PopSci's 6th Annual Brilliant Ten

We visit operating rooms, observatories, and islands full of slightly-less-than-rational monkeys to find the young geniuses who are shaping the future of science

First Light

Homebuilt telescopes [foreground] atop Mauna KeaCourtesy Gaspar Bakos

We take about six months to create our annual list of the most impressive young scientists in the U.S., six months of quizzing academic department heads, professional organizations and journal editors about the most creative and important research in the country and the individuals making it happen. And every year, those leaders-a serious and measured group-nominate hundreds of candidates with barely contained excitement. "There is no doubt in my mind that his work will revolutionize the field," says one. "He has done something that, frankly, I thought was impossible," says another. Exclamation points abound.

So when we say that these 10 are the most creative, the most groundbreaking, the most brilliant, just what does it mean? It means they have the gall to ask the big questions, even if those happen to be outside the traditional areas of inquiry. It means they challenge what we thought it possible to know. It means their answers are opening up ever more perplexing questions.

And because of that, it means they still have a lot of work to do.

DIY Planet Finder

Gáspár Bakos, 31; Harvard-Smithsonian Center for Astrophysics

His homemade telescope network has uncovered entirely new kinds of planets

Somewhere in Manhattan, there's a secondhand camera-shop owner who deserves a bit of credit for the discovery of a new class of planets. Six years ago, astronomer Gáspár Bakos was visiting the U.S. from Hungary when he hit the city's stores with $350 in his pocket, hoping to haggle for a good telephoto lens. At the time, Bakos and three amateur astronomer friends were in the middle of building the first in what is now a growing network of small robotic telescopes. His plan was to search for new worlds, but he was going to do so by looking for them around very bright stars, so he didn't need a giant observatory-the four-inch-wide lens used by the average sports photographer would do just fine. Bakos bought a used Nikon, tucked it in his carry-on for the flight back to Hungary, finished up the telescope, and, a few years later, found a planet unlike any that scientists had ever imagined.

Bakos had always dreamed of being an astronomer. From age five to nine he lived with his parents in a remote part of Nigeria, where he spent many nights lying on his back in the warm sand, staring up at the star-filled sky. Later, as a teenager in Budapest, he conducted evening crash courses in observational astronomy for groups of 20 people at a public observatory. During that time, he met a trio of amateur stargazers who would help provide the funding, sweat and ingenuity for what has become HATnet, the Hungarian-made Automatic Telescope network.

These days, HATnet includes six telescopes-four in Hawaii and two in Arizona. Each one, designed and built in Hungary entirely by Bakos and his three friends, costs less than $50,000. (In contrast, NASA's space-based SIM PlanetQuest observatory, also meant to look for new worlds, is expected to cost $1.8 billion.) Bakos's homemade telescopes repeatedly snap photos of enormous swaths of sky, capturing the light from tens of thousands of stars. His software searches for tiny dips in the brightness of each star that last for a few hours-a sign that a planet may have passed between it and the telescope, blocking some starlight.

In three years, Bakos has found eight strange new worlds. His first find, HAT-P-1b, belongs to a novel class of so-called puffy planets. Larger than Jupiter, HAT-P-1b has only half its mass, making it as dense as a piece of cork. A year there is shorter than one of our workweeks.

As HATnet grows, Bakos remains involved on every level, from redesigning the telescopes to constructing the shelves that will hold the new servers storing all those snapshots. And although a few planets a year might not seem like a great haul, the questions each one spurs have proved to be more than enough to keep him searching. These worlds "are not at all similar to what we find in our solar system," he says. "They open up our view of planets."-Gregory Mone

The Brain Defender

Alfredo Quiñones-Hinojosa, 39; Johns Hopkins School of Medicine

The former farmworker is fighting brain cancer both in the operating room and the laboratory

Alfredo Quiñones-Hinojosa is about to begin a six-hour surgery in which he will remove a tumor the size of a golf ball from his patient's brain, and he has no idea what's going to happen. Never does. "Every time I take a blood vessel, I am scared," he says. "There are no absolutes in what I do." Even if the surgery appears to go well, the patient could wake up blind, or unable to speak, or worse. There's no way to know.

But Quiñones is determined to change that. Few brain surgeons have the time or energy to maintain a research lab; Quiñones runs two. It's another example of the work ethic that has led him from being an an undocumented farm worker 20 years ago to the director of the brain-tumor program at the Johns Hopkins Bayview Medical Center today.

