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"Everything should be as simple as it is, but not simpler", Albert Einstein
Browsing All Posts published on »April, 2012«
Do we have a Theory of Early Universe Cosmology?
Robert Brandenberger The inflationary scenario has become the paradigm of early universe cosmology, and – in conjuction with ideas from superstring theory – has led to speculations about an “inflationary multiverse”. From a point of view of phenomenology, the inflationary universe scenario has been very successful. However, the scenario suffers from some conceptual problems, and […]
Chandra Sees Remarkable Outburst From Old Black Hole
April 30, 2012
An extraordinary outburst produced by a black hole in a nearby galaxy has provided direct evidence for a population of old, volatile stellar black holes. The discovery, made by astronomers using NASA’s Chandra X-ray Observatory, provides new insight into the nature of a mysterious class of black holes that can produce as much energy in […]
Move over graphene, silicene is the new star material
April 30, 2012
AFTER only a few years basking in the limelight, wonder material graphene has a competitor in the shape of silicene. For the first time, silicon has been turned into a sheet just one atom thick. Silicene is thought to have similar electronic properties to graphene but ought to be more compatible with silicon-based electronic devices. […]
Expectation of extraterrestrial life …
April 29, 2012
… built more on optimism than evidence, study finds Recent discoveries of planets similar to Earth in size and proximity to the planets’ respective suns have sparked scientific and public excitement about the possibility of also finding Earth-like life on those worlds. But Princeton University researchers have found that the expectation that life — from bacteria to […]
100 Days and Counting to NASA’s Curiosity Mars Rover Landing
April 28, 2012
The Mars Science Laboratory spacecraft, launched Nov. 26, 2011, will deliver Curiosity to the surface of Mars on the evening of Aug. 5, 2012, PDT (early on Aug. 6, Universal Time and EDT) to begin a two-year prime mission. Curiosity’s landing site is near the base of a mountain inside Gale Crater, near the Martian […]
Was There a Beginning?
April 27, 2012
Leonard Susskind In this note I respond to Vilenkin’s claim that there must have been a beginning. Mithani and Vilenkin have argued that the universe must have had a beginning [1]. I will argue the opposite point of view; namely, for all practical purposes, the universe was past-eternal. To make the point simply, imagine Hilbertville, […]
Space Shuttle Enterprise Arrives in NY
April 27, 2012
The twin paradox in relativity revisited
April 26, 2012
Vasant Natarajan The accepted resolution of the twin paradox in relativity states that the age of the inertial twin `jumps’ when the traveling twin undergoes his turn-around acceleration. This resolution is based on the use of the equivalent gravitational shift in the frame of the accelerating twin. We use the same analysis to propose a […]
The Milky Way’s 100 Billion Planets
April 26, 2012
This artist’s illustration gives an impression of how common planets are around the stars in the Milky Way. The planets, their orbits and their host stars are all vastly magnified compared to their real separations. A six-year search that surveyed millions of stars using the microlensing technique concluded that planets around stars are the rule […]
‘Welcome to the Anthropocene’ Earth Animation
April 26, 2012
This is the animation done by Globaïa for the short film ‘Welcome to the Anthropocene’ commissionned for the Planet Under Pressure conference. Watch the narrated version here: vimeo.com/anthropocene/shortfilm More on the project here: anthropocene.info http://vimeo.com/40940686 www.dailymail.co.uk
Searching for the Higgs Particle
April 26, 2012
In anticipation of the potential for experimental verification of the existence of the Higgs boson?a long-hypothesized particle thought responsible for endowing other elementary particles with mass?the World Leaders Forum hosted a special program, co-sponsored by the Columbia Science Initiative, on April 18 at 4:00 p.m. in the Low Library rotunda. more; http://news.columbia.edu/higgs http://youtu.be/pt8oRWNSwAk http://youtu.be/C0rBKyU1vu0
The Sombrero Galaxy’s Split Personality
April 25, 2012
The infrared vision of NASA’s Spitzer Space Telescope has revealed that the Sombrero galaxy — named after its appearance in visible light to a wide-brimmed hat — is in fact two galaxies in one. It is a large elliptical galaxy (blue-green) with a thin disk galaxy (partly seen in red) embedded within. Previous visible-light images […]
Did the universe have a beginning?
