Back to the main page

Archives Of Science Blog

Subscribe To Science Blog RSS Feed  RSS content feed What is RSS feed?


April 22, 2006, 5:54 PM CT

NSF Web Site Nominated For Webby Award

NSF Web Site Nominated For Webby Award
The Webby Awards, the leading international honor for web sites, this week nominated the National Science Foundation's Web site as a finalist in the government category for 2006. As an independent federal agency, NSF receives public support through Congressional appropriations. NSF's redesigned site was launched in 2005 to better serve both the general public and the science and education community, with a greater emphasis on visual richness and user-friendliness.

Hailed as the "online Oscars" by Time Magazine, The Webby Awards were founded in 1996 and are determined by the International Academy of Digital Arts & Sciences. The award honors outstanding web sites that are setting the standards for the internet, as per awards founder Tiffany Shlain.

NSF's redesign culminated more than a year of study and analysis regarding the most current and effective ways to communicate in today's fast-paced electronic information environment. A new content management system ensures timeliness and reliability of information site-wide. Revamped navigation makes it easier for visitors to find what they need. New content aims to more effectively explain NSF's use of public funds, and the results derived from it. Some of the new features include a help center, a plain-language explanation of NSF and how it works, illustrated overviews on the types of science that NSF supports, results of NSF research, and a classroom resources section aimed at teachers and parents.........

Posted by: John      Permalink         Source


April 20, 2006, 10:55 PM CT

Breakthrough In Black Hole Simulation

Breakthrough In Black Hole Simulation This visualization shows what Einstein envisioned. Researchers crunched Einstein's theory of general relativity on the Columbia supercomputer at the NASA Ames Research Center to create a three-dimensional simulation of merging black holes. This was the largest astrophysical calculation ever performed on a NASA supercomputer. The simulation provides the foundation to explore the universe in an entirely new way, through the detection of gravitational waves. (7.4 Mb - no audio). Click on image to view animation. Credit:Henze, NASA
NASA researchers have reached a breakthrough in computer modeling that allows them to simulate what gravitational waves from merging black holes look like. The three-dimensional simulations, the largest astrophysical calculations ever performed on a NASA supercomputer, provide the foundation to explore the universe in an entirely new way.

As per Einstein's math, when two massive black holes merge, all of space jiggles like a bowl of Jell-O as gravitational waves race out from the collision at light speed.

Prior simulations had been plagued by computer crashes. The necessary equations, based on Einstein's theory of general relativity, were far too complex. But researchers at NASA's Goddard Space Flight Center in Greenbelt, Md., have found a method to translate Einstein's math in a way that computers can understand.

"These mergers are by far the most powerful events occurring in the universe, with each one generating more energy than all of the stars in the universe combined. Now we have realistic simulations to guide gravitational wave detectors coming online," said Joan Centrella, head of the Gravitational Astrophysics Laboratory at Goddard.

The simulations were performed on the Columbia supercomputer at NASA's Ames Research Center near Mountain View, Calif. This work appears in the March 26 issue of Physical Review Letters and will appear in an upcoming issue of Physical Review D. The lead author is John Baker of Goddard.........

Posted by: Edwin      Permalink         Source


April 20, 2006, 0:32 AM CT

Xmm-newton Reveals A Tumbling Neutron Star

Xmm-newton Reveals A Tumbling Neutron Star XMM-Newton image of pulsar 'RX J0720.4-3125'
Using data from ESA's XMM-Newton X-ray observatory, an international group of astrophysicists discovered that one spinning neutron star doesn't appear to be the stable rotator researchers would expect. These X-ray observations promise to give new insights into the thermal evolution and finally the interior structure of neutron stars.

Spinning neutron stars, also known as pulsars, are generally known to be highly stable rotators. Thanks to their periodic signals, emitted either in the radio or in the X-ray wavelength, they can serve as very accurate astronomical 'clocks'.

The researchers found that over the past four and a half years the temperature of one enigmatic object, named RX J0720.4-3125, kept rising. However, very recent observations have shown that this trend reversed and the temperature is now decreasing.

As per the researchers this effect is not due to a real variation in temperature, but instead to a changing viewing geometry. RX J0720.4-3125 is most probably 'precessing', that is it is slowly tumbling and therefore, over time, it exposes to the observers different areas of the surface.

Neutron stars are one of the endpoints of stellar evolution. With a mass comparable to that of our Sun confined into a sphere of 20-40 km diameter, their density is even somewhat higher than that of an atomic nucleus - a billion tonnes per cubic centimetre. Soon after their birth in a supernova explosion their temperature is of the order of 1 000 000 ºC and the bulk of their thermal emission falls in the X-ray band of the electromagnetic spectrum. Young isolated neutron stars are slowly cooling down and it takes a million years before they become too cold to be observable in X-rays.........

