1 – Gravitational waves
The detection of gravitational waves introduced a new era in astronomy. Expect new details about black holes and other cosmic phenomena.
The secrets gleaned from the universe’s most mysterious giants are incongruously subtle when witnessed at Earth: Detectors budge by a tiny fraction of a proton’s breadth, outputting a feeble, birdlike chirp.
For centuries, astronomers have peered out into the universe almost exclusively by observing its light. But 2016’s announcement of the first detection of gravitational waves, produced 1.3 billion years ago in the collision of two monstrous black holes, has given scientists a whole new way of observing the heavens.
The waves tore through the cosmos at the speed of light and arrived at Earth just in time for the start-up of the Advanced Laser Interferometer Gravitational-Wave Observatory, LIGO, which measured the minute stretching and squeezing of space. With a second detection already recorded and more expected in 2017, scientists hope to uncover new details about elusive black holes and their pairings. Soon, as more detectors come online, scientists will even be able to pinpoint where gravitational waves originate and inspect the sky for the aftermath of the cataclysms that caused them.
2 – Zika virus
Zika brought devastation to families in Brazil, where cases of microcephaly surged. Fear has also spread across the Americas.
A Brazilian mother cradles her baby girl under a bruised purple sky. The baby’s face is scrunched up, mouth open wide — like any other crying child. But her head is smaller than normal, as if her skull has collapsed above her eyebrows.
A week earlier, not far away, a doctor wrapped a measuring tape around the forehead of a 1-month-old boy, held in the arms of his grandmother. This baby too has a shrunken head, a birth defect whose name — microcephaly — has now become seared into the public consciousness.
These images and many more told a harrowing story that case reports alone couldn’t convey: A little-known mosquito-borne virus called Zika appeared to be taking a terrible toll on women and babies, and their families. The world got a gut-wrenching view of microcephaly in 2016, along with a mountain of evidence convincing scientists that Zika bears much of the blame for the dramatic increase in cases.
“Once you’ve seen those pictures from Brazil, you realize what a huge impact this kind of outbreak can have,” says Sonja Rasmussen, a pediatrician at the U.S. Centers for Disease Control and Prevention in Atlanta. Brazil logged its first cases of Zika in 2015, but infections there peaked this spring with perhaps up to 8,000 new infections per week. The virus crept northward and infiltrated many more countries including Panama, Haiti and Mexico. Now, the threat has come to the United States: Cases have been reported in every state except Alaska. They stem mostly from travelers infected abroad, but the virus has staked out new territory in Puerto Rico, the U.S. Virgin Islands, American Samoa and Florida.
As of December 1, Puerto Rico had reported more than 34,000 people with Zika infections. More than 2,700 are pregnant women. And elsewhere in the United States, the CDC has reported well over 4,000 laboratory-confirmed cases of Zika. In these places and others, the images from Brazil have filled expectant mothers (and anyone considering having kids) with uncertainty and fear. “It’s really scary to be pregnant right now,” Rasmussen says. “We don’t know what to tell women.”
Astronomers discovered a planet around the closest star to the sun, fueling sci-fi dreams of interstellar travel.
Worlds in the Alpha Centauri system — the trio of stars closest to our sun — have been a staple of science fiction for decades. From Star Trek to Avatar, writers have dreamed up exotic landscapes (and inhabitants) for interstellar explorers to encounter. Now a planet around one of those stars is no longer fiction.
In August, breathless headlines heralded the discovery of a small, potentially habitable planet orbiting Proxima Centauri, a dim red dwarf star just 4.24 light-years away. The planet, Proxima b, isn’t the first roughly Earth-mass planet discovered.
A baby boy born this year has DNA from mom and dad, plus donor mitochondria. The technique raises safety and ethical concerns.
A “three-parent baby” was born in April, the world’s first reported birth from a controversial technique designed to prevent mitochondrial diseases from passing from mother to child.
“As far as we can tell, the baby is normal and free of disease,” says Andrew R. La Barbera, chief scientific officer of the American Society for Reproductive Medicine. “This demonstrates that, in point of fact, the procedure works.”
The baby boy carries DNA not only from his mother and father but also from an egg donor, raising both safety and ethical concerns. In particular, people worry that alterations of the genetic makeup of future generations won’t stop with preventing diseases but could lead to genetically enhanced “designer babies.”
5-Arctic sea ice loss
Researchers are now studying the complex biological consequences of polar melting and the opening of Arctic passageways.
In a better world, it would be the big news of the year just to report that Arctic sea ice shrank to 4.14 million square kilometers this summer, well below the 1981–2010 average of 6.22 million square kilometers. But in this world of changing climate, extreme summer ice loss has become almost expected. More novel in 2016 were glimpses of the complex biological consequences of melting at the poles and the opening of Arctic passageways, talked about for at least a decade and now well under way.