April 25, 2012
Audrey Mithani, Alexander Vilenkin We discuss three candidate scenarios which seem to allow the possibility that the universe could have existed forever with no initial singularity: eternal infation, cyclic evolution, and the emergent universe. The first two of these scenarios are geodesically incomplete to the past, and thus cannot describe a universe without a beginning. […]
Revisiting Bohr’s principle of complementarity …
April 25, 2012
… using a quantum device Jian-Shun Tang, Yu-Long Li, Chuan-Feng Li, Guang-Can Guo Bohr’s principle of complementarity lies at the central place of quantum mechanics, according to which the light is chosen to behave as a wave or particles, depending on some exclusive detecting devices. Later, intermediate cases are found, but the total information of […]
Has Physics Made Philosophy and Religion Obsolete?
April 24, 2012
“I think at some point you need to provoke people. Science is meant to make people uncomfortable.” It is hard to know how our future descendants will regard the little sliver of history that we live in. It is hard to know what events will seem important to them, what the narrative of now will […]
Scientists propose a solution to a critical barrier to producing fusion
April 23, 2012
By John Greenwald Physicists have discovered a possible solution to a mystery that has long baffled researchers working to harness fusion. If confirmed by experiment, the finding could help scientists eliminate a major impediment to the development of fusion as a clean and abundant source of energy for producing electric power. An in-depth analysis by […]
A New View of the Tarantula Nebula
April 23, 2012
To celebrate its 22nd anniversary in orbit, the Hubble Space Telescope released a dramatic new image of the star-forming region 30 Doradus, also known as the Tarantula Nebula because its glowing filaments resemble spider legs. A new image from all three of NASA’s Great Observatories–Chandra, Hubble, and Spitzer–has also been created to mark the event. […]
There are no particles, there are only fields
April 23, 2012
Art Hobson Quantum foundations are still unsettled, with harmful effects on science and society. By now it should be possible to obtain consensus on at least one issue: Are the fundamental constituents fields or particles? Experiment and theory imply a universe made of unbounded fields rather than bounded particles. This is especially clear for relativistic […]
The status of gamma-ray astronomy
April 23, 2012
Stefan Funk Gamma-ray studies are an essential tool in our search for the origin of cosmic rays. Instruments like the Fermi-LAT, H.E.S.S., MAGIC and VERITAS have revolutionized our understanding of the high energy Universe. This paper describes the status of the very rich field of gamma-ray astrophysics that contains a wealth of data on Galactic […]
‘Magnetic Josephson effect’ seen for the first time
April 21, 2012
A fundamental prediction of superconductivity theory has been demonstrated in the lab for the first time. An international team of physicists has observed coherent quantum phase slip, a phenomenon similar to the well-known Josephson effect in which magnetic flux takes the place of electric charge. Its discovery has fundamental implications for our understanding of macroscopic […]
Performance of a 229 Thorium solid-state nuclear clock
April 21, 2012
G. A. Kazakov, A. N. Litvinov, V. I. Romanenko, L. P. Yatsenko, A. V. Romanenko, M. Schreitl, G. Winkler, T. Schumm The 7.8 eV nuclear isomer transition in 229-Thorium has been suggested as an etalon transition in a new type of optical frequency standard. Here we discuss the construction of a “solid-state nuclear clock” from […]
Watch the Lyrids on Ustream!
April 21, 2012
Watch the Skies! All Sky Camera Network › Sandia Sentinel Fireball Camera Network, El Paso, Texas (NMSU All Sky Camera Network) › Sandia Sentinel Fireball Camera Network, Hawley, Texas › Oak Grove Observatory, Prairieville, La. › New Mexico Skies Observatories, Mayhill, N.M. › MMTO Sky Camera, Tuscon, Ariz. › Twin Pines Observatory, Belmont, Calif. › Lick […]
Fermi Uses Gamma Rays to Unearth Clues About “Empty” Space
April 20, 2012
by David Reffkin The SLAC-built Large Area Telescope (LAT), the main instrument of the Fermi Gamma-ray Space Telescope, has been studying the gamma-ray sky for almost four years. During that time, the LAT has identified hundreds of gamma-ray sources, including pulsars and active galactic nuclei. It has shown that the Crab Nebula isn’t the steady emitter […]
Round the world in just six hours (video)
April 20, 2012
Evacuated Tube Transport could take you around the world in just 6 hours http://youtu.be/McpWcn-1RZU
Orbiton: a new quasiparticle
April 19, 2012
Spin–orbital separation in the quasi-one-dimensional Mott insulator Sr2CuO3 J. Schlappa et al When viewed as an elementary particle, the electron has spin and charge. When binding to the atomic nucleus, it also acquires an angular momentum quantum number corresponding to the quantized atomic orbital it occupies. Even if electrons in solids form bands and delocalize […]
The smallest music in the universe
April 18, 2012
The is the orchestrated version of the score, a piano is playing the gamma ray, a pizzicato violin is playing the electron, and a pizzicato cello is playing the positron. Click to play. Read more: http://www.isgtw.org/feature/smallest-music-universe
Serious Blow to Dark Matter Theories?
