Thursday, January 11, 2007

Astronomers use Hubble images to map dark matter in 3-D

Dark matter is an invisible form of matter that accounts for most of the universe’s mass. The top "sliced" image shows how dark matter evolved from 6.5 billion to 3.5 billion years ago. The bottom image shows dark matter "clumping" together over time, confirming theories of how structure formed in our evolving universe. (NASA, ESA, CalTech image)
An international team of astronomers using NASA's Hubble Space Telescope -- launched aboard Space Shuttle Discovery in April 1990 -- has created the first three-dimensional map of the large-scale distribution of dark matter in the universe.
Dark matter is an invisible form of matter whose total mass in the universe is roughly five times that of "normal" matter (i.e., atoms). It can be thought of as the scaffolding of the universe. Visible matter collects inside this scaffolding in the form of stars and galaxies. The first direct detection of dark matter was made this past year through observations of the Bullet Cluster of galaxies.
The new map provides the best evidence yet that normal matter, including all stars and galaxies, collect within the densest concentrations of dark matter.
Mapping dark matter's distribution in space and time is fundamental to understanding how galaxies grew and clustered over billions of years.
The map stretches halfway back in time to the beginning of the universe, and reveals a network of dark matter filaments, collapsing under the relentless pull of gravity and growing clumpier over time. This is consistent with conventional theories of how structure formed in the evolving universe, which has transitioned from a smooth distribution of matter at the time of the Big Bang.
The researchers used data from Hubble Space Telescope's largest survey to date of the universe, the Cosmic Evolution Survey (COSMOS). The COSMOS field covers a sufficiently wide area of sky -- eight times the area of the full moon -- for the large-scale filamentary structure of dark matter to be clearly evident. To add 3-D distance information, the Hubble observations were combined with data from Europe's Very Large Telescope in Chile, Japan's Subaru Telescope in Hawaii, the United States' Very Large Array radio telescope in New Mexico, as well as the European Space Agency's orbiting XMM-Newton X-ray Observatory.
The dark matter map was constructed by measuring the shapes of half a million faraway galaxies. To reach Hubble, their light has had to travel through intervening dark matter, and the path of the light is slightly deflected by the dark matter's gravity. The observed, subtle distortion of the galaxies' shapes was used to reconstruct the distribution of intervening mass along Hubble's line of sight -- a method called weak gravitational lensing.
For astronomers, the challenge of mapping the universe has been similar to mapping a city from nighttime aerial snapshots showing only streetlights. Dark matter is invisible, so only the galaxies can be seen directly.
This new map is equivalent to seeing a city for the first time during the day, where the major arteries and intersections of the asphalt roadways become evident, and a variety of neighborhoods are revealed. Because the survey looks back in time the deeper it looks into the universe, it is also like a time-lapse view of the growth of a city over decades.

Thursday, November 09, 2006

Final Nod to Boeing Completes E-X Project at Last

Korea has averted another delay in its epically drawn-out attempt to acquire four airborne early warning system or AWACS planes by concluding tough final price negotiations with Boeing for the U.S. firm’s E-737 aircraft. The Defense Acquisition Program Agency announced the decision after a Defense Acquisition Committee meeting on the so-called E-X Project chaired by Defense Minister Yoon Kwang-ung on Wednesday. DAPA said it will sign a contract with the U.S. aerospace giant late this month to buy the four planes for some US$1.59 billion, one in 2011 and three in 2012.


A Defense Ministry official said the spy planes are essential for Korea’s independent combat operations after the country takes over wartime operational control of Korean troops from the U.S. Israel’s IAI Elta had been the sole other remaining bidder in the latest round but was dropped because it failed to win export permission for some key parts from the U.S. government by the deadline, DAPA said.


The airborne early warning aircraft E-737/ courtesy of Boeing


The Boeing aircraft has a radar to monitor the entire Korean Peninsula and the skies of neighboring countries within a 360-km radius. It can detect enemy planes flying up to 700 km away. It can track air and sea targets simultaneously with Northrop Grumman's Multi-Role Electronically Scanned Array (MESA) radar and has a device distinguishing between friend and foe. Its introduction here is expected to hugely enhance the Korean military’s independent intelligence and command capabilities.

