Monday afternoon once again here on the East coast. Time to gather around and have a bit of science talk. New discoveries, new takes on old knowledge, and other bits of news are all available for the perusing in today's information world. Over the fold are selections from the past week from a few of the many excellent science news sites around the world. Today's tidbits include extreme melting on the Greenland ice sheet, scientists pin down galaxy collision rate, complex organic materials have been discovered throughout space, plants feel the force, glaciers in southwest China feel the brunt of climate change, ancient Etruscan childbirth image discovered, and asteroid Lutetia is a postcard from the past. Pull up that comfy chair and bask in the sunshine. There is plenty of room for everyone. Get ready for another session of Dr. Possum's science education and entertainment.
Featured Stories
Even when temperatures do not reach new highs extreme melting may continue on the Greenland ice sheet.
The (research) team recorded data on air temperatures, wind speed, exposed ice and its movement, the emergence of streams and lakes of melt water on the surface, and the water’s eventual draining away beneath the glacier. This lost melt water can accelerate the ice sheet’s slide toward the sea where it calves new icebergs. Eventually, melt water reaches the ocean, contributing to the rising sea levels associated with long-term climate change.
The model showed that melting between June and August was well above the average for 1979 to 2010. In fact, melting in 2011 was the third most extensive since 1979, lagging behind only 2010 and 2007. The “mass balance”, or amount of snow gained minus the snow and ice that melted away, ended up tying last year’s record values.
Temperatures and an albedo feedback mechanism accounted for the record losses, Professor Tedesco explained. “Albedo” describes the amount of solar energy absorbed by the surface (e.g. snow, slush, or patches of exposed ice). A white blanket of snow reflects much of the sun’s energy and thus has a high albedo. Bare ice – being darker and absorbing more light and energy – has a lower albedo.
But absorbing more energy from the sun also means that darker patches warm up faster, just like the blacktop of a road in the summer. The more they warm, the faster they melt.
And a year that follows one with record high temperatures can have more dark ice just below the surface, ready to warm and melt as soon as temperatures begin to rise. This also explains why more ice sheet melting can occur even though temperatures did not break records.
Astronomers using data from NASA's Hubble telescope have defined the galaxy collision rate over the past 8 to 9 billion years.
The galaxy merger rate is one of the fundamental measures of galaxy evolution, yielding clues to how galaxies bulked up over time through encounters with other galaxies. And yet, a huge discrepancy exists over how often galaxies coalesced in the past. Measurements of galaxies in deep-field surveys made by NASA’s Hubble Space Telescope generated a broad range of results: anywhere from 5 percent to 25 percent of the galaxies were merging.
Complex organic materials (PDF) have been found throughout the universe.
n the past 30 years we have witnessed major progress in the observation of gas-phase molecules by using radio as- tronomical techniques. The detections of organic molecules of every class left no doubt that stars and interstellar clouds are capable of synthesizing complex molecules from atoms under low-density conditions. However, the radio technique has its own limits and the search for large pre-biotic mole- cules through their rotational transitions will be difficult. Large organic compounds, including organic solids with thousands of atoms, manifest themselves through their vi- brational modes and their chemical nature can be discerned by infrared spectroscopy. Astronomical detections of the stretching and bending modes of aromatic compounds have shown that complex organic matter is widely present in the Universe, from the circumstellar envelopes of stars, to dif- fuse interstellar medium, to distant galaxies.
The response of plants to different forces can be explained on the basis of sensitive pores in the cell membrane.
In the 1980s, work with bacterial cells showed that they have mechanosensitive channels, tiny pores in the cell's membrane that open when the cell bloats with water and the membrane is stretched, letting charged atoms and other molecules rush out of the cell. Water follows the ions, the cell contracts, the membrane relaxes, and the pores close.
Genes encoding seven such channels have been found in the bacterium Escherichia coli and 10 in Arabidopsis thaliana, a small flowering plant related to mustard and cabbage.
As climate change continues glaciers around the world are melting including those in southwest China.
Collating a broad range of research on glaciers during this time period, the researchers, from the Chinese Academy of Sciences, identified three characteristics that were consistent with the increasing trend in temperature; drastic retreats were observed in the glacial regions, along with large losses of mass and an increase in the area of glacial lakes.