April 18, 2012
New study finds mysterious lack of dark matter in Sun’s neighbourhood The most accurate study so far of the motions of stars in the Milky Way has found no evidence for dark matter in a large volume around the Sun. According to widely accepted theories, the solar neighbourhood was expected to be filled with dark […]
Dark Matter Annihilation at the Fermi Large Area Telescope?
April 17, 2012
A Tentative Gamma-Ray Line from Dark Matter Annihilation at the Fermi Large Area Telescope Christoph Weniger The observation of a gamma-ray line in the cosmic-ray fluxes would be a smoking-gun signature for dark matter annihilation or decay in the Universe. We present an improved search for such signatures in the data of the Fermi Large […]
A Big Blast
April 16, 2012
A beautiful prominence eruption producing a coronal mass ejection (CME) shot off the east limb (left side) of the sun on April 16, 2012. Such eruptions are often associated with solar flares, and in this case an M1 class (medium-sized) flare occurred at the same time, peaking at 1:45 PM EDT. The CME was not […]
Introduction to Magnetic Monopoles
April 16, 2012
Arttu Rajantie One of the most basic properties of magnetism is that a magnet always has two poles, north and south, which cannot be separated into isolated poles, i.e., magnetic monopoles. However, there are strong theoretical arguments why magnetic monopoles should exist. In spite of extensive searches they have not been found, but they have […]
The analogue cosmological constant in Bose-Einstein condensates….
April 16, 2012
… a lesson for quantum gravity Stefano Finazzi, Stefano Liberati, Lorenzo Sindoni For almost a century, the cosmological constant has been a mysterious object, in relation to both its origin and its very small value. By using a Bose-Einstein condensate analogue model for gravitational dynamics, we address here the cosmological constant issue from an analogue […]
The Swiss boson
April 15, 2012
by Izabella Kaminska The Swiss boson is a hypothetical condition which is supposed to account for why the Swiss franc has ‘mass’ when all other neighbouring currencies don’t. A multi billion-euro experiment, operated by BERN (but funded outright by tax payers), is currently under way on the borders of Switzerland and the Eurozone to try […]
Hubble Sees Messier 70: Tight and Bright
April 15, 2012
In this image, the NASA/ESA Hubble Space Telescope has captured the brilliance of the compact center of Messier 70, a globular cluster. Quarters are always tight in globular clusters, where the mutual hold of gravity binds together hundreds of thousands of stars in a small region of space. Having this many shining stars piled on […]
Hubble Reveals Curious Auroras on Uranus
April 14, 2012
Astronomers have finally succeeded in capturing the first Earth-based images of the curious and fleeting auroras of Uranus using the Hubble Space Telescope, careful planning… and no small amount of luck. Unlike Earthly auroras, whose long-lived curtains of glowing green, red and purple have been the subject of countless stunning photos over the past months, […]
How Do You Land on Mars?
April 13, 2012
Getting a spacecraft to Mars is one thing; getting it safely to the ground is a whole other challenge! This 60-second video from NASA’s Jet Propulsion Laboratory explains three ways to land on the surface of the Red Planet http://youtu.be/8-X8acD_r38
Higher Dimensions from String Theory
April 13, 2012
String Theory predicts the existence of more than the 3 space dimensions and 1 time dimension we are all familiar with. According to string theory, there are additional dimensions that we are unfamiliar with because they are curled up into tiny complicated shapes that can only be seen on tiny scales. If we could shrink […]
IBEX and TWINS Observe a Solar Storm
April 13, 2012
On April 5, 2010, the sun spewed a two million-mile-per-hour stream of charged particles toward the invisible magnetic fields surrounding Earth, known as the magnetosphere. As the particles interacted with the magnetic fields, the incoming stream of energy caused stormy conditions near Earth. Some scientists believe that it was this solar storm that interfered with […]
Is This Proof of Life on Mars?
