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The CRISPR–Cas9 tool enables scientists to alter genomes practically at will. Hailed as dramatically easier, cheaper and more versatile than previous technologies, it has blazed through labs around the world, finding new applications in medicine and basic research. But for all the devotion, CRISPR–Cas9 has its limitations. It is excellent at going to a particular location on the genome and cutting there, says bioengineer Prashant Mali at the University of California, San Diego....

By Tom Polansek CHICAGO (Reuters) - An Indiana farm has become the first to confirm publicly it suffered a second outbreak of a deadly pig virus, fueling concerns that a disease that has wiped out 10 percent of the U.S. hog population will be harder to contain than producers and veterinarians expected. The farm, through its veterinarian, publicly acknowledged on Tuesday a repeat incident of Porcine Epidemic Diarrhea virus (PEDv), which has killed up to 7 million pigs and pushed pork prices to record highs since it was first identified in the United States a year ago....

One of the deepest problems in epistemology is how we know the nature of reality. Over the millennia philosophers have offered many theories, from solipsism (only one’s mind is known to exist) to the theory that natural selection shaped our senses to give us an accurate, or verdical, model of the world. Now a new theory by University of California, Irvine, cognitive scientist Donald Hoffman is garnering attention. (Google his scholarly papers and TED talk with more than 1....

The polar vortex in recent years has brought the kind of miserable cold to northern states that made it hard to breathe outside. We’re probably in for more of the same. That’s the finding of a new study published yesterday in the journal Nature that finds that as the Arctic warms, it is shifting the polar vortex to Europe. That in turn will bring more bursts of frigid cold to North America....

Bubbles in ancient Australian lava reveal that the early Earth’s atmosphere might have been half as thick as it is today, scientists say. The findings contradict the decades-long belief that Earth’s early atmosphere was thick and, if confirmed, would expand the list of the types of planets capable of supporting life, the researchers said in a new study. [In Photos: Watery Ocean Hidden Beneath Earth’s Surface] Even so, other Earth scientists say the claim is sure to be controversial....

When we experience something painful, our brain produces natural painkillers that are chemically similar to potent drugs such as morphine. Now research suggests these endogenous opioids also play another role: helping regulate the body’s energy balance. Lauri Nummenmaa, a brain-imaging scientist at the University of Turku in Finland, and his colleagues measured endogenous opioid release in the brains of 10 healthy men. The subjects were injected with a radioactive substance that binds to opioid receptors, making it possible to visualize the receptors’ activity using positron-emission tomography....

A couple of million years ago or so, our hominid ancestors began exchanging their lowbrow looks for forehead prominence. The trigger for the large, calorie-hungry brains of ours is cooking, argues Richard W. Wrangham, the Ruth B. Moore Professor of Biological Anthropology at Harvard University’s Peabody Museum of Archaeology and Ethnology. He hit on his theory after decades of study of our closest cousin, the chimpanzee. For the Insights story “Cooking Up Bigger Brains,” appearing in the January 2008 Scientific American, Rachael Moeller Gorman talked with Wrangham about chimps, food, fire, human evolution and the evidence for his controversial theory....

Fruit farmers in the United States have long feared the arrival of harmful citrus tristeza virus to their fields. But now, this devastating pathogen could be their best hope as they battle a much worse disease that is laying waste to citrus crops across the south of the country. The agricultural company Southern Gardens Citrus in Clewiston, Florida, applied to the US Department of Agriculture (USDA) in February for permission to use an engineered version of the citrus tristeza virus (CTV) to attack the bacterium behind citrus greening....

The Supreme Court’s decision to curtail abortion rights has come to fruition. One of the outcomes that will be less discussed is how more people in states with heavy restrictions will turn to search engines and social media to figure out how now to manage their reproductive decisions, and will find themselves reading questionable information. The information they’ll find could be questionable; the number of false and misleading statements online about abortion has grown since the draft opinion on Dobbs v....

President Barack Obama made a poignant comment about the need to address climate change, during his inauguration speech on Monday. Commentators everywhere noted how the remark stood out, and also asked what specific measures the second-term President might actually recommend. Scientific American has some answers, based on an exclusive written response that Obama’s campaign sent to us just before the November 2012 election. Working with ScienceDebate.org, which developed the questions, Scientific American published 14 top science questions for Obama and former Gov....

