The Best American Science and Nature Writing 2017

by Hope Jahren

Lefai’s team found, in animals, that a buildup of SREBP1 in the cell can lead to either extreme muscle atrophy or extreme muscle growth. And that was something Jill was interested in. She sent Lefai a two-line email with a question about his work. He thought it was from a scientist or PhD student and responded.

  Soon Jill told Lefai about her own history and suggested that it is possible that he discovered the actual biological mechanism that makes her and Priscilla so different—SREBP1 interacting with lamin.

  “Okay, that triggers a kind of reflection from my side saying, ‘That’s a really good question. That’s a really, really good question!’ ” Lefai says, in a thick French accent. “Because I had no idea of what I can do with genetic diseases before she contacted me. Now I have changed the path of my team.”

  Since Jill first contacted him, he has learned that lamin proteins—which the body creates using instructions from the lamin gene—can interact with SREBP1. Now Lefai is working to figure out whether a lamin gene mutation alters the ability of lamin proteins to regulate how SREBP1 works, causing simultaneous loss of muscle and fat. It’s possible, though certainly not assured, that his work could ultimately lead to new treatments.

  Given how technical his work is, I asked Lefai if he had ever had someone from outside the science community influence his research. “In my life, no,” he says. “People from outside coming and giving me hope? New ideas? I have no other example of this kind of thing. You know, maybe happen once in a scientific life.”

  It is the dream of many rare-disease patients to have a scientist orient his research agenda around them.

  The first time Jill and I spoke, she told me that she knew there would be no treatment breakthrough in her lifetime. (Although I’m not so sure.) But she doesn’t want what she learned to be lost, and hopes that maybe she’ll have made a small contribution to some therapy that’s developed for some other generation. She told me recently that she has proved her point, and she’s thrilled that she was able to help Priscilla improve her own health.

  The two women have stayed in touch. They talk about their kids. Priscilla is quite sure her daughters got her mutation. She can feel the difference between other kids and her own when she lifts them. Her girls are dense, with solid muscles.

  In my years of reporting on genetics and athleticism, I only know of two other cases where rare versions of single genes were associated with elite athletic performance, and the other two debuted in medical journals.

  Still, Jill told me that she’s officially retiring, for good this time, from DIY diagnosis. She gave me the same line that athletes so often wield when they hang ’em up: I want to spend more time with my family.

  Her mother, Mary, says it would be great if Jill could move on and just focus on the rest of her life. But do you think she’ll really retire? I asked. “Probably not,” Mary told me.

  Lefai laughed when I asked if he thought Jill would quit. “Of course she will continue,” he says. “I don’t believe that retirement. In the last email she told me she was in contact with people in New Zealand.”

  It’s been two and a half years since Jill happened to hear me on television and decided to reach out. Before Priscilla agreed to get a genetic test, I hadn’t really thought of all this as a story I would one day write. I just thought Jill deserved a response. But I don’t believe she’s retiring either.

  Recently Jill sent me an email. She’d picked up on a tidbit in a very technical scientific paper about potentially reversing muscular dystrophy. “I don’t want to read too much into this,” she wrote me. “But of course I’m curious.”

  ANN FINKBEINER

  Inside the Breakthrough Starshot Mission to Alpha Centauri

  FROM Scientific American

  In the spring of 2016, I was at a reception with Freeman Dyson, the brilliant physicist and mathematician, then 92 and emeritus at the Institute for Advanced Study in Princeton, New Jersey. He never says what you expect him to, so I asked him, “What’s new?” He smiled his ambiguous smile and answered, “Apparently we’re going to Alpha Centauri.” This star is one of our sun’s nearest neighbors, and a Silicon Valley billionaire had recently announced that he was funding a project called Breakthrough Starshot to send some kind of spaceship there. “Is that a good idea?” I asked. Dyson’s smile got wider: “No, it’s silly.” Then he added, “But the spacecraft is interesting.”

