Science & TechnologyS


Evil Rays

A New Way To Measure Cosmic Distances


Space Daily
Tue, 09 Jun 2009 02:57 UTC
Image
© UnknownShort period cepheids, those that brighten and dim every few days, make good distance markers in space because their period is directly related to their brightness - and astronomers can use that brightness information to calculate the distance.
Ohio State University researchers have found a way to measure distances to objects three times farther away in outer space than previously possible, by extending a common measurement technique. They discovered that a rare type of giant star, often overlooked by astronomers, could make an excellent signpost for distances up to 300 million light-years - and beyond.

Along the way, they also learned something new about how these stars evolve.

Cepheid variables - giant stars that pulse in brightness - have long been used as reference points for measuring distances in the nearby universe, said Jonathan Bird, doctoral student in astronomy at Ohio State. Classical cepheids are bright, but beyond 100 million light-years from Earth, their signal gets lost among other bright stars.
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Blackbox

Will LISA Find Gravitational Waves And Prove Einstein Right?


Space Daily
Tue, 09 Jun 2009 02:52 UTC
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© UnknownThe three satellites will lie at the corners of a triangle whose sides each measure five million kilometres in length. If a ripple in space is caused by gravitational waves, the distance between the satellites will change.
Space and time are no longer what they used to be - absolute dimensions of the universe without regard to anything external. That is how Isaac Newton described them in the seventeenth century. In 1915, Albert Einstein completed his general theory of relativity, which fundamentally changed our view of space and time.

The general theory of relativity deals with one of the basic physical forces - gravity. This force causes objects to have weight, the planets to move around the Sun and black holes to be created - and it counters the expansion of the universe.

Einstein's theory predicts the existence of what are known as gravitational waves. Gravitational waves change the structure of space-time; they compress and stretch space - similar to the way that a wave ripples through water when a stone is thrown into it. Gravitational waves are created when a mass accelerates. Exploding stars and black holes cause particularly strong gravitational waves.
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Telescope

Astronomers solve mystery of 'dark' gamma ray bursts

Rachel Courtland
New Scientist
Tue, 09 Jun 2009 02:47 UTC
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© NASA/Swift/Aurore SimonnetMost dark gamma-ray bursts, which produce little or no visible light, seem to originate in dusty regions inside ordinary galaxies
The mystery of dark gamma-ray bursts, intense cosmic flashes that are not seen in visible light, may now be solved. Previously, they were suspected of originating too far away to be seen at optical wavelengths, but a new analysis suggests that most simply detonate in cocoons of dust that block out their light.

Gamma-ray bursts (GRBs) are the most brilliant flashes of light in the universe. They are thought to occur when massive, spinning stars collapse to form black holes, spewing jets of gas at nearly the speed of light.

For hours or days after their gamma-ray light has subsided, most bursts shine brightly in visible light when this gas slams into and heats up surrounding matter. But some bursts are 'dark' - they are virtually invisible to optical telescopes.
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Telescope

Texas-Size Computer Finds Most Massive Black Hole In Galaxy M87


Space Daily
Tue, 09 Jun 2009 02:41 UTC
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© Tim Jones/UT-Austin after K. Cordes & S. Brown (STScI)The illustration shows the relationship between the mass of a galaxy’s central black hole and the mass of its central bulge. The new higher mass Gebhardt and Thomas computer modeled for M87’s black hole, 6.4 billion solar masses, could change this relationship.
Astronomers Karl Gebhardt (The University of Texas at Austin) and Jens Thomas (Max Planck Institute for Extraterrestrial Physics) have used new computer modeling techniques to discover that the black hole at the heart of M87, one the largest nearby giant galaxies, is two to three times more massive than previously thought.

