Sunday, February 28, 2010

XA


Anne's Sunday illumination. Click on image to enlarge.

Saturday, February 27, 2010

Dendrites


A piece of coral picked up from the beach, which just happened to be standing next to a plant on the terrace. The one manufactured by animals -- coral polyps. The other from a completely different category of life. They have independently evolved an identical shape of thick trunk and branching limbs. Anchored to earth or seafloor, reaching for the sun.

Dendritic patterns can be found throughout the natural world. The rivulets on the beach on a retreating tide. The mighty Mississippi and its many tributaries. The human nervous system reaching out from the central processor to every extremity of the body. The electrical grid of a power company. The distribution system of the New York Times. Convection cells in the body of the Sun bringing fusion energy from the core to the surface.

Gathering and dispersing.

Is there some abiding philosophical truth embodied in the pattern?

The Greeks called it "the One and the Many." Unity and diversity. The general and the particular. Gathering and dispersing.

Our brains, hearts and lungs communicate with the tips of our fingers and toes. Of what use is a brain without sensory data to process, and how do the sensors work without a constant supply of energy? Our bodies are overlapping meshes of dendrites.

My musing here reaches out in a branching pattern to every one of you, and gathers back your wisdom (at least from those who choose to comment). More. I am like the plant or coral reaching for the sun, and my perimeter does not coincide with my skin. My dendrites reach to the distant galaxies, gathering information, bringing it home, fusing it into a self, and then sending it out again -- well, maybe not to the distant galaxies, but at least to the other side of the globe.

Some of us are trunk people; we are -- by and large -- introverts, contemplative, absorbed in the consolidation of self -- the Cistercian in his cell, the scholar in her ivory tower. Others of us are twig people: extroverts, out and about, insatiably curious about what's over the hill or around the bend -- travelers, Twitterers, political activists.

Gathering and dispersing. Like the universe itself, culture needs both.

Friday, February 26, 2010

Wiggling a finger

Do a little exercise for me. Stick out your arm in front of you. Now wiggle your index finger from side to side. Now bend it back and forth. Now wiggle your pinkie.

"Uh," you say, "what was that all about?"

Think for a minute about what just happened.

Photons from the screen of your computer entered your eyes. They formed images of little squiggles on your retinas and signals were sent to the brain. The brain interpreted the signals as instructions, and sent out electrochemical pulses that were routed specifically to your arm and hand. To muscles specified by the squiggles. That reacted in a certain way. All so fast it seemed instantaneous.

I dare say that for most of human history no one gave any of this a thought, because there was nothing to think about. It just happened. It was part of the self, the spooky inhabitant of the body that was like a -- well, like a spooky inhabitant of the body. It just happened.

Even now, when we know so much about the electrochemistry of neurons, we still don't think about it. Wiggling a finger is a "miracle" of an extraordinary magnitude that we take for granted.

In fact, the more you think about wiggling your finger, the more impossible it seems that all that processing and routing and reaction is just an electrochemical buzz that happens essentially instantaneously. Knowing a little bit about what is happening electrochemically doesn't explain away a mystery; it rubs our noses in mystery. What previously did not register on our consciousness now seems a thing of astonishing grandeur. The wiggling of a finger.

But mystery is not miracle.

Think a bit more about what happened. You clicked on a bookmark. Instantly this post appeared on the screen of your computer, no matter where you are in the world. Pulses of electricity flew through an international maze of routers and servers, packets of data flying hither and yon at almost the speed of light, retrieving something stored on a server even I don't know where, to be assembled on the screen of your computer by the circuitry within.

That vast web of interconnected computers that is the internet is astonishing, but there is nothing miraculous about it. What happens in your body when you wiggle your finger is a system of routers and servers of equal -- or greater -- complexity, and there is nothing miraculous about it.

Oh, I could carry on this theme forever. How did the "internet" that is your nervous system come into existence? It was somehow all programmed into your DNA as a four-letter code, which was expressed in interaction with the environment, assembling -- well, you. And that is the "miracle" of development from a fertilized egg -- which is, of course, another story.

And another behind that.

And another...

Thursday, February 25, 2010

Every place is holy

I have just finished teaching -- gratis -- a creative writing seminar for the island's education center, ten adults and two high-school students, four two-hour sessions. And had a lot of fun. For one assignment, I asked the participants to take an incident from the Old or New Testament, no matter how trivial, and reimagine it in a page or two of rich, descriptive writing. The results were gratifying.

The assignment was suggested by Anita Diamant's wonderful novel The Red Tent, which I have been reading for a second time, a retelling of the biblical story of Jacob and his wives and children from the point of view of Jacob's only daughter, Dinah. The book beautifully evokes the people of 4,000 years ago -- farmers, herdsmen, city builders -- who invented the stories by which we in the Western world -- through the Scriptures and myths -- have pretty much measured our lives ever since. Certainly, on this island, the stories are well known to all.

Allow me to recycle some things I said when I first read the book several years ago?

The gods are everywhere in Diamant's tale. In every tree and stream. In moon, sun, and stars. In menstrual blood and spindle. In the waters that nourish the planted seed and the drought that withers the nanny goat's teats. Dinah learns the stories of the gods in the woman's tent -- the red tent -- as they are told and retold by her mother and aunts.

Jacob and his clan live in constant negotiation with the gods, through prayer and sacrifice. Behind the world of their daily lives is a shadow world of spirits with human faces, or semi-human faces, who act with human willfulness, raising up and striking down, imposing outrageous demands, bestowing blessings.

By Jacob's time the gods were already old. They were born in the minds of our earliest human ancestors, who, finding themselves in an uncertain world, created a measure of order by imagining unseen spirits with human features.

Even today, as a new millennium begins, the ancient gods still haunt our imaginations, investing the world with presumed consciousness and will. This in spite of the fact that science has led us into a very different landscape. What we have discovered in science is not a shadow world of humanlike spirits, but rather an elusive and enigmatic fire that burns in the very stuff of material creation. The fire does not have a human face, but it animates the planet and perhaps the universe.

How do we come to terms with this new knowledge? In Diamant's novel, Jacob decides to return to the land of his ancestors, from which he has lived (and married) in exile. His wives are fearful. Zilpah says to the other women: "All of [our] named gods abide here. This is the place where we are known, where we know how to serve. It will be death to leave. I know it."

And Bilhah answers: "Every place has its holy names, its trees and high places. There will be gods where we go."

We are no less fearful than were Jacob's wives of leaving the familiar. But, as Bilhah says, every place has its sacred meaning, every place is holy. Whatever Mystery we meet in the land of the galaxies and DNA will not greet us with a human face, but, if we are receptive, it cannot fail to drop us to our knees with awe and reverence, fear and trembling, thanksgiving and praise.