His first lab focuses on neural stem cells, elusive characters that Quiñones thinks may offer insight into brain cancer and neurodegenerative diseases. Stem cells-which, famously, can change their function-are often found in cancerous tumors. Quiñones suspects that the cells initially come in to fight the tumor but are then recruited to join it. His second lab is developing a 10,000-patient database to better understand the myriad factors that influence why some patients develop serious complications after surgery while others don't.

Having his feet firmly planted in both science and medicine does come with some downsides, like 16-hour workdays. But it's important to Quiñones to interact with brain-cancer patients and their families every day. Their struggles instill in him a sense of duty to help solve the mysteries of the brain-even if it means working until midnight every night. "If I don't do it, then who will?" he asks. "Someone has to take the lead."-Melinda Wenner

Collision Detective

Frans Pretorius, 34; Princeton University

His computer simulations predict what happens when black holes collide

A black hole is a bit like the Invisible Man: You can't see it directly, but you might be able to catch a glimpse of its footprints. With black holes, however, you must first figure out what these footprints look like. Thanks to Frans Pretorius, we now have a pretty good idea.

Because black holes consume everything, including light, scientists can find them only by searching for their gravitational energy. A collision between two black holes is one of the most powerful events in the universe, a cataclysm equivalent to 500 million supernovae convulsing the fabric of spacetime. Scientists now watch for signs of the resultant ripples-the first gravitational-wave detectors sensitive enough to spot these collisions are already operational, and a handful of others will begin gathering data over the next few decades.

To distinguish these waves from background noise, physicists must simulate how the waves will appear when they reach Earth. They do this by solving Einstein's equations of general relativity at millions of points over a 3-D grid of space-the only way the computers can churn through the calculations. But like a game of Telephone, these translations can introduce minor errors that rapidly accumulate, turning the information into gibberish. Despite 40 years of effort, these errors always crashed the computers of the groups struggling to run the simulations. Some feared the problem was unsolvable.

Then dark horse Pretorius, at the time a postdoc at the California Institute of Technology, single-handedly solved the problem in a year. His trick was to make the translation-and therefore the simulation-as simple as possible. "I said, 'Well, I might as well give this a shot,' " he recalls, shrugging. "It turned out to work."

His colleagues saw it differently. "[It was as if he] went into his garage, built a fully operational Saturn 5 rocket, and flew it to the moon all on his own," says Neil Cornish, a physicist at Montana State University. Other groups achieved success just months later. "By showing that it could be done," Cornish says, "he inspired others to find a way out of the maze."

Pretorius isn't done with Einstein. He's using his models to see what the proton collisions at the Large Hadron Collider-the particle accelerator in Geneva scheduled to switch on next spring-would look like, if those proton collisions created miniature black holes. If they do, it would be the first evidence that we live in a multiverse, a universe with hidden dimensions. Those three dimensions we've always known? They would be revealed as mere footprints, traces from an invisible world.-M.W.

Bacterial Bully

Helen Blackwell, 35; University of Wisconsin–Madison

To stop bacteria from causing infections, she stops them from talking to each other

Courtesy Helen Blackwell

Helen Blackwell takes a quick breath mid-sentence, catches herself, and laughs. "I'm talking all the time," she says sheepishly. It's true-she hasn't stopped speaking for 18 minutes straight. The irony is that the entire time, she's been discussing how to keep organisms from speaking to each other.

To be fair, it's important to note that she's referring specifically to bacteria. These infective agents, Blackwell explains, are fairly idle on their own. Only once they establish a large population and begin chatting to one another do they really get cracking. In a process called quorum sensing, bacterial populations produce chemical signals that coordinate their behavior, change how they grow, and form protective sheaths called biofilms that keep the microbes safe from our immune system.

This process prevents the body from effectively clearing infections, but Blackwell has come up with a solution-75 of them, to be exact. Her lab has created compounds that mimic, yet differ slightly from, these quorum-sensing chemicals. When she adds these compounds to growing bacteria, they inhibit bacterial communication without actually killing them. (Most antibiotics attack all the bacteria in our bodies, including the good ones in our gut; in addition to interfering with our digestion, this fuels antibiotic resistance.) Blackwell's chemicals target specific bacteria, preventing them from forming biofilms and establishing infection, but otherwise keep good microbes safe. "We're just targeting their bad behaviors," she says.

Although the obvious applications are medical-the chemicals could be used in wound creams and as coatings for implantable devices-Blackwell is most excited about their potential as fundamental research tools. Some bacteria make their hosts appear invisible to predators, while others help plants use nitrogen for fuel. By studying the ways bacteria communicate with one another and interact with their hosts, we can learn much about how microbial life functions and evolves. According to Blackwell, these germs have a lot to teach us.-M.W.

