Two teams have for the first time successfully simulated the merger of two black holes and the event's production of gravitational waves. (p. 243)

A new type of eyeglasses that change their focus in response to electric signals may one day replace bifocals and other types of reading glasses. (p. 243)

Babies conceived between 18 months and 5 years after their mothers' previous birth are healthier than are babies conceived before or after these two points in time. (p. 244)

Researchers may be better able to predict drug toxicity in individual patients by examining their metabolisms than by focusing on their genes. (p. 244)

People 65 years of age and older who eat a Mediterranean-style diet that's rich in plant matter and fish and low in saturated fat are less likely than their peers to develop Alzheimer's disease. (p. 245)

Some small molecules affect specific pathways in one of the body's most common cell-regulating systems. (p. 245)

Between the ages of 6 months and 8 months, infants lose the ability to match the vocalizations and facial movements of monkeys shown in video clips, signaling a temporary perceptual narrowing as babies focus on the human social realm. (p. 246)

Scientists are debating whether to continue the practice of occasionally inserting leap seconds in order to keep official, atomic-based time in sync with time based on Earth's rotation. (p. 248)

A simple test of unconscious preferences has achieved great popularity among psychologists and, at the same time, sparked heated debate over how it works and whether it shows widespread implicit biases against black people. (p. 250)

Rising global temperatures are causing Arctic birds to breed earlier in the spring, but for Antarctic birds, the reverse is true. (p. 252)

A newly discovered trio of icy comets, hidden among the thousands of rocks in the main asteroid belt, may be part of a previously unknown class and a primary source of water for the dry, early Earth. (p. 252)

A protein that's more abundant in the blood of obese people inactivates leptin, a hormone that controls hunger. (p. 252)

A parasitic worm can wriggle out through a predator's gills or mouth if the predator eats the worm's insect host. With video. (p. 252)

Short strands of genetic material called microRNAs could allow scientists to determine which colorectal cancers are likely to recur and might offer targets for new anti-cancer drugs. (p. 254)

Capsaicin, the component of red pepper that makes it hot, kills cancer cells in a test tube and inhibits their growth in mice. (p. 254)

A genetic test of cells lining the windpipe can detect lung cancer in smokers. (p. 254)

(p. 255)