Earth might have a kindred planet orbiting the star next door. A world at least 1.3 times as massive as Earth appears to orbit the closest star to the sun: Proxima Centauri, a dim red orb about 4.2 light-years away.
Dubbed Proxima b, the planet is cozied up to its star, needing just 11.2 days to complete one orbit. But despite the proximity to its star — just 5 percent of the distance from Earth to the sun — Proxima b is potentially habitable. Its temperature is just right for liquid water to flow on its surface, Guillem Anglada-Escudé, an astronomer at Queen Mary University of London, and colleagues report in the August 25 Nature. That makes Proxima b the closest known world outside our solar system where life might exist. “It’s an incredible discovery — it’s almost a gift,” says David Kipping, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. With Proxima b, researchers might now have their best chance at characterizing the atmosphere of an Earthlike world in another solar system and probing for hints of life elsewhere in the galaxy. Proxima Centauri, which lies in the southern constellation Centaurus, is a runt of a star. Temperatures at the surface run about 2,800 degrees Celsius cooler than our sun, giving Proxima a feeble, ruddy glow. The star is much closer in size to Jupiter than the sun, and even though it’s relatively close to Earth, Proxima is invisible to the naked eye — it wasn’t discovered until 1915. Part of a triple star system known as Alpha Centauri, it’s not clear whether Proxima is gravitationally bound to its brighter companions (taking hundreds of thousands of years to complete one orbit around both) or just passing by.
The Alpha Centauri system is no stranger to claims of exoplanets. In 2012, astronomers reported in Nature that the star Alpha Centauri B hosts a planet roughly as massive as Earth, though too warm to be habitable (SN: 11/3/12, p. 5). Other researchers are skeptical; a 2015 report in Monthly Notices of the Royal Astronomical Society Letters, for example, found no evidence for the planet. The claim for Proxima b appears to be much stronger. Anglada-Escudé and colleagues found their quarry by looking for a minute wobble in the speed of Proxima Centauri, the sign of a gravitational tug from the orbiting planet. An intensive two-month observing campaign in early 2016 using two telescopes in Chile — the European Southern Observatory’s 3.6-meter and Very Large telescopes — confirmed earlier suspicions of a planet.
“It’s not clear if the planet will be Earthlike,” Anglada-Escudé says. Not much is known about Proxima b, such as its size or what its atmosphere is like. Even its mass is just a minimum estimate. Without knowing how the planet’s orbit is tilted relative to us, the researchers can say only that Proxima b is no lighter than 1.3 Earths — it could be heavier and have more in common with Neptune than Earth.
Even though it’s just one star away, “we will likely have to wait a long time in order to learn anything more about the planet,” says Heather Knutson, a planetary scientist at Caltech. The best bet, says Knutson, is to hope that the planet, when viewed from Earth, passes in front of Proxima Centauri, allowing starlight to filter through the planet’s atmosphere. Molecules in the atmosphere would betray their presence by absorbing specific wavelengths of light. Substances such as oxygen, methane and carbon dioxide are widely considered to be chemical markers of life.
If the planet does cross in front of the star, NASA’s James Webb Space Telescope, scheduled to launch in late 2018, should be able to characterize its atmosphere, says Mark Clampin, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Md. Hundreds of hours of telescope time would need to be dedicated to the task. “It will be an extremely challenging observation, but not impossible,” he says.
Scientists can also estimate the planet’s size by measuring how much light the planet blocks. The size combined with the mass would let researchers determine the density of Proxima b and figure out if the planet is puffy like Jupiter or rocky like Earth.
Kipping has already been monitoring Proxima Centauri with the Canadian MOST satellite, looking for a periodic dip in light caused by the planet partially blocking its sun. There’s only a 1.5 percent chance, however, that the planet lines up just-so with the star. And if it does line up, the inherent variability in Proxima Centauri’s light will make any drop in brightness from the planet hard to detect.
Without a fortuitous alignment, “things get much more difficult,” Knutson says. Astronomers would have to rely on light coming from the planet — either an intrinsic infrared glow or visible light reflected from its sun. James Webb might be able to barely sense infrared light emanating from Proxima b, but it could be a decade or more before any other observatory is up to the challenge (SN: 4/30/16, p. 32). And even then, there are no guarantees. “It’s going to be very difficult to characterize the planet without sending a probe there,” Kipping says.
Breakthrough Starshot, a group funded by Russian entrepreneur Yuri Milner, wants to do just that. In April the group announced a plan to put $100 million toward developing technology that would send a fleet of nanocraft — robotic probes weighing just a few grams — toward Alpha Centauri, nudging them along with an Earth-based 100 gigawatt laser. Accelerating to roughly 20 percent the speed of light, the armada would arrive at Alpha Centauri about 20 years after launch. In comparison, the fastest spacecraft ever to leave Earth — the New Horizons mission to Pluto — would need roughly 90,000 years to complete the journey, traveling at its current speed of about 52,000 kilometers per hour.
“The discovery is likely to energize the project,” says Harvard University astrophysicist Avi Loeb, chairman of Breakthrough’s advisory committee. “A spacecraft equipped with a camera and various filters could take color images of the planet and infer whether it is green (harboring life as we know it), blue (with water oceans on its surface) or just brown (dry rock).”
If anything is alive on Proxima b, it’s probably quite different from anything on Earth. Photosynthesizing organisms would have to deal with a faint, cool star that emits mostly infrared light. Proxima Centauri is also known for exuberant flares, which would buffet any orbiting planets with bursts of ultraviolet radiation and X-rays. “Conditions on such a planet would be very interesting for life,” says Lisa Kaltenegger, an astrophysicist at Cornell University. Given such an alien environment, life might show its presence in unusual ways. Kaltenegger, along with Cornell astronomer Jack O’Malley-James, proposes looking for biofluorescence, a glow from organisms triggered by ultraviolet light, in the wake of stellar flares. Critters on Proxima b could have evolved biofluorescence as protection, taking harmful UV radiation and transforming it into more palatable visible light — a flicker that might be detectable from an Earth-based telescope. “The idea that we could spot a glow seems to be right out of a [science fiction] novel,” says Kaltenegger, whose proposal appears online August 24 at arXiv.org.
