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July 9, 2006, 7:56 PM CT

Supernova And A Mysterious Object

Supernova And A Mysterious Object Puzzling pulsation from the heart of RCW103
Thanks to data from ESA's XMM-Newton satellite, a team of researchers taking a closer look at an object discovered over 25 years ago have found that it is like none other known in our galaxy.

The object is in the heart of supernova remnant RCW103, the gaseous remains of a star that exploded about 2 000 years ago. Taken at face value, RCW103 and its central source would appear to be a textbook example of what is left behind after a supernova explosion: a bubble of ejected material and a neutron star.

A deep, continuous 24.5-hour observation has revealed something far more complex and intriguing, however. The team, from the Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF) of the Istituto Nazionale di Astrofisica (INAF) in Milan, Italy, has found that the emission from the central source varies with a cycle that repeats itself every 6.7 hours. This is an astonishingly long period, tens of thousands of times longer than expected for a young neutron star. Also, the object's spectral and temporal properties differ from an earlier XMM-Newton observation of this very source in 2001.

"The behaviour we see is particularly puzzling in view of its young age, less than 2 000 years," said Andrea De Luca of IASF-INAF, the lead author. "It is reminiscent of a multimillion-year-old source. For years we have had a sense that the object is different, but we never knew how different until now." .........

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July 9, 2006, 7:52 PM CT

Where Craters Tell The Story Of Basalt

Where Craters Tell The Story Of Basalt This mosaic of three images, taken by the advanced Moon Imaging Experiment (AMIE)on board ESA's SMART-1 spacecraft, shows Mare Humorum on the Moon.
This mosaic of three images, taken by the advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft, shows Mare Humorum on the Moon.

AMIE obtained the top frame on 1 January 2006, from a distance of 1087 kilometres from the surface, with a ground resolution of 98 metres per pixel. The remaining two frames were taken on 13 January 2006, from a distance of about 1069 (centre) and 1050 kilometres (bottom) from the surface, with a ground resolution of 97 and 95 metres per pixel, respectively.

The area shown in the top image is centred at a latitude of 40.2º South and longitude 25.9 degree West; the centre image is centred at a latitude of 40.2º South and longitude 27.3 degree West; the bottom image is centred at a latitude of 40.2 degree South and longitude 28.8 degree West.

Mare Humorum, or 'Sea of Moisture', is a small circular mare on the lunar nearside, about 825 kilometres across. The mountains surrounding it mark the edge of an old impact basin which has been flooded and filled by mare lavas. These lavas also extend past the basin rim in several places. In the upper right are several such flows which extend northwest into southern Oceanus Procellarum.

Mare Humorum was not sampled by the Apollo program, so its precise age could not been determined yet. However, geologic mapping indicates that its age is in between that of the Imbrium and the Nectaris basins, suggesting an age of about 3.9 thousand million years (with an uncertainty of 500 million years).........

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July 7, 2006, 7:18 AM CT

Large Quantum Computers

Large Quantum Computers Credit: Signe Seidelin and John Chiaverini/NIST
Physicists at the National Institute of Standards and Technology (NIST) have designed and built a novel electromagnetic trap for ions that could be easily mass produced to potentially make quantum computers large enough for practical use. The new trap, described in the June 30 issue of Physical Review Letters,* may help researchers surmount what is currently the most significant barrier to building a working quantum computer--scaling up components and processes that have been successfully demonstrated individually.

Quantum computers would exploit the unusual behavior of the smallest particles of matter and light. Their theoretical ability to perform vast numbers of operations simultaneously has the potential to solve certain problems, such as breaking data encryption codes or searching large databases, far faster than conventional computers. Ions (electrically charged atoms) are promising candidates for use as quantum bits (qubits) in quantum computers. The NIST team, one of 18 research groups worldwide experimenting with ion qubits, previously has demonstrated at a rudimentary level all the basic building blocks for a quantum computer, including key processes such as error correction, and also has proposed a large-scale architecture.

The new NIST trap is the first functional ion trap in which all electrodes are arranged in one horizontal layer, a "chip-like" geometry that is much easier to manufacture than prior ion traps with two or three layers of electrodes. The new trap, which has gold electrodes that confine ions about 40 micrometers above the electrodes, was constructed using standard microfabrication techniques.........

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July 7, 2006, 6:43 AM CT

Broadband Light Amplifier On A Chip

Broadband Light Amplifier On A Chip
Cornell scientists have created a broadband light amplifier on a silicon chip, a major breakthrough in the quest to create photonic microchips. In such microchips, beams of light traveling through microscopic waveguides will replace electric currents traveling through microscopic wires.

A team of scientists working with Alexander Gaeta, Cornell professor of applied and engineering physics, and Michal Lipson, assistant professor of electrical and computer engineering, used the Cornell NanoScale Facility to make the devices. They reported their results in the June 22 issue of the journal Nature.

