Monday, February 28, 2005

Man's place

According to a recent CBS News/New York Times poll, 55 percent of Americans (67 percent of Republicans, 47 percent of Democrats) believe that God created humans in our present form, presumably as described in Genesis: "And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul." This is up significantly from the last Gallup poll I remember.

I think it was Thomas Huxley who wondered why so many people preferred to be "modified mud rather than modified monkey."

And with that witty zinger from Darwin's bulldog, we'll let the evolution thing rest for a while.

Sunday, February 27, 2005

As April's green endures

For 40 years I walked back and forth each day along The Path from my home in Easton, MA, to my place of work, Stonehill College. And this is the day each year when the first red-winged blackbirds appeared in the trees along Queset Brook. They would haunch forward, lift their wings, and flash their gaudy epaulets. I could set my calendar by the first throaty craaack. The birds know the date as well as I do.

The blackbird's return has been going on for millennia, and will continue far longer than the four score years or so allotted me. A good day then to remember the endless and creative cycle of death and renewal that is the theme of this week's Musing.

Saturday, February 26, 2005

Faint lights

For the next few nights I will be looking for the zodiacal light, a band of faint light reaching up along the band of the zodiac from the western horizon after the Sun has set. It is caused by sunlight reflecting from the swarm of micrometeoroidal particles that dusts the plane of the solar system, orbiting the Sun like a myriad of microscopic planets. (After the planets formed, the cosmic dustmaids didn't do a very good job of tidying up.)

Late February is the best time of the year to see the light, because the ecliptic (plane of the solar system) is steeply inclined to the horizon, lifting the light above the haze. Being in the tropics helps too; the ecliptic doesn't get any steeper than here. And the moon is now rising late enough to have a dark sky for a few hours after sunset.

This island used to be very dark, and I've seen the zodiacal light many times from here. But as the island develops and lights come on, one more of nature's subtle wonders is slipping into invisibility.

Friday, February 25, 2005

What's in a name

My one stalk of corn is as high as a (baby) elephant's eye, and a few little ears are taking shape. I attend its development religiously.

Corn was domesticated in Mexico almost ten thousand years ago, from a large grass of the open woodlands called teosinte. The plant is called maize everywhere except the US, from the name used in the West Indies at the time of Columbus. I have an urge to give my corn plant its own name, but what? We have no tradition of naming individual plants, not even domesticated plants, not in the way we name domesticated animals. Fido doesn't quite work for corn.

Biologically, I am kingdom Animalia, phylum Chordata, class Mammalia, order Primates, family Hominidae, genus Homo, species H. sapiens, to which I eagerly assert my individuality by adding surname Raymo, given name Chet. Corn is Plantae, Anthophyta, Monocotyledonae, Commelinales, Poaceae, Zea, Z. mays, and that's the end of the line. One corn plant is the same as any other.

Here in the Bahamas they take naming seriously. Start with a bunch of syllables -- for "girlbabies," la, de, kera, meka, nique, tika, neisha, essa, and so on -- and combine them in any order. Thus: Dekera, Laneisha, Shakera, Shaquania, ad infinitum, biological nomenclature as various as the individual DNA.

Thursday, February 24, 2005

Making a worm

If you have not already done so, take a look at the little video clip referenced in the Student Activities section of this week's Musing, the one called "Normal Development." Watch a nematode make itself, starting with one cell, ending with 959.

In every one of those 959 cells there are identical copies of the genome, carried on six chromosomes, six little wound-up bundles of DNA, something like 17,800 genes, coded as 100 million paired chemical units of just four kinds along the DNA double helix.

As the DNA spins and weaves, fabricating proteins, it is controlled by its chemical environment; that is, by what has already been fabricated. The earliest cells -- the stem cells -- have the potential to become any other kind of cell. What they become depends upon which genes are expressed at each stage of development. It's a bootstrap process. The worm pulls itself into being.

