Making Science More Better For You on 02/11/08

Headlines of the day
Wienermobile wipes out (Starr-Gazette.com)
No bun intended.

Pa. Lawmaker Eager to Push Beer Sales 'Into 21st Century' (KYW Newsradio.com)


Does Jules Verne know about this? How about Admiral Richard Byrd?

Rubik's Cube In Center Of Earth? Computer Simulations Support New Model Of Earth's Core

ScienceDaily (Feb. 11, 2008) — Swedish researchers have presented evidence to support their new theory about the structure of the earth's core. The findings may be of significance for our understanding of the cooling down of the earth, and of the stability of the earth’s magnetic field.

It has long been known that the inner core of the earth, a sphere consisting of a solid mass with a radius of about 1,200 km, is mainly made up of iron. However, seismic observations have shown that elastic waves pass more rapidly through this core in directions that are parallel to the earth’s axis of rotation than in directions parallel to the equator–-a phenomenon that has not been previously explained. At the high temperatures that prevail in the core of the earth, these waves should pass at the same speed regardless of their direction.

In the present study, scientists from Uppsala University and KTH present an explanation for this puzzling characteristic. The new publication in Science is part of a series of articles published by the same research team in Nature and Science.

Initially, in 2003, they published strong theoretical proof that the earth’s core assumes the so-called body-centered cubic crystal structure at high temperatures–-a structure that despite its high degree of symmetry evinces a surprisingly high level of elastic anisotropy, that is, its elastic properties are contingent on direction. This theory about the crystal structure directly contradicted the then prevailing view, but since then the theory has found both experimental and theoretical support.

In this new study the researchers present simulations of how seismic waves are reproduced in iron under the conditions that prevail in the core of the earth, showing a difference of about 12 percent depending on their direction-–which suffices as an explanation for the puzzling observations. First the trajectories of movement were calculated for several million atoms in strong interaction with each other. On this basis, the scientists were then able to determine that the progress of the sound waves was actually accurately described in the computer-generated model for iron under the conditions prevailing in the core of the earth.

“We found that the body-centered cubic structure of iron is the only structure that could correspond to the experimental observations,” says Börje Johansson, professor of condensed-matter theory at Uppsala University.

The earth’s heat balance, like its magnetic field, is dependent on the amount of heat that is stored in the inner core of the earth. These conditions, in turn, are dependent on the crystal structure of the iron in the inner core. Previously these estimates were based on models deriving from the hexagonal structure of iron in the inner core. The Swedish scientists’ discovery will now entail a critical revaluation of the cooling off of the earth and of the stability of its magnetic field.

“This study opens new perspectives for our understanding of the earth’s past, present, and future,” says Natalia Skorodumova, a researcher at the Department of Physics and Materials Science.

In their studies these researchers have used models based on the so-called density-functional theory for which Walter Kohn was awarded the 1999 Nobel Prize. The calculations were carried out using the most powerful parallel supercomputers in existence, in Stockholm and Linköping.

The body-centered cubic crystal structure forms a cube with atoms in each corner and a further atom in the middle of this cube. It is oriented in such a way that its great diagonal is directed along the earth’s axis of rotation, which makes it possible for the iron to evince sound propagations with the velocities observed.


Social scientists get a grant to point out the obvious. Film at 11.

Spouses more irritating as time goes on

ANN ARBOR, Mich., Feb. 11 (UPI) -- A University of Michigan study of 800 adults found as people age, they are more likely to see their spouses as irritating and demanding.

Study leader Kira Birditt, a research fellow at the University of Michigan Institute for Social Research and colleagues Lisa Jackey and Toni Antonucci interviewed people at different stages in life -- young, middle-aged and older adults -- first in 1992 and again in 2005.

The study participants in their 20s and 30s had the most negative relationships overall.

The study also found that for all age groups, including adults in their 40s and 50s, the spousal relationship was seen as the most negative -- and it tended to increase in negativity over time. However, Birditt said that viewing a spouse more negatively over time may not be all bad.

"As we age, and become closer and more comfortable with one another, it could be that we're more able to express ourselves to each other," Birditt said in a statement. "In other words, it's possible that negativity is a normal aspect of close relationships that include a great deal of daily contact."

The findings were presented at the Gerontological Society of America.



When galaxies fail to move their feet

A Cosmic Fossil? Brilliant But Fuzzy Galaxy May Be Aftermath Of Multi-Galaxy Collision

ScienceDaily (Feb. 7, 2008) — The NASA/ESA Hubble Space Telescope has captured a new image of the galaxy NGC 1132 which is, most likely, a cosmic fossil – the aftermath of an enormous multi-galactic pile-up, where the carnage of collision after collision has built up a brilliant but fuzzy giant elliptical galaxy far outshining typical galaxies.

The elliptical galaxy NGC 1132, seen in this latest image from Hubble, belongs to a category of galaxies called giant ellipticals. NGC 1132, together with the small dwarf galaxies surrounding it, are dubbed a “fossil group” as they are most likely the remains of a group of galaxies that merged together in the recent past.

In visible light NGC 1132 appears as a single, isolated, giant elliptical galaxy, but this is only the tip of the iceberg. Scientists have found that NGC 1132 resides in an enormous halo of dark matter, comparable to the amount of dark matter usually found in an entire group of tens or hundreds of galaxies. It also has a strong X-ray glow from an abundant amount of hot gas – an amount normally only found in galaxy groups. Its X-ray glow extends over a region of space ten times larger than the 120,000 light-year radius it has in visible light. An X-ray glow that is equal in size to that of an entire group of galaxies.

The origin of fossil group systems remains a puzzle. The most likely explanation is that they are the end-products of a cosmic feeding frenzy in which a large cannibal galaxy devours all of its neighbours. A less likely explanation is that they may be very rare objects that formed in a region or period of time where the growth of moderate-sized galaxies was somehow suppressed, and only one large galaxy formed.

Many galaxies reside in groups that are gravitationally bound together, including our own Milky Way, which is part of the Local Group. Sometimes gravity makes galaxies collide and eventually merge into one single galaxy. There is strong evidence that the Milky Way is one such cannibal that has snacked on numerous smaller galaxies during its lifetime, inheriting their stars in the process. Scientists are keenly studying the environment surrounding galaxies such as NGC 1132 using space telescopes like Hubble, and they try to trace the history of the formation these galaxies by analysing their properties.

In this Hubble image, NGC 1132 is seen surrounded by thousands of ancient globular clusters, swarming around the galaxy like bees around a hive. These globular clusters are likely to be the survivors of the disruption of their cannibalised parent galaxies that have been eaten by NGC 1132 and may reveal its merger history. In the background, there is a stunning tapestry of numerous galaxies that are much further away.

Elliptical galaxies are smooth and featureless. They contain hundreds of millions to trillions of stars, and their shapes range from nearly spherical to very elongated in shape. Their overall yellowish colour is a telltale sign of their great age. Because elliptical galaxies do not contain much cool gas they can no longer make new stars.

NGC 1132 is located approximately 320 million light-years away in the constellation of Eridanus, the River. This image of NGC 1132 was taken with Hubble’s Advanced Camera for Surveys. Data obtained in 2005 and 2006 through green and near-infrared filters were used to produce a colour composite.
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