  The spacecraft is indeed interesting. Instead of the usual rocket, powered by chemical reactions and big enough to carry humans or heavy instruments, Starshot is a cloud of tiny multifunction chips called StarChips, each attached to a so-called light sail. The sail would be so insubstantial that when hit by a laser beam, called a light beamer, it would accelerate to 20 percent of the speed of light. At 4.37 light-years away, Alpha Centauri would take the fastest rocket 30,000 years to reach; a StarChip could get there in 20. On arrival the chips would not stop but rather tear past the star and any of its planets in a few minutes, transmitting pictures that will need 4.37 years to return home.

  The “silly” part is that the point of the Starshot mission is not obviously science. The kinds of things astronomers want to know about stars are not the kinds of things that can be learned from a quick flyby—and no one knows whether Alpha Centauri even has a planet, so Starshot could not even promise closeups of other worlds. “We haven’t given nearly as much thought to the science,” says astrophysicist Ed Turner of Princeton University, who is on the Starshot Advisory Committee. “We’ve almost taken for granted that the science will be interesting.” But in August 2016 the Starshot team got lucky: a completely unrelated consortium of European astronomers discovered a planet around the next star over, Proxima Centauri, a tenth of a light-year closer to us than Alpha Centauri. Suddenly Starshot became the only semifeasible way in the foreseeable future to visit a planet orbiting another star. Even so, Starshot sounds a little like the dreams of those fans of science fiction and interstellar travel who talk seriously and endlessly about sending humans beyond the solar system with technologies that would surely work, given enough technological miracles and money.

  Starshot, however, does not need miracles. Its technology, though currently nonexistent, is based on established engineering and violates no laws of physics. And the project has money behind it. Yuri Milner, the entrepreneur who also funds other research projects called Breakthrough Initiatives as well as yearly science awards called Breakthrough Prizes, is kick-starting Starshot’s initial development with $100 million. Furthermore, Milner has enlisted an advisory committee impressive enough to convince a skeptic that Starshot might work, including world experts in lasers, sails, chips, exoplanets, aeronautics, and managing large projects, plus two Nobel Prize winners, the U.K.’s astronomer royal, eminent academic astrophysicists, a cadre of smart, experienced engineers—and Dyson, who, despite thinking Starshot’s mission is silly, also says the laser-driven sail concept makes sense and is worth pursuing. On the whole, few would make a long-range bet against an operation with this much money and good advice and so many smart engineers.

  Whatever its prospects, the project is wholly unlike any space mission that has come before. “Everything about Starshot is unusual,” says Joan Johnson-Freese, a space policy expert at the U.S. Naval War College. Its goals, funding mode, and management structure diverge from all the other players in space travel. Commercial space companies focus on making a profit and on manned missions that stay inside the solar system. NASA, which also has no plans for interstellar travel, is too risk-averse for something this uncertain; its bureaucratic procedures are often cumbersome and redundant; and its missions are at the mercy of inconsistent congressional approval and funding. “NASA has to take time; billionaires can just do it,” says Leroy Chiao, a former astronaut and commander of the International Space Station. “You put this team together, and off you go.”

  The Game Plan

  The man driving the Starshot project has always been inspired by the far reaches. Yuri Milner was born in Moscow
in 1961, the same year Yuri Gagarin became the first human to go into space. “My parents sent me a message when they called me Yuri,” he says—that is, he was supposed to go somewhere that no one had ever been. So he went into physics—“It was my first love,” he says. Milner spent 10 years getting educated, then worked on quantum chromodynamics. “Unfortunately, I did not do very well,” he says. Next he went into business, became an early investor in Facebook and Twitter, and amassed a fortune reported to be nearly $3 billion. “So maybe four years ago,” Milner says, “I started to think again about my first love.”

  In 2013 he set up the Breakthrough Prizes, one each for the life sciences, mathematics, and physics. And in 2015 he started what he calls his hobby, the Breakthrough Initiatives, a kind of outreach to the universe: a $1 million prize for the best message to an extraterrestrial civilization, $100 million for a wider, more sensitive search for extraterrestrial intelligence, and now $100 million to Starshot.

