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Twenty-one people have died and another six are missing as of Sunday evening after heavy rainfall hit Xi’an, Northwest China’s Shaanxi Province, and caused mountain floods and mudslides on Friday evening.  Due to the impact of short-duration heavy rain, mountain floods and mudslides struck a village in Chang’an district in Xi’an around 6 pm on ... Read more

A team of scientists has built a heat engine out of a single atom. Heat engines, like steam engines or internal combustion engines, convert heat into motion. To create the minuscule engine, physicist Johannes Roßnagel of University of Mainz and colleagues heated and cooled a calcium ion with an electric field and a laser, causing ... Read more

Many preschoolers take a surprisingly long and bumpy mental path to the realization that people can have mistaken beliefs — say, thinking that a ball is in a basket when it has secretly been moved to a toy box. Traditional learning curves, in which kids gradually move from knowing nothing to complete understanding, don’t apply ... Read more

One of the most pressing and perplexing questions parents have to answer is what to do about screen time for little ones. Even scientists and doctors are stumped. That’s because no one knows how digital media such as smartphones, iPads and other screens affect children. The American Academy of Pediatrics recently put out guidelines, but ... Read more

The largest marsupial to ever walk the Earth just got another accolade: It’s also the only marsupial known to migrate seasonally. Diprotodon optatum was a massive wombat-like herbivore that lived in what’s now Australia and New Guinea during the Pleistocene, until about 40,000 years ago. Now, an analysis of one animal’s teeth suggests that it ... Read more

Pluto has no rings — New Horizons triple-checked. An exhaustive search for rings and dust particles around the dwarf planet before, during and after the spacecraft flew past Pluto in 2015 has come up empty. “It’s a very long paper to say we didn’t find anything,” says team member Tod Lauer of the analysis, posted ... Read more

What looks like a spider, but with a segmented rear plus a long spike of a tail, has turned up in amber that’s about 100 million years old. Roughly the size of a peppercorn (not including the tail, which stretches several times the body length), this newly described extinct species lived in forests in what ... Read more

A genetic hack to make photosynthesis more efficient could be a boon for agricultural production, at least for some plants. This feat of genetic engineering simplifies a complex, energy-expensive operation that many plants must perform during photosynthesis known as photorespiration. In field tests, genetically modifying tobacco in this way increased plant growth by over 40 ... Read more

THE WOODLANDS, Texas — Grains of dust from the edge of the solar system could be finding their way to Earth. And NASA may already have a handful of the debris, researchers report. With an estimated 40,000 tons of space dust settling in Earth’s stratosphere every year, the U.S. space agency has been flying balloon ... Read more

A new member of the human genus has been found in a cave in the Philippines, researchers report. Fossils with distinctive features indicate that the hominid species inhabited the island now known as Luzon at least 50,000 years ago, according to a study in the April 11 Nature. That species, which the scientists have dubbed ... Read more