That’s assuming anything could survive on the planet. If Earth were placed in the same orbit as Proxima b, it would be stripped of its protective ozone roughly three times per Earth year, Kipping says. “That’s kind of bad,” he says. That rate doesn’t give the atmosphere time to recover, “but it’s not a showstopper,” he adds. A strong planetary magnetic field or a dense atmosphere might be able to withstand the blows. And if life has taken shelter underground or underwater — or is impervious to a lack of oxygen — it might still survive.
Whether or not critters crawl on Proxima b, the discovery of the planet “could really usher new energy into the search for other nearby worlds,” says Margaret Turnbull, an astronomer with the SETI Institute and based in Madison, Wis. Most exoplanets are hundreds to thousands of light-years away. But little is known about the possible planet families huddled up to the stars nearest to us. “I’d love to see interstellar travel,” says Turnbull. “To really inspire that kind of effort, we need interesting destinations like this.”
Hillary Clinton’s “I believe in science” declaration aside, science has not played a starring role in the 2016 presidential election. Far from it. For the most part, the candidates’ science policies have trickled out in dribs and drabs, and in varying degrees of detail — talking points on a website here, a passing comment in response to a spur-of-the-moment question there.
Yet science underpins our understanding of, and response to, the world around us. It answers everything from why our coffee sloshes dangerously to what could happen if the planet warms another degree or two. Science often intersects with public policy, and presidential leadership influences research priorities. With that in mind, Science News examines where Clinton, the Democratic Party nominee, and Republican Party nominee Donald Trump stand on seven scientific issues with the power to impact our future. Our writers looked at what the candidates have said publicly at campaign events and in interviews, what they have written on their websites, relevant planks in their party’s platform, and their responses, released September 13, to 20 questions posed by the nation’s science advocates. (Science News’ parent organization, Society for Science & the Public, is among the groups pushing to make science more prominent in the presidential campaigns, via an initiative called ScienceDebate.org.)
Read on to find out what Clinton and Trump have said on topics ranging from genetic engineering to space exploration, and how their positions accord with the current state of the science. — Macon Morehouse Hillary Clinton: As she tells the story, Clinton wanted to be an astronaut when she was 14 years old, but NASA told her that they weren’t accepting girls. That doesn’t seem to have dampened her enthusiasm. “I really, really do support the space program,” she told a crowd in July 2015 at a town hall meeting in Dover, N.H. “There’s a lot for us to keep learning … Let’s not back off now.”
Clinton has provided few specifics on what the United States should be doing in space, but she told ScienceDebate.org that one of her goals is to “advance our ability to make human exploration of Mars a reality.”
Clinton’s position seems to align with that of her party’s platform: “Democrats believe in continuing the spirit of discovery that has animated NASA’s exploration of space over the last half century. We will strengthen support for NASA and work in partnership with the international scientific community to launch new missions to space.” The platform makes no mention of what role, if any, commercial enterprises such as SpaceX and Blue Origin should play in furthering space exploration. Clinton has said that she doesn’t object to partnering with private ventures, but that their role is more aligned with applied science, whereas the government should be funding basic research and discovery.
Donald Trump: Trump is a big fan of space exploration — “a strong space program will encourage our children to seek STEM [education] and will bring millions of jobs and trillions of dollars in investment to this country,” he told ScienceDebate.org. But he has also repeatedly said that it’s a luxury the country can’t afford. “I love NASA, I love what it represents, I love what it stands for,” he said during a November 11 event in Manchester, N.H. “Right now we have bigger problems.… We’ve got to fix our potholes.”
NASA should focus on exploring new frontiers, Trump told Aerospace America in May. Infrastructure, economics and defense come first, however. “Our first priority is to restore a strong economic base to this country,” he said. “If we are growing with all of our people employed and our military readiness back to acceptable levels, then we can take a look at the timeline for sending more people into space.”
Both Trump and the Republican Party support working with private companies to expand access to space. “I think there needs to be a growing partnership between the government and the private sector as we continue to explore space,” Trump told Aerospace America. “There seems to be tremendous overlap of interests so it seems logical to go forward together.”
State of the science: Pluto reconnaissance. Ripples in spacetime. Discovery of thousands of worlds around other stars. Space exploration is in a golden age, and astronomers as well as policy experts want continued support for basic research, whether by building new telescopes or sending probes to far-flung worlds. NASA is on track to launch James Webb, the next major space-based telescope, late in 2018 and has started work on that telescope’s successor, WFIRST. The agency launched a probe in September to bring samples of an asteroid back to Earth (SN Online: 9/8/16), and plans are under way for the next Mars rover and a mission to Jupiter’s moon Europa (SN Online: 6/18/15).
Current policy regarding the role of humans in space is muddled. “No dream, no vision, no plan, no budget,” said former NASA administrator Michael Griffin at a congressional hearing in February. NASA proclaims it will send humans to Mars in the next 20 years — while others argue for a return to the moon — but there is no clear outline or long-term financial support (SN Online: 5/24/16).
Private companies, despite the occasional rocket explosion, are enjoying a run of success. Dramatic rocket landings are making reusable launch components a reality, and SpaceX and Orbital ATK have been making supply runs to the International Space Station. SpaceX also plans to send an uncrewed mission to Mars in 2018. — Christopher Crockett Q: What, if any, limits should the United States set for genetic engineering, and why? Hillary Clinton: Clinton has not taken a public stance on human genetic engineering or genetic modification of animals or insects. Genetically engineered crops, often called GMOs, are another matter.
“I stand in favor of using seeds and products that have a proven track record … scientifically provable,” she said at a meeting of the Biotechnology Innovation Organization in 2014. “Genetically modified sounds Frankensteinish, [but] drought resistant sounds really [like] something you want.” At a town hall meeting in Fairfield, Iowa, in December, she elaborated: “There are a lot advocates who fight hunger in Africa who are desperate for GMO seeds because they are drought resistant and they don’t know how else they are going to get enough yield to feed people.”
At that same town hall, Clinton said she also favors food labeling. “There’s a right to know,” she said. “There’s also a right to have the best science.… Whatever kind of overall plan we can have that will give us information, we deserve to know and get more science done that is independent science that we can count on that doesn’t get done by some institution, company, whatever, that has a stake in the outcome.”
