Cover; October 1999; Scientific American Magazine; by Staff Editor; 1 Page(s)

Table of Contents; October 1999; Scientific American Magazine; by Staff Editor; 2 Page(s)

From the Editors; October 1999; Scientific American Magazine; by Alda; 1 Page(s)

Letters to the Editors; October 1999; Scientific American Magazine; by Staff Editor; 2 Page(s)

50, 100 and 150 Years Ago; October 1999; Scientific American Magazine; by Staff Editor; 1 Page(s)

THE WHITE PLAGUE-"To find a concrete physiochemical basis of tuberculosis virulence, we undertook a comparative study of virulent and avirulent strains of tubercle bacilli, in the hope that we could thereby recognize some specific differences correlated with the ability to cause disease. This comparative approach may lead to the identification of the peculiar structures or properties that permit the tubercle bacilli to establish themselves, multiply and cause damage in the tissues of the body.-Rene J. Dubos" [Editors' note: Dubos won a Pulitzer Prize in 1969 for So Human an Animal: How We Are Shaped by Our Surroundings.]

PLANKTON MCNUGGETS-"We would like to believe that in the immense, newly explored organic resources of the oceans lies part of the solution to the world's increasingly acute food problem. Lately we have heard some highly hopeful proposals-that 'farming' of the sea by fertilizer may multiply its yield of fish. Some people suggest catching and using plankton. It is not an attractive food, but it is nutritious, and special processing might make it acceptable. But filtering out a sizable quantity of such small creatures would require an enormous output of energy. By and large we must leave the plankton to the fishes."

In Focus: Truth or Consequences; October 1999; Scientific American Magazine; by Beardsley; 2 Page(s)

In earlier centuries, claims of witchcraft may have led to a witchhunt. Today, in the U.S., the sequence has been reversed. Demands in Congress that someone pay the price for supposedly allowing China to steal nuclear secrets from Los Alamos National Laboratory have prompted the Department of Energy to institute polygraph screening to detect spies at three national laboratories that work on nuclear weapons. The screening will cover Sandia and Lawrence Livermore national laboratories as well as Los Alamos and may extend to as many as 5,400 employees. Testing started during the summer for federal workers and some volunteers employed by the contractors who run the labs. Routine testing of contractors deemed to have access to critical information was scheduled to start in October, after a series of public hearings.

The polygraph, sometimes called a lie detector, has been used for years to screen small numbers of laboratory employees involved in various special programs. Workers have also been able to volunteer to take a polygraph examination in order to accelerate top-level clearance. But the new program would be the first time civilian scientists have been required to pass polygraph examinations en masse to gain, or keep, access to secret information. Because the law does not allow passing a polygraph examination to be a condition of employment, anyone who repeatedly fails will not be fired but shunted into a less sensitive position-and possibly referred to the Federal Bureau of Investigation.

Pirate Fear; October 1999; Scientific American Magazine; by Williams; 2 Page(s)

After 20 years of repeated sprayings of the pesticide Malathion, the boll weevil no longer rules the nation's cotton fields. But in its wake, beet armyworms-moth larvae so named for their ever widening swath of destruction-have gained fame for their ability to reduce weather-toughened cotton farmers to tears. The key to the plague was an unintended casualty of Malathion: the wasp that preys on armyworms. "It's unbelievable," says Auburn University ornithologist Geoffrey E. Hill. "I've literally seen them strip a field. There's nothing left."

Mississippi farmer Philip Barbour knows that. The infamous 1995 infestation annihilated his crop, along with those of farmers in south Texas, the Mississippi Delta and points east. "In 1995 there were so many, they were crawling up telephone poles," he recounts. With no effective pesticide, Barbour lost his shirt along with his crop.

Quantum Déjà Vu; October 1999; Scientific American Magazine; by Collins; 2 Page(s)

The microscopic quantum world where Heisenberg's uncertainty principle rules can seem a bit like Heraclitus's river, made all the more mercurial by the river changing course every time you so much as look at it. Try to observe the same quantum particle a second time, and chances are you'll find your first measurement has knocked it about. Individual photons, the quantum particles of light, would seem to be an extreme case in point: the standard ways to detect a photon involve its complete destruction when it is absorbed by, say, a retina, camera film or photomultiplier tube.

