When a red giant star collaps on itself a burst of neutrinos is produced. This occurs before that light is emitted in the explosion, The SuperNova Early Warning System (SNEWS) is a network of neutrino detectors designed to give an early warning to astronomers of a supernova event in the Milky Way. The neutrino pulse from supernova 1987A was detected 3 hours before the photons.
The current members of SNEWS are Borexino, Super-Kamiokande, LVD, SNO and IceCube.
http://en.wikipedia.org/wiki/Supernova_Early_Warning_System
Monday, April 11, 2011
Neutrinos in IceCube
The IceCube Neutrino Observatory (or simply IceCube) is a neutrino telescope constructed at the Amundsen-Scott South Pole Station in Antarctica. Similar to its predecessor, the Antarctic Muon And Neutrino Detector Array (AMANDA), IceCube contains thousands of spherical optical sensors called Digital Optical Modules (DOMs), each with a photomultiplier tube (PMT) and a single board data acquisition computer which sends digital data to the counting house on the surface above the array. More http://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory
"IceCube, which was completed in December 2010, is a kilometer-cubed array of photodetectors that have been drilled down into the Antarctic ice cap... The IceCube team compared 13 months of their data (collected when the array was half finished) to observations of 117 Gamma-Ray Bursts measured independently over the same time period. Contrary to expectations, no high-energy neutrinos were detected within a half-hour of each GRB. Theorists may need to rethink their models of GRBs, as well as look for other possible sources for the highest energy cosmic rays." This is what Michael Schirber writes in
http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.106.141101
"IceCube, which was completed in December 2010, is a kilometer-cubed array of photodetectors that have been drilled down into the Antarctic ice cap... The IceCube team compared 13 months of their data (collected when the array was half finished) to observations of 117 Gamma-Ray Bursts measured independently over the same time period. Contrary to expectations, no high-energy neutrinos were detected within a half-hour of each GRB. Theorists may need to rethink their models of GRBs, as well as look for other possible sources for the highest energy cosmic rays." This is what Michael Schirber writes in
http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.106.141101
Il Buddha dei Leoni
Il Buddha siede su un trono sorretto da tre leoni, che poggia a sua volta su un piedistallo fiancheggiato da due devoti monaci. La veste monastica dalle pieghe accuratamente disegnate e priva di cintura rivela il corpo ben modellato. Il lembo dello scialle scende dalla spalla sinistra terminando in un doppia “coda di pesce”.
Il leone in questa iconografia evoca il suo ruggito (simhanada) ossia la voce del Buddha che penetra lo spazio divulgando la Dottrina.
Museo Arte Orientale, Torino
Friday, April 8, 2011
Planets heated by dark matter
Audacious notion of the week: planets heated by dark matter - March 30, 2011
"It’s dark outside, permanently. The sun twinkles in the distance barely bigger than other stars. But the ground is warm, and oceans are teaming with life. That’s the scenario envisioned by Dan Hooper and Jason Steffen of Fermi National Laboratory in Batavia Illinois, who released a preprint yesterday about the possibility of dark matter heating planets that are otherwise too far from their host stars to be habitable."
"It’s dark outside, permanently. The sun twinkles in the distance barely bigger than other stars. But the ground is warm, and oceans are teaming with life. That’s the scenario envisioned by Dan Hooper and Jason Steffen of Fermi National Laboratory in Batavia Illinois, who released a preprint yesterday about the possibility of dark matter heating planets that are otherwise too far from their host stars to be habitable."
More Nature.com
According to Dan Hooper and Jason Steffen, they " have calculated the capture rate of dark matter particles in Earth-like and super-Earth planets, and determined the resulting surface temperature of those planets that would result from dark matter annihilations. While planets in the local region of our galaxy receive only a negligible quantity of energy from dark matter annihilations," the authors" find that planets in dwarf spheroidal galaxies and in the innermost volume of the Milky Way could plausibly accumulate and annihilate enough dark matter to heat their surfaces to temperatures capable of sustaining liquid water, even in the absence of energy from starlight or other standard sources. Although" they "expect ecologically relevant quantities of energy to be released through dark matter annihilations only within the interiors of planets that reside in very special environments (such as near the Galactic Center, or near the center of a dwarf spheroidal galaxy), and only in the case of dark matter models which feature large elastic scattering cross sections with nuclei (near the current upper limits)," the authors "expect that within such models planets will exist which derive enough heat from dark matter to almost indefi nitely sustain surface temperatures suffi cient to yield liquid water. Even in the absence of starlight, such planets could plausibly contain life. And, given their extremely long lifetimes, such planets may prove to be the ultimate bastion of life in our universe."
