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hanz444

Space and NASA News - Universe and Deep Space Information - 0 views

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    Get the latest outer space and science news, NASA information, watch space flight videos at Space.com. View exclusive solar system Images, latest astronomy news and more.
hanz444

News Conference Features Next Space Station Crew, Interviews - 0 views

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    NASA will host a news conference for the next crew launching to the International Space Station, including NASA astronaut Tim Kopra, on Thursday, Sept. 24, at the agency's Johnson Space Center in Houston. NASA Television will broadcast the news conference live at 2 p.m. EDT, preceded by video of crew training at 1:30 p.m.
Kalyan Roy

SPACE.com -- New Physics? Fundamental Cosmic Constant Now Seems Shifty - 1 views

  • Recent observations of distant galaxies suggest that the strength of the electromagnetic force – the so-called fine-structure constant – actually varies throughout the universe. In one direction, the constant seemed to grow larger the farther astronomers looked; in another direction the constant took on smaller values with greater distance.
  • If confirmed, this revelation could reshape physicists' understanding of cosmology from the ground up. It may even help solve a major conundrum: Why are all the constants of nature perfectly tuned for life to exist?
Todd Suomela

Astronomy & Astrophysics Decadal Survey Home Page - 0 views

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    Astro2010, the current astronomy and astrophysics decadal survey, is the latest in a series of surveys that are produced every 10 years by the National Research Council (NRC) of The National Academy of Sciences.
Todd Suomela

the physics arXiv blog » Blog Archive » The puzzle of planet formation - 0 views

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    "At the heart of the problem is the fascinating question: why are all the planets different? The ones in our solar system ought to have formed out of the same stuff at more or less the same time and yet no two are alike. And now the extrasolar planets seem to be demonstrating a similar variety."
Janos Haits

Astrophysics - 2 views

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    Useful category breakout for astrophysics papers at Arxiv.
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    Astrophysics (since Apr 1992)
Todd Suomela

[astro-ph/0511440] Varying Constants - 0 views

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    We review properties of theories for the variation of the gravitation and fine structure 'constants'. We highlight some general features of the cosmological models that exist in these theories with reference to recent quasar data that are consistent with time-variation in the fine structure 'constant' since a redshift of 3.5. The behaviour of a simple class of varying-alpha cosmologies is outlined in the light of all the observational constraints.
Todd Suomela

[0806.0377] A Hemispherical Power Asymmetry from Inflation - 0 views

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    Measurements of temperature fluctuations by the Wilkinson Microwave Anisotropy Probe (WMAP) indicate that the fluctuation amplitude in one half of the sky differs from the amplitude in the other half. We show that such an asymmetry cannot be generated during single-field slow-roll inflation without violating constraints to the homogeneity of the Universe. In contrast, a multi-field inflationary theory, the curvaton model, can produce this power asymmetry without violating the homogeneity constraint. The mechanism requires the introduction of a large-amplitude superhorizon perturbation to the curvaton field, possibly a pre-inflationary remnant or a superhorizon curvaton-web structure. The model makes several predictions, including non-Gaussianity and modifications to the inflationary consistency relation, that will be tested with forthcoming CMB experiments.
Todd Suomela

Phoenix Mars Mission - Home - 0 views

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    The University of Arizona is honored to be the first public university to lead a mission to Mars. The Phoenix Mars Mission, scheduled to land May 25, 2008, is the first in NASA's "Scout Program." Scouts are designed to be highly innovative and relatively low-cost complements to major missions being planned as part of the agency's Mars Exploration Program.
Todd Suomela

symmetry Magazine - 0 views

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    a joint Fermilab/SLAC publication
Kalyan Roy

Why Are Quark Stars So Strange? : Discovery News - 1 views

  • First things first, neutron stars, quark stars and black holes are all born via the same mechanism: a supernova. But each of the three are progressively more massive, so they originate from supernovae produced by progressively more massive stars. So, what if a star exploded, producing something a little too massive to be called a neutron star? Well, neutron stars resist collapsing under their own gravitational pull by a characteristic of matter known as neutron degeneracy. This produces an outward force called neutron degeneracy pressure. What if the neutron star born after a supernova is too massive for this neutron degeneracy pressure to hold up against the neutron star's own gravity? In this case, it's up to the quarks that make up the neutrons to take over, preventing the body from collapsing any further. Single neutrons are composed of three quarks (two "down" quarks and one "up" quark). When quark degeneracy pressure kicks in, a quark star may be produced; the free "up" and "down" quarks get converted into "strange" quarks. Therefore, a quark star (also known as a "strange star") is made up of strange matter.
  • Using what we know from the Standard Model of particle physics, a massive quark star may have enough gravitational energy to start 'burning' strange matter. The quarks inside the core of the quark star may be abused so badly by gravitational pressure that the quarks will be converted into pure energy and neutrinos.
  • The fascinating thing with this scenario is that the quark star matter will be so dense that even the neutrinos cannot escape. However, this release of energy and generation of neutrinos creates an outward pressure countering the relentless inward gravitational pull.
  • ...2 more annotations...
  • Dai calls this extreme strange matter-burning quark star an "electroweak star"
  • Saving the best till last, the electroweak star's core would therefore be as extreme as the universe was only 10-10 seconds (that's 0.0000000001 seconds) after the Big Bang. These extreme objects would be like mini-Big Bang laboratories, maintaining a pressure where the electromagnetic and weak forces are so intertwined, they cannot be distinguished.
Janos Haits

Extreme Science - 0 views

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    Extreme Science is the place online to find the biggest, baddest, and the best in the world of extremes and learn about the science behind what makes each the most extreme example of its kind. Here you'll find world records in natural science, including earth science and the plant and animal kingdom. Not only will you find out who holds the records, but also key science concepts used to explain the story behind the record.
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