The announcement Feb. 11 of the detection of gravitational waves, predicted by Albert Einstein some 100 years ago, created a surge of excitement among physicists worldwide, including many with ties to Princeton University. (more…)
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Physicists have wondered in recent years if they could control how atoms interact using light. Now they know that they can, by demonstrating games of quantum billiards with unusual new rules. (more…)
Relativitätstheorie auch in anderen Forschungsbereichen anwendbar
Einsteins Allgemeine Relativitätstheorie feiert heuer ihren 100. Geburtstag. Selbst heute noch fasziniert sie PhysikerInnen und Laien zugleich. Eine internationales Team um Časlav Brukner von der Universität Wien, Igor Pikovski von der University of Harvard und WissenschafterInnen von der University of Queensland haben nun entdeckt, dass die Relativitätstheorie auch ein ganz anderes, ungewöhnliches Phänomen erklären kann: den Übergang von der Quantenmechanik zu unserer alltäglichen, klassischen Welt. Die Forschungsergebnisse erscheinen im Journal “Nature Physics”. (more…)
On January 24, the journal Nature published an article entitled “There are no black holes.” 1 It doesn’t take much to spark controversy in the world of physics…But what does this really mean? In a brief article published on arXiv, a scientific preprint server, Stephen Hawking proposed a theory of black holes that could reconcile the principles of general relativity and quantum physics.
To better understand Hawking’s remarks, Forum interviewed Robert Lamontagne, an astrophysicist at the Department of Physics, Université de Montréal, and Executive Director of the Observatoire du Mont-Mégantic.
What is a black hole? (more…)
PASADENA, Calif. — Two X-ray space observatories, NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) and the European Space Agency’s XMM-Newton, have teamed up to measure definitively, for the first time, the spin rate of a black hole with a mass 2 million times that of our sun.
The supermassive black hole lies at the dust- and gas-filled heart of a galaxy called NGC 1365, and it is spinning almost as fast as Einstein’s theory of gravity will allow. The findings, which appear in a new study in the journal Nature, resolve a long-standing debate about similar measurements in other black holes and will lead to a better understanding of how black holes and galaxies evolve. (more…)
The UA’s Chris Impey has taught cosmology to Tibetan Buddhist monastics in remote parts of India each summer for the past five years. With a grant from the John Templeton Foundation, he detailed his experiences in a book, “Humble Before the Void,” which likely will publish in 2014.
Chris Impey thinks back to the time he spent living on the edge of Tibetan Buddhist monasteries, teaching modern cosmology to Buddhist monastics in India: “On a typical day, they would be up at 5 a.m. and have prayed for a few hours or done meditation before you even see them. And their attention is just as good at the end of a long day as at the beginning.” (more…)
AUSTIN, Texas — A team of astronomers led by researchers from The University of Texas at Austin has confirmed the emission of gravitational waves from the second-strongest known source in our galaxy by studying the shrinking orbital period of a unique pair of burnt-out stars. Their observations tested Albert Einstein’s theory of general relativity in a new regime. The results will be published soon in The Astrophysical Journal Letters.
Last year, the same team discovered that the two white dwarf stars are so close together that they make a complete orbit in less than 13 minutes, and they should be gradually slipping closer. The system, called SDSS J065133.338+284423.37 (J0651 for short), contains two white dwarf stars, which are the remnant cores of stars like our sun. (more…)
Berkeley Lab scientists are the leaders of BOSS, the Baryon Oscillation Spectroscopic Survey. They and their colleagues in the third Sloan Digital Sky Survey have announced the most precise measurements ever made of the era when dark energy turned on.
Some six billion light years distant, almost halfway from now back to the big bang, the universe was undergoing an elemental change. Held back until then by the mutual gravitational attraction of all the matter it contained, the universe had been expanding ever more slowly. Then, as matter spread out and its density decreased, dark energy took over and expansion began to accelerate.
Today BOSS, the Baryon Oscillation Spectroscopic Survey, the largest component of the third Sloan Digital Sky Survey (SDSS-III), announced the most accurate measurement yet of the distance scale of the universe during the era when dark energy turned on. (more…)