The aircraft has six multi-purpose “mission consoles” with ultra-high resolution flat-panel tactical displays, and accommodates two pilots and six to 10 crew. It can fly at a speed of up to Mach 0.78 and at an operational ceiling of 12,400 m. Its flying range is 6,482 km. In regional comparison, Japan has 17 AWACS craft -- four E-767s and 13 E-2Cs -- and China is also developing several kinds of spy planes. A DAPA official said Korea won a more advantageous deal than Australia and Turkey, which purchased the same model in 2000 and 2001 for inflation-adjustable prices, while Korea will buy the aircraft at a fixed price with other benefits like technology transfer. Boeing initially asked for US$1.9 billion.

(englishnews@chosun.com )

Thursday, November 02, 2006

Samsung Develops First 16GB Multi-Chip Package

Samsung Electronics announced Wednesday that it had developed the world’s first 16-chip MCP (multi-chip package) technology by stacking 16 memory chips in one package. The new 16-chip MCP is created by staking 16 8Gb (gigabit) NAND flash chips, which has the highest density among products currently being produced, and allows up to a 16 gigabyte (GB) MCP solution, said the company. And the firm added that 16 stack is 30 percent smaller than a 10-chip MCP developed last year. Since the first development of technology with 6-chip MCP in 2003, the company has followed up with 8-chip MCPs in 2004, 10 in 2005, and this year 16-chip varieties, leading the MCP industry four straight years.

As mobile digital devices centered on cell phones are getting smaller and smaller while at the same time being equipped with an increasing array of features, the demand for MCP, which enables stacking several kinds of memory chips in a package, is growing. As the sole firm to possess the memory total solution technology that composes the MCP, Samsung Electronics topped the world MCP market for the first time in 2004, and is expected to maintain the top spot this year for the third straight year with market share of 35 percent. “With Samsung holding technology that is around two years ahead of the competition, who are mired in staking 8 chips, we anticipate the company’s leadership in the next generation package technology field will become even more pronounced,” the company said.

(englishnews@chosun.com )

Friday, October 20, 2006

Samsung Develops 1Gb 50-Nanometer DRAM

Samsung Electronics on Thursday said it has developed the world's first 1 GB 50-nanometer dynamic random access memory (DRAM) chip. The world's largest memory chipmaker said the 50-nanometer process technology will see twice the productivity of the 80 nanometer process now used to produce DRAM chips. Samsung will start mass producing the minuscule memory chips commonly used in laptops from 2008. The company says it expects this year's sales of DRAM products to reach US$ 10 billion.

Arirang News

Thursday, August 24, 2006

This lineup shows the 12 planets that were proposed last week, with a wedge of the sun at far left. Ceres, Pluto, Charon and 2003 UB313 are barely visible. Now Charon will continue to be considered Pluto's satellite, and the three other worlds will be dubbed "dwarf planets" rather than full-fledged planets. The planets are drawn to scale, but without correct relative distances.
View related photos

By Robert Roy Britt

Capping years of intense debate, astronomers resolved Thursday to demote Pluto in a wholesale redefinition of planethood that is being billed as a victory of scientific reasoning over historic and cultural influences. But the decision is already being hotly debated.

Officially, Pluto is no longer a planet.

"Pluto is dead," said Mike Brown, a planetary scientist at the California Institute of Technology who spoke with reporters via a teleconference while monitoring the vote. The decision also means a Pluto-sized object that Brown discovered will not be called a planet.

"Pluto is not a planet," Brown said. "There are finally, officially, eight planets in the solar system."

The vote involved just 424 astronomers who remained for the last day of a meeting of the International Astronomical Union in Prague.

"I'm embarrassed for astronomy. Less than 5 percent of the world's astronomers voted," said Alan Stern, leader of NASA's New Horizons mission to Pluto and a scientist at the Southwest Research Institute.

