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Dark Energy Is Driving Universe Apart: NASA's Galaxy Evolution Explorer Finds Dark Energy Repulsive


Science Daily
Thu, 19 May 2011 00:00 UTC
Image
© NASA/JPL-Caltech
New results from NASA's Galaxy Evolution Explorer and the Anglo-Australian Telescope atop Siding Spring Mountain in Australia confirm that dark energy (represented by purple grid) is a smooth, uniform force that now dominates over the effects of gravity (green grid). The observations follow from careful measurements of the separations between pairs of galaxies (examples of such pairs are illustrated here).
A five-year survey of 200,000 galaxies, stretching back seven billion years in cosmic time, has led to one of the best independent confirmations that dark energy is driving our universe apart at accelerating speeds.

The survey used data from NASA's space-based Galaxy Evolution Explorer and the Anglo-Australian Telescope on Siding Spring Mountain in Australia.

The findings offer new support for the favored theory of how dark energy works -- as a constant force, uniformly affecting the universe and propelling its runaway expansion. They contradict an alternate theory, where gravity, not dark energy, is the force pushing space apart. According to this alternate theory, with which the new survey results are not consistent, Albert Einstein's concept of gravity is wrong, and gravity becomes repulsive instead of attractive when acting at great distances.

"The action of dark energy is as if you threw a ball up in the air, and it kept speeding upward into the sky faster and faster," said Chris Blake of the Swinburne University of Technology in Melbourne, Australia. Blake is lead author of two papers describing the results that appeared in recent issues of the Monthly Notices of the Royal Astronomical Society. "The results tell us that dark energy is a cosmological constant, as Einstein proposed. If gravity were the culprit, then we wouldn't be seeing these constant effects of dark energy throughout time."
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Beaker

New technique sheds light on the mysterious process of cell division


Penn State University
Sat, 21 May 2011 17:05 UTC
Image
© Unknown
After the primitive model cell divides, one daughter cell inherits only one kind of lipid membrane (red) and most of the protein molecules (blue), while the other inherits two kinds of lipids (red and green)

University Park, Pennsylvania - Using a new technique in which models of primitive cells are constructed from the bottom up, scientists have demonstrated that the structure of a cell's membrane and cytoplasm may be as important to cell division as the specialized machinery -- such as enzymes, DNA or RNA -- that are found within living cells.

Christine Keating, an associate professor of chemistry at Penn State, and Meghan Andes-Koback, a graduate student in the Penn State Department of Chemistry, generated simple, nonliving model "cells" with which they established that asymmetric division -- the process by which a cell splits to become two distinct daughter cells -- is possible even in the absence of complex cellular components, such as genes. The study, which will be published in the Journal of the American Chemical Society, may provide important clues to how life originated from nonlife and how modern cells came to exhibit complex behaviors.
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Magnify

Not So Dumb After All: Tyrannosaurus Rex Hunted in Bloodthirsty Packs, Researchers Claim


The Daily Mail, UK
Thu, 19 May 2011 06:47 UTC
T-Rex Research
© Press Association
Lead researcher Dr Philip Currie with a Tyrannosaurid fossil. Scientists now believe the top predator was a highly-intelligent pack animal, despite being popularly depicted as a dangerous but dim-witted loner
Tyrannosaurus rex and its relatives were more intelligent than previously thought and hunted in gangs which included young and older members, researchers have claimed.

Scientists believe they have evidence that the top predator dinosaurs were highly intelligent pack animals, despite T-rex being popularly depicted as a dangerous but dim-witted loner.

This is a myth that has grown up because for many years their fossil skeletons tended to be found on their own, researchers say.

The new theory follows an analysis of skeletons of the tyrannosaur Tarbosaurus bataar from 90 sites in the Gobi Desert, Mongolia.

Tarbosaurus, a cousin of T-rex that lived around 70 million years ago, was a two-legged predator up to 12 metres long and weighing five tonnes.

