PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Experients may force revision of astrophysical models of the universe

Ice giant planets have more water volume than formerly estimated, Sandia Labs Z accelerator tests indicate

2012-03-20
(Press-News.org) ALBUQUERQUE, N.M. — In a challenge to current astrophysical models of the universe, researchers at Sandia National Laboratories Z machine and the University of Rostock in Germany have found that current estimates of ice-giant planetary interiors overstate water's compressibility by as much as 30 percent.

The work was reported in the paper "Probing the Interior of the Ice Giants" in the Feb. 27 Physical Review Letters.

"Our results question science's understanding of the internal structure of these planets," said Sandia lead author Marcus Knudson, "and should require revisiting essentially all the modeling of ice giants within and outside our solar system."

An accurate estimate of water's shrinking volume under the huge gravitational pressures of large planets is essential to astrophysicists trying to model the evolution of the universe. They need to assume how much space is taken up by water trapped under high density and pressure, deep inside a planet, to calculate how much is needed of other elements to flesh out the planet's astronomical image.

To come up with the composition of the so-called ice-giants Neptune and Uranus, as well as any of the ice-giant exoplanets being discovered in distant star systems, astrophysicists begin with the orbit, age, radius and mass of each planet. Then, using equations that describe the behavior of elements as the forming planet cooled, they calculate what light and heavy elements might have contributed to its evolution to end up with the current celestial object.

But if estimates of water volume are off-target, then so is everything else.

The measurements — 10 times more accurate than any previously reported — at Sandia's Z accelerator agree with results from a modern simulation effort that uses the quantum mechanics of Schrödinger's wave equation — the fundamental equation of wave mechanics — to predict the behavior of water under extreme pressure and density.

The model, developed through a University of Rostock and Sandia collaboration, is called "First Principles Modeling" because it contains no tuning parameters.

"You're solving Schrödinger's equation from a quantum mechanical perspective with hydrogen and oxygen as input; there aren't any knobs for finagling the result you want or expect," Knudson said.

The model's results are quite different from earlier chemical pictures of water's behavior under pressure, but agree quite well with the Z machine's test results, said Knudson. These results were achieved by using Z's magnetic fields to shoot tiny plates 40 times faster than a rifle bullet into a water-sample target a few millimeters away. The impact of each plate into the target created a huge shock wave that compressed the water to roughly one-fourth its original volume, momentarily creating conditions similar to those in the interior of the ice giants.

Sub-nanosecond observations captured the behavior of water under pressures and densities that occur somewhere between the surface and core of ice giants.

"We took advantage of recent, more precise methods to measure the speed of the shock wave moving through the water sample by measuring the Doppler shift of laser light reflected from the moving shock front, to 0.1 percent accuracy," said Knudson.

The re-shocked state of water was also determined by observing its behavior as the shock wave reflected back into the water from a quartz rear window (its characteristics also determined) in the target. These results provided a direct test of the First Principles model along a thermodynamic path that mimics the path one would follow if one could bore deep into a planet's interior.

Multiple experiments were performed, providing a series of results at increasing pressures to create an accurate equation of state. Such equations link changes in pressures with changes in temperatures and volumes.

Z can create more pressure — up to 20 megabars — than at Earth's core (roughly 3.5 megabars), and millions of times Earth's atmospheric pressure. The Z projectiles, called flyer plates, achieve velocities from 12 to 27 kilometers a second, or up to 60,000 mph. The pressure at the center of Neptune is roughly 8 megabars.

Water at Z's ice-giant pressures also was found to have reflectivity like that of a weak metal, raising the possibility that water's charged molecular fragments might be capable of generating a magnetic field. This could help explain certain puzzling aspects of the magnetic fields around Neptune and Uranus.

"Reducing uncertainty on the composition of planetary systems by precisely measuring the equation of state of water at extreme conditions can only help us understand how these systems formed," Knudson said.

These experimental techniques also are used at Z to study materials of critical importance to the nuclear weapons program. In addition to producing the largest amount of X-rays on Earth when firing, the huge pressures generated by Z make it useful to astrophysicists seeking data similar to that produced by black holes and neutron stars.