But now Serge Haroche, Jean-Michel Raimond, Michel Brune and co-workers at the Ecole Normale Superieure in Paris have carried out an experimental tour de force by catching an individual photon in a box, detecting it in a way that leaves it in the box and then detecting it again. The result is the first demonstration of a "quantum nondemolition" (QND) measurement on a single particle.

In Brief; October 1999; Scientific American Magazine; by Staff Editors; 2 Page(s)

A Model Tumor-About 15 years ago scientists induced normal mouse cells to become cancerous; now they have finally repeated the trick with human cells. In the July 29 Nature, a team led by Robert A.Weinberg of the Whitehead Institute in Cambridge, Mass., report creating human tumor cells by adding three genes:a telomerase gene, which allows the cell to grow and divide indefinitely; an antigen that turns off the signals that keep cell growth in check; and a cancer-causing gene called ras.The discovery elucidates pathways of tumor formation and may lead to tests that predict whether a benign tumor will become malignant.-Christina Reed

A Less Carbonated Earth-Global emissions of carbon dropped 0. 5 percent in 1998, to 6.32 billion tons-even though the world's economy grew 2.5 percent.The estimates, from the Worldwatch Institute,suggest that economic expansion need not be a casualty of stricter environmental rules.The drop stemmed from tougher standards and subsidy removals,which led to improved energy efficiency and less coal use.And according to a study released by the World Wildlife Fund,aggressively curbing greenhouse gas emissions could create 870,000 new jobs in the U.S.and save the country $43 billion annually.-Philip Yam

Fat in the Fire; October 1999; Scientific American Magazine; by Beardsley; 2 Page(s)

Findings that a biochemist faked experimental results in two published papers have devastated research on possible effects of lowintensity electromagnetic fields. The Department of Health and Human Services's Office of Research Integrity has released a draft of an analysis concluding that Robert P. Liburdy, a biochemist who worked at Lawrence Berkeley National Laboratory until he was forced to retire this year, "intentionally falsified data" to show that such fields affected cultured cells. The assessment concurs with a committee at the Lawrence Berkeley laboratory that found Liburdy had engaged in scientific misconduct. Liburdy, the committee said, "deliberately created artificial data where no such data existed" and sat on data that contradicted his published claims.

Liburdy published the scientific papers at issue in 1992. Graphs in the papers purport to show that 60-hertz electromagnetic fields, such as those emitted by power lines and electrical devices, alter the movement of calcium ions through channels in the membranes surrounding cultured cells. Because calcium ions are an important biological signal, the results suggested how fields might influence cells and perhaps cause illness.

Boom or Bust?; October 1999; Scientific American Magazine; by Musser; 2 Page(s)

They may be halfway across the universe, but distant supernovae have caused quite a ruckus on the earth. Two years ago astronomers discovered that these stellar explosions are dimmer than expected-so much so that the very structure of space seemed to be responsible. Their anomalous dimness intimated that the expansion of the universe may be speeding up rather than slowing down, as cosmologists had always assumed. But now several of the supernova observers worry that their dramatic findings, like some other disputed claims, jumped the gun. Adam G. Riess of the University of California at Berkeley says grimly, "I liken it to the discovery of life in the Mars rock."

The argument for cosmic acceleration depends on two key measurements for each of several dozen supernovae: the maximum brightness of the explosion, which shows how far away it is and hence when it took place; and the redshift, which records how much the universe has expanded since it occurred. The farthest known supernovae went off 8.4 billion years ago, and since then the universe has doubled in size. Yet at its current expansion rate (as inferred from more recent supernovae) the universe would have tripled in size. Therefore, the expansion rate must have increased.

Deserting the Sahara; October 1999; Scientific American Magazine; by Simpson; 2 Page(s)

Plants may seem to sit passively as climate decides their fate, but scientists are beginning to believe that vegetation can strongly amplify the climate's most subtle whims-sometimes with abrupt and devastating results. A new computer simulation indicates that plants helped to turn the Sahara from a lush grassland thriving with hippos and elephants to its current condition as the world's largest desert.

The Sahara's succulent sojourn faced an abrupt end about 5,500 years ago. In a matter of centuries, rainfall levels plummeted, the green grasslands paled to a sandy yellow, and civilizations were forced to relocate. Many scientists have assumed that human beings, who arrived there 7,000 years ago, overused the land, which led to the quick loss in vegetation. But the new simulations show that a steady but slow loss of grasses-stemming from a gradual trend toward less rainfall beginning about 9,000 years ago-ran wildly out of control.