Here's how geneticist Enrico Coen puts it in his book, The Art of Genes: "The software, the program, is responsible for organizing hardware, the organism. Yet throughout the process, it is the organism in its various stages of development that has to run the program." In other words, the hardware runs the software, while at the same time the software is generating the hardware.

Of course, the metaphor is not quite satisfactory, but then there is nothing in our familiar experienece quite as astonishing as embryogenesis.

Wednesday, February 23, 2005

Re-visioning science and spirituality

In high school in Chattanooga, Tennessee, back in the 50s, I was taught by a remarkable group of Dominican nuns. I remember especially Sister Dominica, tall, sophisticated, intellectual, who taught English literature, and Sister Jane Francis, smart, no-nonsense, insightful, who gave me a lifelong love of math and science.

That world is all gone now. My old high school has a smart new campus and the staff is laic. But Dominican women religious have not gone away. In recent years I have become acquainted with sisters who are showing the kind of theological and ecological leadership one wishes was more common in the Church.

Closest to home are the Kentucky Dominican sisters at Crystal Spring Center for Earth Learning in Plainville, MA, "committed to developing a sustainable bioregionally appropriate way of life that reflects and honors the interconnectedness of all things." Their spirituality reverences the "Hidden Mystery," and takes inspiration from the contemporary scientific understanding of the universe.

It has been my honor to meet Sister Miriam McGillis who lives and works at Genesis Farm in New Jersey. She too takes her inspiration from the scientific story of creation, and embraces "a spirituality that reverences Earth as a primary revelation of the divine."

I have also been in contact with Sister Marie Hofstetter, a Kentucky Dominican who lives in New York, who seeks in her writing to promote "an earth-friendly re-visioning of science and spirituality."

It is inspiring to find people so eager to embrace reliable scientific knowledge of the world, and to draw upon that knowledge for inspiration in their spiritual lives.

Tuesday, February 22, 2005

The synthetic sea

Among the most common flotsam to wash up on our beach here in the Bahamas are plastic milk crates. Modular shelving, I call them. Turned on their sides and stacked against the garage wall, they make a great storage system.

Given the number I have collected, there must be tens of thousands of crates floating around out there. They are a wonderfully versatile invention. Fishermen use them to store their gear or their catch, sailors to store food and equipment. Many apparently get tossed or fall overboard.

Milk crates are the tip of the plastic iceberg. In the North Pacific subtropical gyre -- a Texas-sized high pressure system where circulating currents round up floating debris -- it has been estimated that there are 6 pounds of floating plastic for every pound of organic life. Plastic degrades slowly at sea. Birds, seals, fish ingest the stuff. Even plankton are at risk.

It is sometimes said that we are drowning in a sea of plastic. It turns out that "sea of plastic" is more than a metaphor.

Monday, February 21, 2005

Behe redux

One last response to Michael Behe's NYTimes op-ed essay on Intelligent Design.

He describes "little molecular trucks in the cell to ferry supplies, little outboard motors to push a cell through liquid." Trucks and outboard motors, he infers, require an intelligent designer.

All human knowing is metaphorical. We explain the unfamiliar in terms of the familiar. Thus, the "trucks" and "outboard motors."

Thus, also, fairies, angels, Olympian deities, God the Father, Earth Mother, and Intelligent Designer, all contrived in our own image.

Why this need to drag the Ultimate Mystery down to earth, trick it up in familiar garb, make it walk and quack like a duck? Why not simply admit that there is much about the world that we do not as yet understand, perhaps will never understand, and respond to this knowledge of our ignorance with humility, awe, celebration, praise?

Sunday, February 20, 2005

Honey on the tongue

The hummingbird at the aloe plant. A mockingbird trilling on the roof peak. The brown snake slithers towards the wary gecko. On the stereo a choir sings Beethoven's Ode to Joy. Mouths. The subject of this week's Musing.

