Earth

All materials undergo phase transitions between the basic states of matter; solid, liquid and gas. At these transitions, a material's properties can change significantly and quickly. A hypothesis proposed about two decades ago sought to explain some of water's odd behavior by suggesting that a similar transition may take place between two different liquid states, in which the arrangement of the water molecules changes so that the two states have very different densities.

MANHATTAN, KAN. -- Nearly half of the Earth's heat comes from the radioactive decay of materials inside, according to a large international research collaboration that includes a Kansas State University physicist.

The oceans cover 71% of our planet, with over half with a depth greater than 3000 m. Although our knowledge is still very limited, we know that the deep ocean contains a diversity of habitats and ecosystems, supports high biodiversity, and harbors important biological and mineral resources. Human activities are, however increasingly affecting deep-sea habitats, resulting in the potential for biodiversity loss and, with this, the loss of many goods and services provided by deep-sea ecosystems.

All known biological sensory systems, including the familiar examples of the five human senses – vision, hearing, smell, taste and touch – have one thing in common: when exposed to a sustained change in sensory input, the sense eventually acclimates and notices subsequent changes without continuing to compare each new change with the initial condition. This autonomous tuning of perceptions, known as sensory adaptation, has been recognized by scientists for more than a century, but a new study has demonstrated that even a simple microbe can achieve this feat with surprising sophistication.

ANN ARBOR, Mich.---Aerosol particles, including soot and sulfur dioxide from burning fossil fuels, essentially mask the effects of greenhouse gases and are at the heart of the biggest uncertainty in climate change prediction. New research from the University of Michigan shows that satellite-based projections of aerosols' effect on Earth's climate significantly underestimate their impacts.

The findings will be published online the week of Aug. 1 in the early edition of the Proceedings of the National Academy of Sciences.

CORVALLIS, Ore. – An analysis of prehistoric "Heinrich events" that happened many thousands of years ago, creating mass discharges of icebergs into the North Atlantic Ocean, make it clear that very small amounts of subsurface warming of water can trigger a rapid collapse of ice shelves.

The findings, to be published this week in Proceedings of the National Academy of Sciences, provide historical evidence that warming of water by 3-4 degrees was enough to trigger these huge, episodic discharges of ice from the Laurentide Ice Sheet in what is now Canada.

An international team of scientists has amassed the largest data set to date on greenhouse gas emissions from hydroelectric reservoirs. Their analysis, published today in the online version of Nature Geoscience, posits that these human-made systems emit about 1/6 of the carbon dioxide and methane previously attributed to them.

Prior studies based on more limited data cautioned that hydroelectric reservoirs could be a significant and large source of both carbon dioxide and methane to the atmosphere.

A new source of very cold electrons will improve the quality and speed of nanoimaging for drug and materials development to a trillionth of a second.

The study published in Nature Physics today was carried out by researchers from the ARC Centre of Excellence for Coherent X-ray Science (CXS), headquartered at the University of Melbourne.

CORVALLIS, Ore. – The ebb and flow of the ocean tides, generally thought to be one of the most predictable forces on Earth, are actually quite variable over long time periods, in ways that have not been adequately accounted for in most evaluations of prehistoric sea level changes.

Due to phenomena such as ice ages, plate tectonics, land uplift, erosion and sedimentation, tides have changed dramatically over thousands of years and may change again in the future, a new study concludes.

In this month's edition of Physics World, Richard Taylor, director of the Materials Science Institute at the University of Oregon, takes a serious, objective look at a topic that critics might claim is beyond scientific understanding – crop circles.

As the global crop-circle phenomenon grows alongside advances in science and technology, Taylor notes how physics and the arts are coming together to produce more impressive and spectacular crop-circle patterns that still manage to maintain their mystery.

Physicists at Forschungszentrum Jülich and the universities of Kiel and Hamburg are the first to discover a regular lattice of stable magnetic skyrmions – radial spiral structures made up of atomic-scale spins – on a surface instead of in bulk materials. Such tiny formations could one day form the basis of a new generation of smaller and more efficient data storage units in the field of information technology. The scientists discovered the magnetic spirals, each made up of just 15 atoms, in a one-atomic-layer of iron on iridium.

No-one likes a know-it-all but we expect to be able to catch them out: someone who acts like they know everything but doesn't can always be tripped up with a well-chosen question. Can't they? Not so. New research in quantum physics has shown that a quantum know-it-all could lack information about a subject as a whole, yet answer almost perfectly any question about the subject's parts. The work is published in Physical Review Letters.

SANTA CRUZ, CA--Although high-temperature superconductors are widely used in technologies such as MRI machines, explaining the unusual properties of these materials remains an unsolved problem for theoretical physicists. Major progress in this important field has now been reported by physicists at the University of California, Santa Cruz, in a pair of papers published back-to-back in the July 29 issue of Physical Review Letters.

Hailed as the new "wonder material," graphene is being tapped by an international research team to help overcome issues associated with increasing the storage density and speed of electronic memory devices.