Science Musings

Doing the impossible

2009-01-04T13:14:00.001Z

Yesterday's post on the Crab Nebula was inspired by this recent APOD (Astronomy Picture of the Day) showing the ghostly wisps of X-ray radiation surrounding the nebula. The image was made by the Chandra X-Ray Observatory, in orbit around the Earth.

The story of Chandra is told in a book I reviewed several years ago for the Wilson Quarterly: Revealing the Universe: The Making of the Chandra X-Ray Observatory, by Wallace Tucker and Karen Tucker (Harvard University Press). The book might more appropriately have been called Revealing NASA. There is not much in it of the universe; the narrative ends as the first images are coming in from the $2 billion Chandra, named for the great astrophysicist Subrahmanyan Chandrasekhar, and launched into Earth orbit by the Space Shuttle Columbia in 1999. These images, in which invisible X-rays are rendered in false color, are rather less dramatic than the pictures we are used to seeing from the Hubble Space Telescope. They may be packed with valuable information for astronomers, but the average reader can be forgiven for thinking, "Ho, hum."

Which is not to say that the book is a "ho, hum" read. At the beginning, I was put off by an alphabet soup of acronyms (even Chandra started life as AXAF, "Advanced X-ray Astrophysics Facility"). But as the pace picked up, I was sucked into a thrilling revelation of how NASA works, technically and politically, and how an instrument like Chandra gets built and deployed.

Wallace Tucker and Karen Tucker are ideal guides to Chandra's story, science spokesman and science writer, respectively, for the Smithsonian Astrophysical Observatory, parent institution for Chandra science. They saw much of it happen, and they had access to the key players.

The universe reveals itself in every part of the electromagnetic spectrum, from low-energy radio waves to high-energy X-rays and gamma rays. X-rays are produced by the most violent objects in the universe -- black holes, colliding galaxies, exploding stars -- but they are absorbed by Earth's atmosphere, so much of the fun stuff can only be seen if we heave our instruments hundreds or thousands of miles into the sky.

The short wavelengths of X-rays place extraordinary tolerances on the optics used to focus them. At the time I reviewed the book, Chandra's mirrors were the most perfectly shaped and polished ever produced; perhaps they still are. The fragile mirrors and detectors had to be aligned to within the thickness of a few atoms, placed atop a hugely powerful rocket and blasted it into space. Perhaps never in the history of engineering has there been such an incompatible conjunction of delicacy and power.

In fact, as you read the Tuckers' book, you wonder why the astronomers and NASA managers and technicians ever bothered to try. The number of things that could go wrong was so great that the odds against success seem overwhelming. And that does not include the political gauntlet that any project like Chandra must run to even get to the launch pad.

As I finished the book, I had an even more profound respect for the scientists who conceived the great space observatories and made them happen, and for the amazing technical skills that hide behind the alphabet soup of NASA acronyms. Lots of taxpayer dollars were riding on Chandra's success; lots of careers too were in the balance. Nearly 30 years passed between the first proposal for a large X-ray telescope and final deployment. That's a huge chunk of one's life to devote to a chunk of machinery that may never fly -- and may not work if it does fly.

By the time I got to the "Launch" and "First Light" chapters at the end of the book, I was sitting on the edge of my seat.

(This post is a reshaping of the Wilson Quarterly review.)

Capax Dei

2008-12-28T11:46:00.001Z

I'm just getting around to reading Pope Benedict's brief remarks to the members of the Pontifical Academy of Sciences on the occasion of their Vatican meeting in October on "Scientific Insight into the Evolution of the Universe and of Life." I try to keep abreast of these things because of my enduring affection for the church into which I was born and raised.

On the whole, the pope's remarks are far more sympathetic to the scientific enterprise than what might be expected from Protestant evangelical Christians, Islamic religious authorities, or, for that matter, the Roman Catholic Church of my youth.

He accepts in principle the scientific account of cosmic evolution, while reserving a role for an eternal agent who causes the world to be and who continuously supports evolutionary history. Except for the personal pronoun, which may represent a bit of anthropomorphic overreaching, this is a formulation that even the most empirical scientist might reasonably accept. Benedict calls it "God." The religious naturalist might call it the mystery of why there is something rather than nothing, and why the something is "legible" (the pope's word).

Benedict approvingly refers to Galileo's notion of "the book of nature" whose meaning we "read" according to the different approaches of the sciences. Here he is close in spirit to many modern Catholic theologians -- Thomas Berry, for example -- who see nature as the primary revelation. He also thanks the natural sciences for having "greatly increased our understanding of the uniqueness of humanity's place in the cosmos."

He insists that what makes us different from the other animals is our capax Dei, or yearning for God. A kind of spiritual hunger does seem to be part of our biological nature. He diverges from the spirit of science, however, when he insists that every soul "is created immediately by God -- it is not 'produced' by the parents -- and also that it is immortal." But he also suggests that this notion of the soul invites exploration by modern thought.

Which brings us to the Creed.

A few weeks ago I attended a celebration of the 50th anniversary of ordination to the priesthood of a dear friend. The evening began with Mass, and my friend preached a sermon of such theological subtlety, spirituality and natural grace that I was about to join the audience in Communion. Then the congregation recited the Creed -- born of a virgin, rose from the dead, ascended into Heaven, sits at the right hand of the Father, awaits the resurrection of the dead, etc. -- and I was dumped back in my chair. Does anyone really believe that the Creator of the universe is right handed? And if that's just metaphor, why not the other stuff?

If the book of nature is revelation, how is it that after almost two millennia of reading the book the Creed remains the same? Have we learned nothing? Really, dear friends within the Church, isn't it time to call a new council -- a Second Nicaea, so-to-speak -- to reformulate the Creed in language more consistent with both the substance and spirit of modern thought. An "intelligible," "rational" (the pope's words) order does not require miracles. Surely there is more incitement to awe -- more nourisnment for our capax Dei -- in the Hubble Ultra Deep Field Photograph or the molecular machinery of a single cell than in the miracle-ridden, spirit-haunted world of 4th-century Nicaea.

How about something generously inclusive like this:

We believe in God, the source and animator of heaven and earth, and all that is seen and unseen.

We honor the personhood of Jesus Christ, light of the world, who gave his name and inspiration to the Christian fellowship, and who taught us to love all women and men as we love ourselves. For us he made the ultimate sacrifice, that we might live more freely and graciously.

His spirit lives on, in the mystical body of the Church. Together, in his name, we celebrate the mystery of life, and await the time when his dream of universal peace is fulfilled.

With the water of Baptism we affirm our desire to wash away our sins and live the love he exampled in his life. In remembrance of him, we share together the bread and wine of the Eucharist, and invite all persons of good will, regardless of faith, to join our table.

We commit ourselves for as long as we shall live to the continuance of his message of charity and hope, to provident stewardship of the planet, and to the fulness of life in the terrestrial world to come.

Amen

To a Mouse, on turning up her genetic code with a DNA sequencer

2008-12-21T12:01:00.001Z

(with apologies to Robert Burns)

Wee, sleekit, cow'rin, tim'rous mousie,
Astir within the Christmas housie!
Thy DNA, each A, T, G and C
Has now been tapped
For comparison wi' me,
Thy chromosomes mapped.

I'm truly sorry man's dominion
Has meddled wi' thy isolation
Now's confirm'd the old opinion
Which causes some to startle:
Thou art man's near-like companion
An' fellow-mortal,

There's scarce an aspect of medicine
Or biology for which thy laboratory kin
Hath not proved a blessin' - -
Genetics, pharmacology,
Cancer research, memory an'
Learning, immunology,

To name a few -- thy gift, wee beastie,
For which we truly thank thee.
Now, thy code of life all twisty
Is laid bare, 2.5 billion
Base pairs, even more alike to me
Underneath the skin.

Of genes, we 'ave near equal number,
Thirty thousand, less or more,
And almost all of thine are sim'lar
To my own. But please:
I'm taller than thee, an' smarter,
Tho' we both like cheese.

Seventy million years ago we shared
An ancestor, then our paths diverged.
Thou sought the lowly way, brown
And inconspicuous. But look!
Man's cruel utility has found
Thee out, within thy hidden nook.

O, Mousie, thou art not alone
In proving foresight may be vain;
The best-laid plans o' mice and men
Gang aft agley,
An' leave us nought but grief an' pain,
For promis'd joy.

Still, thou art blest, compared wi' me --
Scamperin' 'neath the Christmas tree.
The present only toucheth thee,
While I must backward cast my eye
An' remember all the presents
I forgot to buy.

Bark us all bow-wows of folly

2008-12-14T12:56:00.002Z

FOLKS, DON'T GET UP FROM YOUR CHAIR. DON'T CLICK THAT REMOTE TO CHANGE THE CHANNEL. THE NEXT ITEM WE ARE OFFERING ON THE SHOP-TILL-YOU-DROP NETWORK WILL CHANGE YOUR LIFE. THIS NEXT ITEM IS SOMETHING ABSOLUTELY EVERYONE OUT THERE WILL ABSOLUTELY WANT TO OWN."

"Mike, this next item is something that our viewers cannot afford not to own."

"You're absolutely right, Cathy. I can't recall any item we have offered that has generated so much interest. Here it is, folks. Our new Shop-Till-You-Drop.com internet shopping software. It's called My Personal Shopper. Let the camera move in here. That's right. Pop this snappy CD-ROM into your computer and you need never again miss a bargain."

"That's right, Mike. My Personal Shopper will do your shopping for you. I know many, many of our viewers hate to fall asleep at night because they are afraid they will miss one of our fabulous special late-night offers. Or they spend the whole day at work wondering what fantastic savings they are missing on the Shop-Till-You-Drop Network. My Personal Shopper will put their minds at ease."

"That's right, Cathy. My Personal Shopper continuously monitors our Shop-Till-You-Drop web site, and our television network too. It will watch for the items you like to buy and make those purchases for you, even if you're asleep or on the job."

"That's right, Mike. When you start up My Personal Shopper for the first time, the program will ask you questions about your lifestyle, your likes and dislikes, your favorite colors, and -- oh, golly -- almost everything. Then it creates for you a virtual self..."

"A virtual self?"

"That's right, Mike, a virtual self that will cruise the Shop-Till-You-Drop web site in a ceaseless, exciting search for sales, deals, discounts, and special promotions on those items you love to own. Twenty-four hours a day, seven days a week. If you wish, the program will surf the World Wide Web looking for a better offer, and if it finds one, we will match it."

"That's unbelievable!"

"It certainly is, Mike. And here's the best part. What would you expect to pay for a program like My Personal Shopper. Two hundred dollars? Three hundred dollars? My Personal Shopper can be yours for only $99.99."

"That's unbelievable. Just $99.99! You know, Cathy, this is a case where technology rises to meet a great American need. Shopping is what makes this country great, and My Personal Shopper will insure that no one need ever again miss one of our unbelievable bargains on, say, a zirconium bracelet or a set of freshly minted coins. Or a set of ginsu knives. Or a VeggieDicer. I mean, this software will pay for itself in no time."

"That is correct, Mike. And the phones are starting to ring off the hooks."

"Remember, folks, if you are on the phones, we'll get to you."

"That's another advantage of My Personal Shopper, Mike. The program will do your shopping for you. Just let it know what is the maximum you wish to spend in, say, a week, and you'll never have to wait on our phone lines again. Those Turkish carpets and collectible samurai swords will arrive at your doorstep without you every having to lift a finger."

"Yes, this is an absolutely phenomenal offer, Cathy. So do not wait, do not hesitate. Pick up that phone right now and get in on this life-changing new technology. In technical terms, Cathy, this is the whole kit and kaboodle."

"You are absolutely correct, Mike. This year Americans will spend $50 billion for online Christmas shopping."

"Wow! $50 billion! That's a lot of moola, Cathy."

"That's right, Mike. And speaking of Christmas, what could more perfectly capture the spirit of Christmas than giving a copy of My Personal Shopper to a friend. Maybe you'll want to send My Personal Shopper to all of your friends. I can't imagine a more welcome Christmas gift."

