Science & TechnologyS


Telescope

Black Holes Are The Rhythm At The Heart Of Galaxies


Science Daily
Thu, 20 Nov 2008 22:50 UTC
The powerful black holes at the center of massive galaxies and galaxy clusters act as hearts to the systems, pumping energy out at regular intervals to regulate the growth of the black holes themselves, as well as star formation, according to new data from NASA's Chandra X-Ray Observatory.
Virgo Elliptical Galaxy M84
© X-ray: NASA/CXC/MPE/A.Finoguenov et al.); Radio (NSF/NRAO/VLA/ESO/R.A.Laing et al); Optical: (SDSS)Virgo Elliptical Galaxy M84. The powerful black holes at the center of massive galaxies and galaxy clusters act as hearts to the systems, pumping energy out at regular intervals to regulate the growth of the black holes themselves, as well as star formation, according to new data from NASA's Chandra X-Ray Observatory.

The gravitational pull of black holes is so strong that not even light can escape from them. Supermassive black holes with masses of more than a billion suns have been detected at the center of large galaxies. The material falling on the black holes causes sporadic or isolated bursts of energy, by which black holes are capable of influencing the fate of their host galaxies. The insight gained by this new research shows that black holes can pump energy in a gentler and rhythmic fashion, rather then violently.
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Einstein

Matter is merely vacuum fluctuations

Stephen Battersby
New Scientist
Thu, 20 Nov 2008 22:00 UTC
Matter is built on flaky foundations. Physicists have now confirmed that the apparently substantial stuff is actually no more than fluctuations in the quantum vacuum.

The researchers simulated the frantic activity that goes on inside protons and neutrons. These particles provide almost all the mass of ordinary matter.

Each proton (or neutron) is made of three quarks - but the individual masses of these quarks only add up to about 1% of the proton's mass. So what accounts for the rest of it?
Each proton is made of three quarks
© Forschungszentrum Julich/Seitenplan/NASA/ESA/AURA-CaltechEach proton is made of three quarks, but the individual masses of these quarks only add up to about 1% of the proton's mass.

Theory says it is created by the force that binds quarks together, called the strong nuclear force. In quantum terms, the strong force is carried by a field of virtual particles called gluons, randomly popping into existence and disappearing again. The energy of these vacuum fluctuations has to be included in the total mass of the proton and neutron.
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Info

Plumbing the oceans could bring limitless clean energy

Phil Mckenna
New Scientist
Wed, 19 Nov 2008 21:33 UTC
For a company whose business is rocket science Lockheed Martin has been paying unusual attention to plumbing of late. The aerospace giant has kept its engineers occupied for the past 12 months poring over designs for what amounts to a very long fibreglass pipe.

It is, of course, no ordinary pipe but an integral part of the technology behind Ocean Thermal Energy Conversion (OTEC), a clean, renewable energy source that has the potential to free many economies from their dependence on oil.

"This has the potential to become the biggest source of renewable energy in the world," says Robert Cohen, who headed the US federal ocean thermal energy programme in the early 1970s.

This has the potential to become the biggest source of renewable energy in the world. As the price of fossil fuels soars, private companies from Hawaii to Japan are racing to build commercial OTEC plants. The trick is to exploit the difference in temperature between seawater near the surface and deep down.
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Telescope

Vast stores of water ice surround Martian equator

Rachel Courtland
New Scientist
Thu, 20 Nov 2008 21:26 UTC
Ice glaciers hundreds of metres deep are lurking just underneath the Martian surface around the planet's mid-latitudes, new radar measurements suggest.

The discovery represents the largest cache of ice yet found beyond Mars's polar regions and bolsters the case that the planet's tilt changes periodically. The ice could also be an ideal place to study the ancient Martian climate and look for evidence of life.
Martian mountain near the Hellas impact basin
© NASA/JPL/MSSSA 13-km-long apron of rocky debris seems to have flowed from this Martian mountain near the Hellas impact basin. New radar measurements suggest an icy glacier hundreds of metres thick lies beneath the surface.

The glaciers, found at latitudes between 30 and 60° in both the northern and southern hemispheres, sit underneath fields of rocky debris. The appearance of the landscape suggests the debris flowed from hills lying up to 20 kilometres away.

Mars researchers have debated the origins of these rocky fields, which are called 'lobate debris aprons.' Some suspected that small particles of ice condensed from atmospheric water vapour between rocks and dust; this ice could lubricate the material, allowing it to flow down slopes. Others suggested the rocky aprons actually hid large glaciers.
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Question

Were Neanderthals stoned to death by modern humans?

