Reviews

Sunday, September 01, 2002
Books

Seeing in the Dark: How Backyard Stargazers Are Probing Deep Space and Guarding Earth From Interplanetary Peril
By Timothy Ferris
Simon & Schuster, $26




Gone are the days— or nights— when astronomers kept lonely vigils in cold mountaintop domes, squinting at distant stars through the eyepieces of long, slender telescopes. Computers, automated cameras, and instruments like the Hubble Space Telescope have changed the discipline forever. Hands-on observers are now as rare as lighthouse keepers or elevator operators, at least among the pros. But the amateurs are still out there, thousands of them, every night. And the best are making real contributions to astronomy— finding comets, mapping storms on Mars and Jupiter, discovering new supernovas. This is their golden age, and no one is better suited to chronicle the revolution in observation than Timothy Ferris, the best-selling author of Coming of Age in the Milky Way and an ardent amateur astronomer himself. In telling the story of his brethren, Ferris takes readers on a grand tour of the known universe, from nearby planets to distant galaxies, in a sweeping, elegantly composed narrative rich with historic and scientific detail.

Today hobbyists have access to equipment that only a decade ago would have been the envy of professionals. The thousands of telescopes, computers, and electronic cameras in amateur hands far outnumber the relatively few large university and government observatories. So on any given night, backyard stargazers monitor more of the sky than their professional counterparts. The amateurs have another advantage besides sheer numbers: time. Given the fierce competition for access to the larger observatories, experts can't afford to train one of their big telescopes for a full year on, say, Mars. Amateurs work under no such constraints. Professional astronomers have only just begun to recruit help from this vast pool of observing power.

Ferris explores the work of groups like the Center for Backyard Astrophysics, a global network of amateurs and professionals who are studying "cataclysmic variable stars," double-star systems where the gravitational pull of the denser star rips matter from its neighbor. He also encounters remarkable individuals like Stephen O'Meara, an amateur whose observations of dark, spokelike patterns in Saturn's rings were doubted by astronomers until the Voyager spacecraft reached Saturn and confirmed their existence.

Many of the amateurs who people Ferris's book have sacrificed money, jobs, and marriages in the pursuit of their starry avocation. As you read, you begin to understand their obsession. What other pastime takes you to the edge of the universe or gives you the chance to be the first to see an exploding star?


 
Museums

The Mercer Museum
Doylestown, Pa.
www.mercermuseum.org

The Mercer Museum totters precariously between the present and the past. Henry Mercer's six-story castle looks even older than the surrounding 18th-century town of Doylestown, Pennsylvania, yet it is constructed entirely from reinforced concrete. This tension of ancient versus modern continues inside— in fact, it is the entire point of the museum. Every inch of the building's 73 rooms and alcoves is crammed with tools from the last days before the Industrial Revolution. For centuries, or in some cases millennia, these items were the technology of daily living; they were a defining aspect of what differentiated humans from the animals. Within a few decades, they almost all vanished, displaced by assembly lines, interchangeable parts, electric motors, and internal combustion engines. The Mercer collection, in short, is a snapshot of the moment when muscles and craftsmanship gave way to mechanization and scientific know-how.

The roots of the museum date to 1897, when Mercer, a Pennsylvania tilemaker and archaeologist, happened across a junk dealer's cache of plows, spinning wheels, and other newly obsolete items. Mercer realized he was staring at a hoard that future historians would long to study, and he spent much of the next 30 years gathering other such relics of the manual professions. In 1916 Mercer opened his grand museum, which he designed to have an antiquarian ambience but built out of the latest fire-resistant materials to protect the burgeoning collection.Today the museum's holdings have grown to more than 50,000 objects, meticulously sorted by form and function.

No craft has been ignored, no tool overlooked. Each room quietly but sternly communicates the astonishing amount of labor that once went into even the most mundane creations. A mug of cider began with pairs of workers turning two-foot-thick wooden screws to press the apples; coopers spent a lifetime shaping planks to make the barrels that held the fermented juice. One of the museum's loveliest displays exposes a simple ornamental comb as the end product of exhaustive mechanical manipulations. The shell of the tropical hawksbill sea turtle, imported from the Caribbean, had to be heated, softened, pressed, shaved, filed, and bent to attain the correct look and feel. By the start of the 20th century, functionally equivalent celluloid or plastic combs were flying out of the factories. Again and again, one marvels at how a handful of technological innovations have so radically transformed American culture in little more than a hundred years.

Many of us have encountered these ideas before in history museums or in mock-colonial towns. But the Mercer Museum is a unique portal to the lost world, unfiltered by actors or storybook re-creations.
— Corey S. Powell


 
Books

Darwinism's Dark Secret
The strange case of the mutant moths

By Laurence Marschall

Of Moths and Men:
The Untold Story of Science and the Peppered Moth

By Judith Hooper
W. W. Norton, $26.95


Photograph courtesy of Jens Mortensen
Every branch of science has its stories, oft-told tales that gain the luster of family folklore. Among evolutionary biologists, one of the favorites is that of the peppered moth, Biston betularia. Until 1848, as far as anyone knows, the typical peppered moth resembled a folded wedge of slightly used blotting paper, its delicate white wings splotched with a few flecks of black. That year, however, dark-winged variants called melanics began to appear, first near the belching smokestacks of Manchester, then throughout the industrialized cities of Victorian Britain. By the end of the century, the species had been transformed; the proportion of melanics in some urban areas ran as high as 98 percent.

Ordinarily, the wheels of evolution turn so slowly that Darwin himself despaired of ever elucidating natural selection by any means other than looking closely at the fossil record. Yet here was evolution in action, taking place not over thousands of millennia but within the memory of a single observer. Those pre-1800 salt-and-pepper wings, which had helped the "typical" variety of Biston betularia blend into invisibility among lichen-covered trees, were a positive disadvantage among the industrial mills of the late 19th century. Against a soot-blackened trunk, the typicals were easy marks for hungry birds, while the dark-winged melanic mutants, invisible to avian eyes, survived.