Donald Trump: Trump has been silent on matters concerning genetic engineering, whether it’s involving humans, animals or plants.
But the Republican Party platform weighs in on GMO food and labeling: “We oppose the mandatory labeling of genetically modified food, which has proven to be safe, healthy and a literal life-saver for millions in the developing world.”
State of the science: Genetic engineering has taken on new vigor with the introduction of technologies such as the powerful gene editor CRISPR/Cas9 (SN: 12/12/15, p. 16; SN: 9/3/16, p. 22). Scientists may soon be able to alter genes in any organism, including humans, at will. That has many people, including scientists, worried about social, health, ethical and environmental consequences.
The United States doesn’t have laws to establish what types of genetic engineering are allowed, but does regulate the release of genetically modified organisms into the environment. For instance, the U.S. Food and Drug Administration recently OK’d the first GM mosquito trial in an effort to curb the spread of the Zika virus (SN Online: 8/5/16). And in July, President Obama signed into law a measure that requires labeling of foods that contain genetically modified organisms, or GMOs.
One of the most controversial uses of gene editing is making changes to the human germ line — embryos, eggs, sperm and the cells that give that rise to them — that could be carried to future generations. Such edits could cure genetic diseases permanently, but may also lead to “designer babies” and raises fears of a new kind of eugenics (SN: 5/30/15, p. 16). An international group of scientists said last year that research on human gene editing should go ahead, but that no babies should be born as a result (SN: 12/26/15, p. 12). A federal spending bill prohibits the FDA from considering, or even acknowledging, applications for scientists to make heritable changes in human embryos. Some call it an effective ban on engineering the human germ line, including the creation of “three-parent babies” in which the nucleus from a mother’s egg is transplanted into an empty donor egg to help a mother avoid passing mitochondrial diseases on her children. A panel of scientists have deemed that procedure ethical under certain circumstances (SN Online: 2/3/16). — Tina Hesman Saey Q: What, if any, steps do you think the United States should take to combat climate change and why, or why not? Hillary Clinton: “I believe in science. I believe that climate change is real and that we can save our planet while creating millions of good-paying clean energy jobs,” Clinton said during her acceptance speech at the Democratic National Convention in Philadelphia in July. She has called last December’s 195-nation Paris climate agreement a “historic step forward” and says she’ll deliver on the U.S. pledge to curb warming without “relying on the climate deniers in Congress to pass new legislation.”
Her goal: reduce greenhouse gas emissions in 2025 by up to 30 percent relative to 2005 levels and ultimately by 80 percent by 2050. To reach those ambitious targets, Clinton would invest in renewable energy, including creating a $60 billion Clean Energy Challenge to promote cutting carbon pollution and expanding clean energy. Within 10 years of taking office, she hopes to have enough renewable energy capacity in the United States to power every home and cut oil consumption by a third. “I’m proud that we shaped a global climate agreement,” she said at the convention. “Now we have to hold every country accountable to their commitments, including ourselves.”
Donald Trump: Trump has repeatedly called human-caused climate change a hoax; any efforts to combat it are needlessly burdensome on the economy, he says. “President Obama entered the United States into the Paris climate accords. Unilaterally and without the permission of Congress, this agreement gives foreign bureaucrats control over… what we’re doing on our land in our country,” Trump said May 26 at a campaign event at the Williston Basin Petroleum Conference in Bismarck, N.D. “We’re going to cancel the Paris climate agreement and stop all payments of the United States tax dollars to U.N. global warming programs.”
Trump has said that he would undo many climate initiatives put in place by the Obama administration, such as the U.S. Environmental Protection Agency’s plan to cut emissions from power plants. Trump would also end the Interior Department’s moratorium on coal mining permits and “encourage, not discourage, the use of natural gas and other American energy resources.” According to the Trump campaign, lifting these and other restrictions would increase the country’s economic output by $700 billion annually over the next 30 years, increase wages by $30 billion annually and create millions of new jobs.
State of the science:
Satellite and on-the-ground measurements have recorded a sharp rise in global temperatures over the past several decades that is unprecedented in the last millennium. That warming is in large part caused by emissions from human activities such as fossil fuel burning, computer simulations and direct observations have shown (SN: 4/4/15, p. 14).
Greenhouse gases from these emissions, such as carbon dioxide, trap heat that would otherwise escape into space. As a result, the global average temperature has risen around 1 degree Celsius since the start of the Industrial Revolution, and the rate of warming has nearly doubled over the past half century. If continued unabated, this climate change will raise sea levels, shift rainfall patterns and cause health and economic problems around the world (SN: 4/16/16, p. 22), many scientists warn.
The Paris climate agreement is the most ambitious plan yet to limit and reverse this trend (SN: 1/9/16, p. 6). The pact, reached in December, aims to limit warming to “well below” 2 degrees Celsius above preindustrial levels, with a possibility of adopting an even more ambitious 1.5-degree target down the road. U.S. participation is crucial to the success of the agreement: The United States is the second largest emitter of the greenhouse gas carbon dioxide worldwide and the 10th largest per capita. — Thomas Sumner Q: When it comes to public health initiatives and disease research, what should our priorities be and how would you support those priorities? Hillary Clinton: “I’m committed to ramping up our funding for biomedical research and development, including $2 billion per year for Alzheimer’s research, which is the amount leading researchers say will be necessary to effectively treat the disease and make a cure possible by 2025,” Clinton wrote in an August 8 Quora post.
She has endorsed the Obama administration’s cancer moonshot initiative (SN Online: 9/8/16): “By combining new funding with creative approaches, we will not only catalyze progress against cancer: We will strengthen the nation’s entire scientific enterprise.… As president, I will take up the charge.”
Clinton also has also pushed for additional funding to fight the Zika virus. In another Quora post, she wrote: “If we’re serious about keeping families safe, there’s no time to waste. We need to step up mosquito control and abatement, provide families with critical health services, including access to contraception, develop a vaccine and treatment, and ensure people know how to protect themselves and their kids.” She told ScienceDebate.org that she would create a Public Health Rapid Response Fund with stable funding and the agility “to quickly and aggressively respond to major public health crises and pandemics.”
Donald Trump: Trump has said little on issues regarding biomedical research, but noted on a radio show in 2015, “I hear so much about the NIH [National Institutes of Health] and it’s terrible.”