In the Pengqu basin of the Himalayas, for example, the 999 glaciers had a combined area loss of 131 km2 between 1970 and 2001, whilst the Yalong glacier in the Gangrigabu Mountains retreated over 1500 meters from 1980 to 2001.
The implications of these changes are far more serious than simply altering the landscape; glaciers are an integral part of thousands of ecosystems and play a crucial role in sustaining human populations.
Continued widespread melting of glaciers, caused by increasing temperatures, could potentially lead to floods, mudflows and rock falls, affecting traffic, tourism and wider economic development.
In Italy the excavation of a 2700-year-old Etruscan site uncovered two images of a woman giving birth to a child.
The ceramic fragment is less than 1-3/4 x 1-1/4 inches (4 x 3 cm), from a vessel made of bucchero. Bucchero is a fine, black ceramic material, embellished with stamped and incised decorations, used to make eating and drinking vessels for Etruscan elites.
Typically, stamped designs range from abstract geometric motifs to exotic and mythical animals. There are no known Greek or Roman representations of the moment of birth shown as clearly as the Poggio Colla example until more than 500 years later. The fragment dates to about 600 B.C.E. (Before the Common Era).
ESA's Rosetta spacecraft finds signs that asteroid Lutetia remains from the time of planet formation in our solar system.
Astronomers estimate the age of airless planets, moons, and asteroids by counting craters. Each bowl-shaped depression on the surface is made by an impact. The older the surface, the more impacts it will have accumulated. Some parts of Lutetia are heavily cratered, implying that it is very old.
On the other hand, the youngest areas of Lutetia are landslides, probably triggered by the vibrations from particularly jarring nearby impacts.
Debris resulting from these many impacts now lies across the surface as a 1 km-thick layer of pulverised rock.
There are also boulders strewn across the surface: some are 300–400 m across, or about half the size of Ayers Rock, in Australia.
Some impacts must have been so large that they broke off whole chunks of Lutetia, gradually sculpting it into the battered wreck we see today.
Other Worthy Stories of the Week
Modern algorithms crack 18th Century secret code
Close encounters of the galactic kind
NASA telescopes help solve ancient supernova mystery
Could a computer one day rewire itself?
Watching the motion of electrons in molecules during chemical reactions
Geothermal mapping confirms US coast to coast clean energy supply
Researchers find a country's wealth correlates with its collective knowledge
Secrets of flocking revealed
Ancient cooking pots reveal gradual transition to agriculture
The crisis that hit physics 100 years ago
Ten rare species that may get a chance at survival Photo diary.
A solar cycle primer
Three new planets and a mysterious object discovered outside our solar system
Recycling thermal cash register tapes contaminates paper products with BPA
Holding global warming to 2C may still be possible if nations act
High quality white light produced by 4-color laser source
Prehistoric data from ocean's floor could predict Earth's future
For even more science news:
General Science Collectors:
Alpha-Galileo
BBC News Science and Environment
Eureka Science News
LiveScience
New Scientist
PhysOrg.com
SciDev.net
Science/AAAS
Science Alert
Science Centric
Science Daily
Scientific American
Space Daily
Blogs:
A Few Things Ill Considered Techie and Science News
Cantauri Dreams space exploration
Coctail Party Physics Physics with a twist.
Deep Sea News marine biology
Laelaps more vertebrate paleontology
List of Geoscience Blogs
ScienceBlogs
Space Review
Techonology Review
Tetrapod Zoologyvertebrate paleontology
Science Insider
Scientific Blogging.
Space.com
Wired News
Science RSS Feed: Medworm
The Skeptics Guide to the Universe--a combination of hard science and debunking crap
At Daily Kos:
This Week in Science by DarkSyde
Overnight News Digest:Science Saturday by Neon Vincent. OND tech Thursday by rfall.
Pique the Geek by Translator Sunday evenings about 9 Eastern time
All diaries with the DK GreenRoots Tag.
All diaries with the eKos Tag
A More Ancient World by matching mole
Astro Kos
SciTech at Dkos.
Sunday Science Videos by palantir
NASA picture of the day. For more see the NASA image gallery or the Astronomy Picture of the Day Archive
ARP 148, NASA, Public Domain