Wednesday, February 24, 2010

Wooing the world

...Thisby knows

so little of the world
as yet: the bit

she can see through the
chink in the wall

has made her heart beat
faster in its cage...
A few lines from a poem of Linda Gregerson. Never mind the context; the image is arresting. Beautiful Thisbe is confined by her parents' to her high-walled house in Babylon, with only a crack in the wall through which to communicate with her forbidden lover. And, of course -- as so many parents discover -- the restriction makes her passion all the more intense.

We look out at the universe through a metaphorical chink in the wall. We are prisoners of our limited sensory apparatus, our finite brains. Slowly we have widened the chink -- just think of the Hubble photographs compared to what Ovid, say, knew of the world. But the wider chink has only made us more aware of the limits of our knowing, heightened our curiosity, excited our passion -- made our hearts beat faster in their cages.

We put our lips to the chink, we whisper prayers, not knowing to whom or what we pray, imagining a lover whose remembered image grows ever more indistinct even as our passion grows.

If it were possible, would we want to have the walls down, to have full access to what the physicist Stephen Hawking whimsically called "the mind of God" -- a full and complete knowledge of everything that is? Not me. Woo prolonged is woo sustained. Remember what happened to Thisbe and Pyramus, and for that matter to Eve and Adam when they ate of the Tree of Knowledge. The ancient myths tell a great truth: the tease is more exciting than the consummation.

Tuesday, February 23, 2010

Discomfort and ignorance

Vaclav Havel, the Czech poet, playwright, and statesman, famously said: "Modern science...abolishes as mere fiction the innermost foundations of the natural world: it kills God and takes his place on the vacant throne so henceforth it would be science that would hold the order of being in its hand as its sole legitimate guardian and so be the legitimate arbiter of all relevant truth." He was, of course, chiding what he perceived to be the overweening hubris of scientists.

His remark has been much quoted in an approving way. Mistrust, even fear, of science is rampant. The reason, I think, is clear. Scientific knowledge threatens some of our most cherished notions, in particular the existence of a personal (i.e. humanlike) divinity who minds attentively each and every human life, and, perhaps even more fundamentally, the immortality of self.

The universe revealed by science is not measured on the human scale of space or time. The cozy cosmic egg of our ancestors, with us at the center as the measure of all things has been shown to be a delusion. As D. H. Lawrence sourly opined: "Science has killed the sun, making it a ball of gas with spots."

Add to this the fact that science is complex, difficult and counterintuitive and it's no wonder that it sends a chill up so many spines.

There are two possible responses. The most popular is to simply put science out of mind -- while accepting, of course, the economic, medical and technological benefits science provides -- and go on believing the comfortable myths of our ancestors. The less popular response is to embrace the universe of the DNA and the galaxies, and learn to live with some measure of disillusion. As the biologist Lewis Wolpert has said, "Scientific knowledge and method may be uncomfortable, but [it} is surely better than ignorance."

Science may have toppled God from his throne, but it doesn't take God's place. Science tell us nothing about how to live a good and fulfilling life. For that, we will always need artists and poets, activists and contemplatives, ethicists and saints. But whatever lives we create for ourselves, it would seem advantageous to build them on the foundation of the most reliable knowledge we have of this world, even if that knowledge is tentative and discomfiting. The staggering success of scientific method speaks volumes in its favor where it comes into conflict with the consoling balm of traditional lore.

Monday, February 22, 2010

One of my earliest memories is of an angel

When I was a toddler, a picture of an angel hung on the wall above my bed, a beautiful winged creature guiding a boy and girl across a rickety footbridge. It was, of course, a Guardian Angel, and (according to my parents) each of us had one. Before I went to sleep at night I always said the traditional prayer that begins "Angel of God, my guardian dear..."

It is a consoling idea, that one of the heavenly choir is assigned to each of us, to guide us safely across the rickety bridges of life and watch over us as we sleep. My own Guardian Angel hovered solicitously at my side until about the time I went off to school by myself, slipped from consciousness at adolescence, and vanished completely as I began the study of science.

Angels and empiricism didn't mix.

Still, various polls show that between 55 and 70 percent of American's believe in angels. How is it possible that in the early 21st century so many well-educated people believe in now-you-see-them-now-you-don't humanoid creatures with wings?

Angels are symptomatic of our culture's split personality. On the one hand, we are scientific. Our technology, our economic well-being, our long lives and generally good health -- and perhaps even our political freedoms -- are based on science, and on a scientific attitude that values skepticism, the evidence of the senses, and the rejection of supernatural agencies.

Another part of our culture is skeptical about science, distrustful of reductionism, nostalgic for a world animated by spirits, and possessive of the notion that each of us has a direct line to whatever force or forces rule the universe.

We accept science for the material benefits it contrives on our behalf, but we distrust the materialist philosophy of scientists, preferring to give our attention to anyone claiming commerce with spirits.

We turn to science to remedy our ills, but we are quick to blame science for our misfortunes. We put confidence in the scientific method, but reject the naturalistic philosophy that explains why the method works. In our schools we teach kids biology, chemistry and physics, and in our homes we promote astrology, creationism, health fads, and parapsychology.

No wonder we stumble so uncertainly across the rickety footbridge that leads to the future. Our philosophical compass swings wildly from north to south, lacking any consistent pole to give us a reliable bearing.

And now, having said all that, I offer you Caravaggio's guardian angel (see here and here). Wouldn't you love to have him as your footbridge companion, following you around with his violin, tousled locks and naughty black wings?

Sunday, February 21, 2010

xa


A Sunday illumination from Anne. For those who are new here, Anne is my sister, who lives in a sweet adobe casa on a mesa in New Mexico -- the art yin to my science yang. Call her pics, if you want, Art Musings. Click on the pic to enlarge, and again. The originals are in high definition. I wish we could see them that way here.

Saturday, February 20, 2010

Yet

I mentioned here several times recently Ursula Goodenough's The Sacred Depths of Nature. I just noticed a line in the book that I underlined when I first read it a dozen years ago: "It's all very complicated."

It's in the chapter on Sexuality, and we all know that sex is complicated. However, the same sentence might have been in any other chapter of the book -- Origins of Life, say, or Awareness, or Emotions and Meaning, or Multicellularity and Death. It's all very complicated, and the more we learn about it all, the more complicated it gets. And anyone who tells you otherwise is whistling up the wind.

Which is why I'm always baffled by those folks who think they have it figured out. Who believe everything they need to know has already been written down in a book -- the Bible, say, or the Koran. Or who just trudge through life without an ounce of curiosity about what's underfoot, or overhead, or inside. "Oh, that's just a ladybug," they'll say. As if a ladybug weren't a little six-legged package of mystery we could ponder for a lifetime without getting to the bottom of it. And, of course, some people do ponder it for a lifetime -- ladybugologists we'll call them.

