The mysterious Clovis culture, which appeared in North America about 13,000 years ago, appears to be the forerunner of Native Americans throughout the Americas, according to a study in Nature. Scientists have read the genetic sequence of a baby from a Clovis burial site in Montana to help fill out the story of the earliest Americans.
Olympic sports are marvels of power and beauty. They're also marvels of physics. Take ski jumping. Skiers launch themselves into flight at speeds up to 60 miles per hour. They fly through the air for the length of a football field or more and land usually gracefully. We asked physics professor John Eric Goff, at Lynchburg College, to explain the physical forces at work in ski jumping. He wrote the book "Gold Medal Physics: The Science of Sports."
There's new evidence out today that's raising questions about whether women in their 40's and 50's should routinely undergo mammography to detect breast cancer. A new analysis of a big Canadian study found no evidence that regular mammograms save lives. The study even suggests that for many women, regular breast X-rays may do more harm than good.
NPR's Rob Stein joins us now to talk about this report. It appears in the British medical journal BMJ.
Some strategists still see a small window of opportunity to address climate change before the effects become damaging and costly. At least one economist, for example, says we can make a lot of progress if at least half the world agrees to put a price tag on the carbon we dump into the atmosphere.
But some big thinkers also see a grim, potentially dangerous world ahead — one where nations, confronting a climate crisis, will instead reach for a risky technological fix.
The dinosaurs were killed during the Fifth Extinction — which scientists suspect was caused by an asteroid. Now, we are living through an epoch that many scientists describe as the Sixth Extinction, and this time, human activity is the culprit. As one scientist put it: We're the asteroid.
Elizabeth Kolbert is the author of the new book The Sixth Extinction. It begins with a history of the "big five" extinctions of the past, and goes on to explain how human behavior is creating a sixth one — including our use of fossil fuels and the effects of climate change.
Researchers at a laboratory in California say they've had a breakthrough in producing fusion reactions with a giant laser. The success comes after years of struggling to get the laser to work and is another step in the decades-long quest for fusion energy.
Omar Hurricane, a researcher at Lawrence Livermore National Laboratory, says that for the first time, they've produced significant amounts of fusion by zapping a target with their laser. "We've gotten more energy out of the fusion fuel than we put into the fusion fuel," he says.
If only ... if only, instead of that noisy, bawling, crying little person, you could have produced an antelope baby — and oh, the quiet! The blissful, total silence. When pronghorn antelopes have babies, nobody hears anything for weeks and weeks — which is the whole point.
What should we be worried about? Real Scenarios that keep scientists up at night. This is the title of the new book edited by the literary agent John Brockman, founder of the website Edge.org, a discussion forum that includes novelist Ian McEwan, musician Brian Eno, physicists Frank Wilczek and Freeman Dyson, as well as yours truly, 13.7's Tania Lombrozo, and a couple of hundred of other academics and intellectuals.