Anti Gravity: It's Not Oeuvre Till It's Oeuvre; October 1999; Scientific American Magazine; by Mirsky; 1 Page(s)

You can observe a lot just by watching, according to one of the foremost neurolinguists of our time, Lawrence Peter Berra, known as Yogi to his many disciples. If you've been watching the news, you may have observed the music of Mozart getting a lot of attention in recent years as a brain enhancer. For more than half a century, Yogi has endured ballpark organs playing the decidedly non-Mozartian ditty, "ta ta ta TA ta TAAAA," which implores the fans to then scream "charge." But because Yogi also wondered,"How can you think and hit at the same time?" he probably didn't cry foul at the lack of any brain-building melodies emanating from stadium loudspeakers.

Turns out he probably wasn't missing anything (especially high fastballs). A study in the July issue of the journal Psychological Science, from Kenneth Steele and his colleagues at Appalachian State University, disputes those isolated previous findings indicating that a few minutes of Mozart, specifically the Sonata for Two Pianos (K.448) , raise the spatial reasoning capacity of test subjects, albeit temporarily. The attention paid to the so-called Mozart effect helped to pave the way for some pregnant women to slap headphones on their swelled bellies, so that the symphonic could mix with the amniotic to induce the mnemonic and other brainy stuff. Additional histrionics could be found in Georgia,where all new mothers now get classical Cds as a public health measure.

By the Numbers: Men, Women and College; October 1999; Scientific American Magazine; by Doyle; 1 Page(s)

One of the most extraordinary developments over the past two decades has been the growing prevalence of female students on college campuses, particularly in the English-speaking countries and Europe. In the U.S., women became a majority on campuses in 1979 and by 1982 were awarded more bachelor's degrees than men. The number of female graduates, which has been growing steadily for more than a century, is likely to rise further, a trend reinforced in recent years by an unusually large number of women older than 30 seeking higher degrees.

For reasons not wholly apparent, the number of men receiving bachelor's degrees from U.S.institutions has remained more or less level for the past 25 years. If men had kept pace with women, an additional 1.25 million would have graduated during this time. Perhaps these missing men were high school graduates who, faced with the prospect of delayed earnings and large student loans, went directly to work or to vocational school instead. Perhaps, as Thomas G. Mortenson, editor of the newsletter Postsecondary Education Opportunity suggests, the failure of men to keep up with women traces to stresses earlier in life. Boys have had fewer male role models in recent decades because of the decline of two-parent families.Girls in one-parent families ordinarily remain with their mothers and are more likely to find female role models in public schools,where teachers are overwhelmingly female.One result of this disparity,Mortenson says, is that boys are more apt to have poor grades. Eventually the stresses on males,who also suffer disproportionately from learning disabilities, result in lower college enrollment and graduation rates.

Profile: Infamy and Honor at the Atomic Café; October 1999; Scientific American Magazine; by Stix; 2 Page(s)

As I'm leaving for John F. Kennedy airport, I tell a colleague that I will be away to interview Edward Teller. "Is he still alive?" she asks in amazement. A day later I sit across the room from a 91-year-old man slumped in his desk chair, his five-foot-high carved wooden walking stick leaning against a desk that has a Ronald Reagan-awarded National Medal of Science hanging above it.

With eyes clouded by ulceration, he stares straight ahead. What may have been the world's bushiest eyebrows have thinned. A cowboy boot covers the prosthesis that replaced the foot he lost in a streetcar accident in 1928. His secretary informs me that his memory of recent events has faded in the wake of a stroke. I wonder if he even sees me or whether I will be able to proceed with the interview.

Do-it-Yourself Financial Planning; October 1999; Scientific American Magazine; by Menduno; 1 Page(s)

Consider British mathematician Alan Turing's test to see if a computer's responses could pass for human. Then apply it to investment advising. Consumers query both a computer and a stockbroker, using the Internet to avoid prejudicing the results. According to Turing's formulation, if the consumer is unable to distinguish the computer from the broker on the basis of their respective advice, the computer wins. Now consider that the computerbased service costs less than a subscription to the Wall Street Journal and is available 24 hours a day, and the computer wins again. At least that's the theory behind the emerging wave of Internetbased services designed to help consumers with their investment decisions. But are consumers ready to accept financial advice from a machine?

