Some of them disassembled cars and televisions when they were children. Others chased grasshoppers or grew orchids. One studied molds from her mom's leftover coffee. Each grew up to be recognized as an intellectual wunderkind early on. The average age of these accomplished scientists is only 33, which is more like 18 for a baseball player or 25 for a business CEO.
Far more than CEOs and sports stars, each of these individuals will likely change our fundamental understanding of the world and our place in it. Whether it's physicist Hideo Mabuchi's discoveries about the interface between quantum mechanics and everyday life or conservation biologist Gretchen Daily's rigorous assessments of ecosystems and economics, these young scientists probing the frontiers of knowledge have already shown the promise or the work that makes senior scientists applaud in awe.
Discover surveyed almost 1,000 researchers to find these scientists, asking for nominations of persons under 40 in the United States who have demonstrated once-in-a-generation insight. The response left us optimistic. The talent pool is vast. We could have listed 60 scientists without compromising the quality of the group.
The 20 we did choose are already glowing stars in their respective fields. We expect each of them to shine only brighter as they move through the next 20 years and light the paths to scientific enlightenment.
Don't look now (you'd see nothing anyway), but every particle in your body, every quark, every electron, may have a secret gravitational relationship with molecules from another dimension. Several years ago, theoretical physicists proposed that the universe has many more spatial dimensions than the three we know and love: north-south, east-west, up-down the x-, y-, and z-axes on a three-dimensional graph. Nima Arkani-Hamed, 28, an assistant professor of physics at the University of California at Berkeley, is going even further: He theorizes that these other spatial dimensions (seven at present) could be much larger than previously thought. We don't experience these other dimensions because all matter and the three dominant forces of the universe strong, weak, and electromagnetic are confined to the obvious three. Gravity, however, is another force altogether. If physicists are correct, it appears weaker than the three dominant forces because it is dispersed through other dimensions. Furthermore, if gravity does transcend other dimensions, then perhaps it is interacting with matter in them. That could explain the missing dark matter of the universe: We can't see it because it's in other dimensions. Arkani-Hamed's revolutionary theory suggests that some of the dimensions may be large enough to detect when we build larger particle accelerators. He can hardly wait: "You can be an excellent theorist and yet go through your entire career without ever once knowing you're right."
Scientists may be close to printing out the entire human genome, but they will be able to fully harness the power of that template only when they can "read" each individual's specific DNA sequences. Northwestern University chemical engineer Annelise E. Barron, 32, is building devices to do just that. Ultimately, this "lab on a chip," as researchers call it, will be able to tell doctors if a patient has a strep infection, high cholesterol, even a predisposition to cancer. As a step in creating such chips, Barron is working to get DNA from patient blood samples to separate into discretely identifiable bits. So far she has succeeded in creating a workable technology for the laboratory. Now she's looking for speed real-time, bedside separation of DNA. "When we had the Model T, we could have said, 'Let's stick with that,' " she says. "But it's great to have a Maserati!"
Scientists run in Carolyn Bertozzi's family, but unlike her father and older sister, who became physicists, she found her calling as a chemist. The 34-year-old associate professor at the University of California at Berkeley is making major inroads in our understanding of carbohydrates. These complex, multiunit sugars or polysaccharides appear to mediate communication between cells, a process vital to immune response and the spread of cancer. Researchers have been stymied trying to figure out exactly how carbohydrate molecules operate because their large, complicated structures make them unwieldy to study. As a result, most biochemistry and drug-discovery work over the decades has centered on proteins because they're much simpler. Bertozzi has come up with a new, small molecule that turns on and off synthesis of a specific carbohydrate, thus allowing researchers to precisely assess its influence on various cells. Already she has identified the central role another carbohydrate plays in causing inflammation, a discovery that could lead to a new class of anti-inflammatory drugs.
Vicki L. Colvin got her start in science with old coffee. "My particular interest was in slime molds," says Colvin, 35, a nanochemist at Rice University. "My mom was an avid coffee drinker, and I was always finding old coffee cups with brilliantly colored stuff in them. I cultured the most highly colored strains." To her, mold is quintessential: a self-assembling substance with a basic shape that gives rise to a patterned, large-scale structure. Nature makes it all the time, but humans have found the task all but impossible to duplicate in the lab. Sure, says Colvin, chemists can make wonderful molecules, "like Saran Wrap and Viagra. But so far we haven't been able to be true architects because our molecules are only the bricks, and we have few ways of laying them together to form walls, much less buildings." If she can learn to mimic self-assembling chemistry, the payoff could be remarkable: Using artificial proteins as tiny building blocks, she might be able to construct new types of lenses and lasers.
