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Black Hole Outflows from Centaurus A Detected with APEX


PhysOrg
Wed, 28 Jan 2009 11:00 UTC
Black Hole
© NASA
Colour composite image of Centaurus A, revealing the lobes and jets emanating from the active galaxy’s central black hole.
Astronomers have a new insight into the active galaxy Centaurus A (NGC 5128), as the jets and lobes emanating from the central black hole have been imaged at submillimetre wavelengths for the first time. The new data, from the Atacama Pathfinder Experiment (APEX) telescope in Chile, which is operated by ESO, have been combined with visible and X-ray wavelengths to produce this striking new image.

Centaurus A is our nearest giant galaxy, at a distance of about 13 million light-years in the southern constellation of Centaurus. It is an elliptical galaxy, currently merging with a companion spiral galaxy, resulting in areas of intense star formation and making it one of the most spectacular objects in the sky. Centaurus A hosts a very active and highly luminous central region, caused by the presence of a supermassive black hole, and is the source of strong radio and X-ray emission.

In the image, we see the dust ring encircling the giant galaxy, and the fast-moving radio jets ejected from the galaxy centre, signatures of the supermassive black hole at the heart of Centaurus A. In submillimetre light, we see not only the heat glow from the central dust disc, but also the emission from the central radio source and - for the first time in the submillimetre - the inner radio lobes north and south of the disc. Measurements of this emission, which occurs when fast-moving electrons spiral around the lines of a magnetic field, reveal that the material in the jet is travelling at approximately half the speed of light. In the X-ray emission, we see the jets emerging from the centre of Centaurus A and, to the lower right of the galaxy, the glow where the expanding lobe collides with the surrounding gas, creating a shockwave.
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Frog

Attenborough reveals creationist hate mail for not crediting God

Riazat Butt
The Guardian
Wed, 28 Jan 2009 04:48 UTC
David Attenborough
© BBC/PA
David Attenborough in a still from his series 'Life In Cold Blood'.
Attenborough reveals creationist hate mail for not crediting God

Sir David Attenborough has revealed that he receives hate mail from viewers for failing to credit God in his documentaries. In an interview with this week's Radio Times about his latest documentary, on Charles Darwin and natural selection, the broadcaster said: "They tell me to burn in hell and good riddance."

Telling the magazine that he was asked why he did not give "credit" to God, Attenborough added: "They always mean beautiful things like hummingbirds. I always reply by saying that I think of a little child in east Africa with a worm burrowing through his eyeball. The worm cannot live in any other way, except by burrowing through eyeballs. I find that hard to reconcile with the notion of a divine and benevolent creator."
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Telescope

It's snowing on Mars ...

Ian Sample
Guardian
Wed, 28 Jan 2009 02:31 UTC
... or at least in the sky above it. This is just one extraordinary piece of information being sent back to us by the landers, probes and rovers scanning the planet. Home to the largest mountain in the solar system and a canyon as long as the US is wide, it is a world as fantastic as any imagined by JG Ballard

snowing mars

Cape St Vincent, one of the cliffs of the Victoria crater. Photograph: Nasa/Reuters
High in the sky above Mars, it is snowing right now. Very gently snowing. The snow does not settle on the rubble-strewn land below - not these days, anyway - but instead vaporises into the thin atmosphere long before it reaches the ground.

The first flakes of snow, on a planet that until fairly recently was believed to be waterless, were spotted just a few months ago. A Nasa lander near the planet's north pole was scanning the sky with a laser when it noticed the telltale signs of snowfall. The probe, called Phoenix, announced the news in a radio signal that was picked up by an overhead orbiter and beamed back to Earth. Nothing like it had ever been seen before.

The news of snow falling is just one piece of an extraordinary wealth of information that has recently been sent back from Mars by orbiters, landers and rovers. Together, they have mapped the surface in unprecedented detail, cracked open rocks, sniffed the atmosphere and dug down into the soil. What they have found points to an unimagined Martian history, one where life may have once gained a foothold and may even cling on still in the frigid soils of the permafrost.
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Telescope

Wall Divides East and West Sides of Cosmic Metropolis


PhysOrg
Tue, 27 Jan 2009 00:03 UTC
Wall
© NASA
A new study unveils NGC 604, the largest region of star formation in the nearby galaxy M33, in its first deep, high-resolution view in X- rays. This composite image from Chandra X-ray Observatory data (colored blue), combined with optical light data from the Hubble Space Telescope (red and green), shows a divided neighborhood where some 200 hot, young, massive stars reside.

Throughout the cosmic metropolis, giant bubbles in the cool dust and warm gas are filled with diffuse, multi-million degree gas that emits X-rays. Scientists think these bubbles are generated and heated to X- ray temperatures when powerful stellar winds from the young massive stars collide and push aside the surrounding gas and dust. So, the vacated areas are immediately repopulated with the hotter material seen by Chandra.

