Athletes, coaches and officials will have to use their hand print as a "biometric key" to gain entry to some areas of the Olympic Games in Sydney. The high-tech hand scanner will control access to highly sensitive areas. Anyone seeking access will have to place a hand on a special scanner which reads the handprint to verify identification.

The Commander of Olympic Security, Chief Superintendent Paul McKinnon, said the palm scan "will be in some places, but not across the board, simply because, although reliable, the human factor tends to interfere with its high-speed operation," Mr. McKinnon said. (At the Atlanta games, athletes were known to put chewing gum on their hands to play tricks with the system.) Official accreditation cards, with barcodes, will also provide security.

The co-founder of one of Silicon Valley’s top technology companies believes scientific advances may be ushering humanity into a nightmare world where super–smart machines force mankind into extinction.

In a heartfelt appeal published in the April issue of Wired magazine, Sun Microsystems Inc. chief scientist Bill Joy urges technologists to reconsider the ethics of the drive toward constant scientific innovation.

"We are being propelled into this new century with no plan, no control, no brakes," Joy writes. "The last chance to assert control—the fail-safe point—is rapidly approaching."

Joy’s fears focus on three areas of technology undergoing incredibly rapid change.

The first, robotics, involves the development of "thinking" computers that within three short decades could be as much as a million times more powerful than those now available. Joy sees this as setting the groundwork for a "robot species" of intelligent robots that create evolved copies of themselves. Another computer scientist, Vernor Vinge, says machine intelligence will awaken sometime between 2005 and 2030, a date he calls "the singularity." Dr. Vinge argues that this evolutionary watershed might accelerate progress well beyond human control.

The second, genetics, deals with scientific breakthroughs in manipulating the very structure of biological life. While Joy says this has led to benefits such as pest-resistant crops, it also has set the stage for new, man-made plagues that could literally wipe out the natural world.

The third, nanotechnology, involves the creation of objects on an atom-by-atom basis, which before long could be harnessed to create smart machines that are microscopically small. Or it might be possible to create tough omnivorous bacteria that could out-compete real bacteria. Spread by the wind, like blowing pollen, they could be designed to replicate swiftly and reduce life on earth to dust in a matter of days, according to Eric Drexler, one of the nation’s principal advocates for nanotechnology.

All three of these technologies share one characteristic absent in earlier dangerous human inventions such as the atomic bomb: they could replicate themselves, creating a cascade effect that could sweep through the physical world in much the same way a virus spreads through the computer world.

"It is no exaggeration to say we are on the cusp of the further perfection of extreme evil," Joy writes. "An evil whose possibility spreads well beyond that which weapons of mass destruction bequeathed to nation states on to surprising and terrible empowerment of extreme individuals."

An hour west of Chicago and two miles south of DeKalb, Illinois, Bob Johnson runs a farm. Before turning into his driveway, however, throw out anything you think you know about agriculture.

For starters, there’s no barn (torn down years ago to make way for an equipment shed). Those antennae on the tractors and combines link to positioning satellites overhead for pinpoint accuracy in spraying and harvesting a field. And if the red corn crib seems a throwback to simpler days, don’t be fooled. The small wooden structure houses a computerized system that mixes hog rations two tons at a time.

Even Mr. Johnson’s role has changed. He spends far more time behind a desk than in front of a tractor these days. "We are part of a very sophisticated food-production and delivery system," he says.

Across the Midwest, instead of tending their fields, farmers are hiring full-time crop consultants who pore over computerized yield data collected by the combine. Rather than buying seed and fertilizer from local dealers they’ve known for years, they’re purchasing directly from the manufacturer, increasingly through the Internet.

On the Johnson farm, each field gets broken up into four- or five-acre plots, from which a soil sample is extracted and tested. The results are fed into a computer that tells the farmer exactly how much fertilizer to put on each plot. When the combine rolls through at harvest time, it automatically collects the yield from each plot so Johnson can track how well the crops are responding.

