Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




EARTH OBSERVATION
Promising New Technique for Probing Earth's Deep Interior
by Staff Writers
Washington DC (SPX) Feb 26, 2013


The long-range spin-spin interaction (blue wavy lines) in which the spin-sensitive detector on Earths surface interacts with geoelectrons (red dots) deep in Earths mantle. The arrows on the geoelectrons indicate their spin orientations, opposite that of Earths magnetic field lines (white arcs). Illustration: Marc Airhart (University of Texas at Austin) and Steve Jacobsen (Northwestern University). Credit: Marc Airhart, University of Texas at Austin, and Steve Jacobsen, Northwestern University.

researchers at Amherst College in Massachusetts and the University of Texas at Austin have described a new technique based in particle physics that might one day reveal, in more detail than ever before, the composition and characteristics of the deep Earth.

There's just one catch: the technique relies on a fifth force of nature that has not yet been detected, but some particle physicists think it might exist. The fifth force would be in addition to gravity, the weak and strong nuclear forces and electromagnetism.

Physicists call this fifth force a long-range spin-spin interaction. As theorized, the fifth force would rely on the building blocks of atoms (electrons, protons and neutrons), separated over vast distances, to "feel" each other's presence.

If it does exist, this exotic new force would connect matter at Earth's surface with matter hundreds or even thousands of miles deep within Earth's mantle and could potentially provide new information about the composition and characteristics of deep Earth, which is poorly understood because of its inaccessibility.

"The most rewarding and surprising thing about this project was realizing that particle physics could actually be used to study the deep Earth," says Jung-Fu "Afu" Lin, associate professor at the University of Texas at Austin's Jackson School of Geosciences and co-author of the study appearing this week in the journal Science.

The research was supported by NSF's Geoscience and Mathematical and Physical Science Directorates, the U.S. Department of Energy (DOE), and the Carnegie/DOE Alliance Center.

This new force could help settle a scientific quandary. When earth scientists previously have tried to model how factors such as iron concentration and physical and chemical properties of matter vary with depth - for example, using the way earthquake rumbles travel through the Earth or through laboratory experiments designed to mimic the intense temperatures and pressures of the deep Earth - they get different answers.

The fifth force, assuming it exists, might help reconcile these conflicting lines of evidence.

Earth's mantle is a thick geological layer sandwiched between the thin outer crust and central core, made up mostly of iron-bearing minerals. The atoms in these minerals and the subatomic particles making up the atoms have a property called spin.

Spin can be thought of as an arrow that points in a particular direction. It is thought that Earth's magnetic field causes some of the electrons in these mantle minerals to become slightly spin-polarized, meaning the directions in which they spin are no longer completely random, but have some preferred orientation. These electrons have been dubbed "geoelectrons."

The goal of this project was to see whether the scientists could use the proposed long-range spin-spin interaction to detect the presence of these distant geoelectrons.

The researchers, led by Larry Hunter, professor of physics at Amherst College, first created a computer model of Earth's interior to map the expected densities and spin directions of geoelectrons.

The model was based in part on insights gained from Lin's laboratory experiments, which measure electron spins in minerals at the high temperatures and pressures of Earth's interior. This map gave the researchers clues about the strength and orientations of interactions they might expect to detect in their laboratory in Amherst, Mass.

Second, the researchers used a specially designed apparatus to search for interactions between geoelectrons deep in the mantle and subatomic particles at Earth's surface. The team's experiments essentially explored whether the spins of electrons, neutrons or protons in various laboratories might have a different energy, depending on the direction with respect to the Earth that they were pointing.

"We know, for example, that a magnet has a lower energy when it is oriented parallel to the geomagnetic field and it lines up with this particular direction - that is how a compass works," Hunter says.

"Our experiments removed this magnetic interaction and looked to see if there might be some other interaction with our experimental spins. One interpretation of this 'other' interaction is that it could be a long-range interaction between the spins in our apparatus and the electron spins within the Earth, that have been aligned by the geomagnetic field. This is the long-range spin-spin interaction we were looking for."

Although the apparatus was not able to detect any such interactions, the researchers could at least infer that such interactions, if they exist, must be incredibly weak - no more than a millionth of the strength of the gravitational attraction between the particles. That's useful information as scientists now look for ways to build ever more sensitive instruments to search for the elusive fifth force.

"No one had previously thought about the possible interactions that might occur between the Earth's spin-polarized electrons and precision laboratory spin-measurements," says Hunter.

If the long-range spin-spin interactions are discovered in future experiments, "geoscientists can eventually use such information to reliably understand the geochemistry and geophysics of the planet's interior," says Lin.

.


Related Links
National Science Foundation
Earth Observation News - Suppiliers, Technology and Application






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





EARTH OBSERVATION
New approach alters malaria maps
University Park PA (SPX) Feb 26, 2013
Identifying areas of malarial infection risk depends more on daily temperature variation than on the average monthly temperatures, according to a team of researchers, who believe that their results may also apply to environmentally temperature-dependent organisms other than the malaria parasite. "Temperature is a key driver of several of the essential mosquito and parasite life history tra ... read more


EARTH OBSERVATION
Water On The Moon: It's Been There All Along

Building a lunar base with 3D printing

US, Europe team up for moon fly-by

Russia to Launch Lunar Mission in 2015

EARTH OBSERVATION
Mars rover ingests rock powder for tests

Opportunity Is On A Rock Hunt

Big Nickel Rock Target Ahead

NASA Rover Confirms First Drilled Mars Rock Sample

EARTH OBSERVATION
Choreographed to Perfection

ATK Launch Abort Motor For First Orion Test Vehicle

Supersonic skydiver's records confirmed

Kennedy Engineers Designing Plant Habitat For ISS

EARTH OBSERVATION
Welcome Aboard Shenzhou 10

Reshuffle for Tiangong

China to launch 20 spacecrafts in 2013

Mr Xi in Space

EARTH OBSERVATION
Record Number of Students Control ISS Camera

NASA briefly loses contact with space station

Temporary Comm Loss Interrupts Crew's Day

Low-Gravity Flights Will Aid ISS Fluids and Combustion Experiments

EARTH OBSERVATION
SpaceX 2 Launch Set for March 1

NASA Releases Glory Taurus XL Launch Failure Report Summary

India's 102nd space mission lifts off successfully

Countdown begins for Indo-French satellite launch

EARTH OBSERVATION
NASA's Kepler Mission Discovers Tiny Planet System

Kepler helps astronomers find tiny exo planet

Searching for a Pale Blue SPHERE in the Universe

Earth-like planets are right next door

EARTH OBSERVATION
Tokyo hotel shrinks in new-style urban demolition

Fluids in Space, Shaken Not Stirred

The world's most sensitive plasmon resonance sensor inspired by ancient Roman cup

Sustainable new catalysts fueled by a single proton




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement