Scientific American Online

By Anna Driver and Tom Bergin

VENICE, La./LONDON (Reuters) - Shares of BP Plc gained Monday after it announced progress in containing its Gulf of Mexico oil leak but the energy giant still faced tough questions from investors and U.S. lawmakers as the spill threatened more of the U.S. Gulf coast.

Counterfeiters and money minters constantly try to outsmart each other. But money could become much harder to forge--thanks to butterfly wings.

Butterflies that flit through tropical forests often have brightly colored wings that irridesce in the sun. But it’s not pigments that create those eye-catching shades. It’s microscopic structures on the insects’ wings that reflect the light.

In the late 1960s the renowned University of Oxford physicist and mathematician Roger Penrose came up with a radically new way to develop a unified theory of physics. Instead of seeking to explain how particles move and interact within space and time, he proposed that space and time themselves are secondary constructs that emerge out of a deeper level of reality. But his so-called twistor theory never caught on, and conceptual problems stymied its few proponents. Like so many other attempts to unify physics, twistors were left for dead.

In October 2003 Penrose dropped by the Institute for Advanced Study in Princeton, N.J., to visit Edward Witten, the doyen of today’s leading approach to unification, string theory. Expecting Witten to chastise him for having criticized string theory as a fad, Penrose was surprised to find that Witten wanted to talk about his forgotten brainchild.

[Sound of cricket mating call.] That's a cricket love song. Male crickets rub their legs together to produce the chirp in a bid to lure females. But 64 motion-sensitive infrared cameras have revealed that male crickets don't just sing for their mates--they actively seek them out. [Tregenza et al, http://bit.ly/dkWL1U ] [More]

When your stomach growls and you have the urge to reach for the nearest snack, it is, in a way, your tummy talking . Those signals are in part sparked by the gut-based hunger hormone ghrelin , which blocks certain receptors in the brain, telling your body when it is time to eat. [More]

TOKYO (Reuters) - Tokyo screenings of "The Cove," an Oscar-winning documentary about a grisly annual dolphin hunt have been canceled over planned protests by conservatives who say the film is anti-Japanese, the distributor said on Saturday.

The film, which picked up an Oscar for best documentary feature this year, follows a group of activists who struggle with Japanese police and fishermen to gain access to a secluded cove in Taiji, southern Japan, where dolphins are hunted.

At least two fundamental questions remain about the ongoing environmental disaster in the Gulf of Mexico: how much oil has spilled and where exactly is it located? BP's use of chemical dispersants to address the crisis has complicated the answers to these questions by likely redistributing oil from the surface to locations deeper into the water column--something BP's chief executive Tony Hayward disputes .   [More]

One thing that's both disconcerting and exhilarating about physics is how many seemingly simple questions remain unanswered. When you hear the questions that physicists struggle with, you sometimes say to yourself, Wait, you mean they don't even know that? Physics might be defined as the subject that tries to figure out why the world may look incomprehensibly complex at first, but on closer examination is governed by simple laws. Those laws, applied repeatedly, build up the complexity. From this definition, you'd presume that physicists have at least sorted out what they mean by "law".

Sorry.

NEW YORK--When ancient denizens of central France painted leaping horses on the cave walls at Lascaux, they might not have had the late Renaissance understanding of how to illustrate perspective and three dimensions. But they did, with simple black lines, give the implication of depth, showing the far pair of limbs behind the closer pair. [More]

Ever wondered what it looks like when tumor cells grow inside the body? Drug maker Amgen is hoping to sate this morbid sort of Fantastic Voyage with a new Web site that takes viewers through the various stages of tumor angiogenesis in 3-D. Angiogenesis is a physiological process whereby new blood vessels grow from existing vessels. Although this process is a normal part of the body's ability to grow and heal itself, angiogenesis is also the path through which tumors transition from benign to malignant. [More]

Private access to space took a giant leap forward Friday with a successful test launch of the Falcon 9 rocket, developed and built by SpaceX, a venture headed by PayPal co-founder Elon Musk. [More]

Much of the focus at the Deepwater Horizon disaster site has been on the oil pouring out of the damaged well, but some researchers are beginning to turn their attention to the methane , or natural, gas escaping along with the gushing crude. Careful study of this methane, which comprises about 40 percent of the riser pipe output, is expected to provide scientists with a wealth of information, including a more accurate calculation of the spill's magnitude and thereby a better understanding of its impact on ocean life. [More]

When a mystery object smacked into Jupiter without warning in July 2009 , an event whose aftermath was first spotted by an amateur astronomer in Australia, observers across the globe scrambled to get a look at the planet to figure out just what had happened. [More]

By Kristen Hays

Imagine having a pet in your family for 79 years and through four generations. Now imagine that during that time your pet became an endangered species. Finally, imagine having that pet stolen from your backyard. [More]

July is coming. It’s a time to fire up the barbecue, hit the beaches and watch the fireworks. It’s definitely not a time to be in the hospital. Because fatal medical errors peak in July, an increase that happens to coincide with the annual arrival of new medical residents. That’s according to a study in the Journal of General Internal Medicine . [David Phillips and Gwendolyn Barker, http://bit.ly/aHihSS ]

Could new docs really be deadly? That’s what sociologists at the University of California, San Diego, were wondering. They examined almost a quarter of a million death certificates issued in the U.S. between 1979 and 2006. And they focused on those that showed a mistake with medication as the primary cause of death. They then recorded the month in which the error was made, and whether the incident occurred in a county with teaching hospitals. Turned out that fatal medication errors spiked only in July, which is when new residents hit the wards. And this peak was seen only in regions where training takes place.

The mysterious phenomenon known as quantum entanglement --where objects seemingly communicate at speeds faster than light to instantaneously influence one another, regardless of their distance apart--was famously dismissed by Einstein as "spooky action at a distance." New experiments could soon answer skeptics by enabling people to see entangled pulses of light with the naked eye. [More]

For NASA's Spirit rover, the days of roaming the Red Planet may now be in the past, but the observations the wheeled bot made in its travels are still paying scientific dividends. A new analysis of geologic data gathered by the rover nearly five years ago finds that a rock outcrop on Mars is rich in carbonates, which are minerals that form readily in watery, carbon-rich environments. According to the study, the finding lends more credence to the hypothesis that Mars may have once had a wetter, warmer climate thanks to a dense carbon dioxide atmosphere. What is more, the aqueous processes implicated in the carbonate formation point to a neutral environment more hospitable to life than the acidic waters thought to have existed elsewhere on Mars . [More]