  In early 2015 Milner recruited a central management team for Starshot from people he had met at various Breakthrough gatherings. Starshot’s advisory committee chair and executive director, respectively, are Avi Loeb, chair of Harvard University’s astronomy department, and Pete Worden, who directed the NASA Ames Research Center and was involved in a DARPA/NASA plan for a starship to be launched in 100 years. Worden recruited Pete Klupar, an engineer who had been in and out of the aerospace industry and had worked for him at Ames, as Starshot’s director of engineering. They in turn pulled together the impressive committee, which includes specialists in the relevant technologies who are apparently willing to participate for some or no money, as well as big names such as Facebook’s Mark Zuckerberg and cosmologist Stephen Hawking. Starshot’s management policy seems to be a balance between NASA’s hierarchical decision-tree rigor and the Silicon Valley culture of putting a bunch of smart people in a room, giving them a long-term goal, and standing back. One committee member, James Benford, president of Microwave Sciences, says the charge is to “give us next week and five years from now, and we’ll figure out how to connect the two.”

  The assembled team members began by agreeing that they could rule out sending humans to Alpha Centauri as too far-fetched and planned to focus on an unmanned mission, which they estimated they could launch in roughly 20 years. They then agreed that the big problem was spacecraft propulsion. So in mid-2015 Loeb’s postdocs and graduate students began sorting the options into the impossible, the improbable, and the feasible. In December of that year they received a paper by Philip Lubin, a physicist at the University of California, Santa Barbara, called “A Roadmap to Interstellar Flight.” Lubin’s option for propulsion was a laser-phased array—that is, a large number of small lasers ganged together so that their light would combine coherently into a single beam. The laser beam would push a sail-carried chip that would need to move at a good fraction of light speed to reach another star within a couple of decades. (A similar idea had been published 30 years earlier by a physicist and science fiction writer named Robert Forward; he called it a Starwisp.) Although the technology was still more science fiction than fact, “I basically handed Starshot the road map,” Lubin says, and he joined the project.

  In January 2016, Milner, Worden, Klupar, Loeb, and Lubin met at Milner’s house in Silicon Valley and put together a strategy. “Yuri comes in, holding a paper with sticky notes on it,” Lubin says, “and starts asking the right science and economic questions.” The beauty of the project’s unusual approach was that rather than going through a drawn-out process of soliciting and reviewing proposals, as NASA would, or being concerned about the potential for profit like a commercial company, the Starshot team was free to hash out a basic plan based purely on what sounded best to it.

  Starshot’s only really expensive element was the laser; the sails and chips would be low-cost and expendable. The latter would be bundled into a launcher, sent above the atmosphere, and released like flying fish, one after another—hundreds or thousands of them—so many that like the reptilian reproduction strategy, losing a few would not matter. Each one would get hit by the laser and accelerated to 20 percent the speed of light in a few minutes. Next the laser would cut off, and the chip and sail would just fly. When they got to the star, the chips would call back home. “Ten years ago we couldn’t have had a serious conversation about this,” Milner says. But now, what with lasers and chips improving exponentially and scientists designing and building new materials, “it’s not centuries away, it’s dozens of years away.”

  Starshot management sent the idea out for review, asking scientists to look for deal-breakers. None found any. “I can tell you why it’s hard and why it’s expensive,” Lubin says, “but I can’t tell you why it can’t be done.” By April 2016 the team had agreed on the system, and on April 12 Milner arranged a press conference atop the new Freedom Tower in New York City, featuring videos, animations, and several members of the advisory committee. He announced an “interstellar sailboat” driven by a wind of light. The researchers spent the following summer outlining what had to happen next.

