From left to right: a pregnant woman, a researcher at CERN, and a ghost octopus

(Left to right): Dean Mitchell/Istockphoto; CERN; Courtesy of NOAA Office of Ocean Exploration and Research, Hohonu Moana 2016

Top stories: The Breakthrough of the Year, a heartbreaking ghost octopus story, and how pregnancy reshapes women’s brains

Ripples in spacetime: Science's 2016 Breakthrough of the Year

The discovery of ripples in spacetime—gravitational waves—shook the scientific world this year. It fulfilled a prediction made 100 years ago by Albert Einstein and capped a 40-year quest to spot the infinitesimal ripples. But instead of the end of the story, scientists see the discovery as the birth of a new field: gravitational wave astronomy. Runners-up for 2016’s Breakthrough of the Year include lab-grown human embryos, the discovery of the exoplanet next door, and portable DNA sequencers. Also be sure to check out our favorite science news stories of 2016  along with the top images of the year.

Pregnancy resculpts women’s brains for at least 2 years

A first-of-its-kind study has revealed that the architecture of women’s brains changes strikingly during their first pregnancies, in ways that last for at least 2 years. In particular, gray matter shrinks in areas involved in processing and responding to social signals. This may mean that new mothers’ brains are more efficiently wired in areas that allow them, for instance, to respond to their infant’s needs or to detect threatening people in their environments.

‘Ghost octopus’ has heartbreaking parenting strategy

A little white octopus, dubbed “Casper,” was discovered in March of this year when a National Oceanic and Atmospheric Administration submarine robot found it in a singular sighting. In a study published this week in Current Biology, researchers report that this species (which is so new, it doesn’t have a scientific designation) has a unique—and rather sad—parenting strategy.

Deep probe of antimatter puts Einstein’s special relativity to the test

After decades of effort, physicists have probed the inner workings of atoms of antihydrogen—the antimatter version of hydrogen—by measuring for the first time a particular wavelength of light that they absorb. The advance opens the way to precisely comparing hydrogen and antihydrogen and, oddly, testing the special theory of relativity—Albert Einstein’s 111-year-old theory of how space and time appear to observers moving relative to one another, which, among other things, says that nothing can move faster than light.

U.S. physics society removes chief lobbyist after controversial press release on Trump’s election

The American Physical Society (APS) has dumped its longtime lobbyist, one of the most visible spokespeople for the scientific community, within days of angry reactions from some members to the society’s congratulatory message to President-elect Donald Trump. Michael Lubell was director of public affairs and head of the Washington, D.C., office of the 53,000-member APS, which is based in nearby College Park, Maryland. In his 22 years at APS, Lubell earned a reputation for giving blunt assessments of political developments.

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