Still, skeptics wondered: Was this truly natural selection at work? The mechanism was unclear. Perhaps black wings are linked with some other beneficial trait, or perhaps industrial pollution acted chemically to alter the genes that controlled wing color. What was needed was a controlled experiment to establish the facts.

Judith Hooper, a science writer from Amherst, Massachusetts, examines that experiment, which was carried out in the 1950s. The experimenter, H.B.D. Kettlewell, bred white-winged and dark-winged moths, released them in two forests (one polluted and one pristine), and counted the proportions of the two varieties that he recaptured several days later. As expected, dark-winged survivors outnumbered white-winged survivors in the sooty forest, and vice versa in the clean environment. In addition, Kettlewell's colleague Niko Tinbergen managed to film birds preferentially picking off the non-camouflaged moths in both situations.

Kettlewell's work immediately became the textbook example of evolution. Thus it was a serious matter when re-examinations of that work in the late 1990s began to cast doubt on both his experimental design and his conclusions. The critics noted, for example, that Kettlewell released his moths during the daytime; moths, however, are night fliers, so most of them stayed where he put them, easy prey for birds. Had they been released at night, they would probably have flown to higher branches in the trees, where no birds— nor for that matter, biologists— could have seen them. Such criticism, mounted by fellow evolutionists, hinged on technical points, but this didn't stop creationists from gloating in Internet chat rooms about the death of Darwinism. In retrospect, though, doing the peppered-moth experiment right would have proved nearly impossible for anyone.

Hooper provides a judicious account of the Kettlewell affair, describing the experimenters and the experiments, and how they fit into the normal self-correcting enterprise of 20th-century biology. She is helped by the cast of characters, especially the manic Kettlewell and his Oxford mentor, E. B. "Henry" Ford, who seem to have had little in common but a penchant for tormenting Oxford's secretarial staff and occasionally munching on moths.

This is a lively yarn, but Hooper spends too much time on University of Massachusetts biologist Ted Sargent, whose skepticism regarding Kettlewell's work is so extreme that a reader might think the foundations of evolutionary biology were crumbling. Far from it. When all is said and done, the case for evolution hinges on far more than one high-profile experiment. Today biologists who conduct research on natural selection in the wild do so with an increasing awareness of its complexity. None of the newer experiments is as cut-and-dried as Kettlewell claimed his was. If there is a lesson in the peppered moth, it is that the central story of evolution is written not in blacks and whites but in subtler shades of gray.


 
Toys

The Models
Sean Kinkade,
ParkHawk, $199
Ornithopter Technologies, Swallow, $11.50
Spectra Star, Fearsome Flyers, $5.99
Tedco, Batwing and Butterfly, $10.95



To best test ParkHawk's prowess, you'll need to find a space the size of a football field.
Photograph courtesy of Jens Mortensen
In 1485 Leonardo da Vinci made detailed sketches for a human-powered ornithopter: a contraption designed to mimic bird flight. His wing-flapping device never left the ground, but half a millennium later, flight enthusiasts can choose from a variety of model ornithopters powered by everything from rubber bands to diesel fuel. One of the more impressive designs is the new battery-powered, radio-controlled ParkHawk (for information, write to thopter@earthlink.net). The raptorlike ornithopter, which features a four-foot wingspan, ripstop nylon wings, motor, and fiberglass frame, comes unassembled; the servos and radio receiver required to control its flight must be purchased separately. Once in the air, the ParkHawk can climb overhead to a height of 250 feet and fly 20 miles per hour. The graceful Swallow, from Ornithopter Technologies (www.members.tripod.com/ornitech), is a delicate balsa-wood and tissue-paper creation with a 20-inch wingspan; it requires a few hours to assemble and is powered by a supercoiled rubber-band motor. Spectra Star's preassembled Fearsome Flyers (mvazquez@spectrastar.toybiz.com), shaped like dragonflies, pterodactyls, and other airborne beasts, have Mylar wings and a rubber-band motor that's wound with a simple cord. They're noisy, low-altitude fliers but fun to watch. Tedco's (www.tedcotoys.com) fliers are as gentle as moths in flight and even simpler in design: Their rubber motors are twisted with a crank, and each bat or butterfly model comes with background about the animal it resembles.
— Lauren Gravitz


 


Science Best-sellers

1. A New Kind of Science
By Stephen Wolfram,
Wolfram Media
2. The Universe in a Nutshell
By Stephen Hawking,
Bantam
3. The Theory of Everything: The Origin and Fate of the Universe
By By Stephen Hawking,
New Millennium Press
4. I Have Landed: The End of a Beginning in Natural History
By Stephen Jay Gould,
Harmony
5. The Structure of Evolutionary Theory
By Stephen Jay Gould,
Harvard University Press
6. Tuxedo Park: A Wall Street Tycoon and The Secret Palace of Science That Changed the Course of World War II
By Jennet Conant,
Simon & Schuster
7. The Next Fifty Years: Science in the First Half of the Twenty-First Century
Edited by John Brockman,
Vintage
8. The Future of Life
By E. O. Wilson,
Knopf
9. The Last Lone Inventor: A Tale of Genius, Deceit, and the Birth of Television
By Evan I. Schwartz,
HarperCollins
10. The Turk: The Life and Times of the Famous Eighteenth-Century Chess-playing Machine
By Tom Standage,
Walker & Co.
* Source: Barnes & Noble Booksellers



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Find flapping flight facts at the Ornithopter Society's Web site: indev.hypermart.net.
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