Physics & Mathematics

Diet may improve cognition, slow aging

Eating certain foods can help protect you from heart disease, some types of cancers and other illnesses. But can your diet also help protect your brain if you should suffer a stroke or accidental head injury? Or keep your thinking and memory skills strong as you age? Some scientists believe it might. They even think eating the “right” foods –specifically, those high in antioxidants — may help defend astronauts from brain-damaging cosmic rays on future manned missions to Mars.

Pedro Duque’s diary from space

I am writing these notes in the Soyuz with a cheap ballpoint pen. Why is that important? As it happens, I’ve been working in space programmes for seventeen years, eleven of these as an astronaut, and I’ve always believed, because that is what I’ve always been told, that normal ballpoint pens don’t work in space.

Disneyland-sized asteroid is actually two orbiting objects

An asteroid that has eluded astronomers for decades turns out to be an unusual pair of objects traveling together in space, a UCLA planetary scientist and colleagues report. The asteroid Hermes was rediscovered last week after being lost for 66 years. Now Jean-Luc Margot, a researcher in UCLA’s department of Earth and space sciences, has determined that the asteroid is, in fact, two objects orbiting each other. The two objects together would cover an area approximately the size of Disneyland.

Opening up the dark side of the universe

Physicists in the UK are ready to start construction of a major part of an advanced new experiment, designed to search for elusive gravitational waves. Gravitational waves should be created when massive objects, such as black holes or neutron stars in astronomical binaries interact and spiral-in towards, and eventually collide with, each other emitting a strong burst of gravitational radiation or when a star, at the end of its long evolutionary phase, collapses due to its own gravity resulting in a supernova with the core forming a neutron star or a black hole.

Nanometer-sized particles change crystal structure when they get wet

As scientists shrink materials down to the nanometer scale, creating nanodots, nanoparticles, nanorods and nanotubes a few tens of atoms across, they’ve found weird and puzzling behaviors that have fired their imaginations and promised many unforeseen applications. Now University of California, Berkeley, scientists have found another unusual effect that could have both good and bad implications for semiconductor devices once they’ve been shrunk to the nanometer scale.

Space agency sees stardust storms heading for Solar System

Until ten years ago, most astronomers did not believe stardust could enter our Solar System. Then ESA’s Ulysses spaceprobe discovered minute stardust particles leaking through the Sun’s magnetic shield, into the realm of Earth and the other planets. Now, the same spaceprobe has shown that a flood of dusty particles is heading our way. Since its launch in 1990, Ulysses has constantly monitored how much stardust enters the Solar System from the interstellar space around it. Using an on-board instrument called DUST, scientists have discovered that stardust can actually approach the Earth and other planets, but its flow is governed by the Sun’s magnetic field, which behaves as a powerful gate-keeper bouncing most of it back. However, during solar maximum – a phase of intense activity inside the Sun that marks the end of each 11-year solar cycle – the magnetic field becomes disordered as its polarity reverses. As a result, the Sun’s shielding power weakens and more stardust can sneak in.

Battle lasers edge closer to reality

Laser weapons? This may not be as exotic as fans of Han Solo once thought, thanks to recent leaps forward in the development of a powerful free-electron laser, or FEL. Free electron lasers have been shown to generate very large amounts of power, tunable from the microwave to the visible spectrum. The Office of Naval Research is part of a team that is developing an electrically driven, tunable laser that could transmit infrared light for use in ship-defense systems.

Nanoshells could provide critical info for ER doctors, others

Nanotechnology researchers have developed a new method of testing whole blood that could allow emergency room doctors and other point-of-care health professionals to rapidly diagnose a variety of ailments, including hemorrhagic stroke, heart attack, and various infectious diseases. The test, which is faster than existing whole-blood immunoassays, uses gold nanoshells, tiny optically active gold-coated glass particles that are so small about 700 could fit in the diameter of a human hair.

Chemical ‘scissors’ yield short carbon nanotubes

Chemists at Rice University have identified a chemical process for cutting carbon nanotubes into short segments. The new process yields nanotubes that are suitable for a variety of applications, including biomedical sensors small enough to migrate through cells without triggering immune reactions. The chemical cutting process involves fluorinating the nanotubes, essentially attaching thousands of fluorine atoms to their sides, and then heating the fluoronanotubes to about 1,000 Celsius in an argon atmosphere. During the heating, the fluorine is driven off and the nanotubes are cut into segments ranging in length from 20-300 nanometers.

Icebound Antarctic telescope delivers first neutrino sky map

A novel telescope that uses the Antarctic ice sheet as its window to the cosmos, has produced the first map of the high-energy neutrino sky. The map, unveiled for astronomers here today at a meeting of the International Astronomical Union, provides astronomers with their first tantalizing glimpse of very high energy neutrinos, ghostly particles that are believed to emanate from some of the most violent events in the universe ? crashing black holes, gamma ray bursts, and the violent cores of distant galaxies.

Smoking supernovae belching dust

Astronomers from Cardiff University, in Wales, and the Royal Observatory, Edinburgh, Scotland, believe they have solved one of the long-standing mysteries of the Universe – the origins of cosmic dust. They explain how they have found that some supernovae, or exploding stars, belch out huge quantities of this dust – a discovery which suggests that supernovae were responsible for producing the first solid particles in the Universe.

Nanotech strategy could create new organs

Scientists from Harvard Medical School and the Massachusetts Institute of Technology have developed a strategy that could one day be used to create functional human organs such as kidneys and livers. The technique involves creating a network of microscopic tubes that branch out in a pattern, similar to that seen in the circulatory system, to provide oxygen and nutrients to liver or kidney cells that have been cultured in a lab. Using new fractal computational models, the network is designed and etched onto silicon surfaces which are then used as molds to transfer the pattern to biocompatible polymer films. Two films are then sealed together with a microporous membrane sandwiched between them.