Science & TechnologyS


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Invisibility Uncloaked

Charles Petit
Science News
Fri, 06 Nov 2009 15:00 UTC
Cloaking
© Cary Wolinsky and Rick KyleCloaking devices would steer light or other electromagnetic waves around them like water around a stone in a smooth stream, leaving nary a ripple of difference in the flow.
In race to make things disappear, scientists gain ground on science fiction

Ulf Leonhardt is riding high these days, with a new award from the Royal Society of Great Britain to further develop his ideas on how to make things in plain sight disappear.

Born in East Germany and now occupying the theoretical physics chair at Scotland's University of St. Andrews, Leonhardt is among the leaders of the worldwide race to realize an old dream of science fiction: cloaking devices. They would steer light or other electromagnetic waves around them like water around a stone in a smooth stream, leaving nary a ripple of difference in the flow. Such things, letting light swish past like a boxer ducking every punch, would be invisible.

"Cloaking device" is a common term in technical literature. It also deliberately evokes myth and popular fiction. Allusions include the Romulan technology that first amazed TV viewers of the old Star Trek in the episode "Balance of Terror," when hostile Bird of Prey fighting vessels just disappeared, poof. One finds cloaking in J.K. Rowling's novels about the young wizard Harry Potter with his invisibility cape. Farther back, H.G. Wells' novel The Invisible Man (and the movie of the same name, along with its sequel The Invisible Woman) toyed with much the same idea. J.R.R. Tolkien assigned similar power to The One Ring in his tales of hobbits. Inspiration for the ring apparently came from way back - the magical ring that the shepherd Gyges recovered from an earthquake-spawned chasm in Plato's The Republic.
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Binoculars

Signature of Antimatter Detected in Lightning

Ron Cowen
Science News
Fri, 06 Nov 2009 14:39 UTC
Fermi telescope finds evidence that positrons, not just electrons, are in storms on Earth.

Designed to scan the heavens thousands to billions of light-years beyond the solar system, the Fermi Gamma-ray Space Telescope has now recorded some more down-to-Earth signals. During its first 14 months of operation, the flying observatory has detected 17 gamma-ray flashes associated with terrestrial lightning storms.

The flashes occurred just before, during and immediately after lightning strikes, as tracked by the World Wide Lightning Location Network.

During two recent lightning storms, Fermi recorded gamma-ray emissions of a particular energy that could only have been produced by the decay of energetic positrons, the antimatter equivalent of electrons. The observations are the first of their kind for lightning storms. Michael Briggs of the University of Alabama in Huntsville announced the puzzling findings November 5 at the 2009 Fermi Symposium.
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New Type of Supernova Explosion Reported; Predicted by Theoretical Physicists

Gail Gallessich
University of California - Santa Barbara
Thu, 05 Nov 2009 20:41 UTC
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These are orbiting white dwarf stars.
A new class of supernova was discovered by scientists at Berkeley and may be the first example of a new type of exploding star. A team of astrophysicists at UC Santa Barbara had predicted this kind of explosion in their theoretical work.

Lars Bildsten, professor at UCSB's Kavli Institute for Theoretical Physics (KITP), and colleagues, predicted a new type of supernova in distant galaxies that would be fainter than most and would rise and fall in brightness in only a few weeks.

The discovery, led by UC Berkeley postdoctoral fellow Dovi Poznanski, who is also with Lawrence Berkeley National Laboratory, is reported in the Nov. 5 Express edition of Science Magazine. Bildsten first heard from Poznanski last August when he was organizing the conference "Stellar Death and Supernovae."
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This Day in History 1605: King James Learns of Gunpowder Plot


History
Thu, 05 Nov 2009 00:00 UTC
Guy Fawkes
© History
Early in the morning, King James I of England learns that a plot to explode the Parliament building has been foiled, hours before he was scheduled to sit with the rest of the British government in a general parliamentary session.

At about midnight on the night of November 4-5, Sir Thomas Knyvet, a justice of the peace, found Guy Fawkes lurking in a cellar under the Parliament building and ordered the premises searched. Some 20 barrels of gunpowder were found, and Fawkes was taken into custody. During a torture session on the rack, Fawkes revealed that he was a participant in an English Catholic conspiracy to annihilate England's Protestant government and replace it with Catholic leadership.

What became known as the Gunpowder Plot was organized by Robert Catesby, an English Catholic whose father had been persecuted by Queen Elizabeth I for refusing to conform to the Church of England. Guy Fawkes had converted to Catholicism, and his religious zeal led him to fight in the Spanish army in the Netherlands. Catesby and the handful of other plotters rented a cellar that extended under Parliament, and Fawkes planted the gunpowder there, hiding the barrels under coal and wood.
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Sherlock

Oldest American Artefact Unearthed

Rex Dalton
Nature News
Thu, 05 Nov 2009 15:00 UTC
Oregon cave
© Tom StaffordAn Oregon cave has yielded the oldest artifact ever found in the Americas.
Oregon caves yield evidence of continent's first inhabitants.