Which brings me, as usual, to religious naturalism. Which is a kind of agnosticism. A willingness to say "I don't know, it's all very complicated." Where did the universe come from? "I don't know, it's all very complicated." Why are the laws of nature what they are? "I don't know, it's all very complicated." How did life begin? "I don't know, it's all very complicated." What is self-awareness? "I don't know, it's all very complicated." What is the meaning of it all? "I don't know, it's all very complicated."

We are naturalists in that we don't populate the picture with imaginary anthropomorphic spirits who intervene at will in the course of events. We are religious in that we respond to the world with awe, reverence, and gratitude. To whom or what are we grateful? "I don't know, it's all very complicated."

Friday, February 19, 2010

BioBricks

The New York Times Magazine last week had an article on the International Genetically Engineered Machine Competition (iGEM), held each year at MIT in Cambridge, Massachusetts. Teams of students from all over the world vie for temporary possession of the grand trophy, a large aluminum Lego. Their entries? Bioengineered life forms -- jiggered bacteria, mostly -- that have had their DNA modified to perform some useful activity -- make drugs, synthesize fuel, generate electricity, clean up pollution, and so on. In the process, iGEM is compiling lending libraries of "BioBricks," snippets of DNA that code for different cellular functions. In the somewhat facetious words of Drew Endy, an iGEM founder, you can make a bookcase by cutting down a tree, turn it into lumber, saw it up, plane it, and nail it together, or you can program the DNA in a tree so that it grows into a bookcase.

DNA as a Lego set! I saw this coming back in the year 2000 when I wrote the following tongue-in-cheek fake news story as my Boston Globe Science Musing (which I reproduced here in 2006). I was pretty much on schedule in my predictions. The regulatory and ethical issues remain unresolved. As the NYT Magazine story makes clear, the field of synthetic biology has all the energy, free-spiritedness and wild frontiers that characterized the early days of the internet.

**********************************************

June 11, 2012. Hasbro-Mattel, the toy division of Monsanto Universal, today announced a product that will likely be found under many a Christmas tree later this year: The Little Creator Bioconstruction Set.

It's not cheap, but this spiffy kit lets kids create microbes that they design themselves -- living organisms, unlike any that exist in nature. "The day of Tinker Toys and Erector sets is past," said a spokesperson for Hasbro-Mattel. "No more static or even motorized constructions. With the Little Creator Bioconstruction Set a kid can build things that metabolize, interact with the environment, move about, reproduce."

For the moment, this means one-celled organisms that must be observed under a microscope, but the company promises multicelled creatures within a few years.

The present kit contains an assortment of 600 genes -- the minimum necessary for life, plus enough extras to add variety. With the included apparatus, children can string these genes together into a genome of their own choosing, then insert the genome into an organism of their choice.

The number of possible arrangements is staggering. Not even the toy's manufacturer can predict what sorts of creatures might emerge from the apparatus.

"One exciting part of play will be naming the organisms a child creates," said the company spokesperson. "That privilege belongs to the child alone."

The Little Creator Bioconstruction Set had its origin in scientific research done at the Institute for Genomic Research in Maryland around the turn of the millennium. Scientists at the institute set out to determine the minimum gene set necessary for life.

They started with the free-living organism that had the smallest known number or genes, the bacterium Mycoplasma genitalium, a harmless inhabitant of the human genital tract and lungs. The bacterium has just 480 genes, compared to more than 30,000 in a human.

One by one, the scientists inactivated genes along M. genitalium's single chromosome, to find out which genes the tiny organism couldn't do without. They finally zeroed in on about 300 genes that are essential for viability. These are among the 600 genes included in the Little Creator Bioconstruction Set.

Still, a chromosome construction toy was not possible until the technology of gene splicing and manipulation became sufficiently inexpensive. The Hasbro-Mattel technology uses specially-designed silicon chips to facilitate the selection and splicing of DNA strands.

"Kids today are too sophisticated to accept a goldfish or a hamster as a pet," said the Hasbro-Mattel spokesperson. "They want life forms they have designed themselves, and the Little Creator Bioconstruction Set lets them do just that."

Asked if the new toy lets children "play God," the spokesperson said: "I would rather say it lets them play Steve Jobs. What we are talking about here is unrestricted innovation, a chance for kids to exercise their human creative potential without impediment or restraint."

Nonetheless, some government officials and academic ethicists are concerned.

When the possibility of creating artificial life from a minimum gene set was first broached in the winter of 1999, scientists and ethicists called for a full public debate of the morality of exercising this technology.

However, before the debate could get properly underway, it was left behind by the rapidly developing technology. By the year 2008, genetic engineering of original and modified organisms was commonplace. It was inevitable that sooner or later these powerful technologies would become the basis of a children's toy.

"What seems bizarre or even frightening to one generation, becomes old hat to the next," says ethicist Pascal Swagger of Pfizer University (formerly Harvard). "The ethical implications of new technologies will need to be assessed more quickly if regulatory agencies hope to have any say in shaping our future. By the time a technology in embedded in a child's toy, it is too late."

What about the possibility that organisms built with the Little Creator Bioconstruction Set will pose an environmental hazard? The Hasbro-Mattel spokesperson said: "We are confident that any microbe assembled from the current gene set will be harmless, and certainly negligible compared to the countless genetically-modified organisms that have been released into the environment during the past decade."

"And besides," he added, "so many naturally-occurring animals and plants have gone extinct due to human technological activities, the world can use a little novelty."

More novelty is in the works. If all goes as planned, within a few years kids will have the ability to design pets they can play with without a microscope. Pink hamsters. Polka-dotted gold fish. Parakeets that glow in the dark. "The time for debate is over," says Pascal Swagger. "The future is here."

Thursday, February 18, 2010

Gravy

Yesterday I mused on why we get old and die. From the point of view of evolution, we only need to live long enough to pass on our genes. Everything else is gravy.

Consider the brown marsupial mouse of Australia, a shrewlike creature that does it and dies with remarkable alacrity.

At the appropriate time of year, biological clocks tell male marsupial mice that it is time to mate. Hormones gush -- not a now-and-then trickle, as in humans, but a sudden spate. Docile juveniles, less than a year old, are forthwith turned into sex-crazed adolescents. Their appetite for sex displaces all other concerns, including food, drink, grooming, sleep, and the avoidance of predators.

After a few frenzied days of non-stop copulation, the haggard male marsupial mice expire - every one of them! - having essentially gone from youth to old age in a flash. Their work is done. The next generation is assured. The females of the species can now manage quite well without them, thank you.

And that, my friends, is the gist of the story from the point of view of natural selection. Humans are programmed for a similar sort of existence, although on a rather more extended schedule -- just ask any adolescent. At which point culture intervenes. With increasing success we manage to take a licking and keep on kicking long past our peak reproductive years, in the meantime finding time for lots of other fun and games, like art, and science, and religion, and -- and meditating on the short, urgent life of the brown marsupial mouse of Australia.