###Also listed as paper authors are Mike Desjarlais, Ray Lemke and Thomas Mattsson from Sandia, and Martin French, Nadine Nettelmann and Ronald Redmer from the University of Rostock's Institute of Physics.

Research support was provided by the German Science Foundation and the National Nuclear Security Administration.

Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin company, for the U.S. Department of Energy's National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national security, energy and environmental technologies and economic competitiveness.


ELSE PRESS RELEASES FROM THIS DATE:

Circadian rhythms have profound influence on metabolic output, UCI study reveals

2012-03-20
Irvine, Calif., March 19, 2012 — By analyzing the hundreds of metabolic products present in the liver, researchers with the UC Irvine Center for Epigenetics & Metabolism have discovered that circadian rhythms – our own body clock – greatly control the production of such key building blocks as amino acids, carbohydrates and lipids. They identified more than 600 liver-originated metabolites, which are the chemical substances created by metabolism that sustain and promote cell health and growth. Approximately 60 percent of these metabolites were found to be dependent on ...

Penn researchers find mentoring provides health benefits for African American veterans with diabetes

2012-03-20
(Philadelphia) – Intervention by peer mentors has a statistically significant effect on improving glucose control in African American veterans with diabetes, according to a study by researchers at the Perelman School of Medicine at the University of Pennsylvania and the Philadelphia VA Center for Health Equity Research and Promotion (CHERP). Full results of the study were published in the March 20th issue of the Annals of Internal Medicine. In the study 118 African American veterans aged 50-70 years old with persistently poor diabetes control were randomly assigned to ...

Discovery provides blueprint for new drugs that can inhibit hepatitis C virus

2012-03-20
Chemists at the University of California, San Diego have produced the first high resolution structure of a molecule that when attached to the genetic material of the hepatitis C virus prevents it from reproducing. Hepatitis C is a chronic infectious disease that affects some 170 million people worldwide and causes chronic liver disease and liver cancer. According to the Centers for Disease Control and Prevention, hepatitis C now kills more Americans each year than HIV. The structure of the molecule, which was published in a paper in this week's early online edition ...

1 solution to global overfishing found

1 solution to global overfishing found
2012-03-20
A study by the Wildlife Conservation Society, the ARC Centre for Excellence for Coral Reef Studies, and other groups on more than 40 coral reefs in the Indian and Pacific Oceans indicates that "co-management"—a collaborative arrangement between local communities, conservation groups, and governments—provides one solution to a vexing global problem: overfishing. The finding is the outcome of the largest field investigation of co-managed tropical coral reef fisheries ever conducted, an effort in which researchers studied 42 managed reef systems in five countries. The team ...

MIT research: Study finds room to store CO2 underground

2012-03-20
A new study by researchers at MIT shows that there is enough capacity in deep saline aquifers in the United States to store at least a century's worth of carbon dioxide emissions from the nation's coal-fired powerplants. Though questions remain about the economics of systems to capture and store such gases, this study addresses a major issue that has overshadowed such proposals. The MIT team's analysis — led by Ruben Juanes, the ARCO Associate Professor in Energy Studies in the Department of Civil and Environmental Engineering, and part of the doctoral thesis work of ...

A biplane to break the sound barrier

2012-03-20
For 27 years, the Concorde provided its passengers with a rare luxury: time saved. For a pricey fare, the sleek supersonic jet ferried its ticketholders from New York to Paris in a mere three-and-a-half hours — just enough time for a nap and an aperitif. Over the years, expensive tickets, high fuel costs, limited seating and noise disruption from the jet's sonic boom slowed interest and ticket sales. On Nov. 26, 2003, the Concorde — and commercial supersonic travel — retired from service. Since then, a number of groups have been working on designs for the next generation ...

NASA satellites see rainfall left behind from Cyclone Lua's landfall

NASA satellites see rainfall left behind from Cyclone Luas landfall
2012-03-20
NASA's TRMM satellite added up the rainfall generated from Cyclone Lua as it made landfall in northern Australia on March 17, and tracked southward through March 19. The largest rainfall amounts appeared just off the coast before Lua made landfall, and continued generating heavy rainfall as it moved inland. On Saturday, March 17, 2012, Lua's center crossed the Australia coastline at Pardoo about 3 p.m. (local time/Australia) bringing winds gusting up to 155 mph (250 kph) and heavy rainfall. The Sydney Morning Herald reported that Port Hedland residents experienced maximum ...