The Monkey Economist

Laurie Santos, 32; Yale University

She's found that primates also fall prey to what were long thought to be uniquely human foibles

One after another, the tiny monkey yearlings scramble up a narrow tree trunk, swing dramatically over a little pond, and drop, shrieking, 15 feet into the muddy water below. The monkeys are the youngest members of a population of 800 rhesus macaques that inhabit Cayo Santiago, a small island off Puerto Rico, and their boyish cannonball competition provides an entertaining show from the vantage of the "lunch cage"-a picnic table and storage space enclosed by a chain-link fence-where Laurie Santos and a handful of her Yale students are slathering on sunscreen and preparing for the day's experiments.

Santos has been studying the monkeys on Cayo Santiago since 1993, when she was a freshman at Harvard University working under evolutionary biologist Marc Hauser. Now an associate professor at Yale and the head of the university's four-year-old monkey lab, Santos oversees students carrying out her own carefully designed experiments developed to measure the animals' cognitive abilities-with the goal of comparing the primates' thinking with our own.

Chief among Santos's monkey trials are deceptively simple tests that examine the animals for evidence of "theory of mind," the idea that an individual can infer the beliefs or perceptions of others. The concept has been a source of controversy in cognitive science for decades, with many maintaining that theory of mind is unique to humans, an essential quality that separates us from all other species.

Santos locks the lunch cage behind her and, trailed by two ponytailed undergrads outfitted identically in blue sweats, white T-shirts and huge sunglasses, crosses the island to a densely wooded hill where she kneels in front of a solitary male rhesus. She snaps her fingers to capture the monkey's attention and then steps out of its view and recites a series of instructions to the students, each of whom holds out a single grape on an identical paper plate. Both students place their plates on the ground in front of them. At Santos's command, one of the girls turns around, her back to the treat. The monkey soon snatches the grape from the unwatched plate, an outcome that Santos has recorded in 90 percent of the more than 100 times that she's run this trial. The experiment is straightforward but, like others she's designed, has been heralded in psychology circles as elegant and theoretically rich. Her work reveals powerful evidence that the monkeys are able to contemplate the thoughts of others-that is, they think like us.

Back in Connecticut, Santos is making similarly novel discoveries in the field of primate economics. Together with colleagues in Yale's neuroscience department and School of Management, Santos runs experiments that test fundamental economic principles in laboratory capuchin monkeys. Her groundbreaking approach: investigating whether the monkeys commit the same flaws in reasoning as humans do. "For the most part, people who work with animals look at how they do or do not replicate the smart aspects of human cognition," she explains. "Nobody had thought about looking at the dumb part-our errors and biases. Examining whether primates make the same stupid mistakes we do can actually tell us more than some of the successes."

In fact, Santos's capuchins have consistently demonstrated economic errors in decision-making identical to our own, including loss aversion (overvaluing what is already yours) and anchoring bias (putting too much value on early pieces of information). Trained to use tokens as a form of money, the capuchins in one telling experiment consistently preferred a scenario in which they were promised one apple piece but half the time were given two, over a scenario in which they were promised two and half the time were given only one. In both scenarios, the monkeys paid the same for their snack and had the exact same odds of ending up with one apple piece or two; classic economic theory would predict that the animals would show no preference for one choice over the other. Yet they greatly preferred the scenario in which they didn't perceive a loss, the exact behavior recorded in numerous human studies. What that suggests to cognitive scientists such as Santos, as well as to her economist colleagues, is that some of the errors that make the average citizen less than the perfect _Homo economicus_are probably evolved traits, hardwired into the brain. "It makes you think about human behavior from an evolutionary perspective," Santos says. "The idea that some of our irrationality might be evolved: That's philosophically cool."-Kalee Thompson

Mapping Maverick

Greg Asner, 39; Carnegie Institution, Stanford University

He created a new way to map the environment and everything in it

Greg Asner was just a couple years out of an undergraduate engineering program when he landed a job with an unexpected employer: the Hawaiian Nature Conservancy. He liked the work-which included struggling through dense tropical rainforest to map the path of invasive species-but quickly grew frustrated by how the preservation group was forced to base large-scale land-management decisions on nothing more than the scattered data collected by a handful of guys in the field.

Fifteen years later, Asner is using the world's most advanced methods of aerial data collection to map forest disturbances faster and more systematically than ever before. In 2005 he earned acclaim for an almost decade-long study of logging in the Amazonian rainforest that proved that so-called "selective logging," in which only the most marketable trees are harvested from the forest, can be just as damaging as clear-cutting. Asner's breakthrough was devising a new form of signal processing that could extract high-resolution images from decades-old Landsat satellites-"cracking open the pixels," as he says-to see the forest down to individual felled trees. He found that up to 25 surrounding trees can be killed in the process of harvesting just one.

