How do we “see” with our eyes closed when we are dreaming? —Robert J. Evans, via e-mail Robert O. Duncan, a behavioral scientist at York College, the City University of New York, explains: AS YOU SUGGESTED by the phrasing of your question, people don’t actually see in their dreams. Sight depends on light entering the eye and stimulating the retina—something that doesn’t happen when we are lying in the dark with our eyes shut....
Souls, spirits, ghosts, gods, demons, angels, aliens, intelligent designers, government conspirators, and all manner of invisible agents with power and intention are believed to haunt our world and control our lives. Why? The answer has two parts, starting with the concept of “patternicity,” which I defined in my December 2008 column as the human tendency to find meaningful patterns in meaningless noise. Consider the face on Mars, the Virgin Mary on a grilled cheese sandwich, satanic messages in rock music....
This month my Scientific American column tackled the issue of high-tech trust. Bit by bit the Apples, Googles, Microsofts and, of course, the NSAs of the world have shaken our trust. They’ve abused it, one highly publicized breach after another, and left us fearful and wary. Here, for your sleep-losing pleasure, are some choice examples of the tech industry’s impressive history of trust violations. April 1998: Microsoft orchestrates a phony grassroots campaign....
Key concepts Engineering Pressure Physics Introduction Have you ever watched a sailboat or a windsurfer zip along without the help of a motor? You’re witnessing the power of the wind. But getting speed from the wind is all about harnessing it well. And knowing just a little bit about how pressure works can help you design a better boat. Then you can challenge different sail designs to a breath-powered boat race....
Bank chiefs, oil company executives and louche politicians seem as allergic to admitting guilt as the public is eager to extract contritions from them. If sometimes we seem to scrutinize people more for their failure to say, “I’m sorry,” than for the transgressions themselves, it is partly due to the cultural wisdom that an apology is the first step in mending a broken relationship. But how far does an apology really go in smoothing things over?...
The idea that fish oil and omega-3s are good for your heart has been nutrition orthodoxy for decades. A few dissonant voices have argued that this particular emperor has no clothes. But they have largely been drowned out by the crowd. The American Heart Association recommends a fish oil supplement for those who don’t eat the recommended two 0r more servings of fish per week. And that’s basically everyone. Fish oil supplements are now the third most popular nutritional supplement....
When Frances was an infant, she was late to babble, walk and talk. She was three before she would respond to her own name. Although there were hints that something was unusual about her development, the last thing her parents suspected was autism. “She was very social and a very happy, easy baby,” says Kevin Pelphrey, Frances’s father. Pelphrey is a leading autism researcher at Yale University’s world-renowned Child Study Center....
Blood racing through a brain region’s web of vessels is a sign that nerve cells in that locale have kicked into action. The blood rushes to active areas to supply firing neurons with the oxygen and glucose they need for energy. It is this blood flow, which can last up to a minute, that scientists track in functional magnetic resonance imaging (fMRI) to determine which brain areas are responding to different stimuli....
CHENGDU, China – A convoy of white vans barreled down a dusty road three hours south of this provincial capital in late September. Lush valleys were drying out after another long and turbulent rainy season. U.S. and Chinese government officials and brass from the nations’ biggest oil and gas companies tailed their police escort deeper into Sichuan province. Truck traffic clogged the road, bisecting vegetable patches and rice paddies that seemed to disappear into the fog that morning....
Advocates of Pluto’s planethood are about to fire another salvo in the decade-long debate about the famous object’s status. Scientists on NASA’s New Horizons mission, which performed the first-ever flyby of Pluto in July 2015, will officially propose a new definition of “planet” next month, at the 48th Lunar and Planetary Science Conference in The Woodlands, Texas. The new definition would replace, or supersede, the one devised by the International Astronomical Union (IAU) in 2006....