Saturday, February 19, 2005

Science and Democracy

The resilience of American democracy is founded on the Enlightenment principles of those men -- Madison, Jefferson, Adams, Franklin, etc. -- who gave shape to our governmental institutions. It is no coincidence that many of these men -- Franklin and Jefferson, notably -- had a scientific temperament. As Jacob Bronowski wrote: "The society of scientists must be a democracy. It can keep alive and grow only by a constant tension between dissent and respect, between independence from the views of others and tolerance for them."

Friday, February 18, 2005

Pi-eyed

I must have been in about the 6th grade when I realized there was something special about mathematics.

I learned the formula for the area of a circle, pi-r-squared. And that was not so special. It seemed reasonable that a circle's area should depend on the "square" of the radius, and of course there would be some proportionality constant.

Then I learned that the area of a sphere was 4 -- exactly 4! -- times the area of a circle of the same radius, and that struck me a truly remarkable. From then on I was a geometry junkie.

As I went on with my education, that little constant pi started showing up everywhere. I remember my Dad, who was a quality control engineer, showing me how to calculate pi by dropping needles onto lined paper. Later 3.14159 threaded its way through my studies of engineering and physics, showing up in the darnedest places.

No one knows why mathematics -- presumably an invention of the human mind-- is so amazingly useful for understanding the world. Einstein said that "the creative principle resides in mathematics." Or is it the other way around?

Thursday, February 17, 2005

The death of death?

The last time I wrote about Ray Kurzweil, famed inventor and futurist, it was to review his 2002 book The Age of Spiritual Machines. In that volume, Kurzweil predicted that by 2019 a $1,000 computer will match the processing power of the human brain. By 2029, people will have personal relationships with conscious machines, he said, and use them as companions, teachers, caretakers, and lovers.

Now Kurzweil is back with a new book, Fantastic Voyage: Live Long Enough to Live Forever, in which he predicts human physical immortality in 20 years. Genetic engineering and nanobot technology will keep the body ticking forever, he claims.

Kurzweil may not be right about immortality, but the curve of scientific knowledge and technological innovation will certainly continue to rise at an ever-increasing rate. By the end of this century, humans will possess powers for self-transformation unlike anything even the futurists dream.

We should be asking now: What is a human self? What, if anything, is the essential difference between an organism and a machine? Are constraints on human curiosity desirable or possible? Is the human species as we know it today the final destiny of cosmic evolution?

The old answers are not good enough, unless we want an unjust and increasingly dangerous world divided into the affluent (and long-lived?) secular few and the poor multitudes who console themselves with fundamentalist faiths.

Dogmatic rigidity, religious or secular, will get us nowhere. In his autobiography, the eminent biologist Erwin Chargaff warned against hubris of any stripe: "A balance that does not tremble cannot weigh. A man who does not tremble cannot live."

Wednesday, February 16, 2005

Making cake

It's Valentine's week, and I've just spent an hour pulling love vine out of the garden.

Love vine is a rampant parasite on this island and throughout the Caribbean. With hardly any chlorophyll of its own, it can't make nutrients from sunlight. It must take sustenance from more self-reliant plants. It sends out tendrils -- thick orange strings -- ten, twenty, thirty feet across the ground. When it finds a healthy plant it latches on and turns itself into a voracious tangled mass, twinning on every leaf and branch, sinking its insidious little papillae into the host and sucking the lifeblood dry.

The biologist David Campbell, who has written the book on Bahamian natural history, says of love vine: "Bahamians and people of the Greater Antilles repute it to be an aphrodisiac, a claim that is so pervasive that one hesitates to discard it as mere untutored belief."

The two bush doctors on the island, Christine Rolle and Joe Romer agree. "The love vine is used for what you call the weak spine," says Christine, using a delightful euphemism. "Some people say that the man they love has a weak spine, so they make sure to dose their man with this potion."

