All posts by Mark Wood

Earth’s core is covered with iron particles according to a new study

A kind of snow cover of iron particles has been hypothesized around the hot core of the Earth in a new study appeared on JGR Solid Earth and carried out by a team of researchers led by Jung-Fu Lin, professor at the Jackson School of Geosciences of the University of Texas at Austin. According to the researchers, around the inner core of the Earth, in an environment where there is immense pressure, there would be a precipitation of tiny iron particles falling from the molten outer core accumulating over the inner core. These particles create batteries up to 200 miles thick.

According to the researchers themselves, the way this sort of semi-liquid section is formed around the inner core is similar to the way rocks are formed inside volcanoes. Jung-Fu Lin himself explains: “The metal core of the Earth functions as a magma chamber that we know best in the crust.

These are theoretical insights simply because the Earth’s core cannot be sampled or studied directly. The only way scientists can find information about this hidden section of our planet is to record and analyze the signals of seismic waves as they travel across the Earth. However, some recent studies have raised questions: these waves move slower than expected when they pass through the base of the outer core and move faster when they pass through the eastern hemisphere of the upper inner core.

To explain this phenomenon, Jung-Fu Lin and the other main author of the study, Youjun Zhang, a professor at the University of Sichuan in China, proposed this theory that the iron “snow” covered core would explain these aberrations. It is a theory in some ways already proposed in the 1960s by the scientist S.I. Braginskii according to which there was a layer of slurry between the inner and outer nucleus.

The new data collected for this study show that a sort of crystallization effect is possible in this area and that about 15% of the lower external nucleus can actually be made of iron-based crystals that eventually fall on the solid internal nucleus. “It’s kind of a weird thing to think about,” admits Nick Dygert, a professor at the University of Tennessee who participated in the study. “You have crystals inside the outer core that snow on the inner core over a distance of several hundred miles.” Among other things, this theory supports the idea that the boundary of the inner core is not represented by a simple and smooth surface, as Zhang himself explains.

Scientists simulate with supercomputers the amount of data they will get from the world’s largest radio telescope

The Square Kilometer Array (SKA), considered the largest radio telescope in the world (in fact it will be a network of several radio telescopes), an international project that will allow the analysis of the sky through radio waves and will also probe deep space. The heart of the project will be represented by a central processing plant that will have to offer very high performance as it is expected that this radio telescope will collect huge amounts of data every day.

This amount of data is so high that it has never been processed before, at least as far as the astronomical sector is concerned, and the researchers themselves do not hide the fact that they are worried about running into difficulties once the first data are obtained. And they can’t even carry out experiments because to process such large amounts of data you need very powerful supercomputers. At least until a few weeks ago. A team of researchers from various international institutes has in fact been able to use Summit, currently the most powerful supercomputer in the world, to simulate the processing of the amount of data that the SKA will provide.

Located at the Oak Ridge Leadership Computing Facility, USA, this computer “offered a unique opportunity to test a simple SKA data stream at the scale we expect from the telescope array,” reports Andreas Wicenec, head of the Data Intensive Astronomy project at ICRAR. To simulate the data, the researchers used a particular open source operating system “designed to accelerate the simulations by increasing the efficiency of I/O operations and to facilitate data transfers between high-performance computing systems and other facilities”, as reported in the press release on the Oak Ridge National Laboratory (ORNL) website.

The simulations enabled researchers to process 2.6 petabytes of data at 247 gigabytes per second. This is an amount of data that requires a lot of processing power and thousands of graphics processing units in order to extract useful results. When the real radio telescope is in operation, it will be able to receive radio waves from other galaxies and various other objects of interest, data that will help astronomers themselves to answer some of the most fundamental questions about the universe.

Nuclei of the universe’s largest galaxies were already mature 1.5 billion years after the big bang

The nuclei of the largest and most massive galaxies in the universe have already formed only 1.5 billion years after the big bang: this is the basic assumption of a new study conducted by Masayuki Tanaka, professor of astronomical sciences at the Graduate University for Advanced Studies and one of the operators of Japan’s national astronomical observatory. The researcher has in fact intercepted a distant and massive galaxy, containing more than 1 trillion stars, using the telescope of the Keck observatory in Hawaii in a region of the sky called Subaru/XMM-Newton Deep Field.

Using a particular instrument called MOSFIRE and present on the Keck telescope, the researcher obtained a very precise measurement, in the near infrared spectrum, of the light of this galaxy and discovered that it was emitted only 1.5 billion after the big bang. He also discovered, and perhaps this is the most important information, that the stellar formation within this galaxy seems already suppressed and ended so much that, in jargon, we can speak of “dying galaxy” because it is no longer active in terms of stellar production.

This information, in fact, tells us that the central nucleus of this galaxy had already formed and was mature and this in some ways is surprising considering the so remote period we are talking about. Moreover, this study confirms that our understanding of how galaxies are formed and how they grow, especially the largest and most massive ones, is still limited as Tanaka himself admits.

In any case this identification and analysis of this galaxy so far away and massive has provided several details that will help astronomers to understand more about how the “extinction” of galaxies happens, as explained by Francesco Valentino, one of the authors of the study and professor at the Cosmic Dawn Center (DAWN) in Copenhagen. What astronomers really want to answer is how and when the first “dead” galaxy of the universe appeared, one of the most interesting and intriguing questions regarding the whole field of studies on the so-called “primordial universe”.

Flour moths can eat toxic plastic without consequences

An important discovery was made by a group of researchers at Stanford in relation to the possibility that microorganisms can help us to dispose of all the plastic we produce and that we pour into the environment. The researchers analyzed the methods that are applied by the so-called flour moths, also called tenebrioni mugnai (Tenebrio molitor), small beetles originally native to Europe but now widespread throughout the world, to eat and ingest plastic.

These insects, when still in larval form, are able to consume various forms of plastic and the scientists behind this study, in an attempt to examine where they end up and how these substances are treated once ingested by these insects, discovered that they can also ingest and metabolize toxic plastics including polystyrene containing common chemical additives, something that surprised the researchers themselves.

The flour worms (larvae of Tenebrio molito) are used as feed for various farm animals, from chickens to fish to shrimp. These animals manage to biodegrade the plastic once it arrives in their bowels and can do so safely, as this latest study shows, since the chemical components found in plastics seem not to accumulate in the body of these insects and generally do not cause damage.

It is also an answer to all those questions that arose in relation to the fact that it could be dangerous to feed farm animals with worms that in turn had eaten toxic plastic. This study seems to show that it could be a safe practice, as Wei-Min Wu, an engineer at Stanford’s Department of Civil and Environmental Engineering at the head of the study, openly states.

To arrive at this conclusion, the researchers have ingested polystyrene containing a flame retardant, called hexabromocyclododecane, or HBCD, a plastic additive that serves to reduce flammability but which is under scrutiny by many governments because of its toxicity. The worms, after consuming this polystyrene, then expelled about half of it in the form of small, partially degraded fragments and another half in the form of carbon dioxide.

They were able to expel 90% of HBCD within 24 hours of consuming the plastic and 100% after 48 hours. As a result of this period of time, worms fed HBCD-laden polystyrene seemed as healthy as other specimens fed a normal diet. Currently, the only obstacle for those who already think they can use these worms to reduce the amount of plastic we put into the environment is that the HBCD expelled from worms through faeces is still a danger and therefore it would somehow biodegrade itself. This means that further solutions would have to be found in the future if such a solution were to be adopted.