Month: December 2012
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The band has stopped playing, but we keep dancing
The band has stopped playing, but we keep dancing The world keeps turning, the world keeps turning. –Tom Waits A lot of nonsense has been written over the years about various “prophecies” predicting the end of the world, including stuff by people who should know better. What you see in newspapers, magazines, and TV shows […]
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Holey metal, Batman!
Metal tends to be opaque. However, if you perforate it with small holes in a certain pattern, it will still transmit some light—even if the holes are smaller than the wavelength of the light! This is known as extraordinary optical transmission (EOT), which has found uses in a number of devices since its discovery in […]
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Think of the biggest black hole in the Universe. Now make it 10 times bigger….
The biggest black holes in the Universe reside at the centers of the largest galaxies. However, a new study suggests they may be proportionally even larger, compared with other galaxies. The bright cluster galaxies (BCGs) are huge galaxies found in the middle of galaxy clusters, where they grew by merging with and absorbing smaller galaxies. […]
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Speak softly and carry a 2.3-ton aluminum bar
We have no complete, consistent quantum theory of gravity. However, clues from other theories indicate that the physics we know breaks down at a certain fundamental length scale: the Planck length. In particular, the Heisenberg uncertainty principle in quantum mechanics must be modified if you can’t measure position to arbitrary precision. However, length and energy […]
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A drink from the cosmic cellar shows that some things never change
Certain physical quantities—the fundamental electric charge, the masses of certain particles, the strengths of the basic forces of the Universe—are generally assumed to be constant in time and space. Some of our theories depend on that constancy, but it’s not an absolute certainty: it’s possible that in distant galaxies, the rules might be a little […]
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Schrödinger’s gardenia: Does biology need quantum mechanics?
Erwin Schrödinger is best known to non-scientists for his thought experiment involving a cat (or maybe his unconventional living arrangement), but he also wrote What is Life?, a book that attempted to bring the fields of physics and biology closer to each other. Today, experiment is beginning to reach the point where we can see […]
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A miniature quasar in Andromeda Galaxy
The term “quasar” describes a behavior rather than an object: when a supermassive black hole (SMBH) at the center of a galaxy gorges on gas, the infalling matter produces a lot of light. While most galaxies are known to have SMBHs, not all of those exhibit quasar behavior. Similarly, black holes created from the deaths […]
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Oo’s a widdle bitty baby protostar?
Protostars are, as the name suggests, what we have before a star forms. Clouds of gas and dust collapse under gravitation, heat up, and (at least in some cases) begin fusing hydrogen into helium in their cores. A new observation of a protostar catches it very early in its formation, while it was still accreting […]
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They should have called the probes “Indiana” and “Henry Jones, Sr.”
For most astrophysics purposes, we don’t have to worry about the details of the inner structure of planets and moons. However, if we want to reconstruct their full history, it helps to know all the variations in density and composition. The twin GRAIL spacecraft in orbit around the Moon are designed to do just […]
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Early quasar illuminates a Universe without metals
The moments after the Big Bang left the Universe very hot and dense. In that violent environment, the first nuclei came to be: hydrogen, helium, and lithium…but nothing heavier. The elements more massive than helium (which astronomers perversely refer to as “metals”) were forged by stars and spread through the Universe as those stars died. […]
Bowler Hat Science 