Over the past year, more than 10 vendors-including Internet start-ups Financial Engines and DirectAdvice.com as well as major firms such as Standard & Poor's, Intuit (the makers of the popular personal-finance software Quicken and TurboTax) and Fidelity Investments-have introduced on-line financial-advice services. Most are targeted at the 33 million individuals who participate in 401(k) plans and offer specific advice on how to allocate their investments, which now collectively exceed $1 trillion in assets. The number of plan participants expected to use on-line advice is estimated to grow from 1.7 million this year to 13. 7 million by 2004, according to the TowerGroup, a market research firm in Needham, Mass. A few other services cater to special situations: for example, RestrictedStock.com, from expert-systems developer MultiLogic, based in St. Paul, Minn., helps individuals determine when to sell heavily regulated restricted stock, such as shares acquired in private sales, mergers or via stock options.

In the Drink; October 1999; Scientific American Magazine; by Holmes; 2 Page(s)

Even on a muggy, 90-degree July day in Ithaca, N.Y., the depths of nearby Cayuga Lake are a nippy 40 degrees. This simple fact has pointed Cornell University, the town's largest economic entity, toward a novel solution to its energy demands for cooling. The university has embarked on a $55-million project called Lake Source Cooling, which by mid-2000 will be using cold water from the lake to reduce Cornell's energy consumption for air conditioning by 80 percent.

To make this happen, the university is laying underground a huge pipeline in two distinct segments. One segment, 1.6 meters (5.25 feet) in diameter, will draw water from Cayuga (the longest of the Finger Lakes) from a depth of 76 meters, raise it to a heat-exchange facility on shore and then discharge it into a shallower part of the lake. A separate line of somewhat smaller underground pipes will carry water downhill from Cornell, about three kilometers (two miles) away, to the heat exchanger and back up again. The Cornell water and the lake water will never mix, but heat will be transferred through stainless-steel plates.

To Boldly Grow...; October 1999; Scientific American Magazine; by Beardsley; 2 Page(s)

One of the most useful tricks in a geneticist's toolkit is called gene targeting. It allows researchers to alter specific genes in cells by adding or cutting out fragments of DNA. But standard gene targeting is laborious and inefficient-thousands of cells have to be treated to modify just a few of them. And, to the chagrin of seed companies that would like to use gene targeting to improve crops, it does not work well with plant cells.

Now plant scientists are reporting remarkable success in adapting a controversial new technique previously used to modify genes in animal cells. The technique is known as chimeraplasty, because it is based on molecules that are hybrids, or chimeras, of DNA and its chemical relative, RNA. Several peerreviewed papers have described how chimeraplasty, invented by Eric B. Kmiec of Thomas Jefferson University, can efficiently modify genes in mammalian cells-but results are variable and inconsistent. Mario R. Capecchi, the University of Utah scientist who invented standard gene targeting, is unconvinced that chimeraplasty modifies genes in mammalian cells in the way that Kmiec and his associates suggest. But Capecchi allows that plants may be different.

Cyber View; October 1999; Scientific American Magazine; by Wallich; 1 Page(s)

Moore's Law, the observation that computers' speed and memory capacity double about every 18 months, means that today's mass-market PC can run rings around the past decade's high-end mainframe. Unless you really insist on having the right answers. One unfortunate corollary of Moore's Law is that reliability levels that were perfectly adequate for machines performing a measly few million operations per second may fall short as computer clock rates head for one gigahertz or more. Odds of a billion to one against errors sound fine until you do the math.

Most digital devices today have even lower error rates¿hard-disk drives miss only one bit per 10 trillion or 100 trillion bits per read and the lowly CD-ROM one in a trillion. For a high-speed drive that can transfer 300 million bits a second, that's a mistake every few days of nonstop production. And for a full CD-ROM, that's one undetected error in every 200 software installations. But a few years ago, when desktop disks topped out at 40 million bits a second, you could expect undetected errors about once a month of continuous use.

The Hidden Ocean of Europa; October 1999; Scientific American Magazine; by Pappalardo, Head, Greeley; 10 Page(s)

Do living things flourish elsewhere within our solar system, or is Earth's environment uniquely nurturing? This question is central to planetary exploration today. Three decades into humankind's reconnaissance of the planets and their natural satellites, only a short list of possible abodes remains. Perhaps the most intriguing is Jupiter's ice-rich moon Europa.