Joe uses euphemism too for his eggy love-vine concoction. "Like egg in the cake," he says. "You can't make a cake without the egg."

Tuesday, February 15, 2005

A hymn to xylem

One of the pleasures of living on an island without a furniture store has been furnishing the house ourselves. Of course, we could have gone to Nassau and had furniture shipped out on the boat -- as we did for mattresses and appliances -- but I've always liked woodworking and M. is a handy seamstress, so together we made a pretty good thing of it.

What a wonderful material is wood. Modern materials science has come up with nothing to compare. Warm, organic, porous, deep. Compliant under the whetted blade -- the plane, the chisel, the saw, the drill. No hardwoods are available on the island, just pine, spruce, and fir. But these are good enough, especially with hand tools. The fir is straight and firm, mostly free of knots, and takes a lovely finish.

The life cycle of non-woody plants extends from seed germination to seed formation, then death. It's all over in a season. Woody plants -- including all conifers -- continue to grow and fruit for many seasons, a slow outward division of cells, leaving behind those dead cells known as xylem, tough and supple, which support the plant and conduct through their collective pipes and pores nutrients and water from root to stem.

No two pieces of wood are the same, each is full of surprises -- a particularly attractive grain, a pesty knot. To work with wood is to engage with the beauty and messiness of life.

Monday, February 14, 2005

From Mars with love


Happy Valentine's Day from Mars!

And now for a commercial break

An appropriate day to mention my newest book, a novel -- Valentine: A Love Story -- just published in Ireland/UK and available from AmazonUK. Many of the themes discussed in ScienceMusings find their way into the novel, which is set in the Roman empire of the late-3rd century.

My Valentine is a physician, a secular humanist in the tradition of Galen and Lucretius, caught up in a world awash in religious fundamentalism, violence and superstition. Julia, his love, the blind daughter of Valentine's Roman jailer, is a Christian, at a time when when Christian martyrdom is a not uncommon fate.

(Why Ireland/UK? I gave the novel to my Irish publisher, Brandon Books, who have published Irish/UK editions of three of my previous books. They will be selling Val in other venues, including, one hopes, the US.)

Sunday, February 13, 2005

A Valentine treat

Looking for love? Try the Personals in this week's Musing.

Saturday, February 12, 2005

Step by step

Science is not the big bang, or plate tectonics, or string theory, or natural selection, or any other scheme by which we seek to understand the world.

Science is a social activity, perfected over the centuries, for establishing reliable consensus knowledge. Scientific theories are partial, tentative, refined in the fire of empirical experience, and subject on occasion to radical change. Perhaps the greatest strength of science is that its methodologies and communications make no reference to the faith, gender, politics, culture, or ethnicity of the contributing scientist.

I trust the collectivity of science more than I trust my own instincts for truth. I remember what Francis Bacon wrote: "What a man would like to be true, he preferentially believes." My faith in science is based on humility, and confidence in a way of knowing honed through the ages by men and women with a keen sense of limitations.

The physicist Heinz Pagels wrote: "Centuries ago, when some people suspended their search for absolute truth and began instead to ask how things worked, modern science was born. Curiously, it was by abandoning the search for absolute truth that science began to make progress, opening the material universe to human exploration."

Friday, February 11, 2005

Earthshine

Two nights ago, Jennifer in California saw the day-old young Moon that Tom and I missed because of clouds -- a few hours older in California than on the east coast, but still wonderfully thin. Last evening the Moon here in the Bahamas was two days old, a silver sliver in a clear tropical sky.

A two day old Moon is ideal for seeing what is called "the old Moon in the young Moon's arms" -- a brilliant crescent, and the rest of the Moon's disk bathed in pale light. The illumination on the "old Moon" is earthshine, sunlight reflected from the Earth -- which appears almost full from the Moon -- then back again. Because of the extra Earth-Moon round trip, the light from the "old Moon" is a few seconds older than the light from the crescent.

