Key Concepts Perception Color and light Vision Eyes Introduction Have you ever wanted to make something disappear? You might just be able to. Your eyes collect information with quick movements around your environment and pass this information onto your brain. In this activity we will take advantage of the way your eyes and brain talk to each other to make colored dots seem to appear and disappear. (Sorry, this disappearing act probably won’t work on your homework!...
Cougars (Puma concolor) have not lived in Oklahoma, Missouri and other states around the Midwest since the beginning of the 20th century. Now the cats are returning to and repopulating some of their former Midwestern habitats, according to research published in June by the Journal of Wildlife Management. Cougars once lived throughout most of the U.S. and Canada, but state-sponsored bounties put in place to protect livestock and humans from what were often deemed “undesirable predators” led to the cats’ extermination in eastern North America and the Midwest....
Strolling through an equatorial rain forest or a northern pine forest can be thrilling enough, if only for the lavish scenery. But when you learn that you can eat a lot of what you see, a picturesque landscape takes on added intrigue. That’s the fun behind a burgeoning form of responsible leisure travel called culinary ecotourism–a new breed of gastronomic vacation, different from the languid style of those château-and-bistro foodie tours....
Scientists just completed one of the most comprehensive investigations of Earth’s climate history—and the findings aren’t favorable. They found that the planet could eventually warm to levels it hasn’t reached in at least 34 million years. The researchers, led by Thomas Westerhold of the University of Bremen in Germany, constructed datasets using chemical analyses of ancient sediments, drilled from the bottom of the ocean. These sediments, some of which are 66 million years old, are filled with the preserved shells of tiny organisms that can tell scientists about the temperature and chemical composition of the ocean when they were formed....
Former EPA scientist Dominic DiGiulio never gave up. Eight years ago, people in Pavillion, Wyo., living in the middle of a natural gas basin, complained of a bad taste and smell in their drinking water. U.S. EPA launched an inquiry, helmed by DiGiulio, and preliminary testing suggested that the groundwater contained toxic chemicals. Then, in 2013, the agency suddenly transferred the investigation to state regulators without publishing a final report. Now, DiGiulio has done it for them....
Be aware of how you feel. As soon as you sense that you are tense, obsessed or conflicted, pay attention, advises psychologist Jennifer Crocker of the Ohio State University. These emotions signal that your motivations may be tangled with self-esteem. Ask yourself “Why?” As you think about your situation, ask yourself: What am I trying to prove to others? What do I want to gain? What am I afraid to lose?...
The most valuable and complex component in a modern vehicle typically is also the most unreliable part of the system. Driving accidents usually have both a human cause and a human victim. To certain engineers–especially those who build robots–that is a problem with an obvious solution: replace the easily distracted, readily fatigued driver with an ever attentive, never tiring machine. The U.S. military, which has been losing soldiers to roadside bombs in Iraq for several years, is particularly keen on this idea....
THE WOODLANDS, Texas — The equator of Jupiter’s icy moon Europa may be covered with huge spikes of ice, scientists say. Astronomers have known for some time that Jupiter’s moon Europa is icy, and now scientists are trying to understand just what form that ice takes by using some of the coldest places on Earth as analogues. Huge ice spikes, known as penitents, found on Earth could form on Europa, they said....
What did Yvonne Y. Clark, or Y.Y., actually do as a mechanical engineer? This episode is about the work itself—specifically, the work Y.Y. did at NASA on the Saturn V rocket and the design of the “moon rock box” for transporting lunar samples back to Earth. And we take a deep dive into the history of the American space program, the mechanics of a rocket and how Y.Y. brought her troubleshooter’s mind to a problem that was plaguing some of the country’s top scientists....
Such notions defy conventional wisdom that excess adiposity kills more than 300,000 Americans a year and that the gradual fattening of nations since the 1980s presages coming epidemics of diabetes, cardiovascular disease, cancer and a host of other medical consequences. Indeed, just this past March the New England Journal of Medicine presented a Special Report, by S. Jay Olshansky, David B. Allison and others that seemed to confirm such fears. The authors asserted that because of the obesity epidemic, the steady rise in life expectancy during the past two centuries may soon come to an end....