For centuries, astronomers knew Europa only as a pinprick of light in even the most powerful telescopes. In the 1960s spectroscopy showed that the satellite, like many others in the cold reaches of the outer solar system, is covered with ice. With surface temperatures of 110 kelvins (-260 degrees Fahrenheit) near the equator and 50 kelvins near the poles, that ice must form a rock-hard skin. Researchers had no way to probe deeper and little reason to expect anything special. But in the past two decades and especially in the past few years, spectacular images radioed from visiting spacecraft have revealed a young and tremendously deformed surface. Somewhere under the icy shell, it seems, must be a warm, mobile interior. Is it glacial ice? Or are Europa's innards warm enough to sustain an ocean of liquid water? If the latter, we can stretch our imaginations and ask whether life might have arisen within the lightless depths.

Why Things Break; October 1999; Scientific American Magazine; by Eberhart; 8 Page(s)

For most people, it is a tragedy when something breaks or bends, but for me this is often a highlight of my day. When shattered glass catches my eye, I find myself reassembling the shards and tracing the path of the fracture backward to its origin. Other times, I will stop next to an old tree to chronicle the way its growth has slowly twisted the posts of a wrought iron fence. My interest in the way things break is not rooted in a preoccupation with destruction but rather in the knowledge that all technology is founded on whether materials fail in a brittle manner, like glass, or in a ductile way, like iron.

In fact, the history of technology is linked in large part to the ability to exploit these two forms of failure. Manipulating brittle failure in minerals like flint launched human beings into our first technological era-the Stone Age-about 2.5 million years ago. More recently, about 5,000 years ago, the discovery of substances such as gold and copper, which resist brittle failure, led the way into the early Metal Age. Ancient artisans found these ductile metals good for making jewelry and other ornamentation because they are soft and can be easily stretched or pounded with a mallet. But although they are tough and absorb huge amounts of energy as they deform, these materials have short lives when fashioned for cutting or scraping.

Preserving Nefertari's Legacy; October 1999; Scientific American Magazine; by Agnew, Maekawa; 6 Page(s)

Little is known about Nefertari, favorite wife of Ramses II, the pharaoh who ruled Egypt from about 1290 to 1224 B.C. But it is clear she was beloved by her husband. He ensured that the statue dedicated jointly to Nefertari and the goddess Hathor at Abu Simbel was on the same scale as his, an honor no other Egyptian queen achieved. His names for Nefertari bespoke great love as well: "lady of charm," "sweet of love," "beautiful of face," "for whom the sun shines." And after her death, Ramses II bestowed on Nefertari a final, spectacular tribute: even though she was not of royal lineage, he buried her in a decorated tomb in the Valley of the Queens.

The wall paintings in Nefertari's tomb are among the most beautiful of all pharaonic funerary art. As in other tombs, the images of Nefertari are solely about her journey to the afterlife and her encounters with Osiris and Isis, among other deities; no paintings depict her everyday life with Ramses II or her six or seven children. But even as they describe a ritualized journey--following a strict formula laid out in the 174 or so chapters of the Egyptian Book of the Dead--the paintings in Nefertari's tomb are unique in their vivid color and detail and richness.

The Unmet Challenges of Hepatitis C; October 1999; Scientific American Magazine; by Bisceglie, Bacon; 6 Page(s)

As recently as the late 1980s few people other than physicians had heard of hepatitis C, a slowly progressing viral infection that over a couple of decades can lead to liver failure or liver cancer. Today the condition is widely recognized as a huge public health concern. Some 1.8 percent of the U.S. adult population, almost four million people, are infected with the hepatitis C virus, most of them without knowing it. The virus is one of the major causes of chronic liver disease, probably accounting for even more cases than excessive alcohol use, and is the most common reason for liver transplants. Some 9,000 people die each year in the U.S. from complications of the infection, a number that is expected to triple by 2010. Information about the incidence of hepatitis C in other countries is less reliable, but it is clear that the virus is a major public health problem throughout the world.

Physicians, historians and military leaders have long recognized hepatitis-inflammation of the liver-as a cause of jaundice. This yellow discoloration of the whites of the eyes and skin occurs when the liver fails to excrete a pigment called bilirubin, which then accumulates in the body. In recent decades, however, the diagnosis of hepatitis has progressively improved, and physicians can now distinguish several distinct forms. At least five different viruses can cause the condition, as can drugs and toxins such as alcohol.

