Physics & Mathematics

‘Hormonal’ software could help satellite self-assemble in space

A unique design for self-organizing robots controlled by “hormonal” software is moving toward space. At the Robosphere 2002 conference held at the NASA Ames Research Center in Silicon Valley November 14-15, Wei-Min Shen of the USC School of Engineering’s Information Sciences Institute (ISI) presented an overview of an audacious project to have pieces of the proposed half-mile-long Space Solar Power System satellite put themselves together–self-assemble–without the help of astronauts.

Hubble helps measure massive extrasolar planet

NASA Hubble Space Telescope’s crisp view has allowed an international team of astronomers to apply a previously unproven technique (astrometry) for making a precise measurement of the mass of a planet outside our solar system. The Hubble results place the planet at 1.89 to 2.4 times the mass of Jupiter, our solar system’s largest world. Previous estimates, about which there are some uncertainties, place the planet’s mass between 1.9 and 100 times that of Jupiter.

Dark Edge of Sunspots Reveal Magnetic Melee

In what may be one of the most important steps in understanding sunspots since they were discovered by Chinese sky watchers more than two millennia ago, researchers have discovered that the lines of magnetic force that surge out of sunspots appear to peel apart like husk off an ear of corn as some of the lines are dragged back beneath the surface by a sort of solar quicksand. This “quicksand” and the magnetic fields it bends create the penumbrae around some sunspots, the strange rings of mid-darkness that have eluded explanation by astronomers since Galileo first sketched them. With the help of sophisticated computer models and data from solar telescopes that give spectacular views of the sun, researchers at the University of Rochester, University of Colorado, University of Cambridge, and University of Leeds have reported an answer to several mysteries of sunspots in the current issue of Nature.

Novel Method for Assembly of Nanoparticles

New York engineers have developed a novel method for assembling nanoparticles into three-dimensional structures that one day may be used to produce new nanoscale tools and machines. The work could be an important step in fulfilling the immense potential of nanotechnology because it gives scientists and engineers improved control and flexibility in the creation of materials for the manufacture of many nanoscale devices. The researchers used non-uniform AC electric fields generated by microfabricated electrodes — which create a motion known as dielectrophoresis — to stack latex, silica or graphite microparticles into two- and three-dimensional structures of prescribed lengths and composition, held together by the electrical field.

Scientists Grow Nano Blood Vessels

Traditional heart bypass surgeries require using veins from the leg to replace damaged blood vessels. Using a nanotechnology developed by Virginia Commonwealth University researchers, doctors soon could be using artificial blood vessels grown in a laboratory to help save half a million lives every year. The new technology produces a natural human blood vessel grown around a scaffold, or tube, made of collagen. Using a process called electrospinning, VCU scientists are making tubes as small as one millimeter in diameter. That’s more than four times smaller than the width of a drinking straw and six times smaller than the smallest commercially available vascular graft.

FDA approves wheelchair by Segway inventor Kamen

IbotThe U.S. Food and Drug Administration has approved the sale of a new wheelchair that enables users to operate on two wheels, allowing them to better negotiate obstacles like stairs and uneven pavement. Powered by a rechargeable battery that can operate up to a full day on a single charge, the wheelchair uses an integrated system of electronic, sensor and software components to automatically adjust itself according to the seat’s movement and the user’s center of gravity. These components are accompanied by a backup system to assure the safety of the user. It was invented by Dean Kamen, founder of DEKA Research and Development Corporation, best known for the two-wheeled Segway transporter.

NASA uses ‘extremophile’ microbes to grow nanostructures

NASA scientists have invented a biological method to make ultra-small structures that could be used to produce electronics 10 to 100 times smaller than today’s components. As part of their new method, scientists use modified proteins from ‘extremophile’ microbes that live in near-boiling, acidic hot springs to grow mesh-like structures so small that an electron microscope is needed to see them.
“Our innovation takes advantage of the innate ability of proteins to form into ordered structures and for us to use genetic engineering to change nature’s plans, transforming these structures into something useful,” said one of the project’s lead researchers.

Accidental finding could lead to full-spectrum solar cell

Researchers have found that the electrical properties of the semiconductor indium nitride are different from what been previously thought — by a wide margin. The result is that an alloy incorporating the material can convert virtually the full spectrum of sunlight — from the near infrared to the far ultraviolet — to electrical current. “It’s as if nature designed this material on purpose to match the solar spectrum,” said one researcher involved.

Exceptionally Bright Eruption on Io Rivals Largest in Solar System

Routine monitoring of volcanic activity on Jupiter’s moon Io has turned up the largest eruption to date on Io’s surface or in the solar system. The eruption took place in February 2001, though image analysis was only recently completed by a team of University of California, Berkeley, astronomers. Their results are published in the November issue of the planetary sciences journal Icarus. “The Surt eruption appears to cover an area of 1,900 square kilometers, which is larger than the city of Los Angeles and even larger than the entire city of London,” said the lead researcher. “The total amount of energy being released by the eruption is amazingly high, with the thermal output from this one eruption almost matching the total amount of energy emitted by all of the rest of Io, other volcanoes included.”

Image shows Mars glows in X-rays

This image from the Chandra X-ray Observatory has given scientists their first look at X-rays from Mars. In the sparse upper atmosphere of Mars, about 75 miles above its surface, the observed X-rays are produced by fluorescent radiation from oxygen atoms. X-rays from the Sun impact oxygen atoms, knock electrons out of the inner parts of their electron clouds, and excite the atoms to a higher energy level in the process. The atoms almost immediately return to their lower energy state and may emit a fluorescent X-ray in this process with an energy characteristic of the atom involved ? oxygen in this case. A similar process involving ultraviolet light produces the visible light from fluorescent lamps.

Researchers Develop Chemical Switch to Control Biomolecular Motor

Researchers have created a tiny motor that they can turn on and off at will, bringing scientists one step closer to using such devices to repair cellular damage, manufacture medicines and attack cancer cells. As reported in this month’s Nature Materials, the researchers have developed a chemical switch that gives them control over a biomolecular motor just 11 nanometers, or 11 billionths of a meter, in size ? hundreds of times smaller than the width of a human hair.

Ultracold Gas Shows Strange Behavior

Researchers have created an ultracold gas that has the startling property of bursting outward in a preferred direction when released. According to the scientists, studying the properties of the “lopsided” gas could yield fundamental insights into how matter holds itself together at the subatomic level. Also, the research team leader said their data suggests the possibility that the gas is exhibiting a never-before-seen kind of superfluidity — a property in which matter at extremely low-temperatures behaves in unusual ways

Magnetic processes in space can accelerate electrons to near light speed

A chance observation of high-energy electrons emanating from a tiny region of space where the sun and Earth’s magnetic fields intertwine provides the first solid evidence that a process called magnetic reconnection accelerates electrons to near the speed of light in the Earth’s magnetosphere and perhaps throughout the universe where magnetic fields entangle.