The amplifier uses a phenomenon known as four-wave mixing, in which a signal to be amplified is "pumped" by another light source inside a very narrow waveguide. The waveguide is a channel only 300 x 550 nanometers (nm = a billionth of a meter, about the length of three atoms in a row) wide, smaller than the wavelength of the infrared light traveling through it. The photons of light in the pump and signal beams are tightly confined, allowing for transfer of energy between the two beams.

The advantage this scheme offers over prior methods of light amplification is that it works over a fairly broad range of wavelengths. Photonic circuits are expected to find their first applications as repeaters and routers for fiber-optic communications, where several different wavelengths are sent over a single fiber at the same time. The new broadband device makes it possible to amplify the multiplexed traffic all at once.........

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July 4, 2006, 9:34 AM CT

Polar Year 2007-2008

Polar Year 2007-2008
Thousands of scientists from 60 countries will be conducting research during International Polar Year 2007-2008 and will, for the first time during an International Polar Year, be armed with satellite measurements offering complete coverage of the polar regions, which play a vital role in the Earth's climate and ecosystems.

Having access to near-continuous satellite data of these regions over long periods of time is important for scientists to identify and analyse long-term climatic trends and changes. ESA will provide current and historical data, dating back 15 years, from its ERS-1, ERS-2 and Envisat satellites as well as data collected from a number of non-ESA satellites.

Dr. David Carlson, Director of the International Programme Office for the Polar Year, predicts many uses of satellite data: "Many researchers use satellite data as part of their daily activities. During IPY those researchers will push to extract more and more information from the satellites, particularly to understand recent and current distributions of snow and ice. We will use every form of satellite data - passive visual, active microwave, and even sensitive gravity measurements - to understand changes in the global ice sheets".

Since their advent satellites have contributed to a greater understanding of polar regions, helped identify the strong links these regions have with Earth's terrestrial, ocean and atmospheric processes and made startling observations. For example, within days of its launch in 2002, ESA's environmental satellite Envisat captured the disintegration of the Larsen-B ice shelf in Antarctica, surprising scientists because of the rapid rate at which the shelf broke apart.........

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July 4, 2006, 9:23 AM CT

Jules Verne Passes Acoustic Test

Jules Verne Passes Acoustic Test
Acoustic testing of Jules Verne, the first Automated Transfer Vehicle (ATV), has successfully been completed at ESA's test facilities in Noordwijk, The Netherlands.

The 11-tonne test configuration of the ATV Flight Model (the actual flight launch mass is 20.5 tonnes) was transferred to the Large European Acoustic Facility (LEAF) with the help of an air cushion transfer pad.

The ATV, an unmanned vehicle that will deliver supplies to the International Space Station (ISS), will be put into orbit by the European Ariane-5 launcher. Acoustic testing is vital to ensure the ATV can withstand the vibrations caused by the extreme noise levels generated during launch.

Acoustic vibrations are been used to simulate the stress the ATV will encounter during the first three minutes of launch - due to aero dynamical forces - on top of the powerful European Ariane-5 launcher.

The whole structure of the ATV, which is the size of a double-decker London bus, will have to withstand an overall sound pressure level of 144 dB with main frequencies between 25Hz and 5kHz. The same amount of acoustic vibrations would be lethal for the human body.

Over several days different test runs were conducted in the special enclosed facility, LEAF. Dozens of sensors placed in different areas of the ATV have measured and checked its hardware behaviour. Two-dozen technicians and engineers from Prime Contractor EADS Launch Vehicles, EADS Space Transportation, Alcatel Alenia Space (former Alenia Spazio), Dutch Space (acquired by EADS Space), European Test Services (ETS) and ESA coordinated the test runs.........

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June 29, 2006, 11:49 PM CT

I am Mr. Robot, your companion

I am Mr. Robot, your companion
Robots are changing from single function 'dumb' machines to adaptive learning machines thanks to the fast pace in the development of the robotic technology.

The concept of a cognitive robotic companion inspires some of the best science fiction but one day may be science fact following the work of the four-year COGNIRON project funded since January 2004 by the IST's Future and Emerging Technologies initiative. But what could a cognitive robot companion do?

"Well, that's a difficult question. The example that's often used is a robot that's able to fulfil your needs, like passing you a drink or helping in everyday tasks," says Dr Raja Chatila, research director at the Systems Architecture and Analysis Laboratory of the French Centre National de la Recherche Scientifique (LAAS-CNRS), and COGNIRON project coordinator.

"That might seem a bit trivial, but let me ask you a question: In the 1970s, what was the use of a personal computer?" he asks.

It's a good point. In fact, it was then impossible to imagine how PCs would change the world's economics, politics and society in just 30 years. The eventual uses, once the technology developed, were far from trivial.

