Category: Ars Technica
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Halo star haze helps hidden galaxies look huge
(Not fully alliterative, but it’s the best I can do after driving 6 hours today.) The halos of galaxies are best known for harboring dark matter, but they also contain stars. Only a tiny fraction of the total stars in a galaxy are in the halo, so usually they’re hard to spot, but astronomers are…
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Twisted light on a silicon chip
(In honor of Terry Pratchett, I almost wrote that “Twisted light? Onna chip?”, but that would probably confuse 90% of my readers.) Light is used to carry data, but mostly we don’t use the properties of the photons themselves to convey information. Quantum communication, among other applications, could use the state of the photon to…
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Radioactive titanium powers a supernova afterglow
(Yes, I’m inundating you all with writing. It’s a busy week, and I still have a few more things forthcoming to share with you.) Supernova 1987a was the death of a massive blue star in the Large Magellanic Cloud, one of the satellite galaxies of our Milky Way. Because of its relative proximity and occurrence…
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Not quite ready for the Diamond Age
In his science fiction novel The Diamond Age, Neal Stephenson describes a world filled with electronic paper, tiny flexible computers, and transparent displays. Graphene—a crystal comprised of a single layer of carbon atoms—is perhaps the most promising material to make that world real (though hopefully without the universal surveillance state and environmental collapse that are…
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Quantum communication without entanglement
Information in quantum physics is carried in a system’s quantum state, which is basically a list of all the important properties. An atom’s state, for example, contains the relative orientation of the nucleus and electrons, the energy levels the electrons occupy, and the like. Quantum computing manipulates these states in prescribed ways for calculation purposes,…
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The beautiful spiral of a dying star
Though it may seem sad on the surface, the death of a star is a beautiful thing—and an important precursor to the birth of new stars and planets. The Atacama Large Millimeter Array (ALMA) in Chile has provided a breathtaking view of a star nearing the end of its life. One unexpected feature was a…
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The darkness at the center of the galaxy
Since 1995, a team of astronomers led by Andrea Ghez has been studying the motion of stars near the center of the Milky Way. They just announced the discovery that one of those stars is the closest to the black hole yet, with an orbital period of about 11.5 years—short enough that they’ve been able…
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Spinning pulsar, got to slow down
(This headline was my original choice for the article, which was understandably rejected by my editors. So, you get to read it here instead.) Pulsars are rapidly-spinning neutron stars, the very small dense remnants of stars at least 8 times more massive than the Sun. Their pulses are intense beams of light that sweep across…
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Pore, pore, pitiful solar cells
There’s just one word for the ‘teens: plastics photovoltaics. A new experiment may have solved a problem in nanostructured silicon solar cells: a type of photovoltaic cell that uses pores to increase the effective surface area for collection of light. By separating the contribution by surface and interior recombination effects, the NREL study found that…
Bowler Hat Science 