According to Dan Hooper and Jason Steffen, they " have calculated the capture rate of dark matter particles in Earth-like and super-Earth planets, and determined the resulting surface temperature of those planets that would result from dark matter annihilations. While planets in the local region of our galaxy receive only a negligible quantity of energy from dark matter annihilations," the authors" find that planets in dwarf spheroidal galaxies and in the innermost volume of the Milky Way could plausibly accumulate and annihilate enough dark matter to heat their surfaces to temperatures capable of sustaining liquid water, even in the absence of energy from starlight or other standard sources. Although" they "expect ecologically relevant quantities of energy to be released through dark matter annihilations only within the interiors of planets that reside in very special environments (such as near the Galactic Center, or near the center of a dwarf spheroidal galaxy), and only in the case of dark matter models which feature large elastic scattering cross sections with nuclei (near the current upper limits)," the authors "expect that within such models planets will exist which derive enough heat from dark matter to almost indefi nitely sustain surface temperatures suffi cient to yield liquid water. Even in the absence of starlight, such planets could plausibly contain life. And, given their extremely long lifetimes, such planets may prove to be the ultimate bastion of life in our universe."
Tevatron claims glimpse of particles beyond standard model
Tevatron claims possible glimpse of particles beyond the standard model - April 06, 2011
"Just as the Tevatron, the proton-antiproton collider at Fermilab in Batavia, Illinois, enters its final months of operations, possible signals of new physics are emerging. First came a report from the Collider Detector at Fermilab (CDF) experiment of a puzzling asymmetry in the way top quarks decay into lighter particles. Now the same experiment is reporting on the possible observation of particles beyond the standard model in collisions that produce a W boson – a particle of the weak nuclear force. Spokesmen for the experiment say the signal may be due to random fluctuations, but that it’s nonetheless causing some excitement. “Either what we thought we knew about this process is wrong or there’s a totally new effect,” says Giovanni Punzi, CDF co-spokesman."
"Just as the Tevatron, the proton-antiproton collider at Fermilab in Batavia, Illinois, enters its final months of operations, possible signals of new physics are emerging. First came a report from the Collider Detector at Fermilab (CDF) experiment of a puzzling asymmetry in the way top quarks decay into lighter particles. Now the same experiment is reporting on the possible observation of particles beyond the standard model in collisions that produce a W boson – a particle of the weak nuclear force. Spokesmen for the experiment say the signal may be due to random fluctuations, but that it’s nonetheless causing some excitement. “Either what we thought we knew about this process is wrong or there’s a totally new effect,” says Giovanni Punzi, CDF co-spokesman."
More Nature.com
Chankillo - 2 - Peru
Image obtained after processing Google Maps
The Thirteen Towers of Chankillo are built north to south along a ridge of a low hill, regularly spaced. To the east and west investigators found two observation points, to observe the rising and setting positions of the Sun over the year. This suggests that some activities of the ancient civilization were regulated by a solar calendar. The towers had been known to travelers for centuries, but the astronomical function of the towers was discovered in 2007 by Iván Ghezzi and Clive Ruggle.
Read more Wiki
Chankillo - 1 - Peru
Chankillo
Image obtained after processing Google Maps
Chankillo is an ancient monumental complex in the Peruvian coastal desert, in the Ancash Department of Peru. The ruins include the hilltop Chankillo fort, the nearby Thirteen Towers solar observatory, and residential and gathering areas. The Thirteen Towers are believed to have been a solar observatory built in the 4th century BC. As of 2008, the culture that produced Chankillo is unnamed.
More wiki
Thursday, April 7, 2011
Einstein secret
James Dacey (physicsworld) is blogging on a new iconic image of Einstein, creation of Spanish artist Juan Osbourne. It is a game to find some hidden numbers.
Play the game at
http://www.juanosborne.com/2010/01/playing-with-einstein/
http://www.juanosborne.com/2010/01/playing-with-einstein/
Created by Juan Osborne (under this Creative Commons License)
This is an image from a beautiful collection
The hunt for the elusive Higgs
"Physicists at CERN's Large Hadron Collider (LHC) are confident that they can find the Higgs boson by the end of 2012, when the machine will be shut down temporarily...The most sought after particle in particle physics – the Higgs boson – is believed to endow all other particles with mass. It is also the last undiscovered component of particle physicists' great theoretical framework – the Standard Model. After decades searching for the Higgs in particle collisions at CERN, and at Fermilab in the US, researchers at the LHC believe they may finally have the elusive particle within their grasp."
The hunt for the elusive Higgs - physicsworld.com
Thin film has 'astonishing' ability to rotate light
"Physicists in Austria and Germany have taken the Faraday effect to a new extreme by rotating the polarization of light by 45° by passing it through an extremely thin film. This "giant Faraday effect" could someday be used to create optical transistors that switch light or to improve terahertz imaging systems."
Thin film has 'astonishing' ability to rotate light - physicsworld.com
Thin film has 'astonishing' ability to rotate light - physicsworld.com