There’s no right answer when someone asks you: “How old do you think I am?” Faced with such a dilemma, most of us aim low—erring on the side of flattery rather than honesty. But the truth is, accurately guessing someone’s age is a difficult task, perhaps best left to amusement park workers and street performers. Why is it that some people just look older (or younger) than they really are? Scientists may have found the answer....
Doctors began implanting left ventricular assist devices (LVADs) decades ago to keep heart failure patients alive while they waited for weeks or months for an available transplant organ. Today improved designs are being installed as final fixes. Indeed, the distinction between an LVAD used as a bridge to transplant and as a permanent aid “is disappearing,” says Kiyotaka Fukamachi, head of the Cleveland Clinic’s Cardiovascular Dynamics Laboratory. “Some patients who received an LVAD as a bridge have been living with it for two or three years....
About half of all pregnancies in the U.S. are unintended, and 40 percent of these are terminated by abortion. Those ideologically opposed to abortion often argue that the experience is psychologically harmful to women, citing reports of a link between abortion and later mental health problems such as depression. Now, after an exhaustive review of the literature, experts conclude that the best scientific evidence indicates that having a single abortion does not increase a woman’s risk of emotional problems....
Richard Dawkins, the biologist and author, is complicated. I reached this conclusion in 2005 when I participated in a fellowship for journalists organized by the pro-religion Templeton Foundation. Ten of us spent several weeks at the University of Cambridge listening to 18 scientists and philosophers point out areas where science and religion converge. Alone among the speakers, Dawkins argued, in his usual uncompromising fashion, that science and religion are incompatible. But in his informal interactions with me and other fellows, Dawkins was open-minded and a good listener....
Ever wrestled with a pop-up tent, trying to flatten it to fit into the bag? Help is at hand, in the form of a mathematical theory to describe the shapes adopted by the types of flexible ring from which these tents are made. “We have found the best way to fold rings,” says Alain Jonas, a materials scientist at the French-speaking Catholic University of Leuven in Belgium, who led the research....
By Daniel CresseyOnly around 300 endangered right whales remain in the North Atlantic, and a number of them end up tangled in fishing gear off the east coast of the United States. The nets and ropes cut into the animal’s flesh, and can in rare cases lead to a painful and protracted death. Marine biologist Michael Moore, of the Woods Hole Oceanographic Institution in Massachusetts, is one of those who attempt to free these animals....
Can an old head injury suddenly cause detrimental effects much later in life? —Anonymous, via e-mail Douglas Smith, professor of neurosurgery and director of the Center for Brain Injury and Repair at the University of Pennsylvania, answers: ALTHOUGH A BRAIN INJURY from a car accident or a collision during a football game often seems to cause a sudden change to cognitive ability years later, this change does not just appear out of the blue—the damage has been building up slowly, unnoticed, over time....
After baby loggerhead turtles hatch, they wait until dark and then dart from their sandy nests to the open ocean. A decade or so later they return to spend their teenage years near those same beaches. What the turtles do and where they go in those juvenile years has been a mystery for decades. Marine biologists call the period the “lost years.” Following the tiny turtles has proved to be difficult....
Last year’s dramatic dimming of the star Betelgeuse — familiar to many as the ‘right shoulder’ of the constellation Orion — was caused by a cloud of dust spewed out by the star itself. Astrophysicists reached this conclusion, published on 16 June in Nature, using high-resolution imaging of Betelgeuse before and after the dimming, combined with computer simulations. Normally, Betelgeuse is one of the ten brightest stars in the night sky....
With its lunar sample-return mission in December, China kicked off a new surge in visitors to the Moon. At least eight spacecraft from nations including Russia, India, China, Japan and the United States are set to touch down on the lunar surface in the next three years. For the first time ever, several of the upcoming missions will explore some of the Moon’s most scientifically intriguing, yet sensitive areas—those at its poles....