The Landsat work, though, is antiquated compared to Asner's newest project, conducted from a small twin-engine airplane above his old beat, the Hawaiian rainforest. Using a combination of laser scanning (the beams shoot out 100,000 times a second to create a 3-D map of the forest canopy), hyperspectral imaging (the imager sees up to 144 bands of light, as opposed to six for the Landsat satellites) and a trajectory system derived from missile-guidance technology, Asner is able to map not only the structure of the forests down to the individual plant, but the forest chemistry as well. His instruments can detect the amount of water in an area, which can be used to predict and track drought; the nitrogen levels, which can be used to identify which invasive species are spreading fastest; and the level of carbon, which could be used to regulate tree-planting projects designed to counter global warming. Best of all, Asner's bundle of technologies can do it faster than ever before-up to 40,000 acres a day. His plane-based system has been up and running for less than a year, yet already he's delivered maps to Hawaiian land managers that will allow them to make smarter decisions about controlling invasive species. "We've been sleepless," Asner says. "It feels like a start-up company, except there's no money to make. Instead, we have the truth to find out."-K.T.

Internet Repairman

Emin Gün Sirer, 36; Cornell University

He attacks the near-impossible and all-too-common problems of the information age

Courtesy Cornell University

In 2004, Emin Gün Sirer figured out how to hijack the FBI's Web site. The problem wasn't with the Feds; it was with the structure of the Internet itself. Anytime you type an address like "www.fbi.gov" into your browser, your request feeds through several servers that act as the phone booths of the Internet. Sirer realized that many of these directories were insecure and that a hacker could easily reroute all traffic meant for the FBI to a malicious doppelgnger site. "No one even knew this problem was there," says Ken Birman, Sirer's colleague at Cornell. "Gun showed it was there, and he showed how to fix it."

His modest solution? Reorganize the entire Internet. Sirer created a scheme that eliminates the need for vulnerable central servers by distributing information among thousands of smaller computers. The strategy now helps safeguard Web sites through the PlanetLab worldwide academic network-and could someday protect the Web as a whole.

Sirer once dreamed of studying artificial intelligence. "Then I realized that the problems that we face are really nuts-and-bolts problems," he says. Things don't work the way they should, according to Sirer, because most things were never designed to do what they do. The Internet, for instance, began as a research project. As the Web grew, pieces got "globbed to each other," as Sirer puts it, with no well-thought-out organizational structure in place to keep everything running smoothly.

Consider, for example, his current plan to eliminate an age-old scourge: liars. To sort genuine photos and e-mails from doctored impostors and spam, Sirer has built an operating system that marks files with the details of how they were created. For instance, a photo's digital file incorporates the time and place at which it was taken, and altering even one pixel voids its virtual certificate of authenticity. Soon, the FBI may have Sirer to thank not just for protecting its Web site but for devising the digital world's greatest lie detector.-Lauren Aaronson

Robot Connector

Yoky Matsuoka, 36; University of Washington

She's built incredibly lifelike robots. Now she's connecting them directly to our brains

Yoky Matsuoka grew up dreaming of becoming a top-ranked tennis pro, but she wasn't your average jock. She spent a lot of on-court time pondering how her brain was controlling her hand, allowing her to smoothly swing her racket at just the right time and angle. More than a decade and several mechanical hands later, Matsuoka is still chasing the same question. But now she's pursuing it by trying to build the ultimate prosthetic-a fully functional replica of the human hand, controlled directly by the brain.

Matsuoka, who in graduate school built the hands for MIT's famous humanoid robot COG, is a trailblazer in brain-machine interfaces, the still-experimental effort to control external devices through brain signals. Her new project aims to teach a monkey how to use a three-fingered version of the human hand. The prototype has artificial versions of all the tendons and muscles controlling our thumbs and middle and ring fingers.

In the first experiment, the monkey will be seated before a bottle containing food. Its own arms will be strapped to its sides, and electrodes inside its brain will be wired through a computer to a robotic arm with Matsuoka's artificial hand on the end. The computer will interpret the monkey's brain signals and move the artificial arm and fingers accordingly. If all goes well, the monkey should be able to control Matsuoka's creation with its thoughts, opening the bottle and procuring its snack.