This is the third article in the Mind Matters series on the neuroscience behind visual illusions. The eyes are the windows to the soul. This fact is why we ask people to look us in the eye and tell us the truth. Or why we get worried when someone gives us the evil eye or has a wandering eye. Our everyday language is full of expressions that refer to where people around us are looking....

Although humans love the playful ways and toothy grins of chimpanzees, our primate cousins have the reputation of being competitive, churlish and, at times, aggressive. New research published today in Proceedings of the National Academy of Sciences suggests that despite being prone to occasional violent behavior, chimps actually much prefer cooperating over competing. In fact, the work shows that chimps work together at similar rates as humans—and that when violence does occur among apes, it is often directed toward an individual that is not being a team player....

Key concepts Physics Sound Frequency Vibrations Introduction You might know sound is caused by vibrations, but did you know sound can also make things vibrate? You might have noticed this if you’ve ever been at a concert or in a car with the stereo volume turned up. Sometimes the sound is so loud that you can feel its vibrations! Sounds that loud, however, can damage your hearing—so in this project you’ll investigate quieter noises with something a little more fun!...

WELLINGTON (Reuters) - New Zealand authorities were cutting holes in 300 whale carcasses on Monday, popping the dead animals “like balloons”, to avoid them exploding as they decompose on Golden Bay after more than 600 whales became stranded. Hundreds of rescuers managed to save around 400 pilot whales on the South Island beach on the weekend after one of New Zealand’s largest whale strandings. But hundreds of whales died on the beach and the Department of Conservation (DOC) cordoned off the bodies and urged the public to call them if they found whale carcasses that had floated off the beach and washed up on nearby shores....

The Duwamish River, which winds through Seattle, contains a lot of unpleasant stuff. In one industrially contaminated stretch, which has been designated a Superfund site, levels of many pollutants exceed state health standards. The compounds, which include notorious chemicals such as polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), settle in river sediments and make fish and shellfish unsafe to eat. Swimming amidst this pollution is a population of river otters....

Microscopes have been around for some 400 years, and today they are even accessible via customized cell phones. The act of peering into a microscope of any power can open a whole world of life and beauty that exists right under (or in) our noses. And to capture that rare view for reproduction can also prove to be an art form in itself. The ability to snap an image seen through an optical microscope—whether it’s via fluorescence, polarized-light, dark-field, confocal, deconvolution or other techniques—has brought researchers and novices alike to the intersection of art and science....

Dear EarthTalk: Were Japan to close all its nuclear plants following the recent damage and radiation leaks from the March 11 earthquake and tsunami, what would its energy mix look like? Would it be able to provide all of its power in other ways?—Richard Miller, New York City Most experts agree that Japan would be hard pressed to close all of its 54 nuclear reactors anytime soon, especially given that these plants provide over a third of the nation’s electricity supply and 11 percent of its total energy needs....

HEAVY HOLES I was puzzled by one aspect of “The First Monster Black Holes,” Priyamvada Natarajan’s article on the oldest supermassive black holes: If there were a substantial number of such black holes in the early universe, observable today at great distances, what happened to them? Would we not see them, and the quasars they produce, nearby in the modern universe? JEAN RENARD WARD via e-mail Supermassive black holes have been found at the centers of spiral galaxies....

The U.S. nuclear power industry is at an impasse. Since 2012, 11 of the 104 light-water reactors in operation at the time have closed, mainly as a result of aging infrastructure and the inability to compete with natural gas, wind and solar, which are now the cheapest sources of electricity in the U.S. and most other countries worldwide. One way the industry is trying to reverse the trend is by looking to what it likes to call “advanced” reactors....

By Thomas GroveSOCHI, Russia (Reuters) - The first warning of the problems that eventually swept away Irina Vorochkova’s house near Russia’s Olympic city of Sochi came when the garden began shifting, then the ground slid away downhill towards a river.As builders worked feverishly to get the Black Sea resort ready for winter games so closely tied to President Vladimir Putin’s legacy, they failed to notice the effects their work was having on the village below....