Wednesday, February 17, 2010

Bucking the Hayflick Limit

Ash Wednesday. How we looked forward to this day as children, the day when Lent begins, and the nuns marched us across the yard from school to church where we lined up on our knees at the altar rail and piously dipped our heads while Father Shea marked our foreheads with the ashes of the burnt palms. "Remember man that thou art dust and unto dust thou shalt return," he said, which struck me as a bit of a paradox since we were otherwise made to believe that we would live forever.

No matter. Such theological niceties where not as much on my mind as sweet Carmen who looked so adorable besmirched with her own sign of earthy temporality. We trooped out of church with the badge on our foreheads, a visible sign that we belonged to the One True Faith, going so far as to avoid our foreheads in the bath that evening so that the next day a remnant of the ashes remained.


The paragraphs above are recycled from Ash Wednesday last year. The sweet Carmen of my youth is not (I think) the one who visits here. I wonder where she is today, and if she is still with us. Ashes to ashes, dust to dust. We've had our threescore years and ten. Everything now is gravy.

Why do we get old and die?

Automobile manufacturers would hardly bother to design a machine that will run reliably for 200,000 miles if conditions on the road made it virtually inevitable that the car will be totaled by accident within the first 50,000 miles. Evolution, apparently, takes the same approach. Our bodies are designed to last about as long as our hominid ancestors could expect to survive. Which was not very long at all. Maybe natural selection never bothered eliminating those cellular changes that lead to senescence because almost no one lived long enough to experience senescence.

Advances in technology and agriculture have eliminated the danger of non-human predators and death by starvation. Modern medicine has conquered many of the diseases that used to decimate human populations. Even death by war would appear to be a diminishing threat. Old age is an artifact of human civilization. We get old and die naturally because for most of human prehistory we didn't get old and die naturally.

Tuesday, February 16, 2010

Reading minds

The New York Sunday Times Magazine this week has as its cover story "How Christian Were the Founders?", about the battle going on in the Texas Board of Education over social studies guidelines. Fundamentalist Christians on the Board want the curriculum to stress that America was "intended by God to be a light set on a hill to serve as a beacon of hope and Christian charity to a lost and dying world." Ours is a Christian nation, insist the revisers, intended by the Founding Fathers and the Constitution to be a Christian nation, and all the rest of you Americans -- Jews, Moslems, Hindus, Buddhists, atheists, agnostics, and dozens of other persuasions -- had just better get used to it. Not to mention the original inhabitants of the continent, who had never heard of Christianity, but who where quickly introduced to the "light" or exterminated.

To discern what was in the mind of the founders is a matter for historians to decide, employing their professional skills at unearthing and interpreting written documents and other evidence. The scary thing in all of this is that certain people think they know what is in the mind of the God, and are prepared to dictate that to the rest of us.

I have no quarrel with folks who claim a "personal relationship" with the creator of a hundred billion galaxies -- in fact, if I thought it was true I'd be a little jealous. It's just that the whole idea of knowing the mind of God seems so outrageously presumptuous. I suppose if one imagines that a certain holy book represents the literal thoughts of the Creator, then one can be said to know his thoughts. But which holy book? The Bible? The Koran? The Book of Mormon? They all make equal claim to being divinely inspired.

The U. S. Constitution does not mention God. The Declaration of Independence refers to "the laws of nature and of nature's God," which at least gives us something common to latch onto; after all, we all share the natural world.

A famous story in the history of science has the classical scholar Benjamin Jowett ask the biologist J. B. S. Haldane what he had learned about God from his studies of nature. Haldane answered, "He has an inordinate fondness for beetles." The conversation supposedly took place at high table at Balliol College, Oxford. Never mind that Haldane was born the year before Jowett died. Perhaps it was Haldane's father, a physiologist, or his uncle, later Lord Chancellor, who was questioned by Jowett. Perhaps Jowett wasn't involved at all. Maybe the entire story is an invention. What is not in question is God's fondness for beetles, which constitute one-third of all named animal species and two-fifths of all insects.

Now that is the sort of revelation I can warm to.

Monday, February 15, 2010

Is there Kindle in heaven?

A debate among educators on the New York Times website about whether it's time to get rid of the books in school libraries. It seems in the age of Google and Kindle, the libraries are used less and less. And they are expensive to maintain in a time of tight budgets.

College and university libraries are having the same debate. So far, my own college library hasn't given up on books, but it's the rare student who grazes the stacks where I hang out. Of course, the computer terminals downstairs are fully occupied -- mostly, it seems, by students checking Facebook.

When I started teaching, the college bookstore offered a prize gift-certificate each year to the student who possessed the best personal library on some subject of interest. Those were the days of Steppenwolf, Zen and the Art of Motorcycle Maintenance, On the Road, The Teachings of Don Juan, and other undergraduate classics. Students even read poetry, if you include the likes of Khalil Gibran and e. e. cummings. Not any more (said the old curmugeon). I doubt if there's a student at the college who owns a book you couldn't buy in the local supermarket.

Ah, well. Maybe it's just as well for the libraries to heave the books.

But my whole life has been spent blissfully in libraries, and when I die there will be a pile of real, honest-to-god paper books by my bedside waiting to be read.

Here on the island, my wife volunteers in the high school library. It's a sweet little one-room prefab, with a lovely librarian who has so many other responsibilities she appreciates M's help. Most of the books are donations and range from the sublime to the useless. I build bookshelves as more come in. The older students don't read much, if at all, but the junior-high kids are voracious, especially for the likes of Harry Potter. And the library is there to serve them. Here, at least, books have a tenuous hold on continued existence.


As for the island itself, here is our little public library in Georgetown, under the fig tree across from the straw market. It is only open a few hours each day, staffed by volunteers, and its books too are all donations, many from the boaters who visit the harbor. A mixed bag -- shelves and shelves of supermarket stuff, but some gems too, and after fifteen years I've read my way through most of them. I like to think that one day when all the high school and college libraries have closed, and the big public libraries have digitized their collections and gone out of business, this charming little building will be the world's last holdout for real books.

If the termites don't get them first.

Sunday, February 14, 2010

The glory of love


"Gray is not a popular shade on the internet": A sentence from a recent article in the New York Times Magazine.

Indeed.

Discussion in Comments here is remarkably courteous, but generally the blogosphere is rife with contention. Flame and counter-flame. Bluff and bluster.

Come to think of it, it's not just the internet. In the U.S., at least, public discourse seems ever more shrill. Dueling rants on TV. Discourtesies in Congress. Tea-Party anger. Poor President Obama, whose temperament would appear to be one of moderation, is demonized by the right as a stealth Islamo-Marxist and chastised by the left as a wuss.

