Physics Model Outdated

An international scientific team working at an underground detector in Japan has confirmed that there is no "neutrino deficit," further demonstrating that the Standard Model of particle physics, which explains how matter works at its most basic level, is in need of an update.

Neutrinos, byproducts of solar fusion so tiny they flash unimpeded through enormous thicknesses of any substance known to humankind, can only be studied at special underground facilities where tiny cameras register their presence as they collide with particles inside a closed chamber.

For years scientists puzzled over why they detected significantly fewer neutrinos than scientific models suggested should be there. But in 2001 scientists showed that solar neutrinos "toggled" back and forth among three neutrino types, or "flavors" -- electron, muon and tau -- on their way to Earth. There was no "deficit": Previous experiments had only counted one flavor.

Scientists agree that toggling cannot occur unless neutrinos have mass. The trouble with the discovery, however, is that the Standard Model requires massless neutrinos.

The model apparently needs to be changed, and the experiments reported last week by a joint U.S.-Japanese team working at an underground Japanese facility called KamLAND, confirmed this view by measuring "anti-neutrinos" from nuclear fission reactions and finding the same toggling effect.

Mars Thought to Be Cold, Dry

Scientists have thought that Mars was long a warm, wet planet that would have been hospitable to life before it became the barren hot world we see today. But a new analysis suggests the Red Planet has mostly been a cold, dry world punctuated periodically by scalding rains followed by flash floods.

Based on craters and deep valleys on the surface of Mars today, Teresa L. Segura of the University of Colorado in Boulder and the NASA Ames Research Center in Moffett Field, Calif., and colleagues created computer simulations for what may have occurred on Mars 3.5 billion years ago when that planet was bombarded by a series of large asteroids.

The simulations indicate that the deep valleys that can be seen on Mars today were formed when the heat from massive impacts melted and evaporated ice under the planet's surface and from inside the asteroids, and sent into the atmosphere large amounts of steam. That could have produce months to decades of scalding rains that would have created deluges that formed raging rivers and carved the planet's deep valleys.

"Hypotheses of a warm, wet Mars, based on the presumption that the valley networks formed in a long-lasting greenhouse climate, imply that Mars may once have been teeming with life," the researchers wrote in the Dec. 6 Science.

"In contrast, we envision a cold and dry planet, an almost endless winter broken by episodes of scalding rains followed by flash floods."

Tree Frog Makes Mating Pitch

One species of male tree frog has apparently learned how to use the acoustics of the tree holes where they live to make sure their mating calls travel as far as possible and have the best chance of reaching eligible females.

Bjorn Lardner of the Field Museum in Chicago and Maklain bin Lakim of Sabah Parks in Sabah, Malaysia, studied male Bornean tree-hole frogs, which sit in water-filled tree holes and sing to attract females. The frogs then mate, and the females lay their eggs in the tree holes.

The researchers put males in a plastic container containing water and recorded their songs. The frogs changed the pitch of their songs until they hit on the one that resonated best with the container, and would change the pitch if the water levels changed, the researchers found.

"Several crickets and burrowing frogs benefit from sound amplification by calling from baffles or burrows. However, to our knowledge this is the first evidence of an animal not only sampling resonance properties but also . . . adjusting its call pitch and calling strategy in what seems to be an adaptive manner," they wrote in the Dec. 5 Nature.

Traditional Lacing Is Snuggest

There may be more efficient ways to lace a shoe, but the approaches parents have been teaching their children for generations result in the snuggest fit, according to new research.

Burkard Polster of the Monash University in Australia conducted a mathematical analysis of various techniques for lacing shoes and found that the two most common methods, known as the "criss-cross" and the "straight" lacing methods, were in fact the strongest.

"Hundreds of years of trial and error have led to the strongest way of lacing our shoes," Polster wrote in the Dec. 5 Nature.

Polster added that unfortunately, the same cannot be said about the way in which most of us tie our shoelaces -- with a "granny knot." Granny knots are "notoriously unstable," Polster found. If people alternated the orientation of the loops in the laces before they tied them, they would create more stable "reef" knots, Polster wrote.

-- Compiled from reports by Guy Gugliotta and Rob Stein.

Of the shoe-lacing alternatives, the "criss-cross" and "straight" methods have proved the strongest.