Weighing in at 6.4 billion times the Sun's mass, it is the most massive black hole yet measured with a robust technique, and suggests that the accepted black hole masses in nearby large galaxies may be off by similar amounts. This has consequences for theories of how galaxies form and grow, and might even solve a long-standing astronomical
paradox.
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Rocket

Romania Targets Moon with Balloon-Launched Ball

Jeremy Hsu
Space.com
Tue, 09 Jun 2009 01:29 UTC
Nearly 40 years after Americans first set foot on the moon on July 20, 1969 with NASA's historic Apollo 11 flight, a host of private rocketeers are hoping to follow to win a $30 million prize. Here, SPACE.com looks at ARCA, one of 17 teams competing in the Google Lunar X Prize:

Former X Prize contenders such as the Romanian team ARCA could have called it a day when Scaled Composites' SpaceShipOne won the $10 million Ansari X Prize on Oct. 4, 2004. Instead, ARCA hopes to build on its previous effort to reach the moon and win the Google Lunar X Prize and even more prize money.
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Info

Ancient tombs discovered by Kingston University-led team


Kingston University
Tue, 09 Jun 2009 01:22 UTC
A prehistoric complex including two 6,000-year-old tombs representing some of the earliest monuments built in Britain has been discovered by a team led by a Kingston University archaeologist. Dr Helen Wickstead and her colleagues were stunned and delighted to find the previously undiscovered Neolithic tombs, also known as long barrows at a site at Damerham, Hampshire.

Some artefacts, including fragments of pottery and flint and stone tools, have already been recovered and later in the summer a team of volunteers will make a systematic survey of the site, recovering and recording any artefacts that have been brought to the surface by ploughing.
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Magnify

Mysterious Inscribed Slate Discovered at Jamestown

Paula Neely
National Geographic News
Tue, 09 Jun 2009 01:10 UTC
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© Michael Lavin, courtesy Preservation Virginia
Archaeologists in Jamestown, Virginia, have discovered a rare inscribed slate tablet dating back some 400 years, to the early days of America's first permanent English settlement.

Both sides of the slate are covered with words, numbers, and etchings of people, plants, and birds that its owner likely encountered in the New World in the early 1600s.

The tablet was found a few feet down in what may be the first well at James Fort, dug in early 1609 by Capt. John Smith, Jamestown's best known leader, said Bill Kelso, director of archaeology at the site.
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Question

Google founders' mentor found dead in swimming pool

Matthew Weaver
Guardian
Mon, 08 Jun 2009 22:12 UTC
Rajeev Motwani, Stanford professor who worked with search engine founders Larry Page and Sergey Brin, dies aged 47

A US computer science professor who played a key role in the creation of the internet search giant Google has been found dead at the age of 47 after apparently falling into his swimming pool.

Rajeev Motwani was mentor to Google's founders, Larry Page and Sergey Brin, when they were PhD students at Stanford university. His body was found in the pool of his home in Atherton, California, on Friday.
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MIB

Universal 'Rubik's Cube' Could Become Pentagon Shapeshifter

Noah Shachtman
Signal Magazine
Mon, 08 Jun 2009 11:44 UTC
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© Unknown
Even by the standards of the Pentagon fringe science arm, this project sounds far-out: "" that can be ordered to "self-assemble or alter their shape, perform a function and then disassemble themselves." But researchers back by Darpa are actually making progress on this incredible goal, Henry Kenyon at Signal magazine reports.

One day, that could lead to "morphing aircraft and ground vehicles, uniforms that can alter themselves to be comfortable in any climate, and 'soft' robots that flow like mercury through small openings to enter caves and bunker complexes." A soldier could even reach into a can of unformed goop, and order up a custom-made tool or a "universal spare part."
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People

Just a few on Twitter do all the tweeting: study

Erin Kutz
Reuters
Mon, 08 Jun 2009 04:27 UTC
A tiny fraction of those who use the fast-growing social network phenomenon Twitter generate nearly all the content, a Harvard study shows.

That makes it hard for companies to use the micro-blogging site as an accurate gauge of public opinion, the Harvard Business School study showed.

Twitter Inc is a social networking website in which users post messages of 140 characters or less -- known as "tweets" -- that can be viewed by other users who elect to follow them.

The Harvard study examined public entries of a randomly selected group of 300,000 Twitter users. The researchers studied in May the content created in the lifetime of the users' Twitter accounts.
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