As a teenager, Christopher C. "Kit" Cummins loved to work with the tools readily available at his grandfather's farm in Wisconsin. He used them to keep the old tractor running and to make furniture. When he graduated from high school he was torn between traveling to Sweden to learn cabinetmaking or going to college. He chose higher learning, but he found a way to keep on tinkering with tools. Now they're just microscopic. Stephen Lippard, who chairs Cummins's department at the Massachusetts Institute of Technology, says the 34-year-old chemistry professor is gifted with an ability to find tools that make "unusual impossible! chemical transformations." One example of the power of such transformations was the development of a new process for splitting the nitrogen molecule that makes up about 80 percent of our atmosphere. Scientists had figured out a way of doing so early in the 20th century, and won Nobel prizes for it; the method allowed the synthesis of ammonia, which can be made into artificial fertilizer as well as cleaning solutions. But their process is only possible under extreme pressure conditions. Cummins simplified that by using a tool nature never thought of a specially shaped "saw" of molybdenum, which neatly cuts the nitrogen molecule into two.
Critics charge that all Gretchen Daily does is traipse through nature and paste a price tag on everything. Ecologists, however, applaud the Stanford University conservation biologist's work. It's her job to understand the ecology of an area well enough to predict the economic consequences of land-use decisions. Daily offers a simple example of what can happen without her kind of analysis: In one region of Australia, farmers cleared thousands of acres of trees, arguing the crops they could grow on the land would more than make up for the environmental damage. But afterward, the water table rose. It turned out to be salty and ruined all the croplands. "The fact is we're devastating life on the planet," says Daily, 35. "It's far too late to save everything. We can either continue what we're doing, blindly, and at a great cost to both the environment and society, or we can start figuring out how we depend on particular ecosystems" and plan our use of them accordingly.
There are times during long days at her lab at Yale University that Jennifer A. Doudna "fantasizes about running off to Hawaii to be a papaya farmer." No doubt the island-state native would grow great papayas, but the ribonucleic acid (RNA) she cultivates in New Haven may turn out to be much more useful to all of us than a few more acres of fruit. Doudna, a professor of molecular biophysics and biochemistry, is trying to grow RNA crystals and thus unlock some of their mysteries. Although scientists are well along the path of cracking the code of DNA, they're far from understanding RNA, a substance copied from the DNA molecule and the one that actually puts together the structures that breathe life into us. Says the 35-year-old biologist: "I get chills up and down my spine when I think about the possibility of getting insights into the origin of life."
B. Scott Gaudi, 26, became hooked on astronomy in the second grade when he memorized the names of all the planets in our solar system. Today, at the Institute for Advanced Study in Princeton, Gaudi has many more names to memorize as he searches for planets outside our solar system. So far, astronomers have evidence of 44 other planets, all relatively close to us in our galaxy. Most discovered so far are nothing much like Earth because the techniques used to find them work best at spotting bodies far larger than our planet. Gaudi theorizes that the key to finding smaller planets is to watch for admittedly rare events, like the transit of a small planet across a star, or the bending of light, called gravitational lensing, that occurs when a star and its orbiting planet cross in front of a more distant star. Meanwhile, Gaudi will be watching with optimism. He anticipates the next two decades will yield a startling census of planets and a more reliable sense of whether we really are alone in the cosmos.
Andrea Ghez is about to see what by definition cannot be seen. Through careful study of the sky, she has assembled the best evidence yet for the existence of a supermassive black hole at the center of our galaxy. Stars nearby appear to be orbiting something huge yet imperceptible, with gravity so strong that it sucks in all light, thus making it invisible. These supermassive black holes would be one million to one billion times bigger than the smaller stellar black holes that have already been proven to exist. If Ghez, 35, a professor of physics and astronomy at the University of California at Los Angeles, succeeds in detecting the monstrous black holes, she'll start exploring their relationship to the birth of galaxies.