  StarChips and Light Sails

  The team soon found that, though technically feasible, the plan would be an uphill climb. Even the easiest of the technologies, the StarChip, poses a lot of problems. It needs to be tiny—roughly gram-scale—yet able to collect and send back data, carry its own power supply, and survive the long journey. Several years ago engineer Mason Peck’s group at Cornell University built what they call Sprites, smartphonelike chips that carry a light sensor, solar panels, and a radio and weigh four grams each. The Starshot chips would be modeled on the Sprites but would weigh even less, around a gram, and carry four cameras apiece. Instead of heavy lenses for focusing, one option is to place a tiny diffraction grating called a planar Fourier capture array over the light sensor to break the incoming light into wavelengths that can be reconstructed later by a computer to any focal depth. Other equipment suggested for the chip include a spectrograph to identify the chemistry of a planet’s atmosphere and a magnetometer to measure a star’s magnetic field.

  The chips would also need to send their pictures back over interstellar distances. Satellites currently use single-watt diode lasers to send information, but over shorter distances: So far, Peck says, the longest distance has been from the moon, more than 100 million times closer than Alpha Centauri. To target Earth from the star, the laser’s aim would need to be extraordinarily precise. Yet during the four-year trip the signal will spread out and dilute until, when it reaches us, it will come in as just a few hundred photons. A possible solution would be to send the pictures back by relay, from one StarChip to a series of them flying at regular distances behind. Getting the information back to Earth, says Starshot Advisory Committee member Zac Manchester of Harvard, “is still a really hard problem.”

  The chips also need batteries to run the cameras and onboard computers to transmit data back during the 20-year voyage. Given the distance to Alpha or Proxima Centauri and the few watts achievable on a small chip, the signal would arrive on Earth weak but “with just enough photons for Starshot’s receiver to pick it up,” Peck says. To date, no power source simultaneously works in the dark and the cold, weighs less than a gram, and has enough power. “Power is the hardest problem on the chip,” Peck says. One possible solution, he offers, is to adapt the tiny nuclear batteries used in medical implants. Another is to tap the energy the sail gains as it travels through the gas- and dust-filled interstellar medium and heats up via friction.

  The same interstellar medium could also pose hazards for the Starshot chips. The medium is like highly rarefied cigarette smoke, says Bruce Draine, an astronomer at Princeton University who is also a committee member. No one knows exactly how dense the medium is or what size the dust grains are, so its potential for devastation is hard to estimate. Collisions near the speed of light between the StarChips and grains of any size could create damage that would range from minor craters to complete destruction. If the StarChips are
a square centimeter, Draine says, “you’ll collide with many, many of these things” along the way. One protectant against smaller particles might be a coating of a couple of millimeters of beryllium copper, although dust grains could still cause catastrophic damage. “The chip will either survive or it won’t,” Peck says, but with luck, out of the hundreds or thousands sent off in the chip swarm, some will make it.

  The next hardest technology is the sail. The StarChips would be propelled by the recoil from light reflected off their sails, the way the recoil from a tennis ball pushes a racket. The more light gets reflected, the harder the push and the faster the sail; to get to 20 percent of light speed, the Starshot light sail has to be 99.999 percent reflective. “Any light that isn’t reflected ends up heating the sail,” says Geoffrey Landis, a scientist at the NASA Glenn Research Center and a member of the advisory committee—and given the extraordinary temperatures of the light beamer, “even a small fraction of the laser power heating the sail would be disastrous.” Compared with today’s solar sails, which have used light from the sun to propel a few experimental spacecraft around the solar system, it also has to be much lighter, of a thickness measured in atoms or about “the thickness of a soap bubble,” Landis says. In 2000, in the closest approximation yet, Benford used a microwave beam to accelerate a sail made of a carbon sheet. His test achieved about 13 g’s (13 times the acceleration felt on Earth caused by gravity), whereas Starshot’s sail would need to withstand an acceleration up to 60,000 g’s. The sail, like the StarChip, would also have to stand up to dust in the interstellar medium punching holes in it. So far no material exists that is light, strong, reflective, and heat-resistant and that does not cost many millions of dollars. “One of the several miracles we’ll have to invent is the sail material,” Klupar says.