"This definition stinks, for technical reasons," Stern told Space.com. He expects the astronomy community to overturn the decision. Other astronomers criticized the definition as ambiguous.

The resolution
The decision establishes three main categories of objects in our solar system.

Planets: The eight worlds starting with Mercury and moving out to Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
Dwarf planets: Pluto and any other round object that "has not cleared the neighborhood around its orbit, and is not a satellite."
Small solar system bodies: All other objects orbiting the sun.
Pluto and its moon Charon, which would both have been planets under the initial definition proposed Aug. 16, now get demoted because they are part of a sea of other objects that occupy the same region of space. Earth and the other eight large planets have, on the other hand, cleared broad swaths of space of any other large objects.

"Pluto is a dwarf planet by the ... definition and is recognized as the prototype of a new category of trans-Neptunian objects," states the approved resolution.

Dwarf planets are not planets under the definition, however.

"There will be hundreds of dwarf planets," Brown predicted. He has already found dozens that fit the category.

Contentious logic
The vote came after eight days of contentious debate that involved four separate proposals at the group's meeting in Prague.

The initial proposal, hammered out by a group of seven astronomers, historians and authors, attempted to preserve Pluto as a planet but was widely criticized for diluting the meaning of the word. It would also have made planets out of the asteroid Ceres and Pluto's moon Charon. But not now.

"Ceres is a dwarf planet. it's the only dwarf planet in the asteroid belt," Brown said. "Charon is a satellite."

The category of "dwarf planet" is expected to include dozens of round objects already discovered beyond Neptune. Ultimately, hundreds will probably be found, astronomers say.

The word "planet" originally described wanderers of the sky that moved against the relatively fixed background of star. Pluto, discovered in 1930, was at first thought to be larger than it is. It has an eccentric orbit that crosses the path of Neptune and also takes it well above and below the main plane of the solar system.

Recent discoveries of other round, icy object in Pluto's realm have led most astronomers to agree that the diminutive world should never have been termed a planet.

'A farce'
Stern, in charge of the robotic probe on its way to Pluto, said the language of the resolution is flawed. It requires that a planet "has cleared the neighborhood around its orbit." But Earth, Mars, Jupiter and Neptune all have asteroids as neighbors.

"It's patently clear that Earth's zone is not cleared," Stern told Space.com. "Jupiter has 50,000 Trojan asteroids," which orbit in lockstep with the planet.

Stern called it "absurd" that only 424 astronomers were allowed to vote, out of about 10,000 professional astronomers around the globe.

"It won't stand," he said. "It's a farce."

Stern said astronomers are already circulating a petition that would try to overturn the IAU decision.

Thursday, July 20, 2006

Samsung Starts Making 8 GB Flash Memory Chips

Samsung Electronics has started mass producing 60 nanometer 8 GB NAND Flash memory chips, the company said Wednesday.
The 60 nanometer processing technology uses circuits the size of a hair sliced into 2,000 strands, the smallest circuits of any such product on the market. "The 60-nano technology is up to 25 percent more productive than the existing 70-nano, so we’ll be able to maintain our competitive price advantage,” a staffer with the world's no. 1 semiconductor maker said.
(englishnews@chosun.com )

Tuesday, July 11, 2006

Boeing Poised to Win Spy Plane Bid After All



The U.S. aerospace giant Boeing looks likely to win a W1.58 trillion contract to supply the nation's air force with four airborne warning and control systems (AWACS) planes by 2009. The bid in the epically delayed E-X project earlier looked set to make Korean defense procurement history when a non-U.S. bidder, IAI Elta of Israel, seemed likely to get the nod.

"After both the aircraft by Boeing and IAI Elta were found to meet the combat use requirements, four conditions had to be met,” a Defense Ministry official said. "IAI Elta was unable to meet some of them, so realistically it is likely to be excluded." If Elta, the sole other bidder, has been knocked out, the Defense Acquisition Program Administration (DAPA) will sit down for more price negotiations with Boeing before making the final decision.

DAPA will convene a meeting on Thursday to select the equipment “that best meets the conditions of the military.”
(englishnews@chosun.com )