April 12, 2012
Researchers from universities in Los Angeles, California, Tempe, Arizona and Siena, Italy have published a paper in the International Journal of Aeronautical and Space Sciences (IJASS) citing the results of their work with data obtained by NASA’s Viking mission. The twin Viking 1 and 2 landers, which launched in August and September of 1975, successfully […]
Proton Grease: An Acid Accelerated Molecular Rotor
April 12, 2012
A molecular rotor was designed that rotates 7 orders of magnitude faster upon protonation. The quinoline rotor is based on a rigid N-arylimide framework that displays restricted rotation due to steric interaction between the quinoline nitrogen and imide carbonyls. At rt (23 °C), the rotor rotates slowly (t1/2 = 26 min, ΔG‡ = 22.2 kcal/mol). However, upon addition […]
The ultimate random number generator.
April 12, 2012
The Fastest-Ever Random Number Generator Conjures Digits from Subatomic Noise in a Vacuum It was once thought that vacuums–like the vacuum of space–contained nothing. No particles, no sound, just empty darkness. But it has since come to light, thanks to discoveries in quantum physics, that virtual sub-atomic particles constantly and spontaneously appear and disappear, even […]
The Secret Life of Plankton (video)
April 12, 2012
New videography techniques have opened up the oceans’ microscopic ecosystem, revealing it to be both mesmerizingly beautiful and astoundingly complex. Marine biologist Tierney Thys has used footage from a pioneering project to create a film designed to ignite wonder and curiosity about this hidden world that underpins our own food chain. http://youtu.be/xFQ_fO2D7f0
Footprints of Higher-Dimensional Decaying Black Holes
April 12, 2012
Panagiota Kanti We review the current results for the emission of Hawking radiation by a higher-dimensional black hole during the Schwarzschild and the spin-down phases. We discuss particularly the role of the angular variation of the emitted radiation on the brane during the latter phase, the radiation spectra for gravitons in the bulk, and the […]
Stardust recycling mystery solved
April 12, 2012
A long-standing mystery about how dying stars spew out the material of future planets is now solved, scientists say. While stars like our Sun are known to eject much of their mass in their final years, it has remained unclear just how the dust is blown away. Scientists reporting in Nature describe an astronomical study […]
Cosmic mirages’ confirm accelerated cosmic expansion
April 12, 2012
An international team of researchers led by Masamune Oguri at Kavli IPMU and Naohisa Inada at Nara National College of Technology conduced an unprecedented survey of gravitationally lensed quasars, and used it to measure the expansion history of the universe. The result provides strong evidence that the expansion of the universe is accelerating. There were […]
H3+: the Molecule that Made the Universe
April 11, 2012
In a study that pushed quantum mechanical theory and research capabilities to the limit, UA researchers have found a way to see the molecule that likely made the universe – or at least the hot and fiery bits of it. Lurking in the vast, chilly regions between stars, the unassuming molecule known as a triatomic […]
Can free will emerge from determinism in quantum theory?
April 11, 2012
Gilles Brassard, Paul Raymond-Robichaud Quantum Mechanics is generally considered to be the ultimate theory capable of explaining the emergence of randomness by virtue of the quantum measurement process. Therefore, Quantum Mechanics can be thought of as God’s wonderfully imaginative solution to the problem of providing His creatures with Free Will in an otherwise well-ordered Universe. […]
The Universe, the Cold War, and Dialectical Materialism
April 10, 2012
Helge Kragh Ideological considerations have always influenced science, but rarely as directly and massively as in the Soviet Union during the early Cold War period. Cosmology was among the sciences that became heavily politicized and forced to conform to the doctrines of Marxism-Leninism. This field of science developed entirely differently in the Communist countries than […]
The fundamental mass (this is not about the Higgs)
April 10, 2012
At a time when we are about to shed light on the fundamental question of the creation of mass after the Big Bang, we are also close to solving another basic mass-related problem. The kilogram is the only base unit of the International System of Units (SI) whose official definition is still based on a […]
April 30, 2012
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