On the livestock end of the operation, Johnson and his partners track exactly what each group of hogs is fed, how much it costs to raise them, and what they fetch at the market. The precision gives managers far more control than they ever had before.

But to afford these technologies, farmers are trying to get bigger. And many are trading in their legendary independence for the security of long-term contracts with food companies that dictate every move they make.

Researchers say they have found a way to mate human cells with circuitry in a "bionic chip" that could play a key role in medicine and genetic engineering.

The tiny device--smaller and thinner than a strand of hair--combines a healthy human cell with an electronic circuitry chip. By controlling the chip with a computer, scientists say they can control the activity of the cell. The computer sends electrical impulses to the cell-chip, triggering the cell's membrane pores to open and activating the cell.

Scientists hope they can manufacture cell-chips in large numbers and insert them into the body to replace or correct diseased tissues.

The cell-chip also gives them greater control over the difficult process of gene therapy because they can more precisely open the cell's pores, said lead researcher Boris Rubinsky.

Researchers hope eventually they can develop cell-chips tuned for the precise voltage needed to activate different bodily tissues, from muscle to bone to brain. That way, cell-chips could be applied by the thousands to correct a variety of health problems.

"In the past, any electricity applied to the cell was like hitting it with a hammer in the hopes that something would happen, or it would open for us. Now, we know just how to make it work," Rubinsky said.

IBM has announced a 5-year, 100-million-dollar research initiative to build the world's fastest supercomputer--and analogies are about the only way to understand the raw power and speed that IBM expects from the machine.

The supercomputer has been dubbed "Blue Gene," based on its first major project, delving into the deep mysteries of genetics and the proteins that make up life.

The numbers are admittedly mind-boggling. Blue Gene will run at one petaflop--that's a million, billion operations per second, according to IBM. That will make Blue Gene about two million times more powerful than the fastest desktop PC. It's 500 times more powerful than the machine now considered the world's fastest, a supercomputer at Lawrence Livermore Laboratories used for government research.

IBM is taking a "radical new approach" to computer design, according to Dr. Ambuj Goyal, IBM's vice president for computer science. In order to deliver Blue Gene's power, IBM will use an architecture called SMASH, for Simple, Many, and Self-Healing.

Blue Gene will have one million processors. The final incarnation will consist of 2000 square feet of processor boards and the associated circuitry, running eight million simultaneous processing threads.

The speed of communications within Blue Gene would be fast enough to download the entire contents of the Internet in less than a second, according to Goyal. And because the problems that Blue Gene will work on require non-stop processing, the machine will be self-healing. It is designed to automatically sense and handle problems such as inoperative processors. Researchers say Blue Gene will be the first computer with processing power similar to that of the human brain.

Encyclopedia Britannica now has a highly advertised free Web site. What an extraordinary thing it is that people around the world suddenly have free access to knowledge that would have been the envy of a university professor earlier in my own lifetime.

But the encyclopedia is just one small illustration of the explosion both in knowledge and in our access to it since Thomas Jefferson's modest book collection formed the nucleus of the Library of Congress. Not only does my own house now contain more books than Jefferson ever owned, but my access to public libraries, bookstores and, of course, the Web, gives my family information resources beyond the imagination of world-class scholars a short time ago.

I've just had a phone call from a friend who tells me that, in preparation for an upcoming trip to Benin, she's downloaded 75 to 100 pages of information, from a score of sites, on that West African country--information on everything from the local currency, political situation and weather to the latest local news and the street address of the American Embassy. "I'm starting to feel almost like I know the place, even though I've never been there," she said. Marco Polo, eat your heart out.

Nor is it just information that is so profusely available. Think of the difficulties confronting a 19th-century music lover. He could, of course, hear local folk artists. But if he had a fondness for, say, Bach or Beethoven, he'd have to hire an orchestra and a place for it to perform--which means he'd have to be wealthy. Today, any teenager with a CD player (or even an FM radio) can hear almost any music of his or her choosing, performed by top musicians, virtually at will. The same youngster could, at a whim, look at tens of thousands of paintings from the National Gallery of Art.