"I don't think there is any doubt about it, Cathy. Internet shopping is the ghost of Christmas future, if I may coin a phrase. Move over Amazon.com. Move over eBay. The Shop-Till-You-Drop Network and Shop-Till-You-Drop web site will change the way Americans celebrate this most quintessentially American holiday."

"It's technology at it's best, Mike. It just doesn't get any better than this."

"Oh, absolutely. Just listen to those phones ring. These things are flying out the door."

"Mike, there's something else about My Personal Shopper that you forgot to mention. The program has a special feature that lets you to make Shop-Till-You-Drop, Inc. your legal heir. If you die, your estate will be placed in a special account, and your virtual self can go on shopping until the account is depleted, or indefinitely if it spends only the interest. Not even death need interrupt your shopping."

"Golly, Cathy, shopping immortality! What could be more Christmasy than that?"

The power of the paradigm

2008-12-07T11:16:00.003Z

Remember those Disney comics we loved as kids that featured insects living in cozy cottages under the roots? Matchboxes for beds. Bottlecaps for tables. Thimbles for bath tubs. Postage stamps for carpets. Bucky Bug and his girlfriend June tending a garden with hoes made from safety pins and a wheelbarrow made from a pill box, matchsticks and a button. Just like us, only smaller.

Even without the matchboxes, bottlecaps and buttons, real bugs share lots of attributes with humans.

Consider the leafcutter ants of South and Central America.

The ants cultivate fungal gardens in underground chambers. They leave the nest to cut bits of leaves from nearby vegetation. These they carry home, chew into a pulp, and use to manure their crop, a mushroom fungus. The fungus produces "fruits" called gongylidia which the ants eat.

The arrangement works to the advantage of both ant and fungus. The ants scrape away the waxy coating on the leaves which defends the plant against attack by fungi. The fungus digests chemicals in the leaves which are dangerous to ants.

The ants tend their gardens with loving care. When the time comes to start a new colony, a daughter ant queen takes a bit of fungus from the parental garden and uses it to "seed" a new garden in a new nest.

Like all gardeners, the ants must watch for "weeds," in the form of an unwanted fungus that intrudes upon the food crop, possibly by hitchhiking from outside the nest on the bodies of the ants. If not controlled, these interlopers can destroy a garden.

Remarkably, the ants use pesticides to fight the "weeds."

Antibiotic bacteria live on the bodies of the ants, and are used by them to keep garden "weeds" in check. These bacteria belong to the same genus -- Streptomyces -- from which are derived more than half of the antibiotics used by humans. Humans, it seems, are Johnny-come-latelys to the use of pesticides.

Gardening. Manure. Crops. Weeds. Pesticides. It all sounds terribly familiar -- a transposition of the vocabulary of human culture onto insects. In this case the transposition is generally accurate, but sometimes the use of human analogies to describe nonhuman activities can be misleading -- we get the impression of a group of plucky Bucky Bugs striking out willfully to invent a new kind of life, negotiating agreements with fungi, honing their agricultural skills with determined practice, even discovering the miracle powers of Streptomyces to control pests.

But of course planning and foresight have nothing to do with it. Nor does experiential learning on the part of the ants. Even such highly complex behaviors as those of the leafcutter ants, with their crop fungus, weed fungus, and antibiotic, can be accounted for by natural selection acting on random genetic mutations.

In fact, this is exactly the kind of adaptive balance between organisms that one would expect of Darwinian evolution.

Anyone who doubts the power of natural selection to evolve astonishingly complex systems need only wait and see. My guess is that the next 100 years will be the true Darwinian century, as we learn to apply random mutations and artificial selection to Darwinian machines -- hugely complex systems of interacting agents, both animate and inanimate, that will evolve in unanticipated ways to solve problems that cannot be tackled as efficiently in any other way.

Look for artificial intelligence, purpose-made drugs, scientific theories, even artificial life forms inventing themselves by trial and error, with successful systems proliferating in unexpected ways and failures falling by the wayside. Look for webs of living neurons anchored to silicon chips connecting themselves to solve complex problems. Look for DNA-based computers spinning out undreamed-of innovations. Look for robots that program themselves based on their experience.

It's spooky, maybe scary, you or I may not like it, but it will happen. Next year we celebrate the 200th anniversary of Darwin's birth, but we have only begun to harness the Darwinian paradigm for technological purposes, mimicking artificially what nature does naturally. The kinds of adaptive complexity that took the Bucky Bugs millions of years to evolve will pour forth with mind-spinning rapidity from human ingenuity, sweeping us into a novel world that no one alive today can even remotely imagine.

Making color together

2008-11-30T12:40:00.000Z

There is a low mist in the woods. It is a good day to study lichens," wrote Henry David Thoreau in his journal on the last day of 1851.

To tell the truth, any day is a good day to study lichens, as Thoreau would have acknowledged. "I could study a single piece of bark for hours," he wrote elsewhere in his journal. He meant, of course, a piece of bark covered with lichens.

Winter or summer, as other creatures come and go, lichens endure, in their rainbow of colors, their multiplicity of forms, their prodigious capacity to thrive in the least hospitable environments. They colonize gravelly ground, bare rock, concrete walls, tombstones, and nooks and crannies of the planet snubbed by every other creature.

Lichens are nature's graffiti artists, painting every exposed surface with swaths of color.

Some of the most engaging lichens in New England require getting down on hands and knees: British soldiers, pixie cups, reindeer moss (which is not a moss at all), and pink ground lichen (bubble-gum lichen, my students used to call it, nailing the color exactly) -- tiny forests that invite exploration. A magnifier helps. I carry one in my back pack.

To look for lichens is to "go gnawing the rails and rocks," wrote Thoreau. The person who studies lichens grows fat where others starve, he said -- like the lichens themselves.

Unfortunately, there are few guidebooks to help us as we go a-gnawing. My college library has several shelves of books on algae, and more shelves on fungi, but only a few volumes on the combinations of algae and fungi known as lichens. The best book of all is the magnificent Lichens of North America by Irwin Brodo, Sylvia Sharnoff and Stephen Sharnoff, which has got to be one of the most beautiful nature guides ever published. At almost 9 pounds and $88, I am not likely to carry it in my backpack. This is a book to savor in a comfortable chair, preferably with the book resting on a sturdy table.

And what makes the book so savory are the color photographs, more than 800 of them, almost all taken by the Sharnoffs. Who would guess that lowly lichens could be so beautiful? Perhaps only beetles display such a range of colors, and no other class of living things has such a variety of forms.

A lichen is usually referred to as a symbiosis of an alga and a fungus, which means that the two live together for mutual benefit. The alga makes nutrients with sunlight, photosynthesis, which a fungus cannot do. The fungus provides the alga with a steady water supply, protection from excess light, and a chance to live in habitats -- dry rocks, exposed tree bark -- where it could not survive on its own.

But all things considered, it would appear to be the fungus that gets most out of the collaboration. Lichenologist Trevor Goward goes so far as to say that lichens are "fungi that have discovered agriculture." What he means, I suppose, is that lichen fungi have domesticated algae the way we domesticated corn and cattle. After all, humans could not survive without the nutrients produced by plants, or the flesh and fluids of animals that eat plants.

Lichen fungi feed on the algae that they have enticed or trapped into collaboration. They suck nutrients from the algae, sometimes killing them. It is only because alga cells reproduce faster than they are consumed that a lichen can exist at all; otherwise the lichen would "eat itself alive."

If the alga and fungus components of a lichen are cultured separately, they appear pretty much as monochrome goos, lacking the hues and form of the original lichen. It's the fungus's genes that determine the structure of the lichen. The alga somehow turns its partner's genes on or off, but when if comes to the wonderful lichen shapes you see on rock or rail, it's the fungus that's in charge.

As appreciators of beauty, we humans also gain from the lichen symbiosis. The breathtaking photographs in Lichens of North America raise the question: Why the beautiful colors? The hues of flowers attract insects for pollination; the colors of birds attract mates. It is less clear why lichens display such gaudy colors, but, on a misty autumn morning in the woods, those little flecks of pigment -- British-soldier red, bubble-gum pink, bright yellows and oranges -- are welcome.

Thoreau even took home a moral lesson from his lichenizing: "It fits a man to deal with the barrenest and rockiest experience," he wrote. He might have added: Such is the resourcefulness of all life.

A murmur of myrmecology

2008-11-23T12:46:00.003Z

I see in the paper that Bert Holldobler and E. O. Wilson are on the circuit promoting their big new book The Superorganism: The Beauty, Elegance, and Strangeness of Insect Societies. Already the book is stirring up scientific controversy. Just what role do altruistic cooperation, complex communication, and division of labor play in evolution? Does natural selection act on individuals or groups? And what can we learn about evolution (and ourselves) from the lowly ants?

When I used to write for the Boston Globe, I could expect to get a free review copy of a big and expensive book like this. Not any more. I have ordered the book for the college library, with my name first on the reading list. I'm sure you'll be hearing about it later here.

In the meantime, I checked out the book's illustrious predecessor for another look, Holldobler and Wilson's The Ants. Eighteen years ago I reviewed it in my column. I called it "one of those granddaddy books from which a whole clan of lesser books will descend." Seven hundred hefty pages of ant lore. Everything you wanted to know about ants but were afraid to ask. As it turns out, these tiny, endlessly-active pests of picnic and pantry turn out to be irresistibly interesting.

The ants need their Homer, and Holldobler and Wilson have assumed the role. In spite of La Fontaine's best efforts to draw an edifying moral from the ant's industriousness, we tend to prefer the frivolously fiddling grasshopper. Not even Ogden Nash found much to admire in the ant's unceasing busyness: "Would you be calm and placid," he asks, "If you were full of formic acid."

Formic acid, which is widely used in industrial processes, occurs naturally in the bodies of ants and takes its name from the Latin for "ant" (formica). From the Latin root we also have the scientific name of the ant family, Formicidae, and a bunch of other ant words, such as formicary (a nest of ants), formicate (to swarm with ants), and formication (an abnormal sensation of ants crawling over the skin). The very thought of finding oneself on a formicating formicary is enough to make the skin crawl, and that alone may account for our determined efforts to put ants and their habits out of mind. Holldobler and Wilson claim that ants have been neglected by scientists, in spite of their ecological importance, which is considerable. The 700 pages of myrmecological lore in The Ants no doubt did much to remedy the situation. The Superorganism will do more.

The earlier book includes an anatomical atlas of ants from around the world, each drawn at kitten scale. Some have fat heads and some have thin heads. Some are sleek and some are hairy. Some are spiky and some are corrugated. All of them are ugly and, if we are lucky, they will stay in their formicaries. (Admitting, of course, that the most beautiful thing to an ant is another ant.)

The most unlikely thing about ant anatomy is that little threadlike nexus that attaches the back half of the body to the front half. Wasps get the credit for inventing the wasp waist, but ants are equally pinched-in at the middle. Surely that bottleneck must constrict communication between the two halves of the insect, and according to Holldobler and Wilson, a lot goes on in both halves.

Ants are jampacked chemical factories. They employ the most complex system of chemical communication of any animal. Their glands are endlessly active, puffing and squirting secretions for every purpose. When tastes and scents fail, there are other modes of communication -- tappings, strokings, graspings, nudgings, and antennations. Holldobler and Wilson lay it all out in endless detail, an unabridged Webster's of ant gab.

Sometimes ant communication runs dangerously amuck. We are given the example of a group of army ants that was cut off by rain from the main foraging party. The soldiers of the group were so strongly attracted to each other that they formed a "mill," going blindly round and round in each others tracks for a day and a half until all fell dead. One might ask how animals subject to such self-defeating behavior could reach the pinnacle of insect evolution, and maintain their dominance for 50 million years. This is surely the question the new book will try to answer.

So I sit here in the library waiting for The Superorganism with The Ants heavy in my lap and I marvel that we know so much about these creatures that the new book will address in their plurality. The two Harvard entomologists take note of the ant's particular ability to specialize when the need arises. Instead of a single individual performing all parts of a complex task (for example, check a larva, collect food, feed the larva), different workers devote their efforts to a single part of the task (checking, collecting, or feeding). The human analogy is the assembly line where one worker does nothing all day long but put in a particular screw. Apparently, the same mindless efficiency that caused assembly-line mass production to triumph in the human workplace also accounts for the evolutionary success of the ant.