Gray is not a popular shade.

A week or so ago, I wrote about Nigerian writer Chinua Achebe's "middle ground", which he calls "the home of doubt and indecision, of make-believe, of playfulness, of the unpredictable, of irony." I suggested that there is truth in the middle ground, but it comes wrapped in hesitation, humility, tolerance, and (let us hope) grace.

On this Valentine's Day, let me reinforce that theme with a song, lyrics by Billy Hill, sung in my favorite rendition by the Five Keys:
You've got to give a little, take a little
And let your poor heart break a little
That's the story of, that's the glory of love

You've got to laugh a little, cry a little
Before the clouds roll by a little
That's the story of, that's the glory of love.

As long as there's the two of us
We've got the world and all its charms
And when the world is through with us
We've got each other's arms.

You've got to win a little, lose a little
And always have the blues a little
That's the story of, that's the glory of love.
(Click to enlarge Anne's Valentine pic.)

Saturday, February 13, 2010

Pitching woo

A week or two ago I wrote about Ursula Goodenough, microbiologist and religious naturalist. As you may have noticed, she came across the post and responded in Comments.

I went to her website at Washington University in St. Louis to see what she is up to these days -- and there saw this microphotograph of two Chlamydomonas reinhardtii gametes mating.

Chlamydomonas is a kind of green alga that swims with two little whiplike tails. Haploid gametes of C. reinhardtii come in two types, called mt(+) and mt(-).

Now I don't want to be cutsie or coy, but there was something tender and sexy about the scene, and maybe I even felt a bit voyeuristic looking in on these unicell lovers engaging in foreplay with their fluttering flagella. Was it just the approach of Valentine's Day that put my heart into the mood to see romance where nothing is at work but chemical reactions? Or is what we call romance among humans itself just a highly evolved embellishment of what these two algae are up to on their bower bed of agar?

Certainly, these two microbes seem to know what they are doing, so intent are they on fusing their genes. Tristan and Isolde. Heloise and Abelard. Romeo and Juliet. But soft, what light through yonder petri dish breaks. It is the east, and mt(-) is the sun.

Or is it mt(+)?

Never mind. Leave them to their dalliance. Tomorrow is Valentine's Day and we have our own entanglements to think about. Presumably, mt(+) and mt(-) find each other with some sort of chemical signal -- a come-hither molecule that binds on a receptor. As Goodenough writes in The Sacred Depths of Nature:
Animals with nervous systems take the behavioral possibilities for sexual attraction to every possible limit. Fireflies pulse, houseflies beat their wings, moths send out musk, fish dance, frogs croon, birds display feathers and song, mammals strut and preen. If this is a planet shimmering with awareness, then a great deal of that awareness is focussed on the sexual signals that creatures send to one another.
Have you bought that box of chocolates?

Friday, February 12, 2010

The devils inside

I know it's unworthy of me, but sometime I wish he would just go away -- Nicholas Kristof with his reports in the New York Times from the war zones of the Congo and Sudan. The gratuitous violence he describes churns the stomach and brings tears to the eyes. One feels helpless, and a little bit guilty. And shamed by those brave souls -- I know several young people, the children of friends -- who take themselves to the killing fields to do something for the victims. I'd just as soon not know -- put my hands over my eyes, plug my ears, seal my lips.

A voice from deep inside wants to disassociate from the violence -- "uncivilized savages," it whispers. And then I remember the oh-so-civilized Roman arenas. And the St. Bartholomew's Day Massacre, in the midst of Europe's Renaissance. And Goya's "Disasters of War," sketched at the height of the Enlightenment. And the men who ran the gas chambers at Treblinka and Auschwitz who went home in the evening and listened to Bach. And the university graduates in the Middle East who strap bombs onto their waists and walk into crowded markets. That disassociating voice goes quiet and another one, from a slightly more luminous part of the brain, asks to what extent an appetite for violence resides in all of us, part of our biological makeup.

No, no, not us. But explain then why grossly violent movies, cable television series, and video games are so popular. Does watching a slasher movie satisfy the same itch that Congolese rebels work out with their machetes? Is a shoot-em-up game controller a sublimated AK-47?

I don't know the answers, but I suspect the human animal, the male especially, has blood on the genes. Perhaps someday we will identify genes that predispose us to violence, perhaps even find ways to ameliorate their effect. At the very least, we can face up to the devils inside and cultivate those cultural conventions that hold them in check. And for that, I suppose I should keep reading Kristof and be grateful for his reporting.

Thursday, February 11, 2010

Chasing beauty

Jupiter is prominent in the western sky at sunset. Mind you, it is not as bright as it can be. It is close to the Sun from our viewpoint, which means it is about as far from the Earth in our respective orbits as it ever gets, way out there beyond the Sun on the other side of the solar system. Still, it outshines anything else in that part of the sky and is easily visible in the twilight.

But Jupiter is moving closer to the Sun (from our perspective, not in actual distance), edging ever deeper into the twilight, setting more quickly after the Sun, becoming more difficult to see.

Meanwhile...

Venus is creeping up from the sunset horizon into the western sky, six times brighter than Jupiter. On February 16 the two planets will be about half a degree apart, a spectacular, snugly conjunction. But alas, so close to the horizon and deep in the twilight they will be difficult to see.

I'm in an ideal place to try. Generally clear skies. A sea horizon. And at this latitude at this time of the year the ecliptic (the plane of the solar system) is almost vertical to the horizon, which will lift the conjoining planets more conveniently into view.

And, to add to the show, on the 16th a crescent Moon will shepherd the planets to their western rest.

So, it's time to start checking it out. We are on the eastern side of a long, thin island. Only a low ridge separates us from the sea in the west. It's a short walk to the ridge, and I was up there last evening. Venus was hurrying after the Sun into the drink, but I didn't see it in the overwhelming twilight, not even with binocs. By the time it got dark enough for Jupiter to wink into visibility, Venus had set. The conjunction will be difficult, if not impossible to see. But I will give it my best try.

Wednesday, February 10, 2010

Starlight musings

It takes about five hours flying time to get from my home in New England to this island in the Bahamas. Light can travel the same distance quicker than a snap of my fingers. In fact, light could make the round trip 100 times in a snap of the fingers. Light travels fast.

Bonfire on the beach last evening under a moonless starry sky, the Milky Way arching overhead, red Mars blazing away in Cancer. Actually, of all the objects in the sky, Mars is the only one that's not blazing. As everyone knows, the light we see from Mars is sunlight. Twelve minutes for light to leap from the Sun to Mars -- a thousand snaps of the fingers, more or less. Then four minutes for reflected light to bounce back to Earth. The sunlight I see from Mars is 16 minutes old.

The closest star in the sky is Sirius -- or at least the closest we saw as we sat on the beach. The light from Sirius is nearly nine years old. So there.

