If you have ever peered down a highway on a sunny day, you have probably seen the rising, wavelike ripples of heated air that distort the appearance of objects near the horizon. Similar disturbances in the atmosphere above us make stars twinkle as their light is distorted on the way down to Earth.
Although twinkling stars inspired a well-known nursery rhyme, the effect hampers astronomers attempts to study the heavens. Scientists at Lawrence Livermore National Laboratory are now building systems, known as a synthetic guide stars, to help astronomers accurately account for atmospheric distortions wherever they choose to point their telescopes. Pictures collected by large terrestrial telescopes equipped with such systems often exceed the quality of Hubble Space Telescope images.
Guide stars have long played an important role in correcting atmospheric distortion. Astronomers pick a bright, stable star near a region of the sky that they hope to study and monitor distortions in the guide star image to deduce the optical properties of the atmosphere. They then correct their images with adaptive optics, which distort telescope components to offset atmospherically induced errors. Generally, adaptive optics corrections involve warping light-collecting telescope mirrors with computer controlled motors that respond to changes in the guide star image.
James Riordon | EurekAlert
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22.07.2019 | Universität Augsburg
Augsburg chemists and physicists report how they have succeeded in the extremely difficult separation of hydrogen and deuterium in a gas mixture.
Thanks to the Surface Acoustic Wave (SAW) technology developed here and already widely used, the University of Augsburg is internationally recognized as the...
Adjusting the thermal conductivity of materials is one of the challenges nanoscience is currently facing. Together with colleagues from the Netherlands and Spain, researchers from the University of Basel have shown that the atomic vibrations that determine heat generation in nanowires can be controlled through the arrangement of atoms alone. The scientists will publish the results shortly in the journal Nano Letters.
In the electronics and computer industry, components are becoming ever smaller and more powerful. However, there are problems with the heat generation. It is...
Scientists have visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high performance electronic devices.
Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in...
Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.
Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...
For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.
Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...
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