It is a rather un-calm and un-placid kind of success. Which probably explains why those of us with less formic acid and bigger brains prefer to be out fiddling with the grasshopper.

A world made on Sunday

2008-11-16T14:03:00.002Z

A new multi-artist show at the college gallery, called Move Me: Kineticism in Art, brings several of Arthur Ganson's amazing machines to the campus. I've been a huge Ganson fan since I saw exhibits of his work many years ago at the college and the MIT Museum -- devilishly clever, whimsical contraptions that have an almost organic feel about them, which probably derives from their sense of humor. Can a machine have a sense of humor? Why not? Here is a video of one of the works in the show, called "Thinking Chair."

In my book, Ganson is a genius. Some works I have previously encountered:

-- A machine made of pulleys and levers that spends its time scooping machine oil from a pool at its base and pouring it over itself. The oil glides sensuously down over the mechanism, back into the pool. Ahhh!

-- A machine mounted on wheels that you push like a barrow. As it rolls, a cogged mechanism causes an artificial hand to write on a white piece of paper "Faster!" The faster you roll the cart, the more manically the machine scrawls its urgent message. What a hoot! I was in hysterics.

-- A bird cage filled with a delicate wire mechanism that repeatedly tips two of those cylindrical cardboard toys that make animal noises when you turn them over. These tweeted. The title: "Two Cans from the Island of Taiwan."

-- A train of twelve worm gears, each gear driving the next at a fifty-times slower rate. The first motor-driven gear whirls furiously. The last gear is set in concrete. I'm not sure what made this funny, but I laughed uproariously.

It is great to be around machines that make you laugh. We spend most of our days with machines that haven't a funny bone in their bodies, machines that turn us into dour button-pushers. Of course, we shouldn't blame the machines. It's their designers that are humorless, those glum-faced consortiums of engineers that serve us our daily mechanisms.

In 1738, the mechanical wizard Jacques Vaucanson demonstrated his masterpiece before the court of Louis XV, a copper duck that ate, drank, quacked, flapped its wings, splashed about, and, to the astonishment of all, digested its food and excreted the remains. It was a witty beginning for the age of machines. The king's courtiers had a good titter.

Descriptions of Victorian inventions in early editions of Scientific American also suggest a delightful sense of whimsy. Electric jewels. Cuckoo watches. A mustache food-and-drink guard that clips into the nostrils. Advertising projected onto clouds. An electric trolley on tracks that delivers food from the kitchen directly to the diner's place.

The Victorians liked whacky combinations. A hammock mounted on a tricycle that allows the cyclist occasional rest. A camera hat. A rocking chair connected to a cradle and butter churn that employs "hitherto wasted female power" to sooth the baby and make butter while keeping the hands free for "darning, sewing or other light work."

Now that I think about it, maybe it is only in retrospect that we find these things funny. Never mind; Victorian inventors at least understood that machines are our servants rather than the other way round.

Of course, as always, it is the artists who teach us not to take our machines too seriously.

The Dadaist artist Marcel Duchamp saw the humorous possibilities of a bicycle wheel mounted on a stool, or an ordinary urinal turned upside down and titled "Fountain." His masterpiece, a glass construction called "The Bride Stripped Bare by Her Bachelors, Even," although not quite a machine, is full of wires and painted mechanisms. Duchamp found it necessary to invent a new "amusing physics" to describe this last work, including terms like "oscillating density," "uncontrollable weight," and "emancipated metal."

The undisputed master of whimsical machines was the Swiss sculptor Jean Tinguely, who contrived spindly wire devices that thumbed their noses at Swiss order and efficiency. I have not actually seen an animated Tinguely sculpture, which are said to invariably produce laughter as they click, whir and clatter unpredictably, but even photographs of his works produce a smile.

Tinguely's most famous sculpture is called "Homage to New York," a vast white contraption of wheels, motors, pulleys and wires that was designed to destroy itself in the garden of the Museum of Modern Art. The machine balked short of suicide, but caused an uproarious commotion before the fire department arrived to put it out of its misery. Tinguely was delighted with the unexpected outcome.

"For me," said Tinguely, "the machine is above all an instrument that permits me to be poetic. If you respect the machine, if you enter into a game with the machine, then perhaps you can make a truly joyous machine -- by joyous I mean free. That's a marvelous thing, don't you think?"

Yes, I do so think, and so apparently does Arthur Ganson. One of Ganson's creations is titled "Homage to Tinguely's 'Homage a Marcel Duchamp,'" which places Ganson squarely in a poetic, joyous tradition.

Back in 1993, when I first encountered Ganson's work, I asked him what he was up to. He replied that he is not interested in making political statements. "My machines are investigations of thoughts, dreams, and ideas," he said. "They are about invention, about play, about a childlike way of looking at the world. They are about not taking the world too seriously."

I suspect that deep down Ganson takes the world more seriously than do those of us who take ourselves too seriously. Like Jean Tinguely before him, he seems to believe that a spirit of play lies at the heart of creation.

As for that "Thinking Chair" -- apparently there is a big flat rock near Ganson's home where he likes to walk and think. The piece is autobiographical, with the yellow chair taking the place of the artist himself.

Sacred and profane

2008-11-09T12:46:00.000Z

Since my new book was published, I have been asked several times how it is possible to be a "religious naturalist" -- that is, how can one be religious without a belief in the supernatural. Isn't religiosity precisely the human response to that which is other than nature?

To answer the question properly would require a book -- a book of considerably more depth and scholarship than my own, which is the personal account of a journey from supernaturalism without religion (formulaic Catholicism) to religion without supernaturalism (religious naturalism). A proper answer would have to consider homo religiosus in the broadest possible cultural context.

But perhaps the required book has already been written, and it is not such a big book after all, although the scholarship upon which it is based was formidable. I refer to Mircea Eliade's The Scared and the Profane: The Nature of Religion, a classic that was there for me as I began my own religious journey half-a-century ago.

For Eliade, the defining aspect of the religious experience is the awareness of something we perceive in the natural world that transcends the immediately obvious. The religious experience might begin with something as mundane as a stone or a tree, but then comes the hierophany (sacred+reveal) in which one becomes aware of a sacred reality that elevates and subsumes the profane. "For religious man, nature is never only 'natural'," he writes. In moments of hierophany one catches a glimpse of something that collectively embraces both the perceived and the perceiver. Eliade occasionally uses the term "supernatural" for this transcending thing, but he makes clear that natural and supernatural (in his use of the term) are "indissolubly connected." The profane and the sacred are not a dualism, not two different orders of reality, but rather more like the particular and the universal, the immediately present and the dimly perceived whole.

Homo religiosus has given various names to the thing perceived in the moment of hierophany : God, gods, the world soul, the Wholly Other, the mysterium tremendum, or mysterium fascinans. What unites all religious experience is not the name one gives to the thing perceived as through a glass darkly, but the powerful, soul-shaking sense that one is caught up in something vastly more powerful than oneself to which one ought to pay attention.

To be religious, then, is to be open to the experience of the sacred, to live one's life prepared to be rung like a bell. Science takes place entirely in the world of the profane. But the world exposed by science greatly expands our opportunity to experience the sacred. Who can look at the breathtaking photographs from the Hubble Space Telescope without having a jaw-dropping hierophany of a -- a something, a wonderful and fascinating generative wholeness that transcends the objects photographed, yet is indissolubly connected to them? The poet experiences a hierophany upon beholding a flower in a crannied wall, but to understand what is taking place ceaselessly in every cell of the flower -- the winding and unwinding DNA, spinning out proteins -- taps even deeper into our capacity to marvel. The more we understand, the more we become aware of how little we understand -- and the more we are able to refine the names we place on the thing we perceive. Perhaps the ultimate and most respectful response is not a name, but silence.

The sacred and the profane represent two aspects of our lives, both no doubt grounded in our biological natures. They are inseparable. We live our lives primarily in the profane: work, eating, sleep, sex. The profane is where we pursue reliable scientific knowledge of the world. Science does not diminish the sacred; rather, it expands the realm of experience where we might encounter the sacred. One can be religious without believing in a supernatural being who exists outside of nature. Rather, focusing one's attention on a supernatural phantasm might sharply reduce one's ability to experience the sacred in this world in which we live and breathe and have our being.

I should add: There are those within the naturalist community who will dismiss all talk of the "sacred" and the "holy" as so much mystical hogwash. I trust I have made it abundantly clear that I am not evoking the supernatural in the sense that the word is generally understood. One would have to be particularly insensitive to the world to want to live only with what can be reliably known, oblivious to the greater mystery that so far, and perhaps forever, eludes our grasp.

A walk across the universe

2008-11-02T10:41:00.000Z

You will know by now that my daily walk to college is about a mile. Several thousand steps. Through woods and meadows. Across a stream.

Imagine that the mile represents the distance to the most distant objects we see with our telescope, most of the way back to the big bang itself, 13.7 years ago. As I start my walk in the morning, the big bang is a mile away -- 13.7 billion light-years.

On this scale, the Milk Way Galaxy is about the size of a dime -- one hundred billion stars in a whirling spiral. The next spiral, the Andromeda Galaxy, is another dime (well, maybe a nickel) about as far away as my footprint is long. The Milky Way under my heel, Andromeda under my toe.

I take a step. I span galaxies. As I walk, galaxies flow under my feet. As I approach my destination, I begin to encounter quasars, the violently energetic centers of young galaxies, vast black holes in the making. In my last step, I encounter the creation of matter out of pure energy.

Fling dimes for a mile in every direction, a foot or so apart. Every dime is a galaxy of a hundred billion stars. Every star (perhaps) with planets.

As we look out with our telescopes, we see those other galaxies as they were at some time in the past. No galaxy is closer to the center. There is no center. Nor a boundary. The universe inflates like the surface of a balloon. Inflates from a pinpoint. Space (the surface of the balloon in my analogy) comes into existence as the balloon inflates. The galaxies are dots on the balloon. As the balloon inflates, the dots move apart. But no dot is central, and there is no boundary to the surface. The view from any galaxy is like the view from any other.

Now let the mile of my walk represent time, the 13.7 billion years that the universe as we know it has been in existence. The several million years of our human ancestry would fit into my footprint. All of recorded human history would snuggle under my little toe. My lifetime is the thickness of a slip of paper.

You've taken this walk before. Or something like it. You've seen the Hubble photographs. You've heard the analogies. But one can hear the story a hundred times and still it's hard to grasp the dimensions of cosmic space and time. I've been writing and teaching this sort of thing for half a lifetime, and I still have a hard time getting my head around it.

Surely, no discovery is of greater import. It is a discovery that should shake our ancient theological and philosophical assumptions to their core. But the fact remains that the vast majority of people -- even many who are highly educated -- continue to live psychologically in the cozy human-centered universe of Aquinas and Dante.

The Church knew what it was doing when it burned Giordano Bruno at the stake in 1600. Bruno was one of the first to imagine the plurality of worlds. All the stars were other world systems, he said. Space was infinite. This just decades after Copernicus had moved the Earth from the center of the cosmic egg, and only years before Galileo turned his telescope on the myriad stars of the Milky Way.

Bruno was a rebel from from his youth, and prone to enormous ego and outrageous opinions, but give him this: He dreamed of a universe not unlike the one we subsequently discovered, and he understood its implications. The individual, said Bruno, was a "temporary conglomeration of atoms in the great sea of the world's soul." A whole tablet of heresies followed -- questions about heaven, hell, the Incarnation, and personal immortality -- for which the dreamer paid the ultimate price.

Accept a universe of worlds without end and the power of the Church as divinely appointed broker of God's commerce with humans is threatened. Thus the fiery execution in the Campo de Fiori in Rome, the victim's heretical tongue restrained with a thong or spike so that he might notin extremis compound his blasphemies.

But the Church was not alone in being threatened by cosmic space and time. Each us us must feel a shudder of angst when looking into the abyss. We have been raised to believe a personal creator of the universe is mindful of our every thought and action. Yet everything we have discovered about the universe suggests that we are, as Bruno said, "temporary conglomerations of atoms in the great sea of the world's soul."

