Astronomy and Physics News around the World Dec. 25, 2011
Reported News for this Week:
1. Particle physics is at a turning point — String theory may be connected to the real world
2. 365 Days of Astronomy podcast to continue in 2012 3. The Tunkguska Event
4. Becoming crystal clear about snowflakes 5. The exotic physics of frustrated magnets
6. Caltech chemists propose explanation for superconductivity at high temperatures
7. Stunning! Comet Lovejoy Photographed from the Space Station 8. Metal undergoes novel transition under extreme pressure 9. Top Astronomy Events Coming Up in 2012
Particle physics is at a turning point — String theory may be connected to the real world
Nature - Two quite different detectors at the LHC see a signal of some significance at about the same mass. And they both see the expected signals in two or more channels. This could
represent a profound turning point in the quest for a fundamental unified theory of the physical world. But a major and unexpected clue to the future offered by the CERN discovery is that the reported Higgs boson signal seems to behave as if it were a "standard-model Higgs boson."
Under the Standard Model, this should not be possible. However, when the standard model is extended to a supersymmetric theory, the resulting theory is realistic. Actually the same string theory (more exactly, M-theory) that predicts the Higgs mass correctly also predicts that a spectrum of particle superpartners, and some of their associated signals should be discovered at the LHC. MORE
365 Days of Astronomy podcast to continue in 2012
Space - The award-winning 365 Days of Astronomy podcast is proud to announce that the project will continue for yet another year — its fourth consecutive year — and is now accepting sign-ups for participants for more podcasts in 2012. 365 Days of Astronomy (which will last 366 days in 2012, a leap year) is a legacy project of the International Year of Astronomy and in 2009
was a major project of the IYA. The podcast episodes are written, recorded and produced by people all around the world. MORE
The Tunkguska Event
Fallen trees from the Tunguska Event in 1908.
On June 30th, 1908 “something” exploded over the Tunguska region of Siberia, flattening thousands of square kilometres of forest, and unleashing a force that rivaled the most powerful nuclear weapon ever detonated. What was it? What could unleash that kind of destructive energy? And will it happen again?
Click here to download the episode.
Becoming crystal clear about snowflakes
The Wall Street Journal - Kenneth Libbrecht, California Institute of Technology professor of physics and snowflake guru, thinks he is on the way to explaining unanswered questions about the shapes of snowflakes. Using laboratory-grown snowflakes to glean new insights into the molecular dynamics of crystal growth, Libbrecht has noticed a "sharpening effect" in the crystal structure that impacts the kinetics and dynamics of the growth. MORE
The exotic physics of frustrated magnets
Engineering on the Edge - Frustrated magnetic materials contain a wealth of interesting
magnetic properties. Unlocking the mysteries of these frustrated magnets will not only deepen our understanding of the fundamental physics of these materials, but may also provide clues for potential technological applications in the near future. Therefore, these systems are presently under intense investigation by the physics community. MORE
Caltech chemists propose explanation for superconductivity at high temperatures
California Institute of Technology - Over the last four years, William Goddard and Jamil Tahir- Kheli have been building a hypothesis that explains what makes cuprates superconduct. They have been working with a cuprate in which strontium atoms are the "dopant atoms," replacing lanthanum atoms.
Based on modern quantum-mechanical calculations, Goddard and Tahir-Kheli found that each dopant atom creates a four-center hole on the copper atoms surrounding the strontium, a unit they refer to as a "plaquette." Electrons within the plaquettes form tiny pieces of metal, while those outside the plaquettes are insulating and behave like magnets. Their hypothesis is that when enough dopant atoms are added, the plaquettes are able to create a percolating pathway that allows electrons to flow all the way through the material. The magnetic electrons outside the plaquettes can interact with the electrons traveling through the plaquette pathway, and it is this interaction that leads to the electron pairing — the slight attraction between electrons — that in turn results in superconductivity.
Earlier this year, in paper published in the Journal of Physical Chemistry Letters, Goddard and Tahir-Kheli took their hypothesis a step further by accounting for the so-called pseudogap phase seen in cuprate superconductors. MORE
Stunning! Comet Lovejoy Photographed from the Space Station
Comet Lovejoy is visible near Earth’s horizon in this nighttime image photographed by NASA astronaut Dan Burbank, Expedition 30 commander, onboard the International Space Station on
Dec. 21, 2011. Credit: NASA
*Now updated with video!*
We can’t get enough of Comet Lovejoy! But this latest image is off the charts for its beauty and it’s jaw-dropping to contemplate it was taken from space. Dan Burbank, Expedition 30
commander onboard the International Space Station took this image of Comet Lovejoy on Dec.
21, 2011. See more of Burbank’s shots of Lovejoy here.
NASA now has a timelapse video of Burbank’s observations of Comet Lovejoy:
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Read the rest of Stunning! Comet Lovejoy Photographed from the Space Station (0 words)
Metal undergoes novel transition under extreme pressure
Carnegie Institution for Science - Under extreme pressures and temperatures similar to those at the depth where the Earth's innermost two layers meet, iron oxide, one of the main
materials of the Earth's interior, exhibits a never-before-seen transition in its electrical conductivity. But researchers at the Carnegie Institution for Science report in a forthcoming paper in Physical Review Letters that the conductivity transition is not accompanied by a structural transition. The finding could have implications for our as-yet incomplete understanding of how the Earth's interior gives rise to the planet's magnetic field. MORE
Top Astronomy Events Coming Up in 2012
Stargazing Credit: http://twitter.com/VirtualAstro
As 2011 is drawing to a close, the festive season is here and many of us are winding down and looking forward to the holidays. But this is a great time to look ahead to 2012 and pencil into our calendar and diaries the top astronomical events we don’t want to miss next year.
2012 is going to be a great year for astronomy observing, with some rare and exciting things taking place and a good outlook with some of the regular annual events.
So what top wonders should we expect to see and what will 2012 bring?(...) Read the rest of Top Astronomy Events Coming Up in 2012 (1,142 words)