Tonight the earthshine will be less obvious because the fatter, brighter crescent will tend to obscure it, and because the Earth will be less full as seen from the Moon.

Also, earthshine on the Moon can vary from month to month depending on how much cloud and ice cover there is on the side of the Earth facing the Moon; clouds and ice reflect more light than sea or land.

Thursday, February 10, 2005

Religio

A story on the BBC web site this morning about the Consortium for the Barcode of Life (CBOL). This international alliance of biologists hopes to sequence a single gene, called cytochrome coxidase I, for as many species as possible. The sequence of chemical units along the DNA double helix will serve as a kind of "barcode" that can then be linked to all other information that has been collected concerning that species.

As I read the story, I was thinking of Steve's beautiful comment of yesterday, the "connectedness" he felt one summer evening on the coast of Maine. For all of its prosaic practicality, the CBOL project is a record of connectedness.

Steve's cytochrome coxidase gene differs from mine by perhaps a single "step" out of 648 on the DNA spiral "staircase." Our sequences differ from a chimpanzee by about 60 "steps." And so on, right through the millions of fruiting twigs on the tree of life.

And here is what's astonishing. An evolutionary tree deduced from the information encoded in this single gene (a tiny snippet of a genome) agrees in almost every particular with the tree of life deduced from anatomical studies by generations of biologists and natural historians.

In her wonder-full book The Sacred Depths of Nature, microbiologist (and non-theist) Ursula Goodenough reminds us that the word religion comes from the Latin religio, to bind together again, and she evokes all of what we share with other creatures, including genes. "We are connected," she writes, "all the way down."

Wednesday, February 09, 2005

Young Moon

A reminder: This evening offers a chance to see a 24 hour-old moon, which is about as new and slim as you are likely to see with the unaided eye. You will need a clear western horizon. Look just above and to the south of where the Sun has just set. The eyelash thin crescent will be scarcely brighter than the darkening sky.

God of the gaps

In Michael Behe's NYTimes op-ed piece that I referred to yesterday, he says: "Unintelligent physical forces like plate tectonics and erosion seem quite sufficient to account for the origin of the Rocky Mountains. Yet they are not enough to explain Mount Rushmore."

True enough. But Behe should keep in mind that not so long ago folks of a creationist stripe thought the Rocky Mountains were an artifact of intelligent design. And he should recall that when Alfred Wegener first proposed that continents move, the idea was rejected by most geologists because they could not imagine any natural force that would shift continents laterally on the surface of the Earth. Now plate tectonics and continental drift are thought of as completely natural, even by Behe.

For some folks, an unexplained mystery is cause for throwing up one's hands and invoking a deity. For others, an unexplained mystery is a riddle to be solved.

Tuesday, February 08, 2005

Endless frontier or the end of the road?

I read two essays yesterday about how life works.

The first was Michael Behe's op-ed piece in the NYTimes (free, but registration required) on Intelligent Design. Behe is one of the small but effective cadre of folks at the Discovery Institute trying to foist stealth creationism on America's public school science classrooms.

Behe's argument is the same as that of the 18th-century theologian William Paley: If I don't understand how it happened it must be magic. It is an attitude towards nature that in two centuries has produced precisely zero useful knowledge of the world.

The second essay is by the grand old man of evolutionary biology, Ernst Mayr, written last year on the occasion of his 100th birthday. Mayr died on February 3.

His story is that of brilliant biologists pushing the empirical method as far as it will go, battling out differences, forging a brash and resilient consensus. This is the kind of science that led to the detailed knowledge of the living cell that Behe quotes as evidence of magic.

Mayr concludes by saying: "Evolutionary biology is an endless frontier and there is still plenty to be discovered. I only regret that I won't be present to enjoy these future developments."

Which essay will be most influential in shaping public opinion? Behe's, of course. It's the difference between eating strained peas and something you have to chew on for a while.

