Earth

Helical electron and nuclear spin order in quantum wires

Physicists at the University of Basel have observed a spontaneous magnetic order of electron and nuclear spins in a quantum wire at temperatures of 0.1 kelvin. In the past, this was possible only at much lower temperatures, typically in the microkelvin range. The coupling of nuclei and electrons creates a new state of matter whereby a nuclear spin order arises at a much higher temperature. The results are consistent with a theoretical model developed in Basel a few years ago, as reported by the researchers in the scientific journal Physical Review Letters.

Giant mass extinction may have been quicker than previously thought

The largest mass extinction in the history of animal life occurred some 252 million years ago, wiping out more than 96 percent of marine species and 70 percent of life on land — including the largest insects known to have inhabited the Earth. Multiple theories have aimed to explain the cause of what's now known as the end-Permian extinction, including an asteroid impact, massive volcanic eruptions, or a cataclysmic cascade of environmental events. But pinpointing the cause of the extinction requires better measurements of how long the extinction period lasted.

High pollutant levels in Guánica Bay 'represent serious toxic threat' to corals

The pollutants measured in the sediments of Guánica Bay, Puerto Rico, in a new NOAA study were among the highest concentrations of PCBs, chlordane, chromium and nickel ever measured in the history of NOAA's National Status & Trends, a nationwide contaminant monitoring program that began in 1986.

Massive neutrinos solve a cosmological conundrum

Scientists have solved a major problem with the current standard model of cosmology identified by combining results from the Planck spacecraft and measurements of gravitational lensing in order to deduce the mass of ghostly sub-atomic particles called neutrinos.

The team, from the universities of Manchester and Nottingham, used observations of the Big Bang and the curvature of space-time to accurately measure the mass of these elementary particles for the first time.

Research reveals the give and take of urban temperature mitigating technologies

TEMPE, Ariz. – Life in a warming world is going to require human ingenuity to adapt to the new realities of Earth. Greenhouse-gas induced warming and megapolitan expansion are both significant drivers of our warming planet. Researchers are now assessing adaptation technologies that could help us acclimate to these changing realities.

But how well these adaptation technologies – such as cool roofs, green roofs and hybrids of the two – perform year round and how this performance varies with place remains uncertain.

Pacific trade winds stall global surface warming -- for now

Heat stored in the western Pacific Ocean caused by an unprecedented strengthening of the equatorial trade winds appears to be largely responsible for the hiatus in surface warming observed over the past 13 years.

New research published today in the journal Nature Climate Change indicates that the dramatic acceleration in winds has invigorated the circulation of the Pacific Ocean, causing more heat to be taken out of the atmosphere and transferred into the subsurface ocean, while bringing cooler waters to the surface.

Bottom-up insight into crowd dynamics

Stampedes unfortunately occur on too regular a basis. Previously, physicists developed numerous models of crowd evacuation dynamics. Their analyses focused on disasters such as the yearly Muslim Hajj or of the Love Parade disaster in Germany in 2010. Unfortunately, the casualties at these events may have been linked to the limitations of the crowd dynamics models used at the time. Now, a new study outlines a procedure for quantitatively comparing different crowd models, which also helps to compare these models with real-world data.

Theorists predict new forms of exotic insulating materials

CAMBRIDGE, Mass-- Topological insulators — materials whose surfaces can freely conduct electrons even though their interiors are electrical insulators — have been of great interest to physicists in recent years because of unusual properties that may provide insights into quantum physics. But most analysis of such materials has had to rely on highly simplified models.

Tree roots in the mountains 'acted like a thermostat' for millions of years

For the first time, scientists have discovered how tree roots in the mountains may play an important role in controlling long-term global temperatures. Researchers from Oxford and Sheffield Universities have found that temperatures affect the thickness of the leaf litter and organic soil layers, as well as the rate at which the tree roots grow. In a warmer world, this means that tree roots are more likely to grow into the mineral layer of the soil, breaking down rock into component parts which will eventually combine with carbon dioxide.

Ballistic transport in graphene suggests new type of electronic device

Using electrons more like photons could provide the foundation for a new type of electronic device that would capitalize on the ability of graphene to carry electrons with almost no resistance even at room temperature – a property known as ballistic transport.

Quarks in the looking glass

From matching wings on butterflies to the repeating six-point pattern of snowflakes, symmetries echo through nature, even down to the smallest building blocks of matter. Since the discovery of quarks, the building blocks of protons and neutrons, physicists have been exploiting those symmetries to study quarks' intrinsic properties and to uncover what those properties can reveal about the physical laws that govern them.

Policymakers and scientists agree on top research questions

Natural resource managers, policymakers and their advisers, and scientists have similar ideas about which research questions could, if answered, most increase the effectiveness of US natural resource management policies. A survey of over 600 members of those professional groups revealed how they ranked the importance of 40 management-relevant research questions identified in earlier work.

Water supply availability 'to dominate US natural resource management'

Water supply is the most pressing environmental issue facing the United States according to a survey of policy makers and scientists revealed in a new publication in BioScience by researchers at the University of York and the University of California, Davis.

Forest emissions, wildfires explain why ancient Earth was so hot

The release of volatile organic compounds from Earth's forests and smoke from wildfires 3 million years ago had a far greater impact on global warming than ancient atmospheric levels of carbon dioxide, a new Yale study finds.

The research provides evidence that dynamic atmospheric chemistry played an important role in past warm climates, underscoring the complexity of climate change and the relevance of natural components, according to the authors. They do not address or dispute the significant role in climate change of human-generated CO2 emissions.

Towards tailor-made adhesives

Tape, self-adhesive labels, Post-it notes and masking tape all contain soft adhesives. This makes them easy to remove—a process referred to as debonding. French scientists have studied how soft adhesives work in the hope of facilitating the design of more efficient adhesives. Francois Tanguy, a researcher at ESPCI ParisTech, the School of Industrial Physics and Chemistry, in Paris, France, and colleagues have, for the first time, performed a precise analysis of the material deformation and structure during the course of debonding for several model adhesives.