The False Crisis in Science Education; October 1999; Scientific American Magazine; by Gibbs, Fox; 8 Page(s)

On a cold and rainy day this past February, Bruce Alberts wore a grim expression as he stepped up to the microphones at the National Press Club in Washington, D.C. The final results of the Third International Mathematics and Science Study (TIMSS) had just come in, and America's high school seniors had placed near last.

"There is no excuse for this," President Bill Clinton had already chided. "These results are entirely unacceptable," admonished the secretary of education. The head of the National Education Association declared U.S. schools to be in a state of crisis. And now Alberts, president of the National Academy of Sciences, said that he, too, saw in this report "all the elements of an education tragedy."

High-Speed Data Races Home; October 1999; Scientific American Magazine; by Clark; 6 Page(s)

Within a decade, most people in developed countries will have access to Internet connections that are tens if not hundreds of times faster than the ones in common use today. Although that development may not sound exactly earth-shaking, it will in fact herald an entirely new stage in the evolution of that global network.

Those high-speed connections to the home-whether they take the physical form of a telephone wire, a cable television line or a satellite link will give rise to an entirely new set of applications. Not only will enthusiasts be able to jump instantaneously from page to page on the World Wide Web-and will therefore use the Web much more often-they will also be able to enjoy applications that exist today only as crude prototypes or as concepts in the minds of visionaries and entrepreneurs. Real-time high-fidelity music, telephone, videoconferencing, television and radio programs could all be provided by a single service company over a single hookup. There will be new entertainment options, such as movies-on-demand, and new features, such as the ability to call up information about a movie's director or its actors as they appear on screen. Users will be able to play on-line games-live-against many contestants scattered around the globe. People separated by thousands of kilometers will be able to share virtual-reality experiences and work effectively together on a business or academic project.

The Internet via Cable; October 1999; Scientific American Magazine; by Medin, Rolls; 2 Page(s)

Using cable Internet services for the first time can be a breathtaking experience. Images and text flash before your eyes instantly. Full-motion video and audio play without jitter. When you see this, you realize that this was how the Internet was meant to be. Even for Internet oldtimers, it's like a whole new world.

The cable television network has emerged as the early leader in providing such high-speed data access in the home. With more than a million cable modem subscribers now in North America, the system has matured from a string of experimental deployments in 1995 to a mainstream service available in most major cities.

DSL: Broadband by Phone; October 1999; Scientific American Magazine; by Hawley; 2 Page(s)

Does the humble telephone line, the Victorian technology that transformed the world, have a major role to play in shaping the third millennium? Can a mere pair of thin copper wires twisted around each other transmit Internet data reliably and securely at blazing speed, making it possible to view high-fidelity moving images, sound and vast amounts of data on your personal computer screen or television? The answer is yes, as the growing success of digital subscriber line (DSL) technology abundantly demonstrates.

These trusty copper wires, installed in more than 600 million phone lines worldwide, provide high-quality, dependable voice service, but for a century most of their transmission capacity has lain dormant. DSL technologies exploit this resource, bringing a 50-fold increase in speed to millions of modem users, accelerating the growth of electronic commerce and changing the nature of communications.

The Broadest Broadband; October 1999; Scientific American Magazine; by Shumate, Jr.; 2 Page(s)

Optical fiber has successfully replaced metallic cables in the backbone networks of most local and long-distance telephone carriers, cable television operators and utility companies. So why not extend lines of optical fiber all the way to customers' homes? Doing so would eliminate the so-called last-mile bottleneck that restricts users' access to the Internet and other services. In current fiber-to-the-home systems, customers can download data at up to 100 million bits per second (future fiber networks may perform much more quickly), which is at least 10 times faster than transmissions using metallic cables today. The capacity of optical fiber is so enormous that it can handle all types of communications signals simultaneously; for example, telephone, television, videoconferencing, movieson-demand, telecommuting and Internet traffic could all be carried together on one user's fiber.

Until recently, the major obstacle to fiber-to-the-home has been its high cost. Dedicating one or two lines of fiber to each customer, along with the electronics needed at each end to transmit and receive the optical signals, is very expensive. For a typical suburban home, the one-time installation cost¿including the cost of all the equipment-is currently about $1,500. (Approximately half is attributable to the electronics.) This figure has dropped from about $5,000 a decade ago and is continuing to fall as fiber technology advances. But it is still higher, in most cases, than the cost of connecting a comparable home with metallic cable.