It takes eight minutes for light to get from the Sun to Earth. Five hours to get to Pluto. Think of our solar system as ten light-hours wide, one-half (more or less) of the first day of the year of that calendar hanging on your wall. Go on, get down the calendar and in the box for January 1 draw a circle half as wide as the box. That's the Sun and all of the planets. The next closest star -- Alpha centauri -- is 4.6 light-years away. Four-and-a-half annual calendars cut out in weekly strips and all those strips pasted end to end. Got that? I wonder why I never thought of doing it when I was teaching astronomy. Cutting up and pasting calendars to represent light-time. Rolling it out across the college quadrangle. To really get a sense of how far apart are the stars.

And all those Milky Way stars spilling across the sky! Some of them are a thousand light-years away. A thousand years for light to get from there to here, traveling so fast that it can make 100 round trips between New England and here in the snap of the fingers.

But I'm babbling. And in the time I say "babble," light can travel from here to the Moon.

Tuesday, February 09, 2010

Seeing

I used to pride myself on my ability to see, which is mostly a matter of paying attention. But as my aging eyes have drifted into near and far-sightedness, I find my attention wanders too. Seeing is a cooperative act of eye and brain; one faculty depends upon the other.

Which is why I like to walk the beach with my neighbor Dwight. He has an impressive capacity to see. He'll be walking along, apparently daydreaming, and suddenly draw my attention to a tiny crab scuttling among the seaweed, or the shadow of a stingray drifting fifty feet off shore, or a sea hawk perched at the top of a pine a quarter-mile away. He doesn't miss much. And he does it so effortlessly.

Thoreau was much interested in the art of seeing. He wrote:
I must walk more with free senses. It is as bad to study stars and clouds as flowers and stones. I must let my senses wander as my thoughts, my eyes see without looking. Carlyle said that how to observe was to look, but I say that it is rather to see, and the more you look the less you will observe.
Thoreau has a delicious phrase: "What I need is not to look at all, but a true sauntering of the eye." A sauntering of the eye! That's Dwight as we dawdle along the sand.

Monday, February 08, 2010

Me (and you)

A recent issue of Nature had a special section on "Building a Cell". Here is the editors' introduction. Just scan it, don't worry about comprehension, and then I'll have something to say:
The living cell is a self-organizing, self-replicating, environmentally responsive machine of staggering complexity. The instructions for this complexity are contained within the cell's genetic code, but how this information is accessed, read and interpreted is influenced by development and differentiation.

To divide, a cell needs to create a second set of its genetic material to donate to the daughter cell. The review by Bloom and Joglekar examines how duplicated chromosomes are divided accurately between mother and daughter cells and packaged by proteins, mainly histones, in the nucleus. This packaging regulates gene expression, and Ho and Crabtree discuss how this occurs during development and differentiation. In eukaryotes, protein-coding genes are transcribed into precursor messenger RNAs that contain non-coding regions. As described by Nilsen and Graveley, these non-coding regions must be removed before the RNA can be translated into protein, in a process known as alternative splicing.

The shape, movement and positioning of organelles within the cell depend on dynamic, polymeric cytoskeletal proteins. Fletcher and Mullins analyze the principles that allow these proteins to produce and respond to mechanical forces, as well as to establish order in the cytoplasm over long distances. In a process called endocytosis, portions of the cell membrane are internalized into the cytoplasm. This enables the cell to capture material from the extracellular environment and to respond to cues detected by externally oriented receptors. Scita and Di Fiore discuss the integral role of the endocytic system in the cell's signaling network.
The articles that follow this introduction describe our current understanding of what goes on in every one of the mostly invisibly small 10 trillion cells of our bodies.

Now I know I've written about this before, but I keep coming back to it: The unceasing hive of activity that is our body, every cell like a hugely complex petrochemical factory on full blast, none of which requires the slightest conscious attention from me. Breath. Heartbeat. Digestion. Scratching an itch. The healing of wounds. The maintenance of memories. Dreams. It all happens by autopilot. This huge colony of multiplying, replenishing, differentiated cells which is me. And in it and on it flickering that thing which is self-awareness, the thing I think of as the "real" me, which exists only by the grace of all this other unconscious biochemical activity.

Yes, it all happens without our thinking about it. But it's worth thinking about. It's easy enough to see why our ancestors imagined an immaterial "me" that came into the world full-blown at birth and goes on living after death. They had no clue of the frenetic machinery of life, the buzz of self-sustenance that goes on in every cell of our bodies, the tiny furnaces of the lungs, the throbbing pistons of the heart, the ever-ready mousetraps of the immune system, the recycling plant of the gut. And there, at the top of the spine -- the flame on the wick -- a scintillating ball of neurons, firing, recharging, firing, like the constantly regenerative pixels of a television screen that give the illusion of continuity.

And when it all stops, the self goes off like a light.

Sunday, February 07, 2010

Birds of a feather

I spend a shameful amount of time each day watching the hummingbirds and bananaquits forage at our feeders. The bananaquits can't quite fit their beaks into the hummingbird feeder, with its sugar water, so we put granulated sugar out for them. Still, they feel proprietary about the sugar water and do their best to keep the hummingbirds away. Unsuccessfully, of course. The hummingbirds dart and snitch with a velocity the bananaquits can't match. Beating hearts with feathers.

Lovely thing, the feather! An oar for the air. Featherlight. The association with flight is irresistible. But flight may have been an afterthought. It is now generally agreed that birds descended directly from dinosaurs, and feathers appear to have been a dinosaur feature before birds ever left the ground.

If not for flight, then why did feathers evolve? For insulation, perhaps. Or maybe camouflage. Or -- it is Valentine week, after all -- maybe to attract a mate.

In a recent Nature Online, paleontologists from the University of Bristol in the UK and the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing offer the first evidence for coloration in dinosaurs -- fossilized evidence of pigmented feathers in a dinosaur called Sinosauropteryx. And here they are, in an illustration borrowed from Science, two Sinosauropteryx, with white and chestnut striped tails, doing a mating dance.

Why not more striking colors? Why not a Valentine red, for instance? Natural selection works with what it's got, cobbling together new things from bits and pieces of the old. You like my chestnut striped tail, I'll see if I can make it flashier. You have a taste for sugar, I'll bring you candy.

Cobbling together whatever works, and look! The feathers on my forelimbs help me glide as I lope along the ground, escaping a predator. And look! I take to the air.

Saturday, February 06, 2010

Our better angels

I have just finished reading Andrea Levy's Little Island, a novel that won or was shortlisted for many prizes in 2004 -- and which was dramatized on the BBC this past December. Levy was born in Britain to Jamaican parents in 1956. She lives and works in London today. Her novel explores racism in Jamaica, Britain and India during and just after the Second World War, through the lives of two women and two men, black and white, Jamaican and British.

