Science & TechnologyS


Telescope

Did our cosmos exist before the big bang?

Anil Ananthaswamy
New Scientist
Thu, 11 Dec 2008 16:50 UTC
Conceptual computer artwork representing the origin of the universe
© MEHAU KULYK/SPLConceptual computer artwork representing the origin of the universe.
Abhay Ashtekar remembers his reaction the first time he saw the universe bounce. "I was taken aback," he says. He was watching a simulation of the universe rewind towards the big bang. Mostly the universe behaved as expected, becoming smaller and denser as the galaxies converged. But then, instead of reaching the big bang "singularity", the universe bounced and started expanding again. What on earth was happening?

Ashtekar wanted to be sure of what he was seeing, so he asked his colleagues to sit on the result for six months before publishing it in 2006. And no wonder. The theory that the recycled universe was based on, called loop quantum cosmology (LQC), had managed to illuminate the very birth of the universe - something even Einstein's general theory of relativity fails to do.
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Key

Tunnelling nanotubes: Life's secret network

Anil Ananthaswamy
New Scientist
Tue, 18 Nov 2008 18:23 UTC
Had Amin Rustom not messed up, he would not have stumbled upon one of the biggest discoveries in biology of recent times. It all began in 2000, when he saw something strange under his microscope. A very long, thin tube had formed between two of the rat cells that he was studying. It looked like nothing he had ever seen before.

His supervisor, Hans-Hermann Gerdes, asked him to repeat the experiment. Rustom did, and saw nothing unusual. When Gerdes grilled him, Rustom admitted that the first time around he had not followed the standard protocol of swapping the liquid in which the cells were growing between observations. Gerdes made him redo the experiment, mistakes and all, and there they were again: long, delicate connections between cells. This was something new - a previously unknown way in which animal cells can communicate with each other.

Gerdes and Rustom, then at Heidelberg University in Germany, called the connections tunnelling nanotubes. Aware that they might be onto something significant, the duo slogged away to produce convincing evidence and eventually published a landmark paper in 2004 (Science, vol 303, p 1007).
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Info

Neanderthal genome already giving up its secrets

Ewen Callaway
New Scientist
Wed, 10 Dec 2008 17:49 UTC
Image
© Wikimedia CommonsA rough draft of the Neanderthal genome should be available by the end of 2008.
Half the Neanderthal genome has been decoded and the rest should be sequenced by year's end, a scientist involved in the project told a human evolution conference last week.

Researchers will roll out a rough draft of the Neanderthal nuclear genome after their sequencers have read every letter in the genome on average once - "1x coverage" in genomics speak.

However, the fragmentary state of the DNA sample - from bones recovered in Croatia - means that the first draft will offer only a tantalizing glimpse of the genome to researchers who hope to better understand Neanderthal biology and human evolution.

Some 38,000 years of decay has left the DNA in tatters and strewn with contamination from bacteria and human handlers.

"It's not like sequencing any other genome," says Adrian Briggs, a researcher at Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who is involved in the project, along with colleagues Edward Green and Svante Pääbo.
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Telescope

Star paths reveal secrets of Milky Way's black hole

Jessica Griggs
New Scientist
Wed, 10 Dec 2008 16:31 UTC
Image
© ESO/S Gillessen et al.The central part of the Milky Way is shown in this near-infrared image taken by the NACO instrument on the Very Large Telescope.
Astronomers have crunched 16 years of data to make the most detailed observations yet of the stars orbiting the centre of our galaxy, bolstering the case that a monstrous black hole lurks there.

Black holes are invisible but can be detected by their influence on nearby stars. By observing the motion of 28 stars orbiting the Milky Way's central region, Reinhard Genzel of the Max-Planck-Institute for Extraterrestrial Physics in Germany, says his team has delivered "the best empirical evidence that supermassive black holes do really exist".

Genzel's team found that the black hole, known as Sagittarius A*, is about 4 million times as heavy as our Sun, in line with previous estimates. They also used the observations to work out that the Earth is 27,000 light years away from the centre of the Milky Way, also agreeing with previous estimates.

One star, S2, was orbiting so fast that it completed an entire revolution of the black hole over the 16-year period. Observing one complete orbit of S2 was critical to the high accuracy reached and to understanding the region, says the team.
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Alarm Clock

The Great Sphinx of Giza reborn as a lion in the desert


The Daily Mail
Wed, 10 Dec 2008 13:18 UTC
The Sphinx in Egypt might have originally had the face of a lion, it is claimed.

And it could be much older than previously thought, investigations led by a British geologist suggest.