Satellites: The Strategic High Ground; October 1999; Scientific American Magazine; by Norcross; 2 Page(s)

If you want to see the future of broadband communications, look to the stars. The heavens could soon be filled with more than 400 satellites providing Internet users with low-cost, direct-to-the-home connections that are hundreds of times faster than today's dial-up modems. With unobstructed views of virtually the entire world, satellites are poised to deliver interactive broadband services in ways even advanced ground-based networks will be hard-pressed to match.

The new breed of satellites will act as powerful signal repeaters in the sky, receiving and resending radio transmissions from ground-based antennas. Costing far less per unit capacity than most satellites now in service, they will employ new digital technologies that will improve the capacity, reliability and security of data communications. Moreover, because the systems will operate at extremely high radio frequencies, they will use narrow radio beams capable of communicating with ultrasmall antennas that can be easily mounted on most homes.

LMDS: Broadband Wireless Access; October 1999; Scientific American Magazine; by Skoro; 2 Page(s)

The past decade has seen explosive innovation by the telecommunications industry as it strives to satisfy a worldwide appetite for greater bandwidth. Several developments are fueling this growth-the proliferation of the Internet, increased dependence on data and a global trend toward deregulation of the industry.

Nowhere is the phenomenon more evident than in the quest to alleviate the local-loop bottleneck. This constriction occurs where local-area networks, which link devices within a building or a campus, join to wide-area networks, which criss-cross countries and hold the Internet together.

The Light at the End of the Pipe; October 1999; Scientific American Magazine; by Bane, Bradley; 6 Page(s)

The big picture is well known: the Internet has made it possible to swap digitized information with more speed, ease and convenience than ever before. What is less obvious is that the advent of much higher speed links will bring us more than simply a faster version of the Internet. Over the next several years, as fast broadband technologies begin pervading the Internet, a more fundamental shift will occur. The communications, information and entertainment industries will converge into a single, sprawling business.

This transition will not be smooth or predictable. And now, just as it is getting under way, perhaps the most compelling question is: How might broadband affect our lives?

Mathematical Recreations; October 1999; Scientific American Magazine; by Stewart; 2 Page(s)

The cone is probably most familiar today as an edible container for ice cream, but its past glories lie in higher realms altogether. The geometry of the cone was known to the ancient Greeks, mainly because of the elegant curves that could be constructed by slicing a cone with a plane. The Greeks delighted in the intricate geometry of these conic sections-the ellipse, parabola and hyperbola-and discovered how to use them to solve problems that were beyond the reach of rulers and compasses.

Those problems included trisecting an angle and constructing a cube with twice the volume of a given cube. Both reduce to solving an equation of the third degree-that is, one in which the highest exponent of the variable is three. Conic sections can be used to solve the problems because the points where two sections meet correspond to solutions of equations of the third and fourth degrees. In contrast, rulers and compasses can solve only second-degree equations.

The Amateur Scientist; October 1999; Scientific American Magazine; by Carlson; 2 Page(s)

Grant that the universe is filled with atomic-size billiard balls. Then, with a few insightful definitions and some mathematical gymnastics, physicists can provide you with a near-perfect explanation of our everyday world. The theory is called statistical mechanics. Many people know that it limits the amount of work a machine can deliver. But it actually goes much further. Statistical mechanics describes the engines that drive the earth's weather. It governs the temperatures and pressures inside stars and constrains the evolution of the cosmos. It even sheds light on the arrow of time-why we remember the past and not the future. Indeed, Albert Einstein and Richard Feynman saw the theory as the highest achievement of classical physics.

Sadly, many amateurs have avoided this important subject because, in this case, the highest plateau is also the hardest to reach. One cubic centimeter of air at atmospheric pressure contains more than 10 billion billion atoms of various sizes, all smashing into one another at different speeds. No computer can project the exact trajectories of all these particles, and even if one could, no human mind could make sense of it. Therefore, physicists have devised clever but devilishly difficult mathematical methods to extract comprehension from the chaos.