My children, and especially my grandchildren, would scarcely recognize the world she describes. To me, it is intensely familiar. I came of age at the time of her novel, in a thoroughly segregated Chattanooga, Tennessee. Jim Crow ruled. Public toilets, water fountains, lunch counters, restaurants, movie theaters, parks and recreation facilities were separated by race, and woe betide the person who crossed the line.

All that is gone now. Gone in Chattanooga. Gone in Britain. Gone in these Caribbean islands. Which is not to say that latent racism doesn't still exist. But on the whole things have changed enough that we can read Levy's novel and wonder that we were once beholden to so much hate.

What was the nature of the transformation? Did human nature change? Did a fear of the other inbred by millions of years of evolution suddenly vanish? Or was fear of the other suppressed by a cultural upwelling of an innate altruism?

Maybe it wasn't biological at all? Maybe both the racism and its amelioration are driven by cultural imperatives? Maybe we truly discover our better angels as we evolve culturally?

Since I was raised in a racist culture (although not by racist parents) and now count myself without prejudice (I hope), it would seem that self-reflection might provide something of an answer.

I suspect that both fear of the other and solidarity within a group are deeply embedded in our cultural traditions and maybe our DNA. In which case, it is a broadening of "us" that has diminished the "other", probably driven by technology -- radio, television, movies, air travel, the internet.

Then too, I suspect the growing promise of empirical knowledge over faith-based knowledge -- seeing what is there to see, not what we want to see or have been taught to see -- has lessened our beholdenness to the past and to our genes.

Friday, February 05, 2010

Which came first?

Made an omelet last evening. Four eggs cracked into a bowl. Chopped crisp bacon. Tomatoes and chives from the porch. Grated cheese.

Those eggs! Jumbo. Perfect shells, eggshell white. Golden yolks. Twelve ovoids nestled in their styrofoam box. All the way from Gettysburg, Pennsylvania.

Forget for the moment the miracle of refrigerated transportation that connects those thousands of caged layers in Pennsylvania to our little island a thousand miles away. Try to put out of your mind the chickens that laid the eggs -- plop, plop, one a day, like clockwork, day in day out, chickens that spend their short lives turning chicken feed (containing, no doubt, spent chickens) into delicious globes of nutrients. Forget the factory in Gettysburg and focus on the internal production line, devised by nature and fine tuned by human ingenuity.

Begin with that pinhead-sized dot of white we see attached to the yolk, the germ cell that contains the hen's DNA, one of the several thousand germ cells she is born with in her single ovary. The germ starts growing the yolk, the ball of nutrients that would feed the embryonic chick if there were one. The rest of the egg comes along once the ovary releases the yolk into the oviduct. Down it goes, gathering layers along the way, a biological assembly line -- white, membranes, water, shell, cuticle and color. Plop!

Forget all that if you can -- the external and internal assembly lines. Think instead of Julia Child cracking an egg into a white enamel bowl. Meringue. Mayonnaise. Custard. Smooth sauces. Flavor, substance and nutrition to breads, soups, pastas and cakes. Omelets. Or, what the heck. A fried egg sandwich. A hard boiled egg in a lunch box.

No wonder so many ancient thinkers in so many cultures imagined the cosmos as an egg. A construction of concentric shells. That a clucking, flapping, dirt-pecking chicken could come out of a package that begins as an undifferentiated blob was a fertile metaphor for existence itself.

So bon appetit! You can't make an omelet without breaking a few eggs. And as you are wolfing it down, meditate on the mystery of why there is anything at all.

Thursday, February 04, 2010

The middle ground

We grew up with Chinua Achebe, the Nigerian writer. His 1958 book Things Fall Apart was the perceived epitome of African literature, and a promise of a bright cultural future for that continent. Since that time, some bright things have happened -- notably, the end of apartheid in South Africa. But we have also witnessed chaos and atrocity in Rwanda, Congo, Sudan and elsewhere.

Now Achebe has published a collection of essays called (whimsically and ironically) the Education of a British Protected Child, reviewed in last Sunday's NYT Book Review. Apparently, the overarching theme is the colonial legacy in Africa.

According to the reviewer, Achebe's voice, as always, is moderate, eschewing extremes of radicalism or reaction. He occupies what he calls "the middle ground," what he defines as "the home of doubt and indecision, of make-believe, of playfulness, of the unpredictable, of irony."

I suppose there are those who would chastise Achebe for his moderation, who would call him wishy-washy, and urge him to thunderous wrath in the face of manifest injustice. Yet, there he sits, with his sweet, ironic smile, his critical faculties intact and held on a gentle rein.

In a world so fraught with sloganeering from left and right, with anger, self-righteousness and true belief, I am happy to resort to Achebe's place of measured doubt and playfulness, of humor and irony. There is truth in the middle ground, but it comes wrapped in hesitation, humility, tolerance, and (let us hope) grace.

There is a line of dialogue in another novel I read back in 1958. The narrator asks the eponymous Mr. Blue: "Isn't the golden mean the secret of something or other?" "Yes," replies Blue, "mediocrity." At the time, I was ready to agree with Blue, to opt for a muscular religion and politics, to avoid the namby-pamby gray. No more. I'll leave the doctrines of infallibility and placard-wielding indignations to those who have the stomach for them -- and play with Achebe in the artful middle.

Wednesday, February 03, 2010

Right here, right now, this

Whenever anyone asks me to recommend a good book on biology, I always suggest Ursula Goodenough's The Sacred Depths of Nature. In a little over 100 pages, Ursula presents the most lucid and concise survey of the subject I have ever read. Biology, pure and simple.

Of course, there is another part of the book, the "Reflections" at the end of each chapter, where she puts what she has said into the context of religious naturalism. If you are just interested in biology, you can skip that. But I wouldn't. It's the icing on the cake.

Ursula is a first-rate microbiologist. We've had a sometime e-mail relationship (and one lovely breakfast in Harvard Square). The Sacred Depths of Nature is a demonstration that one can be religious without believing in miracles or the existence of a personal God.

Ursula worships with a traditional Presbyterian congregation, singing in the choir, reciting the liturgy and the prayers. I would find it difficult to do that. On those celebratory occasions when I attend a Catholic Mass, I remain silent and sit out Communion. It seems to me that if one recites the Creed, the words should mean what the universal church assumes them to mean. Anything else strikes me as disingenuous.

