Here are a couple of science based news stories that just caught my eye, so I thought I’d share them with you all … enjoy …
New Type of Moon Volcano Discovered
Silica-rich rocks reveal unusual lunar eruptions.
A 1967 Lunar Orbiter IV picture of the arrowhead-shaped Hansteen Alpha region (left) and the same picture with new LRO data superimposed, showing silica-rich areas in red and yellow.
If the moon were actually made of cheese, there’d be a new flavor of dairy for humans to sample.
Data from NASA’s Lunar Reconnaissance Orbiter (LRO) have revealed a new type of rock on the lunar surface—which scientists say was spat up by a style of volcano never before seen on the moon.
Until now, scientists had believed the moon was made of two basic types of rock: dark basalt and light, calcium-rich feldspar. Both would have come from volcanoes spewing relatively runny basaltic lava.
But the new volcano type oozed thicker lava rich in silica over a light, arrowhead-shaped patch of the moon roughly 18 miles (30 kilometers) across, called Hansteen Alpha, the scientists say.
National Geographic: Continue reading …
When Earth’s Mantle Meets Its Core: Findings Boost Hypothesis of Deep Magma Ocean
Earth’s mantle and its core mix at a distance of 2900 kilometers under our feet in a mysterious zone. A team of geophysicists has just verified that the partial fusion of the mantle is possible in this area when the temperature reaches 4200 Kelvin. This reinforces the hypothesis of the presence of a deep magma ocean.
The originality of this work, carried out by the scientists of the Institut de minéralogie et de physique des milieux condensés (UPMC/Université Paris Diderot/Institut de Physique du Globe/CNRS/IRD), lies in the use of X-ray diffraction at the European
Synchrotron Radiation Facility in Grenoble (France). The results will have an effect in the understanding of the dynamics, composition and the formation of the depths of our planet.
On top of Earth’s core, consisting of liquid iron, lies the solid mantle, which is made up essentially of magnesium oxides, iron and silicon. The border between the core and the mantle, located at 2900 km below Earth’s surface, is highly intriguing to geophysicists. With a pressure of around 1.4 million times the atmospheric pressure and a temperature of more than 4000 Kelvin, this zone is home to chemical reactions and changes in states of matter still unknown. The seismologists who have studied this subject have acknowledged an abrupt reduction of the speed of the seismic waves, which sometimes reach 30% when getting close to this border. This fact has led scientists to formulate the hypothesis, for the last 15 years, of the partial melting of the Earth mantle at the level of this mantle-core border. Today, this hypothesis has been confirmed.
In order to access the depths of our planet, scientists have not only seismological images but also a precious experimental technique: diamond anvil cells, coupled with a heating layer. This instrument allows scientists to re-create the same pressure and temperature conditions as those in Earth’s interior on samples of a few microns. This is the technique used by the researchers of the Institut de minéralogie et de physique des milieux condensés on natural samples that are representatives of Earth’s mantle and that have been put under pressures of more than 140 gigapascals (or 1.4 million times the atmospheric pressure), and temperatures of more than 5000 Kelvin.
A new approach to this study has been the use of the X-ray diffraction technique at the European synchrotron (ESRF). This has allowed the scientists to determine what mineral phases melt first, and they have also established, without extrapolation, fusion curves of the deep Earth mantle — i.e., the characterization of the passage from a solid state to a partially liquid state. Their observations show that the partial fusion of the mantle is possible when the temperature approaches 4200 Kelvin. These experiments also prove that the liquid produced during this partial fusion is dense and that it can hold multiple chemical elements, among which are important markers of the dynamics of Earth’s mantle. These studies will allow geophysicists and geochemists to achieve a deeper knowledge of the mechanisms of differentiation of Earth and the history of its formation, which started around 4.5 billion years ago.
Physicists cross hurdle in quantum manipulation of matter
Team successfully decoupled a single quantum spin from its surroundings
|IMAGE: Spins of nitrogen-vacancy centers in diamond (represented on the center photo as bright spots and denoted as the orange arrow on the figure to the left) interact with a bath…|
Finding ways to control matter at the level of single atoms and electrons fascinates many scientists and engineers because the ability to manipulate single charges and single magnetic moments (spins) may help researchers penetrate deep into the mysteries of quantum mechanics and modern solid-state physics. It may also allow development of new, highly sensitive magnetometers with nanometer resolution, single-spin transistors for coherent spintronics, and solid-state devices for quantum information processing.
Recently, a collaboration of experimentalists from the Kavli Institute of Nanosciences at Delft University of Technology and theorists at the U.S. Department of Energy’s Ames Laboratory made a breakthrough in the area of controlling single quantum spins. The results were published in Science Express on Sept. 9: http://www.sciencemag.org/cgi/content/abstract/science.1192739v1
The researchers developed and implemented a special kind of quantum control over a single quantum magnetic moment (spin) of an atomic-sized impurity in diamond. These impurities, called nitrogen-vacancy (or N-V) centers, have attracted much attention due to their unusual magnetic and optical properties. But their fragile quantum states are easily destroyed by even miniscule interactions with the outside world.
By applying a specially designed sequence of high-precision electromagnetic pulses, the scientists were able to protect the arbitrary quantum state of a single spin, and they made the spin evolve as if it was completely decoupled from the outside world. In this way, scientists achieved a 25-fold increase in the lifetime of the quantum spin state at room temperature. This is the first demonstration of a universal dynamical decoupling realized on a single solid state quantum spin.
“Uncontrolled interactions of the spins with the environment have been the major hurdle for implementing quantum technologies” said the leader of Dutch experimental group, associate professor Ronald Hanson from Kavli Institute of Nanoscience at Delft. “Our results demonstrate that this hurdle can be overcome by advanced control of the spin itself.”
“Implementing dynamical decoupling on a single quantum spin in solid state at room temperature has been an appealing but distant goal for quite a while. In the meantime, much theoretical and experimental knowledge has been accumulated in the community,” added Viatcheslav Dobrovitski, who led the theoretical research effort at the Ames Laboratory. “We used this knowledge to design our pulse sequences, and the collaboration between theory and experiment greatly helped us in this work.”
Besides its importance to fundamental understanding of quantum mechanics, the team’s achievement opens a way to using the impurity centers in diamond as highly sensitive nanoscale magnetic sensors, and potentially, as qubits for larger-scale quantum information processing.
EurekAlert: read here …