Looking into the interior of the Earth or the Sun is a bit similar to examining a baby in its mother`s womb using an ultrasound scan. Light cannot penetrate the area, so we make pictures in these cases using sound waves, which human ears cannot hear. With SOHO, ESA has probed deeply into the Sun using the sound-waves principle, and with great success. The future missions, Solar Orbiter and Eddington, will look inside our Sun and other stars, respectively, in a similar way.
Here on Earth, when scientists recorded slight shakes, or seisms, coming from earthquakes even on distant continents, they began to estimate the routes and the changing speeds of the waves passing through the Earth`s interior. This revealed our planet`s molten core. Nowadays, oil prospectors routinely thump the ground to get seismic echoes from deep-lying strata. Scientists combine earthquake records from seismometers worldwide, to make 3D pictures of the rocks far beneath our feet.
Seismology is the study of earthquake waves. Studying solar sound waves is called helioseismology, from helios, a Greek word for Sun. When you transfer your focus onto the stars, as Eddington will do, you are studying asteroseismology. Although the Sun and stars are made of very hot gas rather than rocks, basic principles about deducing the routes and speeds of internal waves still work.
Monica Talevi | alfa
Abrupt motion sharpens x-ray pulses
28.07.2017 | Max-Planck-Institut für Kernphysik
Physicists Design Ultrafocused Pulses
27.07.2017 | Universität Innsbruck
Spectrally narrow x-ray pulses may be “sharpened” by purely mechanical means. This sounds surprisingly, but a team of theoretical and experimental physicists developed and realized such a method. It is based on fast motions, precisely synchronized with the pulses, of a target interacting with the x-ray light. Thereby, photons are redistributed within the x-ray pulse to the desired spectral region.
A team of theoretical physicists from the MPI for Nuclear Physics (MPIK) in Heidelberg has developed a novel method to intensify the spectrally broad x-ray...
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.
Microwaves, heat radiation, light and X-radiation are examples for electromagnetic waves. Many applications require to focus the electromagnetic fields to...
Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers
Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...
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
A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...
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