An island mystery -- Part 2

Much to the astonishment of everyone who holds it, the mystery rock floats! It is honeycombed with gas bubbles that give it a density just slightly less than water.

Given the direction of the prevailing winds, I would guess it floated here from the Azores or the Canaries, following Columbus across the Atlantic.

Monday, February 07, 2005

An island mystery

Here's a pic of my friend Felix holding a rock that was at the house when we arrived in December. I assume it was found somewhere nearby by one of my children or grandchildren.

The rock is hard, black, and has a nice heft in the hand. It is unlike any other rock I have seen in the Bahamas. These islands are the highest standing parts of a carbonate bank, made entirely of a soft white limestone.

The rock in Felix's hand is in fact volcanic, although there are no volcanoes here, nor have there ever been. So where did the rock come from and how did it get here? The surprising answer tomorrow.

Sunday, February 06, 2005

The music of what happens

"Prayer...is the soliloquy of a beholding and jubilant soul," wrote Ralph Waldo Emerson. Can a skeptic pray? I consider this question in this week's Musing.

Saturday, February 05, 2005

Meteor mystery -- Part 2

A few days ago, Tom posted comments on an "Astronomy Picture of the Day" which appears to show a corkscrewing meteor. He expresses doubt that a meteor entering the upper atmosphere at high speed might wobble with a lateral amplitude of 75 feet.

Hmm? I don't know. I suppose a rotating object outgassing violently on one side might do something like this. But the fact that the star images in the photo are blurred by the same amplitude (and direction) as the wobble suggests a shaky camera. (Tom, you should work out the frequency of oscillation from the photograph, making reasonable assumptions about altitude and speed, and see if it's consistent with a mechanical vibration.)

What I really like about Tom's post is the way he used Starry Night software to identify the star field in the photograph and, thence, the amplitude of the wobble. Starry Night is a wonderful program that anyone interested in the sky would love. With it, one can view the sky from any place, at any time in the past or future -- including what you will see in the sky this evening.

Friday, February 04, 2005

The fragility of human knowledge

It is difficult for a scientific skeptic like myself to get his mind around the minds of those fundamentalist Christians who seek to subvert the teaching of science in the public schools. It seems simply incomprehensible in this day and age that one might believe the Genesis account of creation to be literally true -- and evolution false.

I am grateful, therefore, to find in Irish writer Dermot Healy's fine novel A Goat's Song a perceptive and not unsympathetic portrait of Jonathan Adams, a salt-of-the-earth Protestant Ulsterman, father of one of the novel's principle characters.

Jonathan is an educated man, and a reader, but he has no time for fiction. "Fiction was the shameful stories prisoners made up to escape prison. It was created to obscure guilt. Fiction for him was irreligious, the act of imagination itself was a door opening onto the void."

Jonathan's reality is Scripture. The stories of the Bible are like a roll call of everything that existed in nature and in himself. Here was solid ground, safety, "simple, exact words" authored by the Creator himself.

There is more, much more, in Healy's book about Jonathan Adams and his culture that is deep, insightful, wise. And so fiction become fact -- and fact fiction.

Thursday, February 03, 2005

Ockham's razor

A reader asks by e-mail why I have not taken note here of the new chemical tests that "prove" the Shroud of Turin, the supposed burial cloth of Jesus, is between 1300 and 3000 years old.

The answer is very simple. I prefer to wait until I read the original scientific paper, and analyses of the paper's content by knowledgeable chemists.

It would, of course, be thrilling if the Shroud turned out to be 2000 years old. That any such artifact survived intact so long would be astonishing and wonderful.

In the meantime, an objective observer should assume that the Shroud is a 14th-century religious icon or outright fraud. That is when the Shroud first appears in the historical record, and that is when carbon-dating assigns its origin. It was a time when religious icons were commonly manufactured or assumed. Why evoke miracles when a perfectly natural explanation is more plausible?