At least half a dozen of the animals appear to have belonged to a single social group, including adults and juveniles, that died together.
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Stop

The Unintended Consequences of Artificial Life


The Daily Galaxy
Sat, 21 May 2011 13:24 UTC
Gene Manipulation
© The Daily Galaxy
This is "the first self-replicating species we've had on the planet whose parent is a computer."

Dr. Craig Venter - pioneer of the human genome
2010 might be looked back on as the year of the Earth's first non-biological self-replicating species. The genome pioneer J. Craig Venter has taken another step in his quest to create synthetic life by synthesizing an entire bacterial genome and using it to take over a cell.

In his famous essay, Why the Future Doesn't Need Us, Silicon Valley scientist and software engineer, Bill Joy warns about possible dangers of genetic engineering using a work of fiction as a possible scenario. In The White Plague, by Frank Herbert - a molecular biologist is driven insane by the senseless murder of his family. To seek revenge he constructs and disseminates a new and highly contagious plague that kills widely but selectively.

Joy asks why weren't people more concerned about possible nightmarish scenarios of future genetic creations? Part of the answer, he says, "lies in our bias toward instant familiarity and unquestioning acceptance. Accustomed to living with almost routine scientific breakthroughs, we have yet to come to terms with the fact that the most compelling 21st-century technologies - robotics, genetic engineering, and nanotechnology - pose a different threat than the technologies that have come before. Specifically, robots, engineered organisms, and nanobots share a dangerous amplifying factor: They can self-replicate. A bomb is blown up only once - but one bot can become many, and quickly get out of control."
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Saturn

Skydiving on Saturn

Pete Wilton
PhysOrg.com
Fri, 20 May 2011 11:00 UTC
skydiving Saturn
© OU/ESO/Fletcher/Barry
Illustration of Saturn skydiving.
Daredevils regularly bail out at high altitude to skydive through Earth's atmosphere but what would it be like to skydive on Saturn?

Would you jump in summer into an atmosphere shrouded in a yellow-ochre haze, aim for winter when the planet is tinged blue, or maybe leap into the shadow of those famous rings?

These thoughts were prompted by new research from an international team led by Oxford University scientists into a powerful storm on Saturn first spotted in December 2010.

"What we see when we look at Saturn in visible light is the top of the cloud decks - that's near the top of the troposphere or 'weather zone' - made up of ammonia clouds and other hazy materials," Leigh Fletcher of Oxford University's Department of Physics, who led the work, tells us.
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Eye 2

Mammals' large brains evolved for smell

Victoria Gill
BBC
Fri, 20 May 2011 17:04 UTC
Image
© M A Klinger / Carnegie Museum of Natural History
The researchers scanned the fossilised skulls of tiny, very early mammals
A highly developed sense of smell kick-started the development of mammals' big brains.

Scientists used very high-resolution scanning to study the skulls of two of the earliest known mammal species.

Comparing the shape of their brain cases to those of slightly earlier animals, or "pre-mammals", revealed that the first brain areas to over-develop were those associated with the sense of smell.

The findings are published in Science.

An improved sense of smell may have allowed our tiny, furry ancestors to hunt at night.

The researchers were able to create 3D images of prehistoric animals' brains using the latest computed tomography, or CT, scanning methods.

"Before CT, one had to break open a fossil to get to the internal anatomy," explained Professor Timothy Rowe from the University of Texas at Austin, one of the researchers involved in the study.

"[This technique] is non-destructive, so we can measure internal anatomy in ways that were never before possible."
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Beaker

US: 135-Year-Old Piece of Skin Triggers Smallpox Scare at Museum


Foxnews.com/ The Wall Street Journal
Thu, 19 May 2011 00:00 UTC
Image
© AP
A child affected by the smallpox virus.
An outbreak of smallpox was the furthest thing from historian Dr. Paul Levengood's mind when his staff at the Virginia Historical Society put together an exhibit of "bizarre bits" that were added to the society's collection since its founding in 1831, The Wall Street Journal reported Thursday.

