Health & Science

Echoes of the Big Bang

In an extraordinary breakthrough, scientists have discovered gravitational “ripples” that provide strong evidence of the Big Bang. If confirmed, the findings verify the theory of cosmic inflation, which holds that 13.8 billion years ago, the universe expanded violently from a hot, dense, subatomic speck to the size of a golf ball in a trillionth of a trillionth of a trillionth of a second and then kept expanding. “This work offers new insights into some of our most basic questions: Why do we exist? How did the universe begin?” Harvard theorist Avi Loeb tells Science Daily. “These results are not only a smoking gun for inflation, they also tell us when inflation took place and how powerful the process was.” When inflation was proposed 35 years ago, scientists predicted the event would have been accompanied by waves of gravitational energy—ripples in the fabric of space-time. These ripples would produce a distinct pattern in the bath of microwave radiation that is the afterglow of the Big Bang. That pattern is what scientists have observed using an Antarctic telescope designed to detect incredibly minute differences in the temperatures of the microwaves. The ripples—the oldest evidence mankind has ever found of -anything—also support the theory that our universe may be just one of a vast number that have burst into existence. “This is huge, as big as it gets,” said Marc Kamionkowski, an early-universe expert at Johns Hopkins University.

Why narwhals have horns

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They’re known as the unicorns of the sea. But scientists have long puzzled over why narwhals, a type of arctic whale, sport a spiraled horn protruding from their upper lip. New research now indicates that the horn, which is more akin to an overgrown tooth or tusk, is actually a sensory organ that may help the animals navigate. “People have said it’s everything from an ice pick to an acoustic probe,” Dr. Martin Nweeia of the Harvard School of Dental Medicine tells BBC.com. “But this is the first time that someone has discovered sensory function.” The tusks, which are typically seen on males, can grow up to nine feet long. The outer layer is permeable, while the inner layer contains microscopic tubes that channel seawater toward nerve endings connected to the narwhal’s brain. To determine its function, researchers used plastic sheaths as “tusk jackets,” then bathed the jackets in saline solutions of different concentrations. The whales’ heart rates rose in response to high-salt concentrations and dipped when saline was low. This indicates that the tusks may help narwhals avoid lingering in freezing waters, which tend to be saltier, perhaps to guard against becoming entrapped in ice.

When food hits the floor

Does the “five-second rule” really work? Clumsy eaters have long contended that fallen food is okay to eat if it’s pulled off the floor quickly, and a new study indicates they may be right. A team of British researchers looked at two common bacteria—E. coli and Staphylococcus aureus—to measure how many microbes attached to food when it was dropped on tile, linoleum, or carpet. Scientists tested foods like toast, cookies, pasta, and sticky candy, and left samples on the floor for intervals lasting from three to 30 seconds. The results: Time, flooring, and consistency of the food all contributed to the amount of bacteria transferred. Carpet kept food cleanest, and “moist” foods like noodles and candy tended to be the most infected. “Consuming food dropped on the floor still carries an infection risk,” says study author Anthony Hilton of Aston University, “as it very much depends on which bacteria are present on the floor at the time.” But the study does indicate that the faster you pick it up, the safer that cookie is likely to be.

How dark chocolate helps us

The secret to dark chocolate’s health benefits may be in our guts. New research has found that bacteria in our stomachs feast on an indigestible part of cocoa, fermenting it into anti-inflammatory compounds that are good for the heart, the Los Angeles Times reports. The key lies in anti-oxidants called polyphenols, which are found in dark chocolate and cocoa powder as well as dark berries and black tea. The molecules in many polyphenols are too large to be absorbed through the stomach wall into the blood to be used as nutrients—which is where intestinal microbes lend a hand. In an experimental setting in the lab, researchers found that Bifidobacterium and lactic acid bacteria broke the polyphenols down into smaller molecules capable of making it into the blood. “When these compounds are absorbed by the body, they lessen the inflammation of cardiovascular tissue, reducing the long-term risk of stroke,” Louisiana State University food science professor John Finley says. The amount of cocoa powder needed to produce benefits is about two tablespoons per day.