Tyler O'Neal, Staff Editor EARTH SCIENCES

Japanese researchers perform quantum mechanical simulations of Earth's lower mantle minerals

At the Geodynamics Research Center, Ehime University, Matsuyama, Japan, recent progress in theoretical mineral physics based on the ab initio quantum mechanical computation method has been dramatic in conjunction with the rapid advancement of supercomputer technologies. It is now possible to predict stability, elasticity, and transport properties of complex minerals quantitatively with uncertainties that are comparable or even smaller than those attached in experimental data.

These calculations under in situ high-pressure (P) and high-temperature (T) conditions are of particular interest since they allow them to construct a priori mineralogical model of the deep Earth. In the present article, we briefly review our recent accomplishments in studying high-P phase relations, elasticity, thermal conductivity and rheological properties of major lower mantle silicate and oxide minerals including (Mg,Fe)SiO3 bridgmanite, its high-pressure form post-perovskite, CaSiO3 perovskite, (Mg,Fe)O ferropericlase, and some hydrous phases (AlOOH, MgSiO4H2, FeOOH). CAPTION Crystal structures of major mineral phases composing the Earth's deep mantle, (Mg,Fe)SiO3 bridgmanite (Brg), its high-pressure phase post-perovskite (PPv), CaSiO3 perovskite, and (Mg,Fe)O ferropericlase{module INSIDE STORY}

The analyses indicate that the pyrolitic composition can be used to describe the Earth's properties quite well in terms of all of the densities, and P and S wave velocity. Supercomputations also suggest some new hydrous compounds which could persist down to the deepest mantle and that the post-perovskite phase boundary is the boundary not only of the mineralogy but also of the thermal conductivity.

Russian scientist discovers why photons flying from other galaxies do not reach the Earth

Tyler O'Neal, Staff Editor EARTH SCIENCES

An international group of scientists, including Andrey Savelyev, associate professor of the Institute of Physical and Mathematical Sciences and Information Technologies of the IKBFU, has improved a supercomputer program that helps simulate the behavior of photons when interacting with hydrogen spilled in intergalactic space. Work results were published in an educational journal.

"In the Universe, there are extragalactic objects such as blazars, which very intensively generate a powerful gamma-ray flux, part of photons from this stream reaches the Earth, as they say, directly, and part - are converted along the way into electrons, then again converted into photons and only then get to us. The problem here is that mathematical calculations say that a certain number of photons should reach the Earth, and in fact, it gets much less," said Savelyev.

Scientists, according to Savelyev, today have two versions of why this happens. The first is that a photon, after being converted into an electron (and this, as is known, in contrast to a neutral photon, a charged particle) falls into a magnetic field, deviates from its path and does not reach the Earth, even after being transformed again in the photon. {module INSIDE STORY}

The second version explains the behavior of particles flying to our planet not by their interaction with an electromagnetic field, but by contact with hydrogen "spilled" in the intergalactic space.

"Many people believe that space is completely empty and that there is nothing between the galaxies. In fact, there is a lot of hydrogen in a state of plasma, that is, in other words, very strongly heated hydrogen. And our report is about how particles interact with this plasma. There is a special [super]computer program that calculates models of particle behavior in intergalactic space. We can say that we improved this program by considering several possible options for the development of events in interaction with plasma".

Unfortunately, it is not yet possible to verify the calculations empirically, because people have not yet learned how to create extreme space conditions on Earth, but Savelyev is sure that someday this will become possible to some extent.

It is important to note that the results of the research, despite the fact that while they are what is called "pure science," can theoretically be applied in practice in the future.

Plasma, the fourth state of matter (in addition to gas, liquid and solid), is very difficult for research said Savelyev. At the same time, humanity has high hopes for it, as a source of cheap and very powerful energy. And our study is a small contribution to the collection of plasma knowledge. Perhaps they will be useful in developing effective nuclear fusion.