But I respect Ursula's ability to revel in all forms of traditional religion.
I love traditional religions. Whenever I wander into distinctive churches or mosques or temples, or visit museums of religious art, or hear performances of sacred music, I am enthralled by the beauty and solemnity and power they offer. Once we have our feelings about Nature in place, then I believe hat we can also find important ways to call ourselves Jews, or Muslims, or Taoists, or Hopi, or Hindus, or Christians, or Buddhists. Or some of each. The words in the traditional texts may sound different to us than they did to their authors, but they continue to resonate with our religious selves. We know what they are intended to mean.
Goodenough knows that awe and gratitude in the face of mystery are part of human nature. "Hosannah!" she exclaims; "Not in the highest, but right here, right now, this." Her little book is a splendid manifesto for religious naturalism, and a useful antidote to the stridency of a Dawkins or Hitchens. She exemplifies what William James said about religion: "There must be something solemn, serious and tender about any attitude that we denote religious. If glad, it must not grin or snicker; if sad, it must not scream or curse."

Tuesday, February 02, 2010

Looking for shadows

In the American news this morning you will read about Punxsutawney Phil, the famous Pennsylvania groundhog that will or will not see his shadow when he emerges from his burrow today. If he does, we are in for six more weeks of winter. If it doesn't, we can put away the parkas and welcome spring.

The fat woodchuck is part of a web of solar lore with roots in prehistory. Phil presides at the year's first "cross quarter" day. The fuss that attends his emergence from his burrow is connected to the Sun by more than a shadow.

The story begins 4 1/2 billion years ago in the chaos of the pre-solar nebula from which the solar system was born.

In a corner of the Milky Way Galaxy, a vast cloud of dust and gas began to contract under the influence of gravity. As the cloud got smaller, it spun faster, as an ice skater spins faster as he draws his arms close to his body. As the cloud spun faster, it flattened out, like a mass of spinning pizza dough.

This whirling pancake of dust and gas became our solar system. Most of the material was pulled to the center to form the Sun. Other whirling eddies within the cloud were collected by gravity to become planets. There was considerable chaos within the cloud. When the third planet from the sun settled into place, its spin axis had a tilt of 23 1/2 degrees to the plane of the pancake.

It was the luck of the draw. It might have been 30 degrees. It might have been zero.

If it were zero, no Punxsutawney Phil.

As the Earth revolves in its annual orbit, sometimes the northern hemisphere is tipped towards the Sun, sometimes away. In the first instance, the Sun's rays fall more directly upon the surface and heat it efficiently: our northern summer. In the latter case, the sun's rays shine obliquely and spread their energy more diffusely: winter.

If there had been no tilt, there would be no seasons. Climate, yes -- poles cold, equator hot -- but no seasonal variation. But there was a tilt, and the waxing and waning of the Sun's warmth and light was the central fact of life for our ancestors.

The bonfires of St. John's Eve, June 23rd, which are still lit in some parts of Europe, celebrate the Sun's ascension to its highest point in northern skies. Likewise, the winter solstice, when the Sun stood lowest, was marked with feasts of light to ensure the Sun's return. These ancient rites linger in the Christian feast of Christmas and the Jewish Hanukkah.

The equinoxes, when the Sun is halfway between its extremes of strength and weakness, were celebrated too. The spring equinox retains a place in our calendar through its connection with the Christian feast of Easter, or alternately, as the Ides of March or St. Patrick's Day. Celebrations of the fall equinox have slipped from prominence.

The cross-quarter days, midway between the solstices and equinoxes, are less familiar, but they too figured in ancient rites, and also lurk in our traditions.

The first cross-quarter day should mathematically fall about Feb. 4th or 5th. This became Candlemas Day, Feb. 2nd, in the Christian calendar. An old European rhyme asserts:
If Candlemas be fair and bright,
Come winter, have another flight.
If Candlemas brings clouds and rain,
Go, winter, and come not again.
Some Europeans looked for the shadow of the hedgehog on Candlemas. German immigrants brought the tradition to Pennsylvania and substituted the American woodchuck.

Punxsutawney Phil bears a weight of tradition on his fat, furry shoulders. His contrived appearance may seem inconsequential, a bit of local fun for the folks of Punxsutawney, but it is good that the old traditions live on in secular form to remind us of our common humanity on the tilted third planet from the sun.

(By the way, we celebrate the second cross-quarter day as May Day. The third cross-quarter day, which falls on or about August 7th, was perhaps remembered in the Christian calendar as Lammas, or "loaf-mass," a harvest feast, but it has vanished from our attention. The fourth cross-quarter day remains prominently with us as Halloween.)

Monday, February 01, 2010

Tread softly


It has become something of a habit here to comment on the Astronomy Picture of the Day (APOD), usually to call attention to something not mentioned in the caption. A few days ago it was Kemble's Cascade, an unusual (and accidental) alignment of about twenty stars in the constellation Camelopardalis (the Giraffe), now high in the northern sky in the evening. (Click to enlarge.)

First, note that none of the stars in this view are likely to be seen with the naked eye. There are no stars in the constellation brighter than the 4th magnitude, which means from a typical light-polluted location Camelopardalis is a big blank part of the sky.

But look what a telescope can see in this view which covers about 4 degrees of the sky -- about 8 times the width of the full Moon. What a delicious serving of stars!

The size of the dots on the photograph have nothing to do with the relative size of the stars; at the distance of the stars they are all effectively points of light. Rather, the size of the dots indicates the relative apparent brightness of the stars; how much light soaked into the film while the shutter was open (think of water dripping onto a paper towel). And keep in mind that the apparent brightness of a star is not necessarily an indication of its distance; the intrinsic brightness of stars varies greatly.

But -- it's the colors of the stars that strike me here. Reddish-orange. Yellow. White. Blue. Like a cascade of jewels, or the rainbow of colors in a waterfall's mist.

The celebrated 19th-century British observer William Henry Smyth professed to see stars the color of sardonyx, damson and smalt, which suggests either especially perceptive vision or a vivid imagination. He listed a dozen shades of white, including pearly, lucid, creamy, silvery, and just plain whitely white. Smyth could have had a career as one of those folks who make up names on paint chips.

Smyth's almost exact contemporary, the Russian-German astronomer Wilhelm Struve, used Latin labels to classify star colors: egregie albae, albaesubflavae, aureae, rubrae, caeruleae, virides, purpureae, and even olivaceasubrubicunda, which translates as something like pinkish-olive. I'm not sure I've ever seen a pinkish-olive star, but maybe you can pick one out in the photograph. By the way, the brightest (double) star in the little cluster at left is named for Struve.

The color of stars tells us how hot they are -- red is cool, blue-white is hot. Match up the color of the star to the color of a filament in a clear light bulb and they'll be the same temperature.

Usually we think of stars as uniformly white, but that's because the human eye is not sensitive to color in dim light -- and maybe because we just don't look closely enough. Anyway, as I look at this photograph, I think of lines from Yeats poem "He Wishes for the Cloths of Heaven":
Had I the heavens' embroidered cloths,
Enwrought with golden and silver light,
The blue and the dim and the dark cloths
Of night and light and the half-light,
I would spread the cloths under your feet.
As now I do.