With top-of-the-world trade and tourist shortcuts opening, less ice means more travel. Europe-to-Asia shipping routes will typically shorten by about 10 days by midcentury, a report in Geophysical Research Letters predicted. Hopes for Northwest Passage routes obsessed (and killed) explorers in previous centuries, but in 2016, the thousand-passenger cruise ship Crystal Serenity offered the first megascale tourist trip from Alaska to New York with fine dining, casino gambling and an escort icebreaker vessel.
Biologists are delving into consequences for organisms other than human tourists — or the much-discussed polar bear. “There’s been a marked shift in the research community,” says climate change ecologist Eric Post of the University of California, Davis. There’s new interest in considering more than just species that dwell on sea ice, with researchers looking for the less direct effects of declining ice.
6-Ancient human migration
DNA studies put new twists on the timing of human migrations out of Africa – but genetics alone are not enough to tell the full story.
No paper or digital trails document ancient humans’ journey out of Africa to points around the globe. Fortunately, those intrepid travelers left a DNA trail. Genetic studies released in 2016 put a new molecular spin on humans’ long-ago migrations. These investigations also underscore the long trek ahead for scientists trying to reconstruct Stone Age road trips.
“I’m beginning to suspect that the ancient out-of-Africa process was complex, involving several migrations and subsequent extinctions,” says evolutionary geneticist Carles Lalueza-Fox of the Institute of Evolutionary Biology in Barcelona.
Untangling those comings, goings and dead ends increasingly looks like a collaborative job for related lines of evolutionary research — comparisons of DNA differences across populations of present-day people, DNA samples retrieved from the bones of ancient hominids, archaeological evidence, fossil finds and studies of ancient climates. It’s still hard to say when the clouds will part and a clear picture of humankind’s journey out of Africa will appear.
7 – Minimal genome
A synthetic cell reported this year jettisons unnecessary genes and embraces human design principles.
One of biology’s biggest achievements of 2016 was intentionally as small as possible: building a bacterium with only 473 genes. That pint-size genetic blueprint, the smallest for any known free-living cell, is a milestone in a decades-long effort to create an organism containing just the bare essentials necessary to exist and reproduce. Such “minimal genome” cells might eventually serve as templates for lab-made organisms that pump out medicines, make innovative chemicals for industry and agriculture, or churn out other molecules not yet imagined. The project also identified genes crucial for the microbe’s survival yet largely unfamiliar to science, highlighting major gaps in researchers’ grasp of life’s playbook.
8 – Alzheimer’s treatment
A drug that swept away amyloid brain plaques in people with Alzheimer’s will undergo new tests to see if it also improves cognitive performance.
A quarter century after scientists proposed an idea that profoundly influenced the arc of Alzheimer’s research, they might finally find out whether they are correct. A new antibody drug called aducanumab appears to sweep the brain clean of sticky amyloid-beta protein. The drug may or may not become a breakthrough Alzheimer’s treatment — it’s too soon to say — but either way it will probably answer a key question: Have researchers been aiming at the right target?
9 – Antarctic ozone hole
Research this year confirms that the Antarctic ozone hole is healing – a success attributed to international cooperation and new technologies.
In a rare bright spot for global environmental news, atmospheric scientists reported in 2016 that the ozone hole that forms annually over Antarctica is beginning to heal. Their data nail the case that the Montreal Protocol, the international treaty drawn up in 1987 to limit the use of ozone-destroying chemicals, is working.
The Antarctic ozone hole forms every Southern Hemisphere spring, when chemical reactions involving chlorine and bromine break apart the oxygen atoms that make up ozone molecules. Less protective ozone means that more ultraviolet radiation reaches Earth, where it can damage DNA and lead to higher rates of skin cancer, among other threats.
AlphaGo’s triumph over its human opponent in the board game Go provides a glimpse into the future of artificial intelligence.
In a hotel ballroom in Seoul, South Korea, early in 2016, a centuries-old strategy game offered a glimpse into the fantastic future of computing.
The computer program AlphaGo bested a world champion player at the Chinese board game Go, four games to one . The victory shocked Go players and computer gurus alike. “It happened much faster than people expected,” says Stuart Russell, a computer scientist at the University of California, Berkeley. “A year before the match, people were saying that it would take another 10 years for us to reach this point.”
The match was a powerful demonstration of the potential of computers that can learn from experience. Elements of artificial intelligence are already a reality, from medical diagnostics to self-driving cars , and computer programs can even find the fastest routes through the London Underground. “We don’t know what the limits are,” Russell says. “I’d say there’s at least a decade of work just finding out the things we can do with this technology.”
Source : sciencenews