Posted by: Edwin      Permalink         Source


April 20, 2006, 0:29 AM CT

Low Cost Internet Access At Sea

Low Cost Internet Access At Sea
Vessel used in trials Credits: Wired Ocean Ltd
Through a project supported by the European Space Agency, the UK-based company Wired Ocean Ltd can now provide enhanced Internet access for ships at sea at a much lower cost than was previously possible.

Eventhough satellite links at sea are quite common, the speed of data transmission for most users is very low, from 600 bps to 64 kbps, with around 10 kbps being a typical speed. This, combined with usage costs of around € 20 per megabyte, has created an environment in which a number of ship owners cannot reliably access the Internet, or use it regularly.

The Wired Ocean approach uses a hybrid solution, combining Ku-band satellites for the downlink and narrow L-band satellites for the return channel. While at sea, the downlink (forward) channel offers a speed of 512 kbps and the uplink (return) channel speed is 9.6 kbps for Globalstar and up to 64 kbps for Inmarsat. This configuration promises to be more economical than purely narrowband satellite systems, with cost savings of as much as 70% over current systems.

Telephone, television and now internet

The ship's internet communications are managed through a specialised client server developed by Wired Ocean. This server interfaces with a tracking TV Receive Only (TVRO) antenna for the downlink and various types of narrowband communications equipment for the uplink. The ship's TVRO is used to receive internet data while simultaneously providing signals to the ship's televisions.........

Posted by: John      Permalink         Source


April 19, 2006, 11:53 PM CT

Better Performance, Longer Battery Life For Cell Phones And Gadgets

Better Performance, Longer Battery Life For Cell Phones And Gadgets

Anyone who uses a cell phone or a WiFi laptop knows the irritation of a dead-battery surprise. But now researchers at the University of Rochester have broken a barrier in wireless chip design that uses a tenth as much battery power as current designs and, better yet, will use much less in emerging wireless devices of the future.

Hui Wu, professor of electrical and computer engineering at the University of Rochester, a pioneer in a circuit design called an "injection locked frequency divider," or ILFD, has solved the last hurdle to making the new method work. Wireless chip manufacturers have been aware of ILFD and its ability to ensure accurate data transfer using much less energy than traditional digital methods, but the technique had two fatal flaws: it could not handle a wide range of frequencies, and could not ensure a fine enough resolution within that range. Wu, together with Ali Hajimiri, associate professor of electrical engineering at California Institute of Technology, surmounted the first problem in 2001, and has now found a solution for the latter.

When a cell phone or a laptop using WiFi or Bluetooth communicates wirelessly, the data is transmitted at very specific frequencies. One person can talk on a cell phone at a frequency of 2.0001 gigahertz, and someone else nearby can talk at 2.0002 gigahertz, and neither one will pick up the other's conversation. In order to make sure it is both listening for and sending information on exactly the right frequency at all times, the phone must maintain a very accurate and stable clock, which is generated by a special circuit called "phase-locked loop." This circuit consumes a dramatic portion of the battery usage on wireless devices.........

Posted by: John      Permalink         Source


April 19, 2006, 11:47 PM CT

New Cheaper, More Sophisticated Video-conferencing

New Cheaper, More Sophisticated Video-conferencing
If only Fred Astaire and Ginger Rogers were around today to take a spin with new technology being developed and tested by a team of computer scientists in Illinois and California.

If they were, they'd be dancing circles around each other - only from a considerable distance. That's the beauty of Tele-immersive Environments for EVErybody, or TEEVE, a system that's being test-driven simultaneously across thousands of miles this spring in the labs of Klara Nahrstedt, a computer science professor at the University of Illinois at Urbana-Champaign, and Ruzena Bajcsy, a professor of computer science at the University of California at Berkeley.

In technical terms, TEEVE is a distributed multi-tier application that captures images using 3-D camera clusters and distributes them over Internet2 (the network reserved for research and corporate clients), compressing and decompressing the 3-D video streams, rendering them into immersive video and displaying them on one or multiple large screens.

In layman's terms, think of TEEVE as a turbocharged version of videoconferencing, but with some very fancy new bells and whistles. Most notably, Nahrstedt said, TEEVE makes it possible for people to view their counterparts at remote sites from all angles.

And an important feature that sets it apart from other tele-immersive video-conferencing systems currently being developed or used elsewhere is its potential for delivering high-quality images and communications using relatively inexpensive technology and COTS - or commercial-off-the-shelf products and equipment.........

Posted by: John      Permalink         Source


April 19, 2006, 6:50 PM CT

Graphical World For Visually-impaired People

Graphical World For Visually-impaired People
A new tactile device will allow the widespread use of graphical interfaces visually-impaired people. The tactile graphical display will open up new avenues of employment, communication and personal expression. Conceivably it could do for graphics what Louis Braille did for text in 1824.

Current Braille displays generally show one line at a time using electro-magnetic or piezo-electrical forces to raise and lower the dots that make up Braille letters. Larger multiline displays were developed but never sold commercially because they cost over €200,000 to produce.

The new display uses electro-rheological fluids and will cost about €15,000 when it enters production, a comparable price to current top-of-the-range single line readers.