However, there is a difference between the two sides of this bifurcated stellar city. On the western (right) side, the amount of hot gas found in the bubbles corresponds to about 4300 times the mass of the sun. This value and the brightness of the gas in X-rays imply that the western part of NGC 604 is entirely powered by winds from the 200 hot massive stars.
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Battery

Spinning black holes are ultimate cosmic batteries


Asian News International
Tue, 27 Jan 2009 20:49 UTC
In a new research, scientists have determined that spinning black holes are the ultimate cosmic batteries, as it seems they can store and unleash the energy of billions of supernovae, with potentially devastating consequences for their host galaxies.

Many of the supermassive black holes that lurk at the centre of galaxies fire out powerful plasma jets that extend for millions of light years.

Though the details of how these jets are produced remain murky, there seems to be only two plausible power sources: one is matter falling onto the black hole, which cant explain all the cases.
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Fish

'Fishy' Clue Helps Establish How Proteins Evolve


PhysOrg
Tue, 27 Jan 2009 16:38 UTC
Model
© Marsland/Yale
This is a model of Pyl tRNA and tRNA synthetase interaction.
Three billion years ago, a "new" amino acid was added to the alphabet of 20 that commonly make up proteins in organisms today. Now researchers at Yale and the University of Tokyo have demonstrated how this rare amino acid - and, by example, other amino acids - made its way into the menu for protein synthesis. The study appeared in the December 31 advance online publication of the journal Nature.

The rare amino acid the Yale researchers studied, pyrrolysine (Pyl), gave the researchers a molecular handle by being an extreme example of an amino acid that evolved to serve a highly specific need.

The amino acid alphabet shapes the language of proteins. When the genetic code was deciphered four decades ago, scientists believed that there were no more than 20 amino acid "letters" that universally meshed with the nucleic acid part of the protein code. But, like many alphabets, the language of proteins has letters with modifications - like accent marks - that modify their use.
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Sun

Cosmic Rays Reflect Stratospheric Weather


United Press International
Tue, 27 Jan 2009 15:16 UTC
British scientists say they've detected cosmic rays reaching an underground detector that reflect major weather events occurring in the Earth's stratosphere.

The researchers said the cosmic-rays detected half a mile underground in a unused U.S. iron mine can be used to determine major weather events occurring 20 miles above the Earth.

The researchers from the United Kingdom's National Center for Atmospheric Science and the Science and Technology Facilities Council said the study shows how the number of high-energy cosmic-rays reaching the underground detector closely matched temperature measurements in the stratosphere.
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Sherlock

Earliest Man-Made Cave Houses in China


The Hindu
Tue, 27 Jan 2009 08:40 UTC
Cave
© Xinhua
The site of cave dwellings that date back to 3,500 BC at Yangguan Village in northwest China’s Shaanxi Province.
Rows of two-room houses were built between 3,500 and 3,000 BC.

Archaeologists in China have unearthed the earliest man-made cave houses and privately-owned pottery workshops which date back 5,500 years.

After four years of excavation, a row of 17 cave houses were found on a cliff along the Jinghe river in northwest China's Shaanxi Province, Wang Weilin, deputy director of the Shaanxi Archaeology Institute and chief archaeologist of the excavation, told Xinhua.

They were built between 3,500 and 3,000 BC.

Mr. Wang said the row of houses were within a 16,000-sq.m. site which was being excavated.

The cave houses belonged to a late neolithic culture named Yangshao that originated in the middle reaches of the Yellow river and was considered a main origin of Chinese civilisation. Yangshao was best known for red pottery ware with painted patterns.
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Sherlock

Natural selection is not the only process that drives evolution


PhysOrg
Tue, 27 Jan 2009 09:36 UTC
Why have some of our genes evolved rapidly? It is widely believed that Darwinian natural selection is responsible, but research led by a group at Uppsala University, suggests that a separate neutral (nonadaptive) process has made a significant contribution to human evolution. Their results have been published today in the journal PLoS Biology.

The researchers identified fast evolving human genes by comparing our genome with those of other primates. However, surprisingly, the patterns of molecular evolution in many of the genes they found did not contain signals of natural selection. Instead, their evidence suggests that a separate process known as BGC (biased gene conversion) has speeded up the rate of evolution in certain genes. This process increases the rate at which certain mutations spread through a population, regardless of whether they are beneficial or harmful.

"The research not only increases our understanding of human evolution, but also suggests that many techniques used by evolutionary biologists to detect selection may be flawed" says Matthew Webster.
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Laptop

Physcists Teleport Information using Quantum Entanglement

James Dacey
physicsworld.com
Thu, 22 Jan 2009 02:40 UTC
Physicists have teleported quantum information between two atoms separated by a significant distance, for the first time. Until now this feat had only been achieved between photons, and between two nearby atoms through the intermediary action of a third. According to researchers, this advance could be a significant milestone in the quest for a workable quantum computer.

Quantum teleportation is a remarkable form of transport only available to particles at the atomic and subatomic scales. Information such as the spin of a particle or the polarization of a photon can be transferred between particles without travelling across a physical medium. Teleportation is made possible by the feature of quantum mechanics known as "entanglement".
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