Nearly 400 years ago, Francis Bacon wrote: "What a man would like to be true, he preferentially believes." This is the danger that lurks in every search for truth.

Added Note: Tom points out that Rogers' paper is available here. (PDF file) Thanks, Tom.

Meteor mystery

One of my morning rituals is to check out NASA's Astronomy Picture of the Day. Today's picture shows what appears to be a meteor which has left behind a mysterious spiraling streak of light.

My first reaction to seeing this was "Baloney!" Most meteors or shooting stars are tiny motes of dust which enter the upper atmosphere at high velocity. The glowing streak is the result of super heated air surrounding the speeding particle. It seemed implausible to me that a typical meteoroid could produce a complex sinusoidal corkscrew like that.

Investigating further, I found this article which contains a few key pieces of evidence. The photo was taken by Jimmy Westlake on January 1st, 1986 while he was imaging that year's visitation of Halley's Comet. With that info I could locate the part of the sky the meteor crossed by using my Starry Night sky simulation software. Below is Westlake's original image on the left. On the right is the same field of view as generated by software.

From this you can determine the size of the streak. It turns out to be about 1 arc minute in width, or 1/60th of a degree. Meteoroids typically impact the upper atmosphere at an altitude of 50 miles or more. Straining to remember my high school trigonometry, I did a quick calculation:

sine(1/60˚) x 50 miles = 77 feet

If the meteor is 50 miles high, the apparent width of the wobble is about 77 feet! How could a tiny speck of grit create a spiral so large?

What other explanation could there be? Atmospheric turbulence perhaps? My suspicion is that it wasn't the meteor that was wobbling, but Westlake's telescope was vibrating imperceptibly during the time lapse exposure.

Googling further I found an inconclusive Slashdot discussion on this same subject. One suggestion was that the motor that slews Westlake's homemade telescope has a 60hz hum that spoiled this time lapse photograph in such a curious manner. Hmm...

I hope Chet or any readers out there can share some insight on this. Is it baloney or not?

Wednesday, February 02, 2005

Groundhog Day

Among the pagan Celts of Ireland, the most important festivals seem to have been associated with the solar crossdays, halfway between the equinoxes and solstices. Imbolc, in early February, is the Celtic equivalent of Groundhog Day (today!); Bealtaine is the Celtic Mayday; Lughnasa, near the first of August, is the crossday that has mostly been forgotten, although not in the west of Ireland (it came to international prominence lately in the title of an award-winning play by the Donegal playwright Brian Friel, Dancing at Lughnasa); and Samain, in early November, corresponds to our Halloween, All Saints Day and All Souls Day. `

Little is known of how Imbolc was observed before the coming of Christianity. Days grew noticeably longer, winter's back was broken, and people suffering from claustrophobia and sun deprivation could certainly have used some cheering up. The day is now the feast of Saint Bridgit, an early Irish saint whose story is richly embroidered with pagan associations carried by the Celts on their long migration from Central Europe to the Atlantic fringe.

More of all of this in my latest book, Climbing Brandon: Science and Faith on Ireland's Holy Mountain.

Tuesday, February 01, 2005

Symbiosis

I am harvesting my cherry tomatoes, and at least one pepper is ready for the salad bowl. The beans and zucchinis are still weeks away.

I'm not growing the veggies for nourishment, but for pleasure. Our connection with green things is not only physical, it's aesthetic. And why not? If it weren't for green plants, animals couldn't exist. Green plants are our link to the energy of the sun.

Plants need animals too. They need birds and insects to pollinate their flowers. They need animals to spread their seeds around.

In fact, that's why my plants put so much of their resources into fruits -- tomatoes, peppers, beans, zucchinis. The fruits have no support or nutrition responsibilities to the rest of the plant. They are the tenderest, tastiest part of the plant, designed to be appealing to animals. The reason is entirely selfish on the part of the plant: to entice animals to eat the fruit and carry the indigestible seeds away.