Month: March 2013
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Disentangling environmental influences in photon-atom interactions
Often in physics, we can separate the object from the environment and the experimental apparatus from what’s being measured, but that separation is approximate. In quantum systems, those distinctions break down, to the point where the environment “measures” the system, in ways we don’t fully understand even after nearly a century of study. (A lot…
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Aging binaries provide new calibration for cosmic distances
Cosmology—the study of the Universe as a whole—requires accurate measurements of the distances to galaxies and other objects billions of light-years away. However, the reliability of those estimates depends on how accurately we know the distance to closer objects, such as the Milky Way’s satellite galaxy known as the Large Magellanic Cloud (LMC). A new…
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The case of the missing black holes
No question: supermassive black holes get a lot of the glory, thanks to their obvious presence at the centers of many galaxies. However, stars more than 20 times the mass of our Sun leave behind smaller, stellar-mass black holes after their violent supernova deaths. Despite this model’s wide acceptance, astronomers have only identified about 50…