“We cannot simply throw money at these institutions and assume that the nation will be well served,” he told ScienceDebate.org. “Our efforts to support research and public health initiatives will have to be balanced with other demands for scarce resources.”
When asked a question about Alzheimer’s disease at a New Hampshire town hall, he responded: “It’s a total top priority for me. I have so many friends whose families are devastated by Alzheimer’s. There are some answers. They’ve made less progress than we had hoped, as you know.” (Trump’s father had Alzheimer’s.)
On Zika, he told a Miami television station in August: “Well, first of all you have a great governor, who’s doing a fantastic job, Rick Scott, on the Zika. And it’s a problem, it’s a big problem. But I watch and I see, and I see what they’re doing with the spraying and everything else. And I think he’s doing a fantastic job. And he’s letting everyone know exactly what the problem is and how to get rid of it. He’s going to have it under control. He probably already does.”
State of the science:
The National Institutes of Health funded $32.3 billion of biomedical research during the 2015–2016 fiscal year. Parceling out those dollars and setting research priorities can be controversial, with advocacy groups for specific diseases jostling for more money for their own cause. But with people generally living longer than they did 50 years ago, funding for aging-related diseases like Alzheimer’s is on the rise.
Research into cancer, neuroscience and genetics, among other broad topics, is also funded by the NIH. But some scientists caution against devoting too much energy to curing specific diseases at the expense of basic research — studies that don’t have an immediate application, but that can yield results leading to advances disciplines.
On the public health front, emerging diseases are a growing threat. Warming temperatures are letting infectious tropical diseases thrive in places they couldn’t previously, the World Health Organization warns. Zika virus is a case in point, having blazed a path through the Americas (and beyond) in less than a year (SN Editor’s Picks). Most experts agree that Zika is currently a serious problem in the United States requiring a national response. The virus had infected more than 18,000 people in the states and territories as of early September, and with mosquitoes in Florida now carrying and spreading the disease, the numbers are expected to climb. — Laurel Hamers
Q: What is your position on vaccines, and why? Hillary Clinton: In February 2015, Clinton sent out a tweet heard round the world: “The science is clear: The earth is round, the sky is blue, and #vaccineswork. Let’s protect all our kids. #GrandmothersKnowBest.”
She reiterated her pro-vaccine stance in response to a ScienceDebate.org question, vowing to “speak out and educate parents about vaccines, focusing on their extraordinary track record in saving lives and pointing out the dangers of not vaccinating our children.”
But Clinton hasn’t always been this definitive.
In 2008, in response to a questionnaire from a web newspaper called Age of Autism, Clinton appeared to question one heavily researched area of vaccine safety.
“I am committed to make investments to find the causes of autism, including possible environmental causes like vaccines,” she wrote. “We don’t know what, if any, kind of link there is between vaccines and autism — but we should find out.”
Clinton has since stepped away from this view. Though her campaign website highlights the need to support people with autism, it makes no mention of vaccines. Instead, Clinton pledges to ramp up funding for research “to better understand child brain development and the genetic linkages for autism” and calls for a nationwide study of the prevalence of autism in adults.
Donald Trump: Donald Trump occupies a nebulous, quantum-flux sort of position on vaccines that places him in both the pro- and the anti- camps.
For years, he has championed the idea that vaccines cause autism. In 2014, he tweeted: “Healthy young child goes to doctor, gets pumped with massive shot of many vaccines, doesn’t feel good and changes — AUTISM. Many such cases!”
But Trump objects to being lumped in with anti-vaxxers. In 2014, Trump tweeted: “To all haters and losers: I am NOT anti-vaccine, but I am against shooting massive doses into tiny children. Spread shots out over time.”
Trump’s campaign website does not mention vaccines or autism, but he has admitted to slowing the vaccine schedule for his youngest son, Barron.
But he has also said that as president, he would support vaccinations. “We should educate the public on the values of a comprehensive vaccination program,” Trump told ScienceDebate.org. “This seems to be of enough importance that we should put resources against this task.”
State of the science: Vaccines have all but wiped out dozens of infectious diseases. In the United States, a case of smallpox hasn’t been reported for more than 60 years, polio has been eliminated, and measles deaths have plummeted. Diseases suffered by one generation can be nearly vanquished in the next. Children today, for example, can receive vaccines against the viruses that cause chicken pox and cervical cancer.
Today’s children also receive vaccines for more diseases than they did 20 years ago — 14 by age 2 compared with 10 in 1996. But today’s vaccines contain far fewer of the viral or bacterial particles that rev up the immune system.
Yet many parents worry about the current vaccine schedule. In 2013, 87 percent of pediatricians reported that parents refused at least some vaccines for their children. That’s up from 74.5 percent in 2006. A 2013 report from the Institute of Medicine, however, found no evidence that the vaccine schedule was unsafe. (In fact, the report concluded that a study to spread out vaccines would “needlessly endanger children’s lives.”) And skipping vaccines weakens herd immunity, putting people who can’t get vaccinated — some infants, people with compromised immune systems — at risk (SN Online: 2/11/15).
Scientists have also found no evidence that vaccines cause autism, another concern parents cite (SN Online: 4/1/16). Still, the number of children diagnosed with autism spectrum disorder has risen, from 1 in 150 children in 2002 to 1 in 68 in 2012. Scientists don’t fully understand why, or what triggers the disorder. But researchers around the world have spent years investigating the purported link between vaccines and autism. Their conclusion: It’s just not there. — Meghan Rosen Q: Do you think the effective ban on research into gun-related violence should be lifted, and why or why not? Hillary Clinton: Clinton has staked out a position as the candidate favoring gun control. But her stance on gun research isn’t so clear.
At a campaign event in South Carolina in February, she alluded to the difficulties facing lawmakers and gun violence researchers: “I know we are a smart enough nation to figure out how you protect responsible gun owners’ rights and get guns out of the hands of people who shouldn’t have them.”
Clinton’s campaign website lists a few major gun policy changes she’d make as president, including expanding background checks and making it harder for mentally ill people and violent criminals to buy and own guns. Her website doesn’t, however, address the question of research funding.
Donald Trump: Like Clinton, Trump has not made his position on funding gun research clear. But he has planted himself firmly on the pro-gun side.