In the particle world that 20th-century physics has defined, like charges repel and opposite charges attract, always and forever. So what was physicist David G. Grier seeing when two enormous and thus strongly charged identical molecules he was studying started pulling toward each other? Were the laws of physics breaking down? Not exactly. "Current theories treat electrons and other particles as independent," says the 38-year-old University of Chicago associate professor. But sometimes particles act cooperatively, and their group behavior, as with Grier's molecules, can seemingly flout physical laws. All of which makes for nice job security. "Looking at the inadequacy of current theory," Grier says, opens a whole new world for physicists.
Growing up in South Korea, Young-Kee Kim excelled at almost every subject in school, but she fell in love with math. Today, at age 37, she is a world leader in experimental particle physics. An associate professor at the University of California at Berkeley, Kim has made it her goal to understand the origins of mass. Like many particle physicists, she bemoans the loss of the U.S. supercollider once under construction in Texas, a 54-mile-long machine that would have made her work much easier. Congress cut off funds for the project in 1993. Rather than wait for one to be built, she is making do with the existing collider at the U.S. Department of Energy's Fermilab. With it, she's provided a more precise measure of the subatomic particle "W vector boson." Now her energies are aimed at proving the existence of the elusive Higgs particle, which scientists believe is the basis of mass.
As a child in a one-gas-station town in Michigan, Diane Linda Linne read voraciously, watched Star Trek, and sometimes played with water rockets. Today, she's an engineer at the NASA Glenn Research Center in Ohio and rockets are an everyday part of her life, but her fun has more purpose: figuring out how to build a gas station on Mars. Long-distance space travel creates a fueling problem, explains Linne, 36. If scientists pack a rocket with enough fuel for a manned voyage to Mars and back, the engines would have to be made bigger, which would make them heavier, thus requiring more fuel, which in turn would require bigger rockets, and so on. Linne's solution to this catch-22 is to build a rocket powered by carbon monoxide, which can be obtained by splitting apart carbon dioxide, a gas that happens to be abundant in Mars's atmosphere. If she's successful, future space travelers will simply plot their course and fill 'er up at the Red Pump.
Everyday life outside the lab is predictable and consistent for Hideo Mabuchi. When he kicks a soccer ball, he can watch it soar from his foot to the goal. When he holds a bottle of wine up to the light, he can see if it's empty or full. But life at the smallest scale of the universe is very different. Electrons don't seem to follow a discernible path, like a soccer ball that leaves your foot and then appears in the goal net, leaving no trace of the route between the two. At that tiny scale, where quantum physics operates, a wine bottle could be full and empty at the same time. Yet, somehow, the large-scale, clockwork-precise world we inhabit emerges from this quantum foam. How? No one knows, but Mabuchi, 29, an assistant professor of physics at Caltech, intends to find out. One approach he's taking is to build something no one really understands how to build: a quantum computer. It theoretically could use the ability of a quantum particle to spin two ways at once to compute information. Such a computer, Mabuchi says, could shed light on the fuzzy interface between our everyday world and life at a subatomic level. Stay tuned.
Whether he's looking up at the stars or down at his coffee cup, Harvard University professor of physics Juan Maldacena, 32, imagines strings tiny strings that vibrate to form the electrons in his coffee cup as well as those in the stars. No one has actually seen such a string, but they appear readily in the equations of an army of physicists like Maldacena who are searching for what has come to be known as "the final theory." The fact that we seem to need both quantum theory and relativity theory to explain the variety of particles and forces we've discovered in our universe bothers many physicists: Shouldn't there be just one underlying principle? Moreover, there are difficulties rectifying the equations of quantum mechanics and relativity under extreme conditions, such as those found in a black hole or at the beginning of the universe. The tiny strings might be a better explanation of everything, from the beginnings of time to coffee cups. The Argentine-born Maldacena has recently made a major contribution to string theory by showing that two mathematical pathways other researchers have been pursuing separately are actually similar and interchangeable.
Cells are an egalitarian and selfless bunch, willing to do whatever they're commanded to do for the good of the body around them. Through evolution, they have developed a mechanism for knowing whether the body needs them to multiply and grow, or kill themselves. But the genes that run such delicate machinery, says researcher Nikola P. Pavletich, 34, at Memorial Sloan-Kettering Cancer Center, are subject to damage from environmental toxins as well as normal cellular processes. In healthy cells, a crack team of proteins maintains DNA so that the cell responds properly to its instructions. But if these proteins themselves get altered, the repair work can get shoddy. Then a cell might multiply instead of dying, thereby spurring cancer. Pavletich searches for just such malignant alterations in his lab by growing proteins into crystals and then analyzing their three-dimensional structure. Sometimes all it takes to turn a cell cancerous is for a single molecule to change its shape, he has discovered. If he can change it back, he could be a giant step closer to a cancer cure.