I set out on my daily walk. The sky in the east glows golden with the light of dawn. A long, ragged vee of geese honks overhead, heading south. At the plank bridge the water purls in cold eddies; soon we'll have the first thin films of morning ice. I stop, and listen. A nuthatch? A wind in the willows? I do my best to open my senses to the "world's soul." I stand on the bridge and I shiver in "the immense and the numberless" (to borrow the title of one of Bruno's books). Then I start again along the path, my stride encompassing galaxies.

The Great Silence

2008-10-26T10:41:00.001Z

"Every religion which does not affirm that God is hidden is not true." Pascal, Pensees

"Then a great and powerful wind tore the mountains apart and shattered the rocks before the Lord, but the Lord was not in the wind. After the wind there was an earthquake, but the Lord was not in the earthquake. After the earthquake came a fire, but the Lord was not in the fire. And after the fire came a gentle whisper." 1 Kings 19:11-12

I'm weary of words. Our national discourse has become loud and shrill. Everywhere we go, it seems, we are followed by the strident staccato of Wolf Blitzer urging us towards the edge of our seats. In doctors' offices, airport lounges, bars and restaurants, dozens of talking heads bombard us with opinions. Politics has become a warfare of words, verbal grenades lobbed back and forth, shattering our ear drums. The blogosphere gets ever more angry, metastasizing into a hundred million malignant cells.

Meanwhile, the great debate between scientific skepticism and traditional religion thunders on. On the one side, Dawkins, Hitchens, Harris and their allies, bang the drums of indignation. On the other, megachurch pastors and televangelists rouse their congregations to frenzies of noisy self-certainity.

I weary even of my own words, which have their own abrasive edge. More and more, I long for silence, most especially my own. I'm tired of my own voice, nattering on. That's simple, you say -- just shut up. Close the laptop and put it away.

Easier said than done. Thought and words are inseparable. Thoughts cry out for expression. All the philosophers tell us: Language defines our humanity. Seal your lips and you cease to be human.

Well, yes and no. Thoreau rejoiced in the hoot of the owl in the twilight woods. But he also took note of the interval between the hoots, a deepened silence that suggested "a vast and undeveloped nature which men have not recognized." That's where I want to go, into the silent interval, deepened and made more alluring by the bracketing hoots.

The silence that Thoreau wrote about is not just an absence of sound; it is no less than the voice of the God Pascal speaks of in the epigraph to this essay, the Deus Absconditus of the mystics who eludes every spoken word, most especially, perhaps, the personal pronoun "who." The silence Thoreau speaks of is not separate from nature. It is the vast and unarticulated nature which lies beyond our present knowing.

So, yes, silence is more than mere absence of sound. Ladislaus Boros says that "silence opens up the finite world to the infinite." Note that "finite" and "infinite" are not synonyms for "natural" and "supernatural." The natural universe we inhabit may indeed be infinite, and in any case is effectively so. The finite is that which we presently understand and speak of reliably in language. The infinite is that which is yet unspoken. The infinite is the great silence in which we live and move and have our being.

In all of this, science is closer to the mystics than are many traditionally religious people. Scientists do not speak of what they do not know. Scientists as venerable as Joseph Priestly and Thomas Huxley spoke of knowledge as an island in a sea of mystery. The island grows by our painstaking efforts; the sea remains. If the mystery speaks to us at all, it is a gentle whisper. The typical religious person, on the other hand, never ceases to talk of knowing God, even claiming a "personal relationship." The typical religious person fills the interval between the hoots with chants and prayers and theologies and apologetics and revelations -- a clamorous sea of language where language has no place.

But silence has its champions within all religious traditions. In the last century perhaps no one spoke so poetically of silence as the German Catholic philosopher Max Picard. His best known book is called The World of Silence:

It is a sign of the love of God that a mystery is always separated from man by a layer of silence. And that is a reminder that man should also keep a silence in which to approach the mystery. Today, when there is only noise in and around man, it is difficult to approach the mystery. When the layer of silence is missing, the extraordinary easily becomes connected with the ordinary, with the routine flow of things...What many preachers say about the Mystery of God is often lifeless and therefore ineffectual. What they say comes only from words jumbled up with many thousands of other words...But it is in silence that the first meeting between man and the Mystery of God is accomplished, and from silence the word also receives the power to become extraordinary as the Mystery of God is extraordinary.

One need not be a Christian, or even a theist, to grasp the truth in what Picard has to say. And again let me stress that "ordinary" and "extraordinary" are not synonyms for "natural" and supernatural; every ordinary thing is enveloped within the extraordinary as words are enveloped by silence.

We call the origin of the universe the Big Bang. But there was no "bang." There was energy, light, then matter, and -- and silence. The world came into being wrapped in silence. We speak, we write, we blog, we chatter, and all of that is what makes us human, but it's all idle when disconnected from the the great silence which is the universe. "Silence is God's first language," said John of the Cross. We make sacraments of owls -- audible signs of the silence between the hoots.

Max Picard linked silence to faith. The more important link is to humility. Silence is the great teacher that cautions us to hold our tongue in the face of what we do not know. On which note, I will shut up.

In the beginning

2008-10-19T10:41:00.000Z

A creation myth from Egypt of the third millennium B.C. has God bring the world into being with a sneeze. It's not a bad image for the Creation as currently described by astronomers. Fifteen billion years ago the universe began with an outward explosion of pure energy. A blaze of gamma rays, x-rays and light. Then particles, atoms, stars and galaxies. A spray of material creation.

Ahh, ahhh, ahhhh--CHOO!

The Big Sneeze. Better than the Big Bang. More poetic, more firmly grounded in the ancient human quest for origins. And more evocative of an explosion from nothing. "Big Bang" suggests a firecracker exploding in preexisting space and time. But space-time came into existence along with the universe, the way a sneeze sometimes comes out of nowhere.

Or how about the Big Ha?

God's laugh. A great roaring belly laugh that brings all things into being. An ancient Jewish creation text has God create the world with seven laughs. The first laugh is light. A blazingly luminous hoot of laughter. An side-splitting guffaw of gamma rays, x-rays, and a rainbow of colors.

The Big Ha puts a little fun back into creation.

First, there is nothing. Then an infinitely dense, infinitely hot kernel of energy that expands explosively. Space-time inflates like a balloon that was infinitely small at the beginning. Where does it happen? Everywhere. When does it happen? As time begins.

The universe expands and cools. Energy becomes matter. One hundredth-thousandth of a second after the beginning, the universe is a seething stew of particles and radiation. Fifteen seconds after the beginning the temperature has cooled to a billion degrees and the creation of matter settles down. After 700,000 years, protons and electrons bind together to make atoms of hydrogen and helium. Later still, come stars and galaxies.

The term "Big Bang" was coined in 1950 by astronomer Fred Hoyle, a champion of the so-called Steady State theory of the universe that has things always more or less the way they are now, with no beginning or end. Back in 1950, the primeval fireball theory was a bit of an upstart, and Hoyle dismissed it derisively as "the Big Bang." His scornful label stuck, even as new observations eventually led to an almost universal triumph of the explosive beginning over the Steady State.

Big Bang. The name is a loser, astronomy writer Timothy Ferris suggested some years ago. It is ugly, misleading, and trivializing, more suited for a dormitory brawl than for the primeval fireball that spawned the starry skies. We need a new name, said Ferris, something more dignified, more accurate, less accidental in its origin. Taking up his challenge, the editors of Sky & Telescope invited readers to re-name the Big Bang, in a contest to be judged by Timothy Ferris, Carl Sagan, and Hugh Downs. The magazine received 13,000 entries from around the world. In the end, the Big Bang still held the floor.

I didn't enter the contest, but maybe I should have. I have a feeling the judges wouldn't have looked favorably upon the Big Sneeze or the Big Ha. Too frivolous, they would have said, although these are among the most ancient metaphors we have for Creation.

I pondered other possibilities at the time -- Alpha-1, Cosmodawn, Uniseed, GENesis, Apsutime (from Apsu, the Babylonian begetter of gods), Protophos (from the Greek for "first light") -- but decided they sounded too much like something dreamed up by an ad agency.

I'll stick to my guns. I'll go for something with a mild gamma-burst of humor. Something that doesn't take itself too seriously. Somethin with an ancient pedigree.

How about the Big Speak?

Among ancient myths, the Word is one of the most universal images of creation. In the beginning was the Word, and the Word was made flesh.

Christians have tended to appropriate the Word to themselves, but it can also be found, for example, in creation stories of the Mayas of Central America, the Maoris of New Zealand, and the Tanzanians of Africa. God speaks, and the word becomes the world. The Word was not something that could be seen, says a Tanzanian myth, it was a force that enabled one thing to create another. Exceedingly apt. The Big Speak.

But "Speak" sounds terribly pompous. Like a sermon. Like a snooty pronouncement. How about something more whimsical? How about the Big Squawk?

Raven, the trickster god of the Eskimos, creates the world with a bit of mischief. Let Raven speak. A wonderful, explosive, glottal call. The bird-Word. Ancient. Universal. An infinitely fulsome cr-r-r-cruck of Creation. That's it. The Big Squawk.

Sail on, sail on, sail on and on...

2008-10-12T11:29:00.001Z

My favorite picture book when I was a kid told the story of Christopher Columbus. The illustration I liked best showed Columbus at the court of Ferdinand and Isabella, confounding hidebound churchmen and doubting scholars with solid, scientific reasoning. He is holding a small globe in his hand. "I believe the world is round," he says to the monarchs. "Give me ships and I will prove it."

This was the Columbus we knew as children: a light of reason shining into medieval darkness, an heir to Archimedes, a precursor of Galileo.

Of course, it was all a myth. Although Columbus adopted scientific thinking when it suited his purpose, he was more importantly motivated by an impassioned brand of millennial Christianity. He believed the End Times were near, and that he was God's messenger, anointed to bring all peoples to Christ in a restored Zion.

The prophecies of Isaiah and Ezra were as important to Columbus as the calculations of ancient Greek mapmakers, and if he was initially rejected at the court of Spain, it may have been as much for his religious fanaticism as for his geographical theories. After all, every educated person in the 15th century knew the world was round.

The European discovery of America -- with subsequent encounters of peoples previously unknown to each other -- was indeed a momentous event in human history. And Columbus's navigational skills cannot be denied. But his voyage was put in motion by politics, not, as my storybook suggested, by "man's relentless quest for knowledge." The man who sailed from Palos in 1492 was a pawn in the hands of imperial power.

The Spanish conquests in America were founded on an alliance of greed and evangelical Christianity. On the one hand, the expansive ambitions of the Spanish crown were stoked by an apparently inexhaustible American resource: oro, gold. On the other hand, Europe's "Most Christian Majesties" perceived it to be their duty to convert heathens to the "one true faith" and "civilized" values.

When Columbus appeared on their doorstep, Ferdinand and Isabella had just succeeded in driving the Moors from Spain after centuries of occupation. Throughout the Mediterranean basin, Christianity and Islam were locked in a clash of civilizations, and the antagonism between these two religions colored Spain's relations with other non-Christians: black Africans and native Americans. All were infidels. All required the saving grace of Christ. All could be treated as less than human if Spain's quest for wealth required it.

The horrendous consequences for the indigenous peoples of America need no re-telling. What is less often commented upon are the injurious consequences for Spain: the profligacy, the overweening arrogance, the moral compromise, the shattering repudiation of Christ's injunction to "love thy neighbor."

It was inevitable that sooner or later the peoples of Europe and the Americas would come to know each other. There was indeed a scientific curiosity at work in 15th-century Europe that was reaching out into the unknown. Even in Columbus's time, the Scientific Revolution was aborning, and with it new technologies with the potential to enhance the lives of all people. Globalization was afoot, and unstoppable.

So what went wrong? A lack of restraint. A confusion of might with right. A sense of moral superiority.

It wasn't scientific curiosity that took Columbus and his successors to America. What took Spain to the New World was unbridled political power, claiming God's favor and approbation, with a broad evangelical base of support, armed with overwhelming technological superiority, driven by an insatiable need for gold.

Could the clash of civilizations have been resolved without a clash of arms? Could the peoples of the two hemispheres have merged into one people, without the extermination of one or the other, learning from each other, sharing wisdom and values?