Trump proposes a “national right to carry,” which would let people with concealed weapon permits carry guns in all 50 states. His website questions the efficacy of background checks and calls gun bans “a total failure.” That’s a reversal from a statement he made in his 2000 book, The America We Deserve: “I generally oppose gun control, but I support the ban on assault weapons and I support a slightly longer waiting period to purchase a gun.”
State of the science: In June, the American Medical Association announced a new effort to revive gun violence research.
For the United States, gun violence is a public health crisis “unrivaled in any other developed country,” the doctors’ group declared. Research, the association argued, could help scientists figure out how to reduce the number of gun-related deaths — more than 33,000 per year.
But America doesn’t make researching gun violence easy (SN: 5/14/16). Federal laws limit funding and keep some gun data hidden from the public. There’s no “ban” on gun research — technically — though some scientists argue that one law does essentially just that. Called the Dickey amendment, it prevents the U.S. Centers for Disease Control and Prevention and the National Institutes of Health from using funds to “advocate or promote gun control.”
A second law, called the Tiahrt amendment, limits sharing of gun-crime data. Only law enforcement, not the public, can access the detailed data about gun crimes collected by the Bureau of Alcohol, Tobacco, Firearms and Explosives.
Researchers do have some data to work with — it’s just not all that complete. The National Violent Death Reporting System, for example, tracks deaths by guns, but in only 42 states. In December, the Senate passed the Mental Health Awareness and Improvement Act, which encouraged inclusion of more states. Participation would be voluntary.
“Without research and being brave enough to ask the questions, we’re going to have ill-informed, emotional arguments,” American Academy of Family Physicians president Wanda Filer told The Hill newspaper in June. “What we’re saying is, we need research.” — Meghan Rosen Q: What, if anything, would you do about STEM education in the United States? Hillary Clinton: While Clinton has positioned herself as a proponent of K–12 education, when it comes to STEM — science, technology, engineering and math — she’s been most vocal about needing to boost computer science literacy.
Citing more than a half million open jobs in the tech industry, Clinton’s campaign platform pledges to “provide every student in America an opportunity to learn computer science.” (The pledge is based on President Obama’s current “Computer Science for All” initiative.)
Clinton also supports creating schools — public and charter — that, in part, provide more opportunities for minority students to study science and technology, she told ScienceDebate.org.
To boost interest in STEM fields, she wants to promote partnerships between university research programs and K–12 schools, “makerspaces” (spaces where anyone can create and learn), robotics competitions and online education programs like those offering “nanodegrees” — certifications in specific skills such as machine learning and data analysis.
Donald Trump: Trump has said little on science education, telling ScienceDebate.org that “there are a host of STEM programs already in existence” and that the federal government should “make sure that educational opportunities are available for everyone.” But the bigger issue, he says, is keeping K–12 education close to home. In January, Trump noted that, if elected president, he planned to reduce funding for the Department of Education, saying that “education should be local and locally managed.” In his campaign platform video on education, Trump called Common Core — a national set of standards for reading and math — “a total disaster.”
“We are rated 28 in the world,” he said. “The United States, think of it, 28 in the world, and frankly we spend far more per pupil than any other country in the world. By far it’s not even a close second.”
In March, Trump indicated that he wanted to have former Republican rival Ben Carson be “very involved with education, something that’s an expertise of his.” Carson, a retired neurosurgeon, has stated that he believes that evolution has “become what is scientifically politically correct” and has mentioned writing a book to refute evolution. He has also dismissed the Big Bang as “ridiculous.”
State of the science: The United States is stuck firmly in the middle of the STEM education pack — 35th in math and 27th in science out of 64 countries, according to the 2012 Program for International Student Assessment. Despite spending 6percent of gross domestic product on education, the numbers of women and minorities also still lag in many STEM fields. Roughly equal numbers of boys and girls completed Advanced Placement tests in calculus AB and statistics in 2012, and 59 percent of AP biology test-takers were girls. But fields such as computer science (19 percent female) and physics (23 to 35 percent female) showed significant gender gaps. Racial disparities were also apparent. Of AP calculus AB test-takers, 6.1 percent were black and 12.6 percent were Hispanic. In computer science, those percentages dropped to 4.5 and 8.4.
Equality in STEM education isn’t just a feel-good issue. Women in science, technology, engineering and math careers earn 33 percent more than those outside of STEM fields — a significant step toward closing the wage gap. And a June 2013 fact sheet on women and girls in STEM from the White House Office of Science and Technology policy notes that STEM skills are increasingly in demand. The economic potential “is enormous,” it notes. “However, the administration can’t be satisfied when more than half the world’s population is not participating in this progress.” — Bethany Brookshire
Editor’s note: This story was updated September 14 and September 16 to clarify the description of the change in the vaccine schedule and research efforts related to the alleged vaccines-autism link (in Vaccines); correct the number of states participating in the National Violent Death Reporting System (in Gun Research); correct the characterization of Common Core and clarify which level of calculus has roughly equal numbers of girls and boys (in STEM Education); correct the name of the Biotechnology Innovation Organization (in Genetic Engineering); correct the source of Hillary Clinton’s comments on Alzheimer’s research (in Health); clarify Clinton’s target for reducing greenhouse gas emissions by 2025 (in Climate Change); and clarify the United States’ per capita emissions ranking (in Climate Change).
Book lovers: Scientists have devised a way to read without cracking a volume’s spine or risking paper cuts (and no, we’re not talking about e-books). The new method uses terahertz radiation — light with wavelengths that are between microwave and infrared waves — to view the text of a closed book. The technique is not meant for your average bookworm, but for reading rare books that are too fragile to open.
Barmak Heshmat of MIT and colleagues started small, with a nine-page book of thick paper that had one letter inked on each page. By hitting the book with terahertz radiation and looking at the reflected waves, the scientists could read the letters within. Differences in the way the radiation interacts with ink and paper allowed the researchers to pick out shadowy outlines of the letters, and a letter-recognition algorithm automatically decoded the characters. The scientists could tell one page from another by using precise timing information: On the later pages, the waves penetrated deeper before reflecting and, therefore, took longer to return.
Historians also may be able to use the technique to find an artist’s signature hidden beneath layers of a painting. Sneaking into your sister’s locked diary is another story.