"Piezo-electrical devices manufacture the dots in pairs, whereas in our system we can manufacture the entire display in one sweep, which keeps down the costs," said Dr Sami Ahmed, managing director of Smart Technology Group the scientific coordinator of the interactive Tactile Interface (ITACTI) project, backed by funding from the European Commission's IST programme.

Smart were responsible for developing the electro-rheological (ER) fluids which change their state from liquid to semi-solid when a charge is applied. Developing the ER fluids was the greatest challenge faced by the project. Smart also was responsible for design and manufacture of the new display unit.........

Posted by: John      Permalink         Source


April 18, 2006, 11:20 PM CT

Gamma Radiation From The Cosmos Unlikely

Gamma Radiation From The Cosmos Unlikely

Are you losing sleep at night because you're afraid that all life on Earth will suddenly be annihilated by a massive dose of gamma radiation from the cosmos?

Well, now you can rest easy.

Some researchers have wondered whether a deadly astronomical event called a gamma ray burst could happen in a galaxy like ours, but a group of astronomers at Ohio State University and their colleagues have determined that such an event would be nearly impossible.

Gamma ray bursts (GRBs) are high-energy beams of radiation that shoot out from the north and south magnetic poles of a particular kind of star during a supernova explosion, explained Krzysztof Stanek, associate professor of astronomy at Ohio State. Researchers suspect that if a GRB were to occur near our solar system, and one of the beams were to hit Earth, it could cause mass extinctions all over the planet.

The GRB would have to be less than 3,000 light years away to pose a danger, Stanek said. One light year is approximately 6 trillion miles, and our galaxy measures 100,000 light years across. So the event would not only have to occur in our galaxy, but relatively close by, as well.

In the new study, which Stanek and his coauthors submitted to the Astrophysical Journal, they found that GRBs tend to occur in small, misshapen galaxies that lack heavy chemical elements (astronomers often refer to all elements other than the very lightest ones -- hydrogen, helium, and lithium -- as metals). Even among metal-poor galaxies, the events are rare -- astronomers only detect a GRB once every few years.........

Posted by: Edwin      Permalink         Source


April 18, 2006, 10:45 PM CT

Unbreakable Quantum Encryption

Unbreakable Quantum Encryption NIST physicist Xiao Tang and colleagues have developed a quantum communications system that uses single photons to produce a "raw" encryption key at the rate of 4 million bits per second. Image credit: © Robert Rathe
Raw code for "unbreakable" encryption, based on the principles of quantum physics, has been generated at record speed over optical fiber at the Commerce Department's National Institute of Standards and Technology (NIST). The work, reported today at the SPIE Defense & Security Symposium in Orlando, Fla.,* is a step toward using conventional high-speed networks such as broadband Internet and local-area networks to transmit ultra-secure video for applications such as surveillance.

The NIST quantum key distribution (QKD) system uses single photons, the smallest particles of light, in different orientations to produce a continuous binary code, or "key," for encrypting information. The rules of quantum mechanics ensure that anyone intercepting the key is detected, thus providing highly secure key exchange. The laboratory system produced this "raw" key at a rate of more than 4 million bits per second (4 million bps) over 1 kilometer (km) of optical fiber, twice the speed of NIST's previous record, reported just last month.** The system also worked successfully, although more slowly, over 4 km of fiber.

The record speed was achieved with an error rate of only 3.6 percent, considered very low. The next step will be to process the raw key, using NIST-developed methods for correcting errors and increasing privacy, to generate "secret" key at about half the original speed, or about 2 million bps.........

Posted by: John      Permalink         Source


April 17, 2006, 10:17 PM CT

Wintering on Mars

Wintering on Mars
NASA's Mars rover Spirit has reached a safe site for the Martian winter, while its twin, Opportunity, is making fast progress toward a destination of its own.

The two rovers recently set out on important -- but very different -- drives after earlier weeks inspecting sites with layers of Mars history. Opportunity finished examining sedimentary evidence of ancient water at a crater called "Erebus," and is now rapidly crossing flat ground toward the scientific lure of a much larger crater, "Victoria."

Spirit studied signs of a long-ago explosion at a bright, low plateau called "Home Plate" during February and March. Then one of its six wheels quit working, and Spirit struggled to complete a short advance to a north-facing slope for the winter. "For Spirit, the priority has been to reach a safe winter haven," said Dr. Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for the Mars Exploration Rover project.

The rovers have operated more than eight times as long as their originally planned three-month explorations on Mars. Each has driven more than 6.8 kilometers (4.2 miles) about 11 times as far as planned. Combined, they have returned more than 150,000 images. Two years ago, the project had already confirmed that at least one place on Mars had a wet and possibly habitable environment long ago. The scientific findings continue. ........

Posted by: Edwin      Permalink         Source


Older Blog Entries   1   2   3   4   5   6   7   8   9   10   11   12   13   14   15   16   17   18   19   20   21   22   23