Your answer depends, I suppose, upon your view of human nature.

My childhood storybook presented Columbus as we wish he might have been: a man exemplifying humankind's highest aspirations of intellectual curiosity and moral courage. The message of the storybook strayed far from the truth, but the fact that we wrap ourselves so fervently in the Columbian myth suggests that we understand intuitively what we have the power to become.

Tunk-tunk

2008-10-05T10:04:00.003Z

Two sounds of autumn are unmistakable," says the naturalist Hal Borland, "the hurrying rustle of crisp leaves blown along the street or road by a gusty wind, and the gabble of a flock of migrating geese."

To these one might add the tunk-tunk of acorns falling onto the roof of the house.

The squirrels are up there, playing Tarzan among the branches. And down comes the shower of acorns -- tunk-tunk -- bouncing off the shingles.

The squirrels, it seems, are enjoying a last boisterous fling before gathering the harvest. There's plenty to go around: The gutters are full of acorns and the ground is littered.

According to Indian lore, a rich crop of acorns means we are in for a hard winter. If so, then nature has a generous way of anticipating the rigors of the season. Squirrels stash away acorns in huge numbers as winter reserves, often burying them in the ground and forgetting where they are. The seeds in the nuts are in a perfect position for germinating, protected from the winter freeze by a few inches of soil. In his A Guide to Nature in Winter, Donald Stokes suggests that a considerable number of our northern oaks have grown from forgotten squirrel snacks.

Birds eat acorns too -- ruffed grouse, blue jay, nuthatch, titmouse -- pecking open the shell and gobbling the nut. Wild turkeys gulp down shells and all, dozens in a single meal. Bear, deer, and raccoons, too, depend on acorns in winter. Donald Stokes observes that no other tree provides so much food for so many as do the oaks. Acorns are probably our wildlife's must important sustenance.

Humans eat them too, usually after lots of boiling, but sometimes right off the ground. I've nibbled acorns and found them decidedly unpalatable. Which is why it always surprises me that Henry David Thoreau goes on about them so in his journals. The Concord hermit waxes rhapsodic about the sweet taste of acorns. You would think he was talking about French truffles or Italian chocolates.

It's white oak acorns he's talking about, the least bitter of these bitter-tasting fruits. "To my taste they are quite as good as chestnuts," says Thoreau. "Their sweetness is like the sweetness of bread." Can he possibly be talking about the same acorns I've tasted? He professes to prefer acorns to a slice of imported pineapple. Come off it, Henry, you are trying too hard to be the woodsy epicure.

In an unguarded moment in his journal Thoreau admits that acorns, like wild apples, require an "outdoor appetite." Apparently, when he tried them in the house they were not so pineapple-tasty. Catching himself out of character, he quickly adds, "Is not the outdoor appetite the one to be prayed for?"

Well, I dunno. What about Chinook olives? Here's a recipe to add to your edible wild-food collection. It's from a book called "Wanderings of an Artist" by Paul Kane, published in 1859. Kane spent four years traveling thousands of miles across Canada, recording in his sketchbook the lives and habits of Native Americans. Among the Chinooks he observed the following culinary practice:

"About a bushel of acorns are placed in a hole dug for the purpose close to the entrance of the lodge or hut, covered over with a thin layer of grass, on top of which is laid about half a foot of earth. Every member of the family henceforth regards this hole as the special place of deposit for his urine, which is on no occasion to be diverted from its legitimate receptacle. In this hole the acorns are allowed to remain four or five months before they are considered fit for use...the product is regarded by them as the greatest of all delicacies."

Chinook olives. That's what the whites called this Chinook treat.

Acorns were the staff of life for many Native American tribes. Acorn soup or mush was the main daily food for most native Californians. In our part of the continent a hearty black bread was made from acorn flour, but first the tannic acid had to be leached from the nuts. This usually meant buying the acorns underground for long periods of time or suspending them in running water. During their first bleak winter in Massachusetts the Pilgrims were lucky enough to find baskets of acorns the Indians had buried in the ground. Sometimes when food was scarce the Indians went looking for hoards of acorns buried by animals.

Eating wild plants does not seem to be as popular today as it was some years back when Euell Gibbons taught us how to stalk the wild asparagus and blue-eyed scallop. But for New England's wildlife the search goes on. For the squirrels on the roof, acorns are more than a fashionable snack; they are life or death. In nourishment and abundance, there is no more important wild food.

Thoreau tells us that after an acorn snack he felt like he possessed "the heart and back of oak." Well, maybe. The tunk-tunk of acorns on the roof of the house doesn't whet my appetite. Taking a bite of white oak acorn on a brisk November day may have a certain daring-do charm, but no one wants to live on them, not any more at any rate, and especially not prepared in the Chinook way. The fruits of oaks may please the palettes of squirrels and hermits, but most of us prefer a store-bought steak smothered in tomatoes and onions.

Stretching the imagination

2008-09-28T10:59:00.001Z

Professor, that stuff you spoke of in class this morning -- about the beginning of the universe..."

Yes?

"Well, you know how you said that the universe began 14 billion years ago as an infinitely small point...?"

Yes, that appears to be the case. An explosion from a point of infinite energy. Space and time expanding from nothing. Matter coalescing from cooling radiation. Stars, galaxies...

"To tell the truth, I'm having a hard time believing it. I mean, the idea that everything that exists today, the billions and billions of galaxies, stars and planets, life, everything, was contained within something no bigger than a pinprick. I mean, come on...do you really expect me to swallow that?"

You will recall that I listed some pretty convincing evidence: The galaxies are racing apart, as from a primordial explosion; the amount of hydrogen and helium in the universe is just what theory predicts for a Big Bang beginning; and, not least, we see the flash of the Big Bang in every direction of space, with precisely the predicted spectrum.

"Yeah, I know. I understand most of that stuff. But I keep coming back to the idea of the whole universe contained within a pinprick. I mean, it's impossible to imagine."

It is difficult to imagine, I'll grant you. But not impossible. Mathematically, it can be described exactly. Mathematics is a big help to the imagination.

"It sounds impossible."

Let me tell you a story. More than 2,000 years ago in Alexandria, Egypt, there were two fellows, named Eratosthenes and Aristarchus. They were excellent mathematicians.

Eratosthenes was a geographer. He imagined that the Earth was a sphere. He figured out how to measure the size of the sphere by using shadows cast by the Sun at Alexandria and another place down the valley of the Nile. He used some mathematics that at the time was pretty advanced stuff -- geometry, trig.

He calculated the size of the Earth and got it nearly dead-on, without ever leaving Alexandria. That's what I mean about mathematics being an aid to the imagination.

Then Aristarchus used the size of the Earth to figure out the sizes and distances of the Sun and the Moon. He observed eclipses of the Moon, and measured the time it takes the moon to move through the shadow of the Earth. Then he did some high-powered mathematics with circles and triangles. According to his calculations, the Sun is many times bigger than the Earth.

Aristarchus told his fellow Alexandrians about his discovery. If the Earth is the size of a grape, he may have said, then the Sun is the size of a melon. They laughed. Any fool can see that the Sun is tiny compared to the vast, wide Earth. Why, for heaven's sake, one can cover up the Sun with the tip of one's little finger, but travel across the Earth for weeks without ever leaving Egypt.

The Sun bigger than the Earth? No way, it was simply impossible to imagine.

"But. .."

And Aristarchus got one crucial observation wrong, through no fault of his own. In fact, the relative sizes of the Earth and Sun are more like a grape and a washing machine, something every school child accepts today.

The moral of the story is -- the "impossible" can turn out to be true.

"But the whole universe contained within a pinprick? It violates common sense."

Einstein once said that common sense is the collection of prejudices we acquire by age 18. I'm not telling you to believe the Big Bang if you don't want to, but keep your options open. One generation's impossibility often turns out to be the next generation's common sense.

"You're asking me to take it on faith?"

Yes, on faith. But not on blind faith. As we saw this morning in class, there is impressive observational evidence. The calculations are based on Einstein's general theory of relativity, which has many important successes to its credit. Then there's the record of success by the successors of Eratosthenes and Aristarchus. Just think of all the scientific discoveries that were thought to be nonsense in their time. The Earth going around the Sun. The evolution of life over bilions of years. Continents drifting and colliding. A chemical blueprint for a human being in the DNA of a single microscopic cell.

And besides, it's a wonderful, wonderful story -- a universe unfolding from a mathematical point!

"Yeah, it's an wonderful story, all right. But..."

But?

"But I still don't believe it."

Thinking like a hobbit

2008-09-21T10:36:00.000Z

I first read J. R. R. Tolkien's The Lord of the Rings in the early 1960s. The maps of Middle-earth attracted my interest. I had not previously heard of Tolkien, and his books were only beginning to become cult favorites of the college crowd.

I was a graduate student at the time. As I read the books, I retold the tale in a much condensed version to a recurring gathering of children in the housing complex for married students in which I lived. They hung on every word of hobbits, elves, orcs and ents, and, of course, wise Gandalf and dashing Aragorn.

In the 1990s, The Lord of the Rings was selected in four separate polls as the "greatest book of the century." It is a classic story of good and evil -- power, ambition, greed, courage and heroism. On the face of it, it is a magical tale set in a fantasy place in a mythic past, but that hasn't stopped any number of interpreters from finding in it lessons for our time. Tolkien wrote the Ring as his beloved England waged war against a Nazi empire that threatened to drag all the world into darkness. It is tempting to identify Sauron, the book's embodiment of unmitigated evil, with Hitler.

But another character from the trilogy, perhaps more than Sauron, has contemporary relevance -- the wizard Saruman, Gandalf's traitorous counterpart.

Saruman professes to be interested in knowledge, but his real objective is control. Language and meaning are slippery on his tongue. Ends justify means, and he is willing to make an alliance with evil if it serves what he believes to be the greater good. When Saruman speaks, "mostly [his listeners] remembered only that it was a delight to hear the voice speaking, all that it said seemed wise and reasonable, and desire awoke in them by swift agreement to seem wise themselves."

"We can bide our time," Saruman says, "we can keep our thoughts in our hearts, deploring maybe evils done by the way, but approving the high and ultimate purpose: Knowledge, Rule, Order, all things that we have so far striven in vain to accomplish, hindered rather than helped by our weak and idle friends."

Hubris, moral pragmatism, and high-sounding doubletalk. Sauron, the Dark Lord, is the enemy we contend with abroad; Saruman, who calls himself Wise, is the enemy within ourselves.

Not least in science.

Knowledge, rule, order: These are the goals of science and its handmaiden technology. Worthy goals, too: Saruman's professed goals. As Tom Shippey noted in his study of Tolkien, Saruman is the consummate technologist. His name derives from the Old English searu, which means cunning, with connotations of metalwork and craft. Treebeard the Ent says of Saruman, "He has a mind of metal and wheels."

In Saruman, the wheels spin out of control. Shippey writes of Saruman's treason: "It starts as intellectual curiosity, develops as engineering skill, turns into greed and the desire to dominate, corrupts further into a hatred and contempt of the natural world, which goes beyond any rational desire to use it. Saruman's orcs start by felling trees for the furnaces, but they end up felling them for the fun of it."

Saruman's dream, which is often our own, is of a future techno-utopia contrived by human cunning. What we often get instead are fouled wildlife refuges, nuclear waste dumps, poisoned rivers, unbreathable air.

Tolkien's answer to Saruman is the folksy Shire, home of the hobbits with fuzzy feet, a sort of pre-Industrial-Revolution English countryside untouched by the curse of iron or gold. But, of course, there can be no going back to a pretechnological past. Knowledge once learned cannot be unlearned. What can be done, will be done. As Gandalf says: "It is wisdom to recognize necessity."

But Gandalf also says: "He who breaks a thing to find out what it is has left the path of wisdom." What is required is a brake on hubris, an abiding love for the natural world, and a willingness to resist what Tolkien calls the "bewilderment" of treasure. The solution to our technological dilemma is nothing so simple (or so dangerous) as throwing a ring into the fire in which it was forged. But a little Hobbit pluck and Hobbit restraint might serve us well as we feel our way into an uncertain future, embracing the beneficent artifacts of knowledge, but holding fast to all things that live and breathe and grow.

