During Earth formation, decay of short-lived radioactive isotopes and surface bombardment from large bodies heated Earths mantle and created a deep magma ocean
Earth’s future was determined at birth. Using refined techniques to study rocks, researchers at the Carnegie Institution’s Department of Terrestrial Magnetism (DTM) found that Earth’s mantle--the layer between the core and the crust--separated into chemically distinct layers faster and earlier than previously believed. The layering happened within 30 million years of the solar system’s formation, instead of occurring gradually over more than 4 billion years, as the standard model suggests. The new work was recognized by Science magazine, in its December 23 issue, as one of the science breakthroughs for 2005.
Carnegie scientists Maud Boyet and Richard Carlson analyzed isotopes--atoms of an element with the same number of protons, but a different number of neutrons--of elements in rock samples for their work. As Carlson explains, "Isotopes exist naturally in different proportions and are used to determine conditions under which rock forms. Radioactive isotopes are particularly handy because they decay at a predictable rate and can reveal a sample’s age and when its chemical composition was established."
In the standard model of the geochemical evolution of the Earth, the Earth’s mantle has been evolving gradually over Earth’s 4.567-billion-year history primarily through the formation of the chemically distinct continental crust. Shortly after solid material began condensing from the hot gas of the cooling early solar system, the object that would become Earth grew by the collision and accretion of smaller rocky bodies. The chemical composition of these building blocks is preserved today in primitive meteorites called chondrites.
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Physicists working with researcher Oriol Romero-Isart devised a new simple scheme to theoretically generate arbitrarily short and focused electromagnetic fields. This new tool could be used for precise sensing and in microscopy.
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Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers
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Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.
At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...
3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects
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Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
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27.07.2017 | Life Sciences
27.07.2017 | Life Sciences
27.07.2017 | Health and Medicine