Satellite images have revealed that a remote Arctic ice cap has thinned by more than 50 meters since 2012 -- about one sixth of its original thickness -- and that it is now flowing 25 times faster.
Gravitational theories with broken Lorentz invariance have attracted a great deal of interest as they provide a test-bed of LI and offer a mechanism to improve their ultraviolet behavior, so that the theories may be renormalizable. However in such theories, particles can travel with arbitrary velocities and black holes may not exist at all. In contrast to this expectation, it has been shown that an absolute horizon exists, which traps signals despite infinitely large velocities.
The High Energy Stereoscopic System telescopes have again demonstrated their excellent capabilities in searching for high-energy gamma rays.
Sound waves passing through the air, objects that break a body of water and cause ripples, or shockwaves from earthquakes all are considered 'elastic' waves. These waves travel at the surface or through a material without causing any permanent changes to the substance's makeup. Now, engineering researchers at the University of Missouri have developed a material that has the ability to control these waves, creating possible medical, military and commercial applications with the potential to greatly benefit society.
Yale University astronomers have identified the first 'changing look' quasar, a gleaming object in deep space that appears to have its own dimmer switch.
After making its social debut in the Southern Pacific Ocean, NASA's Aqua satellite spotted Tropical Cyclone Niko moving through the Society Islands.
In some of the first research findings to be published from the European Space Agency's Rosetta Mission to the comet 67P/Churyumov-Gerasimenko, scientists including astronomer Peter Schloerb of the University of Massachusetts Amherst report early measurements of the comet's subsurface temperature and production of gas from the surface of its nucleus.
Half the heavy elements in nature are created during stellar explosions such as supernovae or star collisions. Analyzing deep-sea samples of stardust that fell to Earth over millions of years, researchers made a surprising discovery about how frequently far-away stars produce heavy elements like gold and uranium. 'Our analysis shows about 100 times less plutonium than we expected,' says co-author professor Michael Paul at the Hebrew University's Racah Institute of Physics.
As the Rosetta spacecraft orbits comet 67P/Churyumov-Gerasimenko, an international team of scientists have discovered that the comet's atmosphere, or coma, is much less homogenous than expected and comet outgassing varies significantly over time, as reported in a paper published in the Jan. 23, 2015, issue of Science. Dr. Myrtha Hässig is lead author of the paper titled 'Time Variability and Heterogeneity in the Coma of 67P/Churyumov-Gerasimenko' and a postdoctoral researcher at Southwest Research Institute.
On Nov. 12, 2014, the Rosetta mission's Philae lander touched down on the surface of comet 67P/Churyumov-Gerasimenko. While this achievement gained lots of headlines, it was only the beginning for researchers back on Earth. New data provides the closest and most detailed look at a comet that scientists have ever seen. The results--including four papers co-authored by UMD scientists--appear in a special issue of the journal Science on Jan. 23, 2015.