The average American’s carbon dioxide emissions are responsible for shrinking Arctic sea ice by nearly 50 square meters each year.
That’s the implication of a new study that finds that each additional metric ton of CO₂ released into the atmosphere directly results in a 3-square-meter loss of sea ice cover at summer’s end — comparable to losing a chunk of ice with a footprint a bit smaller than a two-seat Smart car.
“For the first time now, it is possible to grasp how each one of us contributes to tangible consequences for the global climate system,” says study coauthor Dirk Notz, a climate scientist at the Max Planck Institute for Meteorology in Hamburg. Globally, humans are responsible for the release of some 36 billion metric tons of CO₂ each year. With another trillion metric tons, the Arctic Ocean will have a completely iceless summer — possibly the first in 125,000 years. That threshold could be crossed before 2050, Notz and Julienne Stroeve of University College London estimate online November 3 in Science. Many previous studies projected that summertime ice would stick around for years longer (SN Online: 8/3/15).
“Sea ice feels so substantial when you’re standing on ice that can hold your own weight, that you can land an airplane on,” says Cecilia Bitz, an atmospheric scientist at the University of Washington in Seattle who was not involved in the study. The new work “makes it feel very fragile.” Dwindling ice at the top of the world threatens Arctic species (SN Online: 5/14/08), can spread pollution (SN: 1/23/16, p. 9) and could open the region to transpolar shipping. In 2012, Arctic sea ice hit a record low since satellite observations began: just 3.39 million square kilometers, far below the average of 6.22 million square kilometers set from 1981 through 2010. How quickly the ice will continue to disappear remains unclear.
For their estimate, Notz and Stroeve analyzed records of Arctic sea surface temperature and minimum sea ice extent since 1953. The average extent of September sea ice declined in lockstep with the rising total amount of CO2 released from human sources, the researchers found.
This simple relationship between emissions and ice loss stems from one similarly straightforward mechanism, the researchers propose. As CO2 concentrates in the atmosphere, it strengthens the greenhouse effect, sending some heat back to Earth that would otherwise escape into space. This increases the amount of ice-warming infrared radiation hitting the Arctic, causing the outermost edge of the sea ice to retreat northward, where less sunlight hits the planet, and reducing total ice coverage.
Climate simulations underestimate this effect and don’t accurately re-create the sensitivity of Arctic sea ice to rising CO2 levels, the researchers argue. Other factors linked to sea ice loss, such as changes in ocean heat flowing from the Atlantic Ocean and in the region’s reflectiveness, were minor over the studied period compared with the increased radiative heating, Notz says.
Downplaying the role of ocean heating is a mistake, says Rong Zhang, an oceanographer at the National Oceanic and Atmospheric Administration’s Geophysical Fluid Dynamics Laboratory in Princeton, N.J. Sea ice coverage peaks in area during winter, when little light shines on the Arctic and the greenhouse effect is less important. But like the minimum, the maximum extent of Arctic sea ice has also declined over recent decades, reaching a record low in March (SN Online: 3/28/16). More observations are needed to determine whether warming from below or above the ice plays a larger role, Zhang says. “There’s not just one explanation,” she says.
Even tiny brains can learn strange and tricky stuff, especially by watching tiny experts.
Buff-tailed bumblebees got several chances to watch a trained bee roll a ball to a goal. These observers then quickly mastered the unusual task themselves when given a chance, researchers report in the Feb. 24 Science. And most of the newcomers even improved on the goal-sinking by taking a shortcut demo-bees hadn’t used, says behavioral ecologist Olli Loukola at Queen Mary University of London. Learning abilities of animals without big vertebrate brains often get severely underestimated, Loukola says. “The idea that small brains constrain insects is kind of wrong, or old-fashioned.”
He and colleagues had previously challenged bees to learn, in stages, the not very beelike skill of pulling a string to reveal a hidden flower. Bees eventually succeeded. So the researchers devised an even more fiendish protocol to see how far insect learning could go.
Loukola invented six-legged sort-of soccer (or football for bees in London) in which a Bombus terrestris rolls a yellow ball about the size of its own body down a trackway to a central goal, where researchers dispense sugary rewards. This time, there was no pampering, no working up in stages to full completion of the test. But bees could observe a trained ball roller, a ball moving on its own (thanks to a researcher sliding a magnet under the arena) or get no advance ball-movement hints at all.
The 10 bees that saw an expert bee roll the ball and score three times before their own attempt succeeded in almost every trial at the task. Watching ghostly movement didn’t help as much, and only a few bees happened on the solution on their own. Social learning matters, but Loukola highlights the way bees changed the technique they watched. Most of the successful bees ignored the ball they had seen rolled and instead used one closer to the goal, doing less work for the same reward. “Fascinating,” says Dave Goulson of the University of Sussex in England, who studies bumblebees. Ball rolling may not be part of routine foraging behavior, but he notes that bees do drag around nesting material, moving backward as they do when playing soccer in the test. And they occasionally remove fat almost ball-like grubs from the nest with a similar technique.
Exactly how the bees solved the problem remains a puzzle, says Bennett Galef of McMaster University in Hamilton, Canada, who has studied social learning. He would like to know more details, for instance, about how untrained bees react to a ball.
Loukola often gets a different question: Could he train bumblebees to play a soccer match? He says he could certainly train some to score on one side of an arena and some on the opposite side. Then he might be able to study whether bumblebees could share a ball.
NEW ORLEANS — Rodeo riders’ recent scientific reputation, as the best modern examples of a Neandertal pattern of excess head knocks, has taken a tumble. Taking their place: People who like to be dragged behind powerboats on big inner tubes, among others.
An exhaustive comparison of Neandertals’ injuries to those of people today finds that water tubing and mishaps involving tables, not rodeo riding, result in top-heavy fracture patterns most similar to those observed on Neandertal fossils. This analysis illustrates just how little modern evidence reveals about ways in which our evolutionary relatives ended up so battered, said anthropologist Libby Cowgill of the University of Missouri in Columbia. She presented data highlighting the mystery of Neandertals’ many preserved bone fractures on April 22 at the annual meeting of the American Association of Physical Anthropologists. Her study, conducted with Missouri anthropologist James Bain, was inspired by an influential 1995 report that Neandertals, like modern rodeo riders, suffered lots of head and above-the-waist injuries and little hip and leg damage. Authors of the 1995 study explained their finding by suggesting that, unlike rodeo riders who get catapulted off bucking broncos, Neandertals’ hard knocks came during violent, up-close clashes with large prey.