Archaeologists claim to have found the oldest known artefact in the Americas, a scraper-like tool in an Oregon cave that dates back 14,230 years.

The tool shows that people were living in North America well before the widespread Clovis culture of 12,900 to 12,400 years ago, says archaeologist Dennis Jenkins of the University of Oregon in Eugene.

Studies of sediment and radiocarbon dating showed the bone's age. Jenkins presented the finding late last month in a lecture at the University of Oregon.

His team found the tool in a rock shelter overlooking a lake in south-central Oregon, one of a series of caves near the town of Paisley.

Kevin Smith, the team member who uncovered the artefact, remembers the discovery. "We had bumped into a lot of extinct horse, bison and camel bone - then I heard and felt the familiar ring and feel when trowel hits bone," says Smith, now a master's student at California State University, Los Angeles. "I switched to a brush. Soon this huge bone emerged, then I saw the serrated edge. I stepped back and said: 'Hey everybody - we got something here.'"
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Neural Stem Cells in Mice Affected by Gene Associated with Longevity


ScienceDaily
Thu, 05 Nov 2009 05:00 UTC
A gene associated with longevity in roundworms and humans has been shown to affect the function of stem cells that generate new neurons in the adult brain, according to researchers at the Stanford University School of Medicine. The study in mice suggests that the gene may play an important role in maintaining cognitive function during aging.

"It's intriguing to think that genes that regulate life span in invertebrates may have evolved to control stem cell pools in mammals," said Anne Brunet, PhD, assistant professor of genetics. She is the senior author of the research, which will be published Nov. 6 in Cell Stem Cell.

Unlike your skin or your intestine, your adult brain doesn't make a lot of new cells. But those it does are critical to learning, memory and spatial awareness. To meet these demands, your brain maintains two small caches of neural stem cells, which can both self-renew and give rise to neurons and other cells known as oligodendrocytes and astrocytes. Properly balancing these functions allows you to generate new nerve cells as needed while also maintaining a robust neural stem cell pool.
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Telescope

Dark matter "wrecking ball" may have hit Milky Way

Dan Vergano
USA Today
Sun, 01 Nov 2009 10:03 UTC
Darth Vader's Death Star? Ming the Merciless and his war rockets? The awesome power of Chuck Norris?

Piffle, suggests one astrophysicist, at least when it comes to explaining what force could have permanently bent a ring in our Milky Way Galaxy within the last 60 million years. The real explanation may be the power of an invisible wrecking ball made of dark matter - a cloud of the enigmatic physics particles born in the fiery aftermath of the Big Bang and weighing as much as 10 million suns.
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In the Mediterranean, Killer Tsunamis From an Ancient Eruption

William J. Broad
New York Times
Wed, 04 Nov 2009 21:50 UTC
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The massive eruption of the Thera volcano in the Aegean Sea more than 3,000 years ago produced killer waves that raced across hundreds of miles of the Eastern Mediterranean to inundate the area that is now Israel and probably other coastal sites, a team of scientists has found.

The team, writing in the October issue of Geology, said the new evidence suggested that giant tsunamis from the catastrophic eruption hit "coastal sites across the Eastern Mediterranean littoral." Tsunamis are giant waves that can crash into shore, rearrange the seabed, inundate vast areas of land and carry terrestrial material out to sea.
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Archaeologists uncover prehistoric landscape beneath Oxford


PhysOrg.com
Wed, 04 Nov 2009 21:43 UTC
Image
© PhysOrg.comArchaeologists excavating the former Radcliffe Infirmary site in Oxford have uncovered evidence of a prehistoric monumental landscape stretching across the gravel terrace between the Thames and Cherwell rivers.
The work was carried out over the summer in preparation for Oxford University's proposed Radcliffe Observatory Quarter - plans for which were revealed earlier this month.

In addition to these findings, the work has also uncovered evidence of a 6th century Saxon settlement, including a sunken featured craft hut known as a Grübenhauser and a pit containing unfired clay loom weights.
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Rocket

Elevator to Space? They're Really Trying


The Associated Press
Wed, 04 Nov 2009 06:03 UTC
Rocketing into space? Some think an elevator might be the way to go.

That's the future goal of this week's $2 million Space Elevator Games in the Mojave Desert.

In a major test of the concept, robotic machines powered by laser beams will try to climb a cable suspended from a helicopter hovering more than a half-mile (one kilometer) high.

Three teams have qualified to participate in the event on the dry lakebed near NASA's Dryden Flight Research Center at Edwards. Attempts were expected from early Wednesday through Thursday.

Funded by a space agency program to explore bold technology, the contest is a step toward bringing the idea of a space elevator out of the realm of science fiction and into reality.
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