Ewen Callaway
New Scientist
Thu, 20 Nov 2008 21:21 UTC
Human aerial bombardments might have pushed Neanderthals to extinction, suggests new research. Changes in bone shape left by a life of overhand throwing hint that Stone Age humans regularly threw heavy objects, such as stones or spears, while Neanderthals did not.

"The anatomically modern humans would have this more effective and efficient form of hunting," says Jill Rhodes, a biological anthropologist at Bryn Mawr College in Pennsylvania, who led the new study. A warmer Europe would have opened up forests, enabling longer range hunting, she says.

Rhodes and a colleague studied changes to the arm bone that connects the shoulder to the elbow - the humerus - to determine when humans may have begun using projectile weapons.
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Star

Binary Star Explosion Inside Nebula Challenges Star Theory


Science Daily
Wed, 19 Nov 2008 21:15 UTC
V458 Vul
© Roger Wesson / University College LondonV458 Vul: Images taken in May 2008 (top) and September 2008 (bottom) show the dramatic changes occurring in the nebula as a result of the central star's explosion
The explosion of a binary star inside a planetary nebula has been captured by a team led by UCL (University College London) researchers - an event that has not been witnessed for more than 100 years. The study, published in Astrophysical Journal Letters, predicts that the combined mass of the two stars in the system may be high enough for the stars to eventually spiral into each other, triggering a much bigger supernova explosion.

A planetary nebula is an astronomical object consisting of a glowing shell of gas and plasma formed by many stars as they approach the end of their lives, while a nova is a cataclysmic nuclear explosion caused by the accretion of hydrogen onto the surface of a nearly-dead white dwarf star in a close binary.
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Telescope

Betelgeuse shocker

Phil Plait
Discover Magazine
Wed, 19 Nov 2008 21:07 UTC
Distance crushes perspective. Objects hurtle through space at mind-numbing speeds, some moving so quickly they could cross the United States in just seconds; yet, due to their distance, we could wait thousands of years to be able to perceive their motion at all.

Unless, that is, they leave behind some tell-tale sign of their rapid movement. Space is not empty, and a star plowing through this ethereally thin gas at dozens of kilometers per second reveals itself. The gas gets compressed ahead of the star, and flows around it in graceful arcs. Like water flowing around the bow of a ship, such a formation is called a bow shock.

This shock wave can be invisible to the unaided eye, but when we train infrared telescopes on them they leap out of the picture. Behold the bow shock of Betelgeuse:
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Telescope

Hair in book helps identify Copernicus's remains


Associated Press
Thu, 20 Nov 2008 18:05 UTC
Nicolaus Copernicus
Nicolaus Copernicus
Researchers said Thursday they had identified the remains of Nicolaus Copernicus by comparing DNA from a skeleton and hair retrieved from one of the 16th-century astronomer's books.

The findings could put an end to centuries of speculation about the exact resting spot of Copernicus, a priest and astronomer whose theories identified the Sun, not the Earth, as the center of the solar system.

Polish archaeologist Jerzy Gassowski told a news conference that forensic facial reconstruction of the skull that his team found in 2005 buried in a Roman Catholic Cathedral in Frombork, Poland, bears striking resemblance to existing portraits of Copernicus.
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Calculator

Quantum computing spins closer


PhysOrg.com
Wed, 19 Nov 2008 01:33 UTC
The promise of quantum computing is that it will dramatically outshine traditional computers in tackling certain key problems: searching large databases, factoring large numbers, creating uncrackable codes and simulating the atomic structure of materials.
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Info

Sniffing out a rumbling volcano

Katharine Sanderson
Nature News
Mon, 17 Nov 2008 20:38 UTC
Andrew McGonigle
© RolexAwards/Marc LatzelGeophysicist Andrew McGonigle on Vulcano Island, Italy with his prototype helicopter.
A radio-controlled helicopter could help predict when a volcano will blow its top.

A large toy helicopter could help to predict volcanic eruptions in time to safely evacuate the surrounding area, according to geophysicists who have just been awarded $100,000 to develop their idea.

When fresh, eruption-ready magma arrives deep in the heart of a volcano, it tends to release carbon dioxide. As the magma rises, it also pushes sulfur dioxide out of the volcano. Spotting changes in the ratio of these gases around a volcano should indicate whether it is about to blow - but although sulfur dioxide is routinely measured by vulcanologists, taking carbon dioxide measurements is a much bigger challenge.
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