Who vets the web?

2008-09-14T08:34:00.000Z

Anyone who has visited amazon.com to order my new book will perhaps have noticed a surprisingly large number of reader reviews for a book that has only just been made available. A closer look will reveal that all of these reviews are part of something new called the Amazon Vine Program.

According to Amazon: "Vine is a program that enables a select group of Amazon customers to post opinions about new and pre-release items to help their fellow customers make educated purchase decisions. Customers are invited to become Amazon Vine Voices based on the trust they have earned in the Amazon community for writing accurate and insightful reviews. Amazon provides Amazon Vine members with free copies of products that have been submitted to the program by vendors. Amazon does not influence the opinions of Amazon Vine members, nor do we modify or edit their reviews."

What this means, I suppose, is that my publisher provides free copies of my book to Amazon, which then passes them on to readers who undertake to provide a review. And so Web 2.0 -- the democratization of web content -- further extends its all-embracing reach.

I will take my publisher's word for it that "generating a buzz" in this way is good for sales. It seems to me that the reviews so generated are of an uneven quality, and utterly predictable. Given the fact that the vast majority of Americans are believers in the supernatural, I wouldn't expect the untargeted provision of review copies of my more skeptical book would serve the cause -- but what do I know? The score, so far, is pretty good. Buzz is buzz, they say.

Is the democratization of web content a good thing? Certainly, as a card-carrying member of the blogosphere, I shouldn't suggest otherwise. As a good democrat I should be all for it. So bring it on. The whole glorious, anarchic flood of user-generated content. MySpace, Facebook, YouTube, blogs, Wikipedia, Amazon reviews, spam. The essence of the Internet is its promiscuousness. No more gatekeepers between sources and consumers of information. No more authorities telling us what we should or can read.

But let's not suppose that this promiscuity of content is without peril.

A few keystrokes will bring into our homes newspapers of record and the ravings of madmen, works of art by the great masters and by Sunday painters, Shakespeare's plays and the scribbles of the person next door, stock market wisdom and money-gouging scams, science and pseudoscience -- a vast unsorted sea of information and opinion, some valuable, some off the wall. Amazon reader reviews? You would be surprised to discover just how many unscrupulous writers have their friends stack the deck with raves.

We have entered the Age of Unfiltered Information.

Previously, we obtained information from books, magazines, newspapers, radio, television, libraries and schools. Editors, librarians, and teachers decided what information is "true," "legitimate," "useful" or "appropriate." This had certain advantages. We were saved from drowning in a sea of superfluous information. We were instructed by those who are wiser and better educated than ourselves. Our society gathered a stabilizing degree of cohesiveness.

By contrast, the Internet is a gate flung wide open. The loony web pages of civilian militias are as readily accessible as the web pages of a Nobel prize-winning peacemaker. The web pages of the International UFO Museum and Research Center have equal standing with the web pages of the American Association for the Advancement of Science.

This all-inclusive anarchy can be exhilarating, liberating, fun. For the first time in history, individuals can interact with the world of information without the constraints of official filters. The schools are fast becoming obsolete as purveyors of facts; facts come flooding from our computers faster than we can assimilate them. What the schools must now provide -- and quickly! -- are skills of critical thinking. Our children must learn to become their own gatekeepers.

How does one filter the information that gushes from the net? How does one distinguish information that has the backing of a broad base of educated opinion from fringe or crackpot information? In which web pages can we place our trust without the risk of getting burned?

Let's say a kid in a science class does a net search for "cold fusion." She gets over 5 million hits, more information than she could have obtained in a dozen years of teachers and books. However, these hits range the gamut from respectable scientific research to the incoherent thoughts of perpetual motion cranks. And to make things more confusing, some of the goofier opinions are found on the glitzier web pages. How does the student separate the wheat from the chaff?

Another student finds his way to the classy home page of the Institute for Creation Research in California. He notes that the institute has a faculty with Ph.Ds, a graduate program, a Science Education Center, even a list of ideas for science fair projects -- all the trappings of real science. How is the student to know that the Institute for Creation Research has pariah status within the professional scientific community?

The Internet is like a vast marketplace of ideas where every purveyor has the same size stall. Some stalls are decked out with neon and flashing lights; others are shabby and drab. Some stall-keepers promise the world; others offer only modest helpings of "fact." Where does one shop?

If we are to live in a society without information gatekeepers, we must educate our children to be open-minded but skeptical, tolerant of diversity but passionate about truth, respectful of received opinion but equipped with tried-and-true critical skills of history, rhetoric, logic, statistics, and the experimental method.

A vigorous marketplace of ideas is healthy, but a society needs a certain degree of shared conviction if it is not to disintegrate into anarchy. If all ideas in the marketplace are equal, then no ideas will truly matter.

Saying yes to the universe

2008-09-07T06:22:00.002Z

Let me return once again to the Hubble Ultra Deep Field Photo, a document of simply mind-blowing significance (click to enlarge).

The photo was made by the Hubble Space Telescope during 400 orbits of the Earth, a total exposure of 11.3 days. It shows a tiny spot of the southern sky in the constellation Fornax, a speck of the dark night you could cover up with the intersection of crossed sewing pins held at arm's length. There appears to be five or six foreground stars in the photo (the dots with spikes), stars in our own Milky Way Galaxy. Then, beyond, at ever increasing distances, reaching back almost to the beginning of time -- galaxies. Spirals, ellipticals, sphericals. Ten thousand galaxies in all. And these are presumably only the brightest, the galaxies with upwards of 100 billion stars or more.

We would see more or less the same thing looking out from Earth in any direction. It would require 20,000 photos like this to cover the bowl of the Big Dipper, 13 million to blanket the entire sky. A whole-sky survey at the same resolution would reveal 130 billion galaxies.

In The Soul of the Night I describe making a galaxy for my students by pouring a one-pound box of salt in a spiral on the classroom floor, each grain of salt representing a star. It's a dramatic demonstration, but not a patch on reality. The salt grains are actually way too big to be stars on the scale of the classroom floor. To have as many stars as there are in the Milky Way Galaxy would require ten-thousand boxes of salt!

At the scale of the Hubble Ultra Deep Field Photo we can see as many galaxies as there are grains in ten-thousand boxes of salt. And each of those galaxies contains as many stars as there are grains in ten-thousand boxes of salt. And that's just the universe we can see.

I've spent a lifetime trying to get my head around the scale of the universe, and the apparent utter randomness of our place in it. Just a few hundred years ago humans imagined themselves to live at the center of a cozy cosmic egg, embraced by a sphere of stars just up there. Psychologically, we still linger in that anthropocentric cosmos.

If the Hubble Ultra Deep Field Photo whispers anything in our ear, it is that the neolithic myths so many of us live by are hopelessly out-of-date. We need new, more capacious stories commensurate with the stunning achievements of human knowing. We need theologies that consist of more than projections of human qualities onto a mystery that burns like a hidden flame in the "ten thousand times ten thousand boxes of salt." When I tried to convey some sense of cosmic scale, my students sometimes said to me, "It makes me feel so insignificant." My reply: You are part of a species who flung a magnificent instrument into space and managed to keep it pointed at a tiny dot of sky for 11.3 days as the instrument whirled around the Earth. You made visible 130 billion galaxies. You carry a universe of 130 billion galaxies in your head. If that doesn't make you feel significant, nothing will.

The Hubble Ultra Deep Field Photo is an extraordinary step in human knowing. And, ironically, it confirms our ultimate ignorance. We are blown and stirred and battered by a wind of galaxies that rushes outwards from a deeply mysterious beginning, We are the stuff of it. Every atom in our body vibrates with the tempo of it. We let go of our ancient moorings and swim in the sea of it.

And more. Saying yes to the universe of the galaxies makes it easier to say yes to the universe here and now. To say with Walt Whitman: "...the pismire is equally perfect, and a grain of sand, and the egg of the wren..."

Yes. Yes. Yes.

Moderate with fog patches becoming good

2008-08-31T06:06:00.005Z

Anyone who has lived in Britain or Ireland for any length of time will recognize the names in today's blog post. They are the sea areas for the shipping forecasts broadcast four times daily by BBC Radio 4, at 5:20, 12:01, 17:54, and 00:48 hours.

Needless to say, I have never heard the midnight or early morning forecasts, but I have lived in England and Ireland long enough to have listened to the midday and late-afternoon forecasts many, many times. Anyone in these islands who goes to sea will tune their radios to the appropriate frequency, but of course the forecasts will be heard by everyone who listens to Radio 4, and that includes a goodly part of the housebound population. It is probably fair to say that the shipping forecast is as much a part of the British national consciousness as Buckingham Palace, afternoon tea, and Beefeater Gin.

For all of their serious intent, the forecasts are a kind of poetry, felicitous to the ear and provocative to the imagination. A typical segment might go something like this:

Shannon, Lundy, Sole. Westerly backing southwesterly 3 or 4 increasing 6 later. Showers, wintry at times. Good.

This is a kind of code. A translation: The wind will initially be from the west, swinging anti-clockwise to the southwest later, at force 3 or 4 on the Beaufort scale, later increasing to force 6. The weather will be showery, with wintry rain at times. Visibility will be at least five miles.

The Beaufort wind scale was devised in 1806 by Captain Francis Beaufort, later Admiral. He used as his standard the effect of the wind on a typical British man-of-war. For example, a force 2 wind would move a full-rigged vessel at 5 or 6 knots. In a force 12 wind, a ship could carry no rigging at all. Force 0 is dead calm. Force 12 is hurricane.

Dogger, Fisher, German Bight. Southerly 6 or 7 decreasing 4. Occasional rain. Moderate or poor.

Visibility is defined in a curious combination of meters and nautical miles. For example, "Fog" is less than 1000 meters. "Poor" is between 1000 meters and two nautical miles. So deeply entrenched are these conventions that is is unlikely they will be rationalized.

Trafalgar, Fitzroy, Biscay. Variable 3 or 4. Fair. Moderate with fog patches.

Ah, Trafalgar! There's a name to elicit British emotion! The great sea battle in which Nelson defeated the French and lost his life takes its name from Cape Trafalgar in Spain. The Trafalgar sea area is only included in the after midnight report, unless gale warnings are involved.

And Fitzroy! What is this sea area Fitzroy? During my several residences in England it was Finisterre.

In a rare disruption of tradition, the Finisterre sea area in the shipping forecast was renamed Fitzroy in 2002 to honor Captain Robert Fitzroy, later Vice Admiral, who in 1854 was named head of the newly-established Meteorological Department of the Board of Trade. He introduced the first British storm forecasting service, and apparently was the first to use the word "forecast." Most of us will know him best as the Captain of H.M.S. Beagle during young Charles Darwin's voyage into history. He was in the audience at the famous 1860 Oxford debate on evolution between Thomas Huxley, Darwin's young protege, and Bishop Samuel Wilberforce. In the uproar that followed that debate's climatic confrontation, Fitzroy leapt to his feet in a rage, waving a copy of the Scriptures. "Here is truth," he cried, "nowhere else." He was shouted down. I had more to say about Fitzroy here.

Fair Isle, Viking, Cromarty, Forties, Forth, Tyne. The names have become as familiar in these isles as a list of the kings and queens of England. The seventh Glanmore Sonnet by the Irish poet Seamus Heaney begins with "Dogger, Rockall, Malin, Irish Sea," the words rolling off the tongue in a long, ominous swell. "Green, swift upsurges, North Atlantic flux/ Conjured by that strong gale-warning voice," the poet continues, and one can imagine a young Northern Irish lad sitting by the wireless on a stormy night, learning something of his future craft from the refined accents of the BBC continuity announcer and the names that give a stirring substance to the enclosing sea.

Humber, Thames, Dover, Wight. Easterly 3 or 4 occasionally 5 at first. Rain later. Good.

Will the shipping forecast survive? Even small pleasure craft now carry an array of electronic devices to monitor place and depth and weather forecasts. In a sense, the BBC broadcasts have become as redundant as the monarchy. But I would not expect either the Queen or the shipping forecast to abdicate anytime soon.

The fastest? The boldest? The luckiest?

2008-08-24T06:19:00.002Z

Question: Why does it take 200 million male sperm to fertilize a single female egg?

