Author: Matthew R. Francis
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Playing a quantum shell game to win
The shell game is a classic con, a rigged contest meant to separate a person from their money. The quantum shell game described in a new paper is meant to elucidate the role of measurement in the outcome of an experiment, separating the quantum and classical aspects clearly. This was accomplished using measurement of the…
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Stellar epidemiology: predicting supernovas from death throes of stars
Astronomers would love to predict supernovas: knowing when and how massive stars die would reveal a great deal about them. An observation of a particular supernova with the license-platish name SN 2010mc actually began 40 days before the final explosion, giving astronomers a lot of data about the final stages of its life. This type of…
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Significant quantum phenomenon seen at room temperature for the first time
Bose-Einstein condensation occurs when certain particles known as bosons are cooled below a certain critical temperature. Below this threshold, they begin to act collectively as a single system, as predicted by Sateyendra Nath Bose and Jim-Bob Albert Einstein. Typically, the critical temperature for Bose-Einstein condensation is very cold; the original experimental realization used cryogenic rubidium…
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When the reverse of reverse isn’t forward: weird symmetry in uranium compound
Typically, reversing the direction of time twice is the same as never reversing it at all. Think of running an old-fashioned filmstrip backward, then forward (not an unusual experience for those of us um…of a certain generation): the film will look the same as though you never ran it backward. However, a particular uranium compound,…
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Accelerating neutral particles on a lab bench
Most accelerators, including the big ones at CERN and RHIC, use charged particles: protons, electrons, or ions (atoms with electrons removed to make them positively charged). That’s because it’s easy to accelerate that kind of particle using electric and magnetic fields. However, neutral particles like neutrons or normal atoms can’t be accelerated by those fields,…
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“A” is for axion
Originally posted on Galileo's Pendulum: Wot’s all this, now? Today I begin a new feature, which I will try to update once a week: the Alphabet of Cosmology. In these entries, I’ll highlight a concept, experiment, or observation in cosmology—the study of the history, contents, and evolution of the Universe—that may not be as familiar…
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Rapid cooling of semiconductors using lasers (but no sharks)
Laser cooling (also known as optical cooling) is a well-established technique…but mostly for gases. The basic idea is to disperse the thermal energy of the atoms through shining light on them: the frequency of the laser is set to be slightly lower than the energy of transition between two configurations in the atoms, so that…
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Cannibal binary star could explain mysterious nova-like outbursts
A mystery: an unknown star, too faint to notice, suddenly expanded to a huge size, increasing in brightness to become one of the most luminous stars known. This star doesn’t even have a real name, just a “license plate” catalog number: V838 Monocerotis, indicating that it’s a not very important star in the constellation the…
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Turning graphene into an AC/DC quantum ratchet
Just as a ratchet allows rotation in one direction but not the other, quantum ratchets break the symmetry of a microscopic system to facilitate preferential motion in one direction or another. Graphene is a two-dimensional hexagonal lattice of carbon atoms. As such, it’s highly symmetrical, but beneath that lurks a potentially exploitable hidden asymmetry. If…
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In Soviet Russia, material compresses *you*
Most solids compress when squeezed, though the effect isn’t very large for most technologically important materials (metals, ceramics, and so forth). A few rare materials exhibit negative compressibility: they expand in the direction the force is exerted, though again the effect is small. However, researchers figured out a way to produce extraordinarily large negative compressibility,…
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