COGNIRON set out on the same principle, given that society is constantly evolving, and the project partners hope to tackle some of the key issues that need to be resolved for the development of a cognitive robot companion, which could be used as assistants for disabled and elderly people or the general population. Who wouldn't like, for instance, their breakfast ready when they awoke, deliveries accepted while they were at work and their apartment cleaned upon their return?........

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June 29, 2006, 0:02 AM CT

How To Record A Smell?

How To Record A Smell?
Engineers at the Tokyo Institute of Technology in Japan are building an odour recorder capable of doing just that. Simply point the gadget at a freshly baked cookie, for example, and it will analyse its odour and reproduce it for you using a host of non-toxic chemicals.

The device could be used to improve online shopping by allowing you to sniff foods or fragrances before you buy, to add an extra dimension to virtual reality environments and even to assist military doctors treating soldiers remotely by recreating bile, blood or urine odours that might help a diagnosis.

While many companies have produced aroma generators designed to enhance computer games or TV shows, they have failed commercially because they have been very limited in the range of smells they can produce, says Pambuk Somboon of the Tokyo team.

So he has done away with pre-prepared smells and developed a system that records and later reproduces the odours. It's no easy task: "In video, you just need to record shades of red, green and blue," he says. "But humans have 347 olfactory sensors, so we need a lot of source chemicals".

Somboon's system will use 15 chemical-sensing microchips, or electronic noses, to pick up a broad range of aromas. These are then used to create a digital recipe from a set of 96 chemicals that can be chosen as per the purpose of each individual gadget. When you want to replay a smell, drops from the relevant vials are mixed, heated and vaporised. In tests so far, the system has successfully recorded and reproduced the smell of orange, lemon, apple, banana and melon.........

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June 28, 2006, 11:46 PM CT

The Hooked Galaxy

The Hooked Galaxy ESO PR Photo
The Hooked Galaxy and its Companion
Because of the importance of exploding stars, and particularly of supernovae of Type Ia [1], for cosmological studies (e.g. relating to claims of an accelerated cosmic expansion and the existence of a new, unknown, constituent of the universe - the so called 'Dark Energy'), they are a preferred target of study for astronomers. Thus, on several occasions, they pointed ESO's Very Large Telescope (VLT) towards a region of the sky that portrays a trio of amazing galaxies.

MCG-01-39-003 (bottom right) is a peculiar spiral galaxy, with a telephone number name, that presents a hook at one side, most probably due to the interaction with its neighbour, the spiral galaxy NGC 5917 (upper right). In fact, further enhancement of the image reveals that matter is pulled off MCG-01-39-003 by NGC 5917. Both these galaxies are located at similar distances, about 87 million light-years away, towards the constellation of Libra (The Balance).

NGC 5917 (also known as Arp 254 and MCG-01-39-002) is about 750 times fainter than can be seen by the unaided eye and is about 40,000 light-years across. It was discovered in 1835 by William Herschel, who strangely enough, seems to have missed its hooked companion, only 2.5 times fainter.

As seen at the bottom left of this exceptional VLT image, a still fainter and nameless, but intricately beautiful, barred spiral galaxy looks from a distance the entangled pair, while many 'island universes' perform a cosmic dance in the background.........

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June 28, 2006, 11:41 PM CT

Breakthrough in Silicon Photonics Devices

Breakthrough in Silicon Photonics Devices
Building on a series of recent breakthroughs in silicon photonics, researchers at the UCLA Henry Samueli School of Engineering and Applied Science have developed a novel approach to silicon devices that combines light amplification with a photovoltaic - or solar panel - effect.

In a study to be presented today at the 2006 International Optical Amplifiers and Applications Conference in Vancouver, Canada, UCLA Engineering researchers report that not only can optical amplification in silicon be achieved with zero power consumption, but power can now be generated in the process.

The team's research shows that silicon Raman amplifiers possess nonlinear photovoltaic properties, a phenomenon related to power generation in solar cells. In 2004, the same group at UCLA Engineering demonstrated the first silicon laser, a device that took advantage of Raman amplification.

"After dominating the electronics industry for decades, silicon is now on the verge of becoming the material of choice for the photonics industry, the traditional stronghold of today's semiconductors," said Bahram Jalali, the UCLA Engineering professor who led researcher Sasan Fathpour and graduate student Kevin Tsia in making the recent discovery.

The amount of information that can be sent through an optical wire is directly related to the intensity of the light. In order to perform some of the key functions in optical networking - such as amplification, wavelength conversion, and optical switching - silicon must be illuminated with high intensity light to take advantage of its nonlinear properties. One example is the Raman effect, a phenomenon that occurs at high optical intensities and is behind many recent breakthroughs in silicon photonics, including the first optical amplifiers and lasers made in silicon.........

Posted by: John      Permalink         Source

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