A shower of matter from space millions of years ago could have led to drastic changes in the Earth’s climate, followed by the extinction of life on a massive scale, which also killed off the dinosaurs. This at least is a theory put forward by scientists from the University of Bonn. Normally, the solar wind acts as a shield against showers of cosmic particles, which prevents too many energy-rich particles from raining down on our atmosphere. Since 1997 scientists from Bonn, funded by the German Research Council (Deutsche Forschungsgemeinschaft or DFG), have been examining how and why this gigantic shield works.
They were the undisputed masters of a whole geological era until they suddenly disappeared 65 million years ago. ‘Perhaps Earth just became too damp and too cold for dinosaurs at that time,’ Professor Hans Jörg Fahr from the Bonn Institute of Astrophysics and Extraterrestrial Research surmises. The reason for the sudden change in climate could have been excessive pressure on our cosmic umbrella.
The solar system does not stand still, in fact it orbits the centre of the Milky Way once every 250 million years. In the process it also passes through dense clouds of interstellar matter, which causes problems for the solar wind and thus for the Earth. Whereas the solar wind normally protects the Earth from a hail of interstellar particles like a huge bullet-proof vest, there are then suddenly up to a hundred times more particles raining down into the earth’s atmosphere at enormous speeds. On impact they smash the air molecules into electrically charged fragments. These function as condensation nuclei on which droplets of water form. “The result is dense cloud cover with greater precipitation and sinking temperatures,” says Professor Fahr, who bases his remarks on research worldwide.
Professor Hans Jörg Fahr | alphagalileo
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At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
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Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
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