Other scientists are working on mind-controlled prosthetics that would translate these signals into basic actions, like grasping an object, but Matsuoka wants all the coin-rolling-over-the-knuckles capabilities of the real deal. Her eventual goal is to create a pop-it-on-and-go prosthetic for humans-like the kind that Luke Skywalker receives at the end of The Empire Strikes Back. She points out that for the average amputee, the hand might be lost, but the neural signals dispatched to control it are still flowing fine. "Your brain could still do exactly the same thing it had been doing," she says, "but naturally control this new mechanical hand."-G.M.

Mind Reader

Mark Schnitzer, 37; Stanford University

He's created a microscope that can uncover the smallest bits of our thoughts

Walk into Mark Schnitzer's lab while an experiment is in progress, and you'll see mice scampering around tethered to wire leashes. Sounds like a standard research setup for a neuroscientist-until you consider what's in the Lilliputian headpieces the mice are wearing. The plastic contraptions hold strands of clear fiber a bit thicker than a human hair, each containing a lens powerful enough to focus on individual neurons. "See that little needle?" Schnitzer says, angling one of the delicate fibers so it catches the light. "We can insert it directly into a mouse's brain to view regions that weren't accessible before." These fibers are giving researchers their first look at how individual cells behave deep in the brain.

Schnitzer didn't always aspire to survey uncharted biological territory; he started graduate school at Princeton University intending to become a physicist. But while there, he became entranced by the possibilities of mapping parts of the human body that had previously seemed too small and remote to study. He first helped develop a way to measure the forces produced by minuscule molecular "motors" inside cells, and soon resolved to uncover the biggest anatomical mystery of all: how simple neurons, firing together, can add up to create thoughts and memories.

MRI and CAT scanners give doctors a comprehensive view of entire regions of the brain, but they can't show what happens at the cellular level. Schnitzer zooms in on individual neurons by injecting areas to be imaged with a fluorescent dye. He then threads his lens deep into the brain and shines a titanium-sapphire laser through it. The laser light has the right energy level to activate the dye, so only the targeted brain areas absorb the light and glow. This method produces crisp, haze-free images that provide close-up views of neurons at work.

"Mark's work will revolutionize neuroscience, providing a new window-literally-to watch neurons in the brain work as they guide behavior," says Baylor College of Medicine neurobiologist Ron Davis. Although Schnitzer now stays busy using his neuro-microscope to study the ways mice store and forget memories (and what happens when that process goes awry), much of the thrill of making a completely new tool is watching other scientists devise creative ways to use it. "One of the most exciting things," Schnitzer says, "is knowing that there's such a demand for this."
-Elizabeth Svoboda

Theoretical Plumber

Martin Bazant, 37; Massachusetts Institute of Technology

He's shown how to exploit the bizarre properties of microscopic fluid flow

Courtesy John Nikolai

This is what happens when a mathematician comes from a family of engineers: Even his theoretical achievements end up making things work. Martin Bazant's father, grandfather and great-grandfather were all prominent civil engineers. Now Martin's studies of the strange behavior of fluids at the microscopic level are helping others to build portable diagnostic labs, miniature drug-infusion devices and more.

Microfluidics, the nascent field that promises to deliver these gadgets, is the ideal arena for this applications-bent mathematician-it's just the right mix of theoretical and real-world thinking. Take his approach to building the microfluidic lab-on-a-chip. Inside, thousands of channels, each a tenth the width of a human hair, would separate out individual cells from, say, a blood sample, and shuttle them off to different areas of the device for testing. Not only would the portable device need just a very small sample, "you could do hundreds or thousands of experiments all at once," Bazant says. Unfortunately, no one has been able to pump 8-micron-wide blood cells down 10-micron-wide tubes without huge machinery or high voltages, which makes the devices impractical for real-world use.

Bazant's breakthrough idea was to use electrokinetics: the way charged particles drag pockets of liquid around as they move in response to an electric field. Scientists initially observed the phenomenon long ago, but the systems they engineered to exploit it could only shoot the fluid down a channel in a straight line.

Bazant created a mathematical structure that showed how to control the fluids at the microlevel. The mathematics describes how electrodes spaced throughout a channel could move fluid along like a miniature conveyor belt. Then, by strategically placing tiny metal rods at the intersection of several channels and applying current, he can redirect fluids coming from multiple directions down unique paths. Bazant turns a simple wire into a microfluidic traffic cop.

Several groups are developing devices based on his ideas, and Bazant hasn't avoided the lab, either. One of his recent prototypes, built with MIT engineers, is 10 times as fast as other battery-powered microfluidic pumps even though it requires only a fraction of the battery power. The theoretician might end up as an engineer after all.-G.M.