A coauthor of the 1995 paper, anthropologist Erik Trinkaus of Washington University in St. Louis, later questioned those conclusions in the December 2012 Journal of Archaeological Science. Trinkaus pointed out, for instance, that up-close clashes with members of their own species or with Homo sapiens also could have inflicted a lot of upper-body damage. Neandertals immobilized by lower-body injuries may have been left to die before reaching rock-shelters where most fossils have been found, he added. In that case, the limited sample of Neandertal fossils misleadingly portrays these Stone Age hominids as prone to upper-body fractures.
Trinkaus’ doubts were well placed. Neandertals’ pattern of bone fractures differs from that produced by a wide variety of present-day activities, including rodeo riding, Cowgill reported. Activities that cause injuries most resembling the Neandertal pattern have no apparent relation to Stone Age behavior, Cowgill said. No one can accuse Neandertals of having practiced reckless water tubing or having suffered what Cowgill described as “unfortunate run-ins with tables.”
About 30 percent of Neandertals’ injuries affected the face and head, a rate far greater than that for nearly all modern activities, Cowgill said. Only diving board accidents produce a slightly higher proportion of face and head injuries than seen on Neandertal fossils. In a U.S. sample of modern-day injuries, Cowgill and Bain looked specifically at bone fractures, not at a broader range of skeletal injuries, including signs of degenerative bone disease, considered in the 1995 study. That may help to explain why the rodeo-rider comparison doesn’t hold up anymore: The new study found fewer skull injuries and substantially more hand wounds among rodeo riders than reported for them in the original paper.
Fracture data came from the National Electronic Injury Surveillance System, which compiles information from a national sample of hospitals on injuries from consumer products and sports activities. Of 84 activities that resulted in bone fractures to 61,851 patients between January 2009 and December 2014, only 16 activities showed any statistical similarities to Neandertals’ injury patterns. Along with water tubing and table run-ins, accidents involving golf, lawn chairs and Frisbee and boomerang games produced somewhat Neandertal-like injury patterns.
The lesson here is that there are so many ways to hurt one’s noggin that it’s meaningless to compare injury patterns today with those of Neandertals or Stone Age humans, Trinkaus said. Neandertal injuries may not even reflect particular behaviors. Fractures that occurred during fossilization, as well as greater susceptibility of the braincase — relative to other body parts — to minor dents and dings, could have contributed to Neandertals’ head wounds, Trinkaus suggested.
“The rodeo-rider idea was a great one 20-plus years ago, but we have moved beyond it,” Trinkaus said.
The supermoms of the mammal world are big, shy redheads. Studying growth layers in orangutan teeth shows that mothers can nurse their youngsters for eight-plus years, a record for wild mammals.
Teeth from a museum specimen of a young Bornean orangutan (Pongo pygmaeus) don’t show signs of weaning until 8.1 years of age. And a Sumatran orangutan (P. abelii) was still nursing during the few months before it was killed at 8.8 years, researchers report May 17 in Science Advances.
Tests also show that youngsters periodically start to taper off their dependence on their mother’s milk and then, perhaps if solid food grows scarce, go back to what looks like an all-mom diet. Such on-again, off-again nursing cycles aren’t known in other wild mammals, says study coauthor Tanya Smith, an evolutionary anthropologist at Griffith University in Nathan, Australia. Before this work, weaning information for orangutans was sparse. Field biologists’ best efforts to track weaning in Bornean orangutans with known birthdays had pegged 7.5 years as the longest probable nursing time, Smith says. The only other weaning report in the wild for a Bornean youngster of known age was 5.75 years. Smith knows of no such reports for Sumatra’s orangutans.
Orangutans in their native forests don’t make weaning easy to detect, says Serge Wich of Liverpool John Moores University in England, who was not involved in the new study. He started watching the apes in 1993, and points out that “lactating happens very high up in trees, so we are always under a bit of an awkward angle to observe. Also, they’re quite furry.” Determining whether an infant is suckling or just cuddling is not an exact science.
For more accurate dating, Smith and colleagues turned to information preserved in teeth. Primate teeth grow with a circadian rhythm, laying down a microscopic layer every day, starting before birth. Babies grow bones and teeth using milk calcium, which their moms pull from their own skeletons. A similar element, barium, hitchhikes along and ends up in bones and teeth, too. “Mothers dissolve parts of themselves to feed their children,” as Smith puts it. Greater concentrations of barium in a tooth layer mark a time when the tooth was being built up with a greater proportion of mother’s milk.
To read the history of mother’s milk, Smith used a method to track barium concentrations that was developed with colleagues at the Icahn School of Medicine at Mount Sinai in New York City. The researchers sampled sets of molars from four immature specimens, two of each orangutan species, which were preserved in museum collections. The teeth came from decades ago when collectors “went around randomly shooting endangered species,” Smith says.
Now, both Bornean and Sumatran orangutans rank as critically endangered. A fever of logging and oil palm planting is eating away their scraps of forest, and the pet trade rewards hunters who shoot a mom to bag a cute baby to sell. Neither species had lush resources to begin with, as the animals evolved in forests with booms and long busts in food supplies. Prolonged nursing of young may be part of their slow-lane accommodation to continuing uncertainty and scarcity in their environment.
Researchers debate whether some similar uncertainty shaped human evolution. Among apes, the human species has evolved a “stretched-out” childhood, though with different pacing from that of orangutans, Smith says. “Studying our cousins puts our own history in context.”
When nocturnal aardvarks start sunbathing, something’s wrong.
If the animals are desperate enough to bask like some cold, sluggish turtle, it’s because they’ve got the chills. Robyn Hetem, an ecophysiologist, has the body temperature data to prove it — collected from late 2012 into 2013, the hottest summer the arid Kalahari region in South Africa had seen in more than 30 years.