Egyptologists have long argued the monument outside Cairo, which has the head of a pharaoh and the body of a lion, was built soon after the first pyramid - around 4,500 years ago.
Alternate Sphinx
© Daily MailUncovering the secret face: This digital recreation shows the Sphinx with the face of a lion
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Telescope

Hubble Telescope Finds Carbon Dioxide On An Extrasolar Planet


Science Daily
Wed, 10 Dec 2008 03:43 UTC
Image
© ESA, NASA, M. Kornmesser (ESA/Hubble), and STScl.Artist's view of exoplanet orbiting the star HD 189733.
NASA's Hubble Space Telescope has discovered carbon dioxide in the atmosphere of a planet orbiting another star. This breakthrough is an important step toward finding chemical biotracers of extraterrestrial life.

The Jupiter-sized planet, called HD 189733b, is too hot for life. But the Hubble observations are a proof-of-concept demonstration that the basic chemistry for life can be measured on planets orbiting other stars. Organic compounds also can be a by-product of life processes, and their detection on an Earthlike planet someday may provide the first evidence of life beyond our planet.

Previous observations of HD 189733b by Hubble and NASA's Spitzer Space Telescope found water vapor. Earlier this year, Hubble found methane in the planet's atmosphere.
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Better Earth

Brain swelling blamed in many Mount Everest deaths

Will Dunham
Reuters
Tue, 09 Dec 2008 02:18 UTC
Reuters Everest
© ReutersMount Everest
A brain swelling condition related to low oxygen levels in the air may have caused many of the deaths of people climbing Mount Everest, researchers said on Tuesday.

In this condition, low oxygen levels cause cerebral blood vessels to leak fluid into surrounding brain tissue, triggering swelling. Confusion and loss of coordination follow.

The study showed that 1.3 percent of mountaineers who climbed above their Everest base camp died.
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Magic Wand

Snowflakes as you've never seen them before

Lucy Dodwell
New Scientist
Tue, 09 Dec 2008 19:01 UTC
snowflake
© Kenneth LibbrechtThis snowflake has fernlike stellar dendrites - so called because the crystals have so many sidebranches that they look like ferns. Follow the link in the text to see many more types of snowflake.
As anyone who has tried to examine them under a microscope will appreciate, you've got to be quick - or in a very cold place - to investigate snowflake structure. It doesn't help if you live somewhere like California where there isn't much snow to start with.

Kenneth Libbrecht at the California Institute of Technology has come up with a solution. His team have built a machine that creates snowflakes in conditions similar to those in the atmosphere. They hope that their freefall convection chamber will shed light on the mechanisms responsible for generating the amazingly diverse shapes of snowflakes.
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Telescope

Rivers Of Gas Flow Around Stars In New Space Image


Science Daily
Tue, 09 Dec 2008 18:55 UTC
Swan nebula
© NASA/JPL-Caltech/University of WisconsinAn infrared view of the choppy star-making cloud called M17, or the Swan nebula.
A new image from NASA's Spitzer Space Telescope shows a turbulent star-forming region, where rivers of gas and stellar winds are eroding thickets of dusty material.

The picture provides some of the best examples yet of the ripples of gas, or bow shocks, that can form around stars in choppy cosmic waters.

"The stars are like rocks in a rushing river," said Matt Povich of the University of Wisconsin, Madison. "Powerful winds from the most massive stars at the center of the cloud produce a large flow of expanding gas. This gas then piles up with dust in front of winds from other massive stars that are pushing back against the flow." Povich is lead author of a paper describing the new findings in the Dec. 10 issue of the Astrophysical Journal.

Spitzer's new infrared view of the stormy region, called M17, or the Swan nebula, is now online. The Swan is located about 6,000 light-years away in the constellation Sagittarius.
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Info

Men Are Red, Women Are Green


Science Daily
Mon, 08 Dec 2008 20:25 UTC
Image
© Michael J. Tarr/Brown UniversityTest subjects tended to confirm subtle color differences associated with gender. Even when viewing pixelated or distorted images, subjects identified redder images as male and greener images as female.
Michael J. Tarr, a Brown University scientist, and graduate student Adrian Nestor have discovered this color difference in an analysis of dozens of faces. They determined that men tend to have more reddish skin and greenish skin is more common for women.

The finding has important implications in cognitive science research, such as the study of face perception. But the information also has a number of potential industry or consumer applications in areas such as facial recognition technology, advertising, and studies of how and why women apply makeup.

"Color information is very robust and useful for telling a man from a woman," said Tarr, the Sidney A. and Dorothea Doctors Fox Professor of Ophthalmology and Visual Sciences and professor of cognitive and linguistic sciences at Brown. "It's a demonstration that color can be useful in visual object recognition."
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