Answer: Because they won't stop to ask for directions.

OK, just kidding. But the truth may be just as strange -- if only we knew the truth.

We don't know much about the mystery of fertilization. All we know is that in the act of sex a few hundred million little wigglers are ejected into a women's vagina and go racing toward the egg, which is waiting somewhere up a long dark tunnel.

In fact, about six inches of long dark tunnel, at the upper end of a Fallopian tube. That would be equivalent to me swimming through a dark cave about three miles long. A cave with lots of twists and turns and blind passages. Against a stream of toxic female secretions flowing in the opposite direction.

The journey from ejaculation to fertilization can take a hour or two. If the female partner in coitus has had other recent lovers, the sperm may face competing sperm on their way to the egg. A sexually promiscuous woman's reproductive tract can be an arena of tiny tadpole gladiators locked in chemical combat.

It is all rather like one of those computer games where you have to blast your way through a labyrinth of fiends and hazards to reach the ultimate prize. Not easy for the eager swimmers.

Only a few thousand sperm make it as far as the Fallopian tubes. Less than a hundred may find the egg.

Microphotographs of a fat round egg in the midst of swarming suitors are, I think, among the most wonderful artifacts of human ingenuity. What is invisible to the human eye -- the central event of human existence! -- is revealed as a frenzy of desire. Even at the level of single cells, what we see looks a lot like lust.

The writhing sperm release an enzyme that breaks apart the egg's outer layer of cells, the corona, revealing a second wrapping, the elegantly named zona pellucida. One sperm -- the fastest? the boldest? the luckiest? -- latches onto the zona pellucida and penetrates the egg.

Immediately, a chemical switch (of sorts) is thrown, closing the door to any other suitors. The single successful bearer of male chromosomes is embraced by the egg, and -- glory of glories -- a new human being begins its journey to selfhood.

How do the sperm know where to go in that dark cavern? How do they protect themselves from the hazards of the journey? What causes them to release an enzyme when they reach the egg? How does the egg shut the door when the first sperm has gained entry?

Communication between egg and sperm -- the come-hither wink, the whispered sweet nothings -- is chemical. The mystery of fertilization, like most of what goes on in the human body, is a cacophonous chatter of proteins.

One protein binds to another like a jigsaw-puzzle piece with its neighbor. This causes the receptor molecule to change its shape. Another protein now binds with the new configuration of the receptor. And so on, in a sequence of shapeshifting and binding -- called a signal-transduction cascade -- until the appropriate response is established.

Biologists have pretty much solved the riddle of how the genes make proteins. Now the challenge is to decipher the language of proteins, to read the book of human biology in the language in which it is written.

The hundreds of millions of sperm that begin their journey toward the egg don't need to ask for directions. Millions of years of evolution have perfected a commerce of proteins that guides them to their target.

And the egg by no means waits in solitary indifference for the first of Cupid's darts to plunge into its zona pellucida. The egg has its own part in the protein dialogue, marshaling the whole of a woman's biology to beckon and select the best of male genes.

...he preferentially believes

2008-08-17T06:27:00.002Z

(This essay appeared in the Boston Globe on March 6, 1989, shortly after the tests described here were reported in Nature. No doubt some water has since passed under the bridge that I am not aware of, but I think the point of the essay remains important.)

By now everyone has heard the result of the carbon-14 dating tests on the Shroud of Turin, the linen cloth preserved in the cathedral at Turin, Italy, bearing the likeness of a man and purported to be the winding sheet of Christ. The official report of the investigating scientists has now appeared (Nature, February 16). The report is itself in many ways more interesting than the result. It is a classic illustration of the scientific way of knowing and deserves a wider circulation.

Question: How old is a certain piece of cloth? Forget for the moment what makes this particular piece of cloth historically interesting; can we determine its age? The answer: Yes, by a method known as carbon-14 dating.

Carbon dating exploits the precisely measurable radioactive decay of carbon 14 atoms. The details of how the method works are not -- in this context -- important. The point is that there are people who claim they can find out how old something is by counting atoms. Can we believe them? Can we trust their results?

Let's put them to the test. Take wood from the heart of a 1,000 year-old sequoia tree whose age can be determined by counting rings. Or bone from the tomb of an Egyptian king. Or a thread from your great-great-grandmother's wedding dress. Send the sample to a carbon-dating lab and ask them to determine the age. Don't tell them you already know the answer. See if they get it right.

Now, take my word for it, this has been done, over and over again. Carbon dating has been thoroughly tested and calibrated with objects of known age. The method is complicated -- it is based on some high-power chemistry and physics and expensive equipment -- but it works. Any skeptic who can afford the fee can put it to the test.

Three carbon-dating labs, in Zurich, Oxford, and Arizona, participated in the test on the Shroud of Turin. Along with samples from the shroud, each group was given three control samples of cloth -- linen from a 900 year-old Nubian tomb, linen from a 2nd-century AD mummy of Cleopatra, and threads from an 800 year-old garment of St. Louis d'Anjou. None of the samples were identified. None of the labs communicated with each other until the results were in.

The final report of the investigation describes in detail the methods by which samples were taken from the shroud, then cleaned and prepared for analysis by laboratory staffs. Also described is a statistical analysis of the results. All three labs agree on the ages of all four samples within experimental error, and correctly dated the control samples. Conclusion: The Shroud of Turin is medieval.

Is that conclusion absolute? Of course not. No scientific test can prove anything with absolute certainty. As one of the Oxford investigators wrote (in a letter to Nature), "If we accept a scientific result, we must exercise a critical notion of the probabilities involved. If we demand absolute certainty, we shall have to rely on faith."

Science is not faith. Science is common sense. There is always a remote possibility that some unknown agency acted on the shroud in such a way as to cause the carbon-dating experiments to give a false result. For example, a Harvard University physicist has proposed (whether seriously or not I do not know) that neutron emission from the radiant body of the resurrected Christ might have transformed some non-radioactive carbon into carbon 14 by neutron capture, thus invalidating an important assumption upon which the age measurement is based.

The three laboratories apparently considered this bizarre possibility, and their reply (articulated by R. E. M. Hedges of Oxford) goes something like this: 1. No known physical process could produce a neutron flux of the required magnitude, and if a supernatural explanation is proposed, then there is hardly any point in doing the experiments. 2. It would be an amazing coincidence if the proposed neutron emission was such as to make the apparent age of the cloth coincide with the very time -- mid-14th century -- when the shroud is first mentioned in history.

Science cannot disprove supposed miracles. What science can do is confirm a perfectly natural explanation for this remarkable object which is consistent with everything else we know about the world. Namely, the shroud is a medieval icon or forgery.

It is to the credit of Church officials in Italy that they authorized the tests and accept the results. Their actions are consistent with a recent declaration of Pope John Paul II on the proper relationship of science and theology. "Science can purify religion from error and superstition," wrote the Pope, "[and] religion can purify science from idolatry and false absolutes." He continued: "The unprecedented opportunity we have today is for a common interactive relationship in which each discipline retains its integrity and yet is radically open to the discoveries and insights of the other."

Some people will still want to believe that the Shroud of Turin is the winding sheet of Christ, and that is their right; no carbon-14 test, or any other test, will dissuade them. They prefer the apparent certainties of miracles to the considered probabilities of natural science.

Addendum 1: On February 3, 2005, I wrote this on the blog:

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 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.

Addendum 2: You will have noted that a commenter here suggested recently that I am not aware of the considerable literature on the Shroud. I am indeed aware of it, but I have better things to do that read the many books and web sites that support the Shroud cult, just as I don't bother reading the voluminous literature on alien abductions or astrology. In matters such as this, for which I have very little personal interest, I reply on the filter of the peer-reviewed scientific literature. When one of the two weekly peer-reviewed journals to which I subscribe -- Nature and Science -- takes notice, so will I. Be assured that I am open to any possibility.

The workbench

2008-08-10T06:46:00.001Z

Our family home in Chattanooga was built in 1941, and like most other homes in the city was heated by coal. It had a coal bin in the basement, and a big galvanized furnace with cast iron doors and grates and air ducts sprouting from the top like the hair of Medusa. Keeping it going during the winter required a lot of shoveling, and riddling, and hauling ashes. If the darn thing went out, getting it started again was a chore. All this my father bore with about as much grace as you could expect of a young man with a new house and a growing family.

Then, at war's end, came gas, and a furnace conversion. Perhaps no single technological development of the last century made a greater change in a man's life than the automatic gas or oil-burning furnace.

But for me -- ten years old -- the real import of the conversion was the workbench.

My father ripped out the coal bin and used the lumber to build a workbench. A real doozy of a six-footer, with a double-planked top and a backboard for hanging tools and an overhanging shelf under which could be tacked the screwtops of two dozen peanut butter jars containing screws, nails, washers, nuts and bolts.

Even at that young age I was astute enough to know that the workbench fulfilled an ambition of my engineer father, the ultimate expression of secure, middle-class, suburban life. All that time spent shoveling and riddling and hauling ashes could now be spent fiddling and tinkering and mending. My quintessential memory of my father is of him hunched over the workbench with white sleeves rolled to his elbows, his tie tucked into the buttoned front of his shirt, a dismantled lamp or toaster on the worktop, a soldering iron sizzling in his hand.

Here are some things that were essential to a good workbench:

--It had to be in a basement or garage or other space separate from the house. It was an altar for male liturgies, like the sanctuary of the church a place where women were excluded, an escape from the perplexing entanglements of matrimony.

--On the shelf above the workbench there must be a pile of Popular Mechanics and Popular Science magazines, with their tips for home improvements, Saturday projects, and news of innovations for the tinkerer -- multi-tipped screwdrivers, leaf-proof gutters, self-rosining solder, jigs, rigs and thingamabobs. Here too was a vision of the future that the basement mechanic could aspire to at least in dream: ocean-going hovercraft, folding-wing airplanes for the family garage, radio transmissions with pictures, colonies on the moon.

--At the corner of the workbench there must be a vise. The right vise must be neither too bulky nor too delicate; it was an extension of one's own hands. My father had a dandy, with shiny steel jaws, that he kept nicely lubricated; you could open or close it with a twirl of your little finger.

--The location of tools on the backboard must be marked by painted silhouettes of the tools -- hammer (claw and ball peen), hacksaw, pliers, screwdrivers, brace, rasp, wrenches, etc. -- a shadow tool kit.

--Wood chisels were kept wrapped in oiled cloth. A whetstone in its homemade wooden cradle kept the blades shiny and sharp.

--Somewhere nearby there must be a cabinet with a big drawer in which anything could be thrown that didn't have an assigned place on the workbench. Nothing was discarded. Odd screws, clips, springs, brackets, bits of metal, lengths of wire, broken tools, slightly bent nails. You never knew when you'd need exactly that thing.

--There must always to a project pushed to the back of the bench at an indeterminate state of completion. A pouty wife might lock herself in the bathroom; a sulking husband needed a more manly retreat.

That workbench in our basement was my refuge too as I entered adolescence, a place to learn and hone my masculine skills -- mechanical, electrical, plumbing, woodworking -- and subdue my hormonal frustrations in a balm of solder splatters and sawdust. Yes, it was a male thing, hard, and bright, and suffused with the smells of burning rosin, wood chips and oil, guaranteed to hold at bay -- for at least an hour or so -- the softer, gentler puzzlements that attached themselves to the feminine, never, ever to be understood.

My father's workbench served me well. I learned how to repair an electric iron, change a washer in a faucet, and stay married to the same woman for fifty years. The surface of a good workbench is akin to the bench in a science lab; it is a place apart, disentangled from the complexities of the emotional life, where one can take apart bits and pieces of the natural world and put them back together again in working order, in the process learning how the world works.

Nitpicking

2008-08-03T06:11:00.003Z

If you are reading this at breakfast, you might want to put it aside until a less gastronomically sensitive moment. This is about lice, about a nasty bacterium named Rickettsia prowazekii, and about life and death.

Let's start with the lice. More specifically, let's start with the human louse, Pediculus humanus, better known as the cootie.

Lice have inhabited the human body since...well, since the beginning. Head lice love the dark jungles of the scalp. Body lice may have descended (in both senses of the word) from head lice when humans started wearing clothes.

