Sunday, December 02, 2007

Physical sciences news, 11/26/07-12/2/07

Climate change
To the surprise of practically nobody except climate change denialists, levels of CO2 in the atmosphere continued to increase in 2006 to new record levels. And Scientific American comes up with a nice suite of several articles (two listed here), which key off the recent report of the U.N. Intergovernmental Panel on Climate Change.

U.N.: Greenhouse Gases Hit High in 2006
Beyond the Worst Case Climate Change Scenario
10 Solutions for Climate Change

Some results are in from the European Space Agency's Venus Express mission, and they paint a picture of Venus as not such a great place for your next summer vacation. Much of the crappy climate is due to a CO2-induced greenhouse effect. Uh, oh.

How Earth's twin became so hellishly hot
NASA Scientist Confirms Light Show on Venus
Probe likens young Venus to Earth
Twin Planets Earth and Venus Were "Separated at Birth"
Signs of Lightning on Venus
Venus offers Earth climate clues
Did life once thrive on Evil Twin Venus?

The Milky Way and its neighborhood
Two things here about our galactic neighborhood. We might have another neighbor galaxy that has never actually been seen yet, even though it's almost as close and as large as the Andromeda galaxy. And there's a cluster of very young stars – only 100 light-years from our galactic center – that's moving way too fast.

Milky Way galaxy may have hidden twin
Dynamical Constraints on the Local Group from the CMB and 2MRS Dipoles
Star cluster's extreme speed puzzles astronomers
The proper motion of the Arches cluster with Keck Laser-Guide Star Adaptive Optics

Early galaxies
Astronomers using Europe's new Very Large Telescope, located in Chile, have observed 27 young "proto-galaxies" as they appeared about 2.5 billion years after the big bang. This provides evidence that larger galaxies like our own may have formed by the amalgamation of a number of such proto-galaxies.

Faint galaxies spotted in the early universe
Proto-galaxies tip cold dark matter
A Long, Hard Look at the Early Universe
Discovering Teenage Galaxies
Sighting of 'teenage' galaxies gives scientists
stellar return

New population of faint protogalaxies discovered
A Population of Faint Extended Line Emitters and the Host Galaxies of Optically Thick QSO Absorption Systems

Formation of planetary systems
Astronomers think they have found the two youngest solar systems ever detected, about 450 light-years from Earth. Elsewhere, one bright, massive young star in the Trapezium of the Orion Nebula is pumping out hot gas at a temperature of about 2 million degrees C, and this probably affects the formation of planetary systems around other nearby young stars.

Planet Formation is Child's Play
Of Young Stars and Ancient Planets
Huge Stars Seen as Source of Glowing Gas
Million-Degree Plasma Pervading the Extended Orion Nebula

Preon nuggets
Preons are hypothetical particles that have been proposed to make up quarks. Although there is as yet no experimental evidence for preons, if they ever existed in the universe soon after the big bang, a few preon clumps might still survive as objects a few centimeters in size but with as much mass as the Moon.

Nuggets of New Physics
The observational legacy of preon stars - probing new physics beyond the LHC

Large clumps of hydrogen and helium in the early universe may have condensed into star-like objects initially 1000 times as massive as the Sun. Although the core would collapse into a black hole, the resulting "quasistar" might be massive enough to avoid destruction, and continue to accrete matter, evolving into a supermassive black hole such as seems to exist in the center of most galaxies.

Biggest black holes may grow inside 'quasistars'
Quasistars: Accreting black holes inside massive envelopes


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