Editor’s note: This story is the final entry in a four-part series that Anne Casselman, a freelance writer and regular contributor to Scientific American, reported in early June during a rare opportunity to conduct field reporting on grizzly bears in Heiltsuk First Nation traditional territory in British Columbia. For more on her experience there, see this slide show, story and blog post. HEILTSUK TRADITIONAL TERRITORY, British Columbia—“Two sub-legal Manilas, 25 grams,” says Ed Carpenter as he watches the electric scale’s reading settle under the weight of the two clams....
Ever since researchers discovered that the mammalian brain produces neurons during adulthood, neuroscientists have been wondering what roles these new nerve cells play. One area where the cells crop up is the dentate gyrus, which helps to record memories in a way that distinguishes them as unique and thus prevents them from blurring one into the next. The newly born neurons turn out to be key to this discriminatory activity, called pattern separation, as is evident from what happens when the cells are blocked from being produced; in response to such treatment, animals have trouble differentiating between experiences they have had in similar settings....
Editor’s Note: We are posting this feature from our September 2006 issue in light of the Obama administration’s renewed focus on how to power the country without overloading the atmosphere with greenhouse gases. If we are honest, most of us in the world’s richer countries would concede that we like our transportation systems. They allow us to travel when we want to, usually door-to-door, alone or with family and friends, and with our baggage....
The history of life on Earth has been marked by the evolution of new genes—humans clearly have more genes with more diverse functions than do amoebas. So where do these additional genes, with their new roles, come from? Analysis of genomes shows that the duplication and modification of existing genes seems to be a major avenue for such innovation. Conventional wisdom had it that duplicate genes provide raw material for evolution....
For three years researchers have feuded over the rightful classification of the Hobbit, a diminutive, 18,000-year-old specimen unearthed from the Indonesian island of Flores. Is it an entirely new species, as its discoverers have maintained, or merely a small-brained human? Last week, officials reopened the site where the Hobbit was found as well as a newly discovered cavern underneath it, raising hope that diggers might soon bring convincing new evidence to bear....
On a scorching summer day in Darwin, Australia, I stood 10 feet abreast of a 17-foot-long, 1,200-pound adult male saltwater crocodile—the world’s largest reptile. It stared me down with eerie, catlike eyes, its chest heaving periodically to exhale a loud blast of spent air through its nostrils like a locomotive purging steam. Perhaps, I thought, my colleagues and I were taking our research beyond the realm of sensibility. I had worked with crocs many times before but never with such a massive one....
It has been less than four weeks since the announcement that a mutation-laden coronavirus variant had been discovered in southern Africa. Since then, dozens of countries around the world have reported Omicron cases—including a worrying number of infections in people who have either been vaccinated or experienced previous SARS-CoV-2 infections. But as political leaders and public-health officials try to chart a course through oncoming Omicron surges, they must do so without a firm answer to a key question: how severe will those Omicron infections be?...
When the ancient Egyptians prepared a mummy they would scoop out the brain through the nostrils and throw it away. While other organs were preserved and entombed, the brain was considered separately from the rest of the body, and unnecessary for life or afterlife. Eventually, of course, healers and scientists realized that the three pounds of entangled neurons beneath our crania serve some rather critical functions. Yet even now the brain is often viewed as somewhat divorced from the rest of the body; a neurobiological Oz crewing our bodies and minds from behind the scenes with unique biology and unique pathologies....
No, it’s not photoshopped—that dolphin’s fin really is on backward. It is a type of spinner dolphin that lives in the eastern tropical Pacific. The really peculiar thing about these cetaceans is that only the adult males have backward fins. The juveniles and females of the species look completely normal. “We’ve known about these dolphins for 50 years,” says Matt Leslie, a graduate student at the Scripps Institution of Oceanography, “but not a lot has been done to actually study why it’s on backwards....
People across the world are alarmingly confused about the role of antibiotics and the right way to take them, and this ignorance is fuelling the rise of drug-resistant superbugs, the World Health Organization said on Monday. “The rise of antibiotic resistance is a global health crisis,” WHO Director-General Margaret Chan told reporters in a telebriefing from the organization’s Geneva headquarters. She said the problem was “reaching dangerously high levels” in all parts of the world and could lead to “the end of modern medicine as we know it”....