If apes can count, use tools, and learn sign language like humans, can they think like us too? If so, why don't they study us the way we study them? Those are the kind of questions that fascinate Daniel Povinelli, 36, a comparative psychologist at the University of Louisiana. "Apes' minds are not just duller, less-talkative versions of our own," he says. "They are different in very peculiar and interesting ways." For nine years, Povinelli has studied seven chimps in his Lafayette lab, using tools, mirrors, and nonverbal games to learn the architecture of chimp thought. His conclusion: Abstract conceptualizing is beyond a chimp's ken. The reason apes don't study humans to find out how we think, he says, is because they do not think about thinking. And that may ultimately be the greatest difference between us and them. The most important concept underlying Povinelli's work is that it's not really about the apes. Only by studying animals similar to us, says Povinelli, will we come to understand ourselves better. His real goal is to discover what it means to be human.
Growing up in a Colorado farming community, Daphne Preuss took every opportunity to escape from the work. She was too busy tracking grasshoppers through the surrounding plains or poring over biographies of famous inventors. She still remembers reading of Thomas Edison about his "invention factory" and how he tested thousands of filament fibers before coming up with a workable lightbulb and the lessons she took from his efforts: Be imaginative, practical, and persistent. Now she has invented something remarkable of her own. In a daring feat uniting biology and technology, the 37-year-old assistant professor of molecular genetics at the University of Chicago has created entirely new plant chromosomes. While current genetic engineering relies on inserting single genes into natural chromosomes, Preuss is aiming to place multiple genes into artificial chromosomes. Instead of inscribing a single word into a plant's encyclopedia of genetic information, she hopes to compose her own separate volume. In a university lab the first crop of plants from her tinkering are growing each day, and Preuss watches to see what specific properties each will deliver. Within 20 years, she predicts, scientists will be able to construct artificial chromosomes to create plants that not only resist insects, fungi, and droughts as they do already but that also make vitamins, pharmaceuticals, and biodegradable plastics.
Mathematician Terry Tao, at 25 the youngest full professor the University of California at Los Angeles has employed in decades, lives in a world that has no connection to reality. Put in the simplest of terms, he studies how to "control the number of times a wave focuses at a point," and readily admits this abstract mathematical concept is complicated and "very theoretical." Still, he believes the ultimate reverberations from his research are simply not foreseeable. Descartes, he notes, had no idea that his calculus would one day make predicting the orbit of a satellite possible. "The work of mathematicians from even a millennium ago is still routinely used," Tao observes, "and the stuff that we do today is going to be part of the math of the future."
Several months ago, Dutch-born theoretical seismologist Jereon Tromp, 34, traded his job at Harvard for one at Caltech so he could be closer to the action. Many seismologists focus on what past earthquakes did to the surface of Earth what moved, where, and by how much. Tromp goes further, using the data to derive complex mathematical equations and rules that he hopes will express how the earth beneath his feet might behave during the next earthquake. With enough data, he says, he might even be able to predict how individual neighborhoods in a city will shake in a specific type of earthquake. That sort of early-warning map would give building engineers, city planners, and rescue teams what they really need to know to prevent tragedy.
Scientists had been trying to clone mice for 16 years when, in 1997, Japanese-born biologist Teruhiko Wakayama proposed the novel idea of using unfertilized rather than fertilized eggs in the process. Wakayama says he didn't believe the unfertilized eggs would create a clone. Nor did senior scientists cloning is an incredibly difficult technology dependent on all the complexities of life itself. Wakayama says he simply hoped that data from a different approach might be helpful. "My interest is solely to find mechanisms in biology to explain why living things are alive," says the 33-year-old research assistant professor at Rockefeller University in New York City. "I am not interested in making another animal." To everyone's surprise, the technique succeeded. Wakayama's colleague, Tony Perry, thinks this biologist triumphed where others failed because "he has an incredible insight . . . he can see what will work." Perry contends Wakayama was humble when he said he had doubts about trying to clone a mouse from an unfertilized egg: "He knew it would work."