Reviews; October 1999; Scientific American Magazine; by Robinson, Panosian, Staff Editors; 4 Page(s)

Images, images, images-how easily the bounty of astronomy seduces us! What other science can showcase portraits as profound as the birth of the universe or the death of a star? It's all Galileo's fault. In 1610, through the newly invented telescope, tiny as it was, he began to sketch a realm beyond the ken of anyone who had looked before. The moon, he discovered, had mountains and plains; Venus cycled through phases; Jupiter sported four satellites; new stars were everywhere. Ancient ideas about our world's place in the universe started to crumble: science, religion and philosophy have never since been the same.

David Malin, it is fair to say, invented spectacular astronomical imaging-the kind that catches the eye of even the most disinterested modern passerby. He accomplishes it "the old-fashioned way," through laborious hours in a smelly darkroom. There he fuses multiple images of star-filled galaxies and glowing gaseous nebulae into colorful and scientifically valid artwork, much as a painter layers watercolors to create the perfect tone and ambience. He suppresses film's artificial harshness to reveal delicate celestial texture. In short, like Galileo, he unveils a hitherto unknown universe.

Commentary: A Total Eclipse of Reason; October 1999; Scientific American Magazine; by John Rennie; 1 Page(s)

This past August took me to Munich for a viewing of the total solar eclipse. Years of casual study about total eclipses could not prepare me for the merciless beauty of our sun as an unfathomable black disk ringed in angry white fire. And the experience reminded me of how thin the veneer of human rationality could be: standing in a field under the weird end-of-the-world light, I felt some of the historical fear of those events, as though monsters might suddenly claw their way out of the earth to carry us away. But then the bright light of reason returned, and I got over it.

Meanwhile, back in the U.S., the Kansas State Board of Education was trying to turn out the lights more permanently. Acting out of a covert social agenda, it decided that teachers could omit mentioning those inconvenient ideas, evolution and the big bang.

Wonders: Nitrogen: The Dark Side; October 1999; Scientific American Magazine; by Philip Morrison, Philis Morrison; 2 Page(s)

In our August column we described the bright virtues of nitrogen as a nutrient. After the return of the Star Wars myth, we are drawn to consider nitrogen again, this time its dark side, for most explosives are nitrogenous.

In the beginning came saltpeter, the indispensable nitrogenous ingredient of an experiment first reported in the ninth century by a Taoist alchemist. He warned that a mix of saltpeter, sulfur and a carbonaceous stuff (dried honey?) Had burned hands and faces "and even the whole house." From that quixotic hint, the Chinese high technicians developed gunpowder and before 1200 had gone all the way to the devices we know as guns and cannons. The lagging West was not slow to catch on, and in a demonstration of the compelling power of reality, some unsigned peers of the old Taoist ended their own recipe, a little before 1300, with a similar caution, save in Latin: "It is forbidden to make this...under a roof because of the danger."

Connections: A Matter of Degree; October 1999; Scientific American Magazine; by James Burke; 2 Page(s)

I was on the flight deck of a transatlantic triple-7 recently, watching the onboard navigational magic, when it occurred to me that it all went back to those two 18th-century French expeditions, sent to see if one degree of the meridian was longer up north than at the equator. The guy they sent south to Peru was the intrepid Charles-Marie de La Condamine, who discovered that the equatorial degree was the shorter (because of the earth's being an oblate sphere). On his way home in 1743, La Condamine rafted down the Amazon, scribbling busily as he floated along. One of the zillion things he described in passing was the hevea tree. Whose dried sap made a miracle substance that did something that, to 18th-century eyes, was weird and wonderful. It bounced.

By 1820 an English coach builder name of Thos. Hancock was buying all of this South American stuff he could get his hands on (not much) and making elastic waistbands and garters, soles and heels, false teeth, and all kinds of surgical trusses, belts, bandages and so on. The market for rubber was soon insatiable, particularly when Hancock and partner Chas. Macintosh spread it between sheets of cotton and invented the raincoat. So they wrote to the authorities saying, Let's grow this stuff in our Eastern colonies. Make a million, right? The silence from Kew Royal Botanic Gardens (whose job such transplantations were) was deafening.

Working Knowledge; October 1999; Scientific American Magazine; by Bloomfield; 1 Page(s)

A laser printer combines the printing technology of a xerographic copier [see Working Knowledge, October 1996] with a small laser light show. The printer's main component is a rotating metal drum coated with a photoconducting material that is initially negatively charged and that cannot conduct electricity unless it is exposed to light.