Hotter, drier conditions are predicted to become the norm for southern Africa as the climate changes. Now Hetem and colleagues have used that foretaste of change to show that higher temperatures might hammer the normally heat-tolerant aardvarks by shrinking the animals’ food supply. Aardvarks live their burrow-digging lives just about anywhere in sub-Saharan Africa except the desert. The toothless night-foragers dine by slurping insect colonies. One of Hetem’s students at the University of the Witwatersrand in Johannesburg spent two years collecting hundreds of aardvark droppings and can confirm that Orycteropus afer in the Kalahari eat only termites and ants. Yet the solitary, long-snouted, knee-high mammals are more closely related to elephants than to any pointy-nosed South American anteater.
An aardvark looks “very lethargic but is incredibly strong and fast,” Hetem says. The researchers wanted to fit wild aardvarks with tracking devices and data loggers but first had to catch the animals. Nets failed. Traps failed. One cornered aardvark burst out of a burrow, knocked four men to the ground and then outran them. Eventually, researchers placed instruments on six animals. When the Kalahari baked and good rains were months late, the aardvarks grew thin and bony. They started hunting during the day and sunbathing. The animals, once able to internally stabilize their body temperatures, started to have great plunging chills at night, according to data loggers. That’s a sign of starvation, Hetem says, and occurs when the body no longer has energy to warm itself. Five of the six tracked animals died, along with at least 11 other aardvarks in the neighborhood. Aardvark heat tolerance wasn’t the problem. The animals were dying off because their food couldn’t take the heat and drought, Hetem and colleagues argue in the July Biology Letters. Hot, dry spells can make ant and termite colonies shrink and retreat to hard-to-reach hideouts. Other African wildlife might suffer from a shortage of aardvarks, which are prodigious burrow diggers. In a Kalahari study, one aardvark used more than 100 burrows in two years. So many hideaways are a boon for others. Bat-eared foxes, warthogs, birds called ant-eating chats and at least two dozen other species pop into aardvark architecture, sometimes outright moving in. If aardvarks dwindle, shelter might grow scarcer for other animals.
“We kind of think of climate change as: Things are going to get hotter and species might be sensitive to it,” Hetem says. “There’s so much more we need to understand.”
Kenneth Catania knows just how much it hurts to be zapped by an electric eel. For the first time, the biologist at Vanderbilt University in Nashville has measured the strength of a defensive electrical attack on a real-life potential predator — himself.
Catania placed his arm in a tank with a 40-centimeter-long electric eel (relatively small as eels go) and determined, in amperes, the electrical current that flowed into him when the eel struck. At its peak, the current reached 40 to 50 milliamperes in his arm, he reports online September 14 in Current Biology. This zap was painful enough to cause him to jerk his hand from the tank during each trial. “If you’ve ever been on a farm and touched an electric fence, it’s pretty similar to that,” he says. This is Catania’s latest study in a body of research analyzing the intricacies of an electric eel’s behavior. The way electric eels have been described by biologists in the past has been fairly primitive, says Jason Gallant, a biologist who heads the Michigan State University Electric Fish Lab in East Lansing who was not involved in the study. Catania’s work reveals that “what the electric eel is doing is taking the electric ability that it has and using that to its absolute advantage in a very sophisticated, deliberate way,” he says.
Electric eels use electric current to navigate, communicate and hunt for small prey. But when faced with a large land-based predator, eels will launch themselves from the water and electrify the animal with a touch of the head. Using electrical measurements he collected during the eel attacks, Catania came up with an equation to estimate the amount of electric current flowing from the eel into his arm. The electric shock was strongest when the electric eel was farthest out of the water. That makes sense because when an eel is mostly submerged, the majority of the electricity dissipates in the water. As the eel rises out of the water, the only place left for the electricity to flow is into whatever the fish head-bumps (SN Online: 6/9/16).
Catania cannot say, however, whether a leap attack from an electric eel is equally as shocking for all potential predators. Electrical currents travel through an animal more or less effectively depending on its outer layer. The internal resistance, or opposition to electrical current flow, may be different for a human arm than for an animal with scales or fur, like a crocodile or a dog, Catania notes. More research is needed to understand how powerful the shock is for other land animals. Extrapolating from his experience with a small eel, Catania estimates that a human struck on the trunk by a larger, 1.8-meter-long electric eel might endure a current of 0.24 amperes, or 63 watts of power. That’s about 8½ times as powerful as the zap from a typical law-enforcement Taser gun.
Remote Bouvet Island, a tiny, glacier-smothered landmass in the South Atlantic rimmed by 500-meter-tall cliffs, has a notable distinction: It’s the only known spot on Earth, scientists say, that has zero invasive species. Every other place, and every person, on the planet is at least indirectly affected by one or more species that has been transported — either intentionally or inadvertently — to new lands from the ecosystems in which the species evolved. In The Aliens Among Us, biologist and science journalist Leslie Anthony chronicles the detrimental effects of invasive species, as well as how these organisms spread and how they can be fought. In the United States, such interlopers — everything from zebra mussels in the Great Lakes to Burmese pythons in the Everglades — damage crops, infrastructure or otherwise cost taxpayers about $145 billion annually.
Invasive species, Anthony writes, are “children born of globalization and consumerism.” Their numbers increase as international trade widens and accelerates. Some species surreptitiously hitch a ride to their new homes on human transport: Think seeds and burrs on hikers’ clothing, or fish in ballast water of cargo ships. Others have been deliberately released, like earthworms or baitfish set loose by fishermen, or exotic lizards and snakes set free by careless pet owners. Rats, the world’s foremost invasive species, have traveled the world with explorers and traders; so have tropical fire ants, which genetic studies suggest have hitchhiked from southwestern Mexico to Asia and beyond starting in the 16th century in soil used as ballast in Spanish ships.
The Aliens Among Us is a thoroughly engaging book that draws from Anthony’s fieldwork and interviews with scientists, community volunteers, government researchers and policy makers. These groups are struggling to intercept species before they establish a beachhead on new shores, as well as eradicate those that have already gained a foothold. Discussion of people fighting the spread of Zika virus and other exotic diseases — big threats despite their minuscule size — makes the book especially timely. Some battles against invasives seem almost doomed to fail. Besides the inexorable increase of trade, the inescapable specter of climate change continues to open new vistas for species to colonize (SN: 12/24/16, p. 23).