Foundation Frenzy? Cosmetic Catastrophe? Don't Panic - Help is on Hand!

2012-03-20
Ladies don't worry! We all know how hard it is to choose the perfect cosmetic foundation! The markets flooded with products, ranging from mousses to tinted moisturisers, which often overwhelm the customer with choice! But don't fear we have help on hand with our simple foundation guide because we understand that when you are choosing a foundation it's important to go back to basics. Firstly the most important thing to ask when you are looking for a new foundation is not (like everyone thinks it is) whether it will look great and give you a flawless finish but actually ...

Beyond the microscope: Identifying specific cancers using molecular analysis

2012-03-20
SALT LAKE CITY, March 19, 2012—Researchers from Huntsman Cancer Institute (HCI) at the University of Utah report they have discovered a method to identify cancer-causing rearrangements of genetic material called chromosomal translocations quickly, accurately, and inexpensively. A description of the method and the research results appear online in this month's issue of the EMBO Molecular Medicine journal. Many cancers result from chromosomal translocations in tumor cells. Hundreds of cancer-causing translocations have been discovered, but current methods for detecting ...

New genetic path for scleroderma

2012-03-20
CHICAGO --- A genetic pathway previously known for its role in embryonic development and cancer has been identified as a target for systemic sclerosis, or scleroderma, therapy. The finding, discovered by a cross-disciplinary team led by John Varga, MD, John and Nancy Hughes Distinguished Professor of Rheumatology at Northwestern University Feinberg School of Medicine, was recently published in the journal Arthritis & Rheumatism. "We showed, for the first time, that the Wnt signaling pathway is abnormally activated in scleroderma patients," said Varga, who is also a physician ...

LAST 30 PRESS RELEASES:

Signs identified that precede sudden arrhythmic death syndrome in young people

Discovery of bacteria's defence against viruses becomes a piece of the puzzle against resistance

Pre-eclampsia is associated with earlier onset and higher incidence of cardiovascular risk factors

Warwick astronomers discover doomed pair of spiralling stars on our cosmic doorstep

Soil conditions significantly increase rainfall in world’s megastorm hotspots

NK cells complexed with bispecific antibody yield high response rates in patients with lymphoma

Planetary health diet and mediterranean diet associated with similar survival and sustainability benefits

Singapore launches national standard to validate antimicrobial disinfectant products

Molecular stool test could improve detection of tuberculosis in adults with HIV

Suspected fibrocartilaginous embolus in Asian small-clawed otter (Aonyx cinereus)

Enhancing heat transfer using the turbulent flow of viscoelastic fluids

Exercise as an anti-ageing intervention to avoid detrimental impact of mental fatigue

UMass Amherst Nursing Professor Emerita honored as ‘Living Legend’

New guidelines aim to improve cystic fibrosis screening

Picky eaters by day, buffet by night: Butterfly, moth diets sync to plant aromas

Pennington Biomedical’s Dr. Leanne Redman honored with the E. V. McCollum Award from the American Society for Nutrition

CCNY physicists uncover electronic interactions mediated via spin waves

Researchers’ 3D-printing formula may transform future of foam

Nurture more important than nature for robotic hand

Drug-delivering aptamers target leukemia stem cells for one-two knockout punch

New study finds that over 95% of sponsored influencer posts on Twitter were not disclosed

New sea grant report helps great lakes fish farmers navigate aquaculture regulations

Strain “trick” improves perovskite solar cells’ efficiency

How GPS helps older drivers stay on the roads

Estrogen and progesterone stimulate the body to make opioids

Dancing with the cells – how acoustically levitating a diamond led to a breakthrough in biotech automation

Machine learning helps construct an evolutionary timeline of bacteria

Cellular regulator of mRNA vaccine revealed... offering new therapeutic options

Animal behavioral diversity at risk in the face of declining biodiversity

Finding their way: GPS ignites independence in older adult drivers

[Press-News.org] Experients may force revision of astrophysical models of the universe
Ice giant planets have more water volume than formerly estimated, Sandia Labs Z accelerator tests indicate