Lice have a knack for getting around. They flourish wherever humans live in crowded, unsanitary conditions, hopping from person to person.

Scanning electron microscopes show every pore, crease, and bristle of the creature's beastly visage. It is a blessing that lice are too small for us to see these details with the unaided eye; some things are better left unseen, especially at breakfast. If you insist on seeing lice close up, go to the web site of the Australian louse authority Rick Speare and see the lobster-like claws by which they swing from hair to hair, the blood-sucking mouth, the prickly genitalia.

What you won't see in the photographs are the tiny pickle-shaped bacteria, Rickettsia prowazekii, that in many parts of the world inhabit the louse's gut. These are the infectious agents of the disease typhus. Rickettsia prowazekii is a parasite. It can only live within other cells, at the host cell's expense. And guess whose cells it prefers, indeed, demands? Our own. And lice are the vehicles by which the parasite bacteria travel from human to human, making mischief.

Here's how it usually works: A louse -- on the scalp, say -- sucks blood from someone who carries the typhus pathogen. Once infected, the louse has only a few weeks to live, but during that time it might make the jump to another person. There, it feeds again by sucking blood. And defecates. The new host human scratches the itch, rubbing the louse's infected feces into the wound -- and another person has contracted typhus.

The disease is most often fatal for people who are elderly, malnourished, or physically exhausted. Typhus typically follows in the wake of wars. Between 1918 and 1922, at the close of World War I, a typhus epidemic in Russia and eastern Europe claimed 20 million victims and caused 3 million deaths. Today, the disease is most prevalent in the central highlands of Africa and parts of Asia, South America, and Central America. The United States and Europe are mostly typhus free.

Geneticists have sequenced the Rickettsia prowazekii genome; that is, they have identified the more than 1 million chemical units along the bacterium's DNA and mapped the genes. And the news is this: Rickettsia prowazekii appears closely related to mitochondria, the oxygen-respiring compartments in the eukaryotic cells that make up the bodies of all complex animals, including ourselves.

Billions of years ago, a free-living common ancestor of both mitochondria and the typhus pathogen evolved the chemical machinery of respiration, the ability to oxidize carbohydrates. This was a hugely important step in the history of life, providing far more energy than is available to non-respiring organisms.

One line of descent from that ancestral organism took up a symbiotic existence inside larger host cells, and eventually became integral and useful parts of our cellular machinery -- the mitochondria. Permanently ensconced within their hosts, the mitochondria "de-evolved." They shed redundant genes, simplifying their DNA, and relied on the genetic resources of the cell's nucleus to supply most of what they needed. It's an old story. Two can live almost as cheaply as one if they don't duplicate resources.

Another line of descent from the ancestral organism led to the typhus pathogen, the louse-borne scourge of humanity. These also took up a parasitic lifesyle, casting off redundant genes and relying for most of what they need upon the genes of host cells. But unlike the mitochrondria, the typhus pathogen provided no benefits to its hosts, and a heap of trouble.

If the typhus pathogen and mitochrondria are cousins of a sort, then they are the Cain and Abel of cell invaders; the one causing disease and death, the other facilitating the breath of life.

Both lines of descent from the ancestral organism are successful in their own way. From the human point of view, however, the mitochondria are useful, hard-working members of society, and Rickettsia prowazekii is a lawless buccaneer. If there is a lesson in all of this it is that we are up to our necks -- nay, up to our lousy scalps - in a tangled, tangled web of life.

Reasonable guesses

2008-07-27T05:56:00.001Z

Problem: A person wants to build a square house with an area of 500 square feet. What should be the length of the side of the house?

That's easy. Get out the calculator. Punch in 500. Push the square-root button. The answer: 22.36067977 feet.

The Calculator Monster has struck again!

Every math or science teacher will recognize the monster's track. Answers that run to 10 digits, most of them meaningless.

OK gang, put away the calculator. Now figure out the answer on the back of an envelope. 20 times 20 is 400. Too small. 25 times 25 is 625. Too big. Split the difference. Try 22.5 feet for the side of the house. That's 506 square feet. Close enough. The person who lives in the house will never know the difference.

There's nothing wrong with calculators. The calculator is probably the greatest boon to quantitative thinking since the invention of Arabic numerals. Everyone should own one and know how to use it. But sometimes they take all the fun out of thinking.

When I went off to college to study engineering in the 1950s my dad gave me his well-worn K+E slide rule. A precision instrument. A thing of beauty. "Wear it with pride," he might have said. And off we went to class, engineering nerds, slip-sticks dangling at our sides.

If someone had told us then that we would soon carry in the palm of our hand a device costing less than my slide rule that could do arithmetic and a host of higher mathematical functions instantly and accurately (to ten significant figures!) we would have said, "impossible." But slide rules had one advantage over calculators: They rounded off, by necessity. They lent themselves to back-of-the-envelope calculations. They encouraged judicious approximation.

Yes, everyone should own a calculator -- one comes as a extra with your iPhone! -- and know how to use it. But kids should be taught the art of rounding off, and of making reasonable guesses. Too much precision can sometimes obscure understanding. A lot of good science can be done with "let's assume," "more or less," and "to a first approximation."

In one episode of Philip Morrison's television series The Ring of Truth, he makes a clever order-of-magnitude measurement of the size of a molecule by watching oil spread out on a pool of water. One teaspoon of oil poured on water will spread to cover half-an-acre, he observes. Assume that the oil slick at maximum extent is one molecule thick; how big is a molecule?

Any smart high-school student should be able to solve this problem, but few will have the confidence to try. It helps in solving problems like this to think metrically, and of course the United States is the only country in the world (more or less) that continues to hobble the brain with feet, inches, ounces, teaspoons, and acres.

The first thing an enterprising, metrically-inclined student will want to know is how many cubic centimeters there are in a teaspoon and how many square meters in an acre. So, make reasonable guesses. The side of a sugar cube is about a centimeter; how many crumbled sugar cubes would fill a teaspoon? How big is the lot your house sits on, in acres? An adult's pace spans about a meter; how many paces to walk the length and breadth of your lot?

What else do we need to know? The formula for the volume of a sphere. Some junior-high geometry. A little quick pencil work on the back of an envelope and -- voila! -- we have the size of an oil molecule. And not a bad estimate at that.

Now for a follow up question. Assume that the 240,000 barrels of oil spilled from the Exxon Valdez spreads out into a slick of maximum extent. What is the area of the slick? How many barrels of water are there in the world's oceans to dilute the oil? Assuming complete mixing, how many Exxon Valdezes would have to empty their contents into the oceans to contaminate the water to one part in a billion with crude oil?

There's no end to the instructive questions students can answer with a little help from their teachers, with nothing but reasonable guesses and rough-and-ready calculations. How many trees must be cut down to supply the junk mail that enters American households each year? How large a landfill would be required to receive the junk mail that enters your town in ten years? How long would it take for all the cars and trucks on Earth to cycle the entire atmosphere through their engines? If a warming climate melts the mile-thick ice caps on Greenland and Antarctica, by how much will the level of the the oceans rise?

When I was teaching, I loved to step students through questions like these, letting them do all the thinking. Order-of-magnitude, back-of-the-envelope kind of questions. They were always amazed that answers were so readily obtained. These were the rules: Don't look up anything you can reasonably guess. Think in metric and powers of ten. Calculators are permitted, but only as a handy tool; don't bother with any more significant figures than are in your roughest guess.

Thinking about thinking

2008-07-20T05:45:00.000Z

It is not easy to live in that continuous awareness of things which alone is true living," wrote the naturalist Joseph Wood Krutch. And, of course, he was right. Our brains are separated from the world by a permeable membrane. Attention flows outwards. Sense impressions flow inwards. Of this two-way traffic -- this awareness -- we create a soul.

At this moment, as I sit at my desk on a hillside in the west of Ireland, I try to be aware. Sunlight streams across my computer keyboard; eight minutes ago these photons were on the surface of the sun. A Pholcus phalangioides spider spins its web under the shelf above the desk; I touch the web with a pencil point and the spider does a dervish dance. Outside the window, clouds scud in from the Atlantic; there will be rain in the afternoon.

Continuous awareness: It can be exhausting. Which is why, I suppose, we sometimes wish for the mind to go blank, for the windows of the soul to close, for darkness to fall.

Fortunately, the one thing we don't have to attend to is awareness itself. The brain does its thing without the least bit of conscious control on our part. And a good thing, too; if we had to attend to what is going on in the brain when we attend to the world, we'd...

We'd go nuts.

Nothing we know about in the universe approaches the complexity of the human brain. What is it? A vast spider web of neurons, cells with a thousand octopuslike arms, called dendrites. The dendrites reach out and make contact at their tips with the dendrites of other cells, at junctions called synapses.

A hundred billion neurons in the human brain, with an average of 1,000 dendrites each. A hundred trillion octopus arms touching like fingertips, and each synapse exquisitely controlled by the cells themselves, strengthening or weakening the contact, building webs of interlinked cells that are knowledge, memory, consciousness -- self.

A hundred billion neurons. That's more brain cells than there are grains of salt in 1,000 one-pound boxes of salt. A roomful of salt grains, floor to ceiling. Each in contact with hundreds, thousands, or tens of thousands of others. The contacts flickering with variable strength. Continuously. Unconsciously. Never ceasing. Remembering. Forgetting. Feeling joy. Feeling pain. Thinking. Speaking. Lifting a foot, moving it forward, putting it down again. Flickering. A hundred trillion flickering synapses.

Just thinking about it is exhausting.

Neuroscientists are busy trying to figure it all out. Some folks would say that bringing the scrutiny of science to bear upon the human soul is the height of presumption. Others would say that the more we learn about what makes our brains tick, the more we stand in awe at the mystery of soul.

The sheer complexity of the human brain makes any adequate description a daunting task. Which is why some neuroscientists choose to work with simpler organisms -- sea snails, for example -- to get a grip on the basic structure and chemistry.

In recent years, new scanning technologies enable neuroscientists to watch live human brains at work. Active neural regions flicker on the screens of computer monitors as subjects think, speak, recite poems, do math. Continuous awareness, displayed on the screen of a scanning monitor, can look like a grass fire exploding across a prairie.

Still other scientists attempt to model the brain in silicon, building electronic circuits called neural networks that mimic the activity of the brain as it creates constantly changing webs of neurons. So far, no electronic network begins to approach the complexity of the human brain, but the time is not far off when silicon brains will rival brains of flesh and blood. Just trying to make it happen teaches us a lot about how human brains work.

Perhaps the most exciting research is that of the scientists who study the biochemistry of neurons: How do the cells regulate synaptic connections to build new neural webs?

One big surprise is just how much of the "thinking" of neurons is done by the dendrites, those hundreds of spidery arms that connect neurons to one another. DNA in a neuron's nucleus sends messenger RNA down along the dendrites to active synapses, where they are translated into proteins that regulate the strength of synaptic connections. Tiny protein factories in the dendrites are apparently key to learning and memory.

Once the regulation of these protein factories is understood, drugs that ameliorate some kinds of hereditary mental retardation might be possible. As will drugs that help all of us to learn and remember. Are we ready for "smart" pills? Memory pills?

What all this amounts to is awareness of awareness. For the first time in the history of consciousness, the machinery of awareness has been turned upon itself. As neuroscientists have discovered, thinking about thinking is not easy. Thank goodness we don't have to think about thinking to think.

Science Musings

Doing the impossible

Capax Dei

To a Mouse, on turning up her genetic code with a DNA sequencer

Bark us all bow-wows of folly

The power of the paradigm

Making color together

Further Reading

A murmur of myrmecology

Further Reading

A world made on Sunday

Further Reading

Sacred and profane

A walk across the universe

Further Reading

The Great Silence

Further Reading

In the beginning

Sail on, sail on, sail on and on...

Tunk-tunk

Further Reading

Stretching the imagination

Thinking like a hobbit

Who vets the web?

Saying yes to the universe

Moderate with fog patches becoming good

Further Reading

The fastest? The boldest? The luckiest?

...he preferentially believes

The workbench

Further Reading

Nitpicking

Further Reading

Reasonable guesses

Thinking about thinking