I begin a series of three posts about Henry David Thoreau, adapted from my two encyclopedias. The first is a general biography of this remarkable person, who was an inconvenient man in both his academic and cultural surroundings.  In the second essay, I describe his contributions to modern science (something that is often overlooked). In the third, I share thoughts from a recent biography about him.


Henry David Thoreau is widely revered as a “prophet of environmentalism” because the ideas he wrote and put them into action appear to have been at least a century ahead of their time. He is less often mentioned as one of the leading scientists of early 19th century America. He was an amateur scientist, but laid the groundwork for the ecological study of seed dispersal and ecological succession. He collected data that constitute one of the earliest studies of the adjustment of organisms to changing seasons. His data sets have been used by modern scientists to document climate change that has occurred since his time.

Thoreau went out into a woodlot owned by Emerson (one of the few forest tracts near Concord that had not been cut down) and built a cabin near Walden Pond. The woodlot was not wilderness, but was a second-growth forest, and was less than two miles (a little over two km) from Concord. He started his work on July 4 of that year, intending it as a statement of independence from the pursuit of wealth (which, he said, led most people into “lives of quiet desperation”) just as July 4 marked American independence and just as Concord was the site of the first battle of the Revolutionary War. But he also intended his cabin as an experiment. He kept a journal the rest of his life, some of which he published in the book Walden, or Life in the Woods, which has become the environmental classic of the 19th century. In the journal, and book, he wrote detailed records of how much it cost him to build the cabin, and how he raised or caught much of his own food, going to town only for a few staple food items. He even built the cabin from wood and nails left over from a laborer family’s shanty. He spent only a couple of years in the cabin. He did not intend it as a permanent change in lifestyle, but to demonstrate that it could be done.

Thoreau was also famous for his essay “Resistance to Civil Government,” later known as “On Civil Disobedience,” which was based upon an experience he had in 1846. For six years, he had refused to pay poll taxes because of his opposition to slavery and to the Mexican-American war. Massachusetts had no slaves but profited from goods produced by slaves, and the federal Fugitive Slave Act required all citizens to aid in the capture of slaves who had escaped from the South. He also considered the war to be nothing more than aggression. The Concord tax collector liked Thoreau but was obligated to arrest him. Thoreau was ready to spend a long period of time in jail as a protest, but his aunt paid his taxes and he was released after one night.

Thoreau’s civil disobedience inspired generations of social reformers, such as Russian writer Leo Tolstoy, Indian leader Mahatma Ghandi, and American reformer Martin Luther King, Jr. But his insistence that frugal living (what today would be called “having a small ecological footprint”) is not only possible but enjoyable contributed to his modern reputation as the prophet of environmentalism. Since the most ancient times, prophets have predicted disastrous outcomes to the way most people in their society lived; called for repentance from that way; and themselves lived in a way that was a constant reminder of the way of repentance. This is exactly what Henry David Thoreau did. Like all prophets, Thoreau was an inconvenient man. Though by no means a hermit (he went to town every couple of days even during his cabin phase), he was always separated from the normal crowd: when in town, he observed people as might an anthropologist from another planet. His presence was a prophetic denouncement of materialistic society. Thoreau was particularly vivid (and virtually alone) in his criticism of people who did not take care of their land. Thoreau wrote that Flint’s Pond (also near Concord) was named after an “unclean and stupid” farmer who laid its shores bare, loved a shiny dollar more than a shiny pond, reflecting “his own brazen face,” “regarded even the wild ducks…as trespassers…” “…who never saw it, who never bathed in it, who never loved it, who never protected it, who never spoke a good word for it, nor thanked God that He had made it…who exhausted the land around it…he would carry his God to market…whose fields bear no crops, whose meadows no flowers, whose trees no fruits, but dollars.” Thoreau defended biodiversity against an agricultural mindset that, then as now, reduced a farm or a woodlot to its economic value, and evaluated every plot of land on Earth, however different each was from the other, according to just one scale of value.

The most famous Thoreau quote, which reflects his important insights into the environment and science, was “…in wildness is the preservation of the world,” often misquoted as “wilderness.” To Thoreau, wildness could be found in a well-managed woodlot as easily as in the Maine woods that he visited as a young man.

Thoreau was inspired by the writings of scientists who closely observed the world during their travels, particularly American botanist William Bartram who traveled among the Cherokees of the Appalachians in the late 18th century, and Charles Darwin’s Voyage of the Beagle. Thoreau strongly believed in the complete connectedness of humans and nature (“Am I not partly leaves and vegetable mold myself?”) but did not fully understand it until he read Darwin’s Origin of Species shortly before his death. Previous to this, he had believed, as a transcendentalist, that all of nature reflected spiritual patterns. He was very serious when he observed leaf-like patterns in thawing clay and said that it was the same natural law that produced the shapes of real leaves and also of human internal organs. The Earth had a body, but its organs were on the outside: “What is man but a mass of thawing clay?” When he saw a mouse girdling a pine tree (chewing a ring of bark), he thought it was the Earth’s way of thinning out the pines. Darwin’s Origin of Species undermined Thoreau’s faith, and Thoreau spent his last years making scientific observations with few transcendentalist insights.

Without Ralph Waldo Emerson, there would have been no remembrance of Thoreau. It was Emerson’s woodlot in which Thoreau briefly lived. Emerson popularized Thoreau after the latter’s death. But they were very different. Emerson would write long flowery-tongued passages about things, whether about the world of nature or the breathlessness of love, which he had not closely observed. To Thoreau, nature was a living world from which to learn; to Emerson, it was a canvas upon which to paint his grand ideas. For example, Emerson said that “savage” languages were simple and consisted mostly of nouns. Had he even bothered to ask anyone who had learned Native American languages—and there were plenty in his scholarly circle—he would have known this was wrong. But Thoreau was fascinated by what he could learn from Native Americans. (His last words were “moose” and “Indian.”)

Thoreau caught pneumonia when he was in the woods counting tree rings. He was only 44 years old when he died on May 6, 1862.

Friday, June 3, 2016

New video: Look on the bright side of death

What do scientists do when a catastrophe, such as global warming, is beyond their control? Why, they use it as an opportunity to do research, that's what! See the new Darwin video "Darwin looks on the bright side of death"!