Early on the morning of 30 June 1908, the vast forest of western Siberia was illuminated by a strange apparition: an alien object streaking across the cloudless sky. White hot from its headlong plunge into the Earth’s atmosphere, the intruder exploded about 8 km above the ground, flattening trees over an area of 2000 square kilometres.
Despite the huge detonation, equivalent to a 10 megaton nuclear warhead (about 500 times the energy of the Hiroshima atomic bomb), there were few if any casualties in the sparsely populated taiga. If the Tunguska object – probably an asteroid about twice the size of a tennis court – had exploded over London or Paris, the list of casualties would have run into millions.
Fortunately, cataclysmic events caused by incoming near-earth objects (NEOs) are few and far between. Current estimates suggest that a 50 metre Tunguska-like object is likely to collide with the Earth once every 100-300 years. A 1 km object, which typically arrives every few hundred thousand years, could wipe out an entire country. An impact in the ocean would be no better, generating enormous waves (known as tsunamis) that would devastate coastal areas thousands of kilometres away.
Franco Bonacina | alfa
Water without windows: Capturing water vapor inside an electron microscope
13.12.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University
Columbia engineers create artificial graphene in a nanofabricated semiconductor structure
13.12.2017 | Columbia University School of Engineering and Applied Science
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
13.12.2017 | Health and Medicine
13.12.2017 | Physics and Astronomy
13.12.2017 | Life Sciences