There was Confederate president Jefferson Davis's cigar, confiscated by Union troops. There was a fungus carving of Robert E. Lee on his horse, Traveller, and a wreath made of human hair.

Then someone mentioned a letter, handwritten and dated 1876, with what appeared to be a smallpox scab pinned inside -- light brown, about the size of a pencil eraser and crumbling.

The scab got the attention of the Centers for Disease Control and Prevention (CDC), home to one of the world's two known caches of live smallpox viruses.

Alerted by a government scientist in Maryland who was concerned that the scab might transmit infection, the agency dispatched two CDC representatives to Richmond. They donned disposable surgical gowns and gloves, lifted the scab from a display case, sealed it in bio-bags inside a red cooler and whisked it back to a high-security lab deep within the CDC's Atlanta headquarters.
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Better Earth

Weather 101: The Atmosphere

Ed Buckner
Todaysthv.com
Fri, 20 May 2011 16:25 UTC

The atmosphere is more than just the air above us. It's 5 layers protect us. Ed has more in this Weather 101.
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Question

Amondawa Tribe Lacks Abstract Idea of Time, Study Says

Jason Palmer
BBC
Fri, 20 May 2011 01:04 UTC
Amondawa Village
© V Da Silva Sinha
Amondawa village. The Amondawa were first "discovered" by anthropologists in 1986.

An Amazonian tribe has no abstract concept of time, say researchers.

The Amondawa lacks the linguistic structures that relate time and space - as in our idea of, for example, "working through the night".

The study, in Language and Cognition, shows that while the Amondawa recognise events occuring in time, it does not exist as a separate concept.

The idea is a controversial one, and further study will bear out if it is also true among other Amazon languages.

The Amondawa were first contacted by the outside world in 1986, and now researchers from the University of Portsmouth and the Federal University of Rondonia in Brazil have begun to analyse the idea of time as it appears in Amondawa language.

"We're really not saying these are a 'people without time' or 'outside time'," said Chris Sinha, a professor of psychology of language at the University of Portsmouth.

"Amondawa people, like any other people, can talk about events and sequences of events," he told BBC News.

"What we don't find is a notion of time as being independent of the events which are occurring; they don't have a notion of time which is something the events occur in."

The Amondawa language has no word for "time", or indeed of time periods such as "month" or "year".
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Info

Milky Way Has Rare Symmetry

Ron Cowen
Discovery News
Fri, 20 May 2011 12:35 UTC
Milky Way
© JPL-NASA
Virtually every spiral arm in the Milky Way has been found in sections.

A new study suggests the Milky Way doesn't need a makeover: It's already just about perfect.

Astronomers base that assertion on their discovery of a vast section of a spiral, star-forming arm at the Milky Way's outskirts. The finding suggests that the galaxy is a rare beauty with an uncommon symmetry -- one half of the Milky Way is essentially the mirror image of the other half.

Thomas Dame and Patrick Thaddeus of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., say the structure they've discovered is most likely the outer extension of the Scutum-Centaurus arm from the inner galaxy. The finding suggests that Scutum-Centaurus wraps all the way around the Milky Way, making it a symmetric counterpart to the galaxy's other major star-forming arm, Perseus.

The two arms appear to extend from opposite ends of the galaxy's central, bar-shaped cluster of stars, each winding around the galaxy, the researchers note in an upcoming issue of Astrophysical Journal Letters.

Dame found evidence for the new structure while reviewing galactic data on atomic hydrogen gas, which radiates at a radio wavelength of 21 centimeters. After tracing the extension of the arm in the 21-centimeter radio emission, "I was in the unique position of being able to walk up two flights of stairs to the roof of my building [at Harvard] and search for carbon monoxide emissions from molecular clouds using the CfA 1.2-meter radio telescope," says Dame. Molecular gas clouds contain the raw material for making stars.
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