A bevy of satellites buzzing around in the Earths magnetosphere has found at least part of the answer to a long-standing puzzle about the source of the charged particles that feed the aurora.
Three-dimensional computer simulation of the space waves or vortices that inject the solar wind plasma into the Earths magnetic field. Green-blue areas represent the solar wind plasma, and red-orange areas represent plasma trapped in Earths magnetic field. Earths magnetosphere develops ripples and folds like a flag in the wind as the solar wind blows past. This turbulence creates rolling waves on the edges of the magnetosphere that engulf the solar wind into the magnetosphere (see orange wavelike structure in the cut-away portion of the image). The blue, green and orange swirl behind the wave is the vortex that mixes the solar wind into the magnetosphere. The vortices are huge structures, measuring more than 20,000 miles across. (Kentaro Tanaka of Tokyo Institute of Technology)
The charged particles come from explosions on the sun and smash into the Earths magnetic field, which repels the bulk of them. But many slip through, often via a physical process called magnetic reconnection, where the magnetic field traveling with the particles breaks and reconnects with the Earths field, opening a window for the particles to surge through. Once inside, these excited particles can spiral down toward the poles and create brilliant auroras when they hit the atmosphere.
But magnetic reconnection happens only when the solar winds magnetic field direction is 180 degrees opposite from that of the magnetic field of the Earth. When the two fields are aligned, there is no obvious physical process allowing entry of charged particles, at least at the leading edge of the Earths magnetosphere.
Significantly more productivity in USP lasers
06.12.2016 | Fraunhofer-Institut für Lasertechnik ILT
Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
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07.12.2016 | Health and Medicine
07.12.2016 | Life Sciences
07.12.2016 | Health and Medicine