American Scientist

This roundup summarizes some notable recent items about scientific research, selected from news reports compiled in Sigma Xi's free electronic newsletters.

Planets Galore

Astronomers have found 16 candidate planets hidden deep within the Galactic bulge, making them the most distant sampling of extrasolar planets yet. Five of the candidates were deemed "ultra-short-period planets," because they circle so close to their parent stars that their orbital periods are less than a day. These results indicate that the abundance of extrasolar planets in the Galactic bulge is similar to that previously determined for the solar neighborhood, suggesting that the Milky Way as a whole must harbor a rich endowment of other worlds.

Sahu, K. C., et al. Transiting extrasolar planetary candidates in the Galactic bulge. Nature 443:534-540 (October 5)

Element 118 Redux

Using a cyclotron to shoot calcium 48 at californium 249 and curium 245, nuclear physicists from the Joint Institute for Nuclear Research in Dubna, Russian Federation, and from Lawrence Livermore National Laboratory in California have managed to produce an element with 118 protons in its nucleus. The naming of this new element and its decay product with 116 protons in the nucleus is being postponed until the results can be confirmed at other labs. Investigators from California’s Lawrence Berkeley National Laboratory said they produced element 118 in 1999, but retracted that claim three years later when one of the people involved admitted to fabricating data. If confirmed, the new discovery would support the existence of an "island of stability," a group of theoretically stable atoms with relatively high numbers of protons and neutrons.

Oganessian, Yu. Ts., et al.Synthesis of the isotopes of elements 118 and 116 in the ²⁴⁹Cf and ²⁴⁵Cm + ⁴⁸Ca fusion reactions. Physical Review C74:044602 (October 9)

Veggies Slow Mental Decline

Investigators at Rush University Medical Center in Chicago mounted a prospective study of nearly 4,000 people who were 65 or older to test whether their consumption of fruits and vegetables might affect their mental functioning. Follow-up examinations were performed three and six years after baseline measurements were made. These tests showed that eating vegetables was associated with a slower rate of cognitive decline. The consumption of fruit did not, however, appear to confer the same benefit.

Morris, M. C., et al.Associations of vegetable and fruit consumption with age-related cognitive change. Neurology 67:1370-1376 (October 24)

Bird-Brain Has a New Meaning

The largest known avian skull has been unearthed from Miocene-age rocks of Patagonia, Argentina. The skull, which is bigger than the head of a horse, belonged to a species of phorusrhacid or "terror bird," flightless carnivores that probably fed on sheep-sized rodents that populated the area some 15 million years ago. The strangely slender lower leg bones of this massive bird, which stood about 3 meters high, indicates that it may have been swifter than was previously believed, a conclusion that brings into question the commonly held view that body size is inversely correlated with an animal’s agility.

Chiappe, L. M., and S. Bertelli. Skull morphology of giant terror birds. Nature 443:929 (October 26)

Elephant, Know Thyself

Experiments at the Bronx Zoo have demonstrated that elephants are able to recognize themselves in a mirror, suggesting that pachyderms possess a higher level of self-awareness than was previously suspected. Before this point, only great apes (including Homo sapiens) and dolphins had been thought to have such abilities. But the behavior of the elephants tested by placing real and sham marks on the right sides of their heads showed that they were indeed able to recognize that they were looking at themselves and not another elephant when they gazed into a large mirror.

Plotnik, J. M., F. B. M. de Waal and D. Reiss. Self-recognition in an Asian elephant. Proceedings of the National Academy of Sciences of the U.S.A.103:17053-17057 (November 7)

Bee It That Old

The oldest known bee has been found preserved in a piece of amber—fossilized tree sap—from Myanmar (Burma). The species, Melittosphex burmensis, is estimated to have lived about 100 million years ago. Previously known examples of fossil bees are 35 to 45 million years younger. The new amber-bound specimen measures just under 3 millimeters long, demonstrating that at least some of the earliest bees were tiny, which is consistent with the small size of some contemporary flowers. M. burmensis shows some traits that are similar to those of wasps, suggesting that the find may represent a transitional form.

Poinar, G. O., and B. N. Danforth. A fossil bee from Early Cretaceous Burmese amber. Science 314:614 (October 27)

Cloak of Invisibility

Physicists and engineers have created a working model of an "invisibility cloak" that lets microwave radiation pass through it with minimal distortion. The device contains a set of concentric circles that deflect electromagnetic plane waves  around a copper cylinder hidden inside while minimizing reflections and shadows. The circles are fashioned of a "metamaterial," being made up of an array of special shapes cut from copper film. Although investigators are a long way from being able to repeat this feat for visible light, this demonstration suggests that such a cloaking device could, at least in theory, be possible.

Schurig, D., et al Metamaterial electromagnetic cloak at microwave frequencies. Science 314:997-980 (November 10)