Category: Hellraisin’
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Supernova over south pole caused Ordovician mass extinction
About 444 million years ago, more than half of all marine invertebrates were wiped out at the end of the Ordovician era in the third worst mass extinction in history. A couple of years ago, Brian Thomas at the University of Kansas pointed out that this holocaust could have been caused by a nearby supernova…
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The LHC: let the lead fly
There’s no doubt that protons will be the stars of the show when the LHC switches on this morning. But in all the fuss it’s easy to forget that the machine is designed to carry other particles too. So Paolo Giubellino at the National Institute of Nuclear Physics in Turin, Italy, outlines what to…
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Do nuclear decay rates depend on our distance from the sun?
Here’s an interesting conundrum involving nuclear decay rates. We think that the decay rates of elements are constant regardless of the ambient conditions (except in a few special cases where beta decay can be influenced by powerful electric fields). So that makes it hard to explain the curious periodic variations in the decay rates of…
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How to find another Earth
“We stand on a great divide in the detection and study of exoplanets,” says the Exoplanet Task Force on the arXiv today in describing their plan for finding another Earth orbiting another star. On one side of this divide are the hundreds of known massive exoplanets, they say. And on the other” lies the…
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The black hole at the center of our galaxy
Is there a supermassive black hole at the center our galaxy, asks Mark Reid from the Harvard Smithsonian Center for Astrophysics in Cambridge. There sure is and Reid gives a good account of the evidence to prove it. How can astronomers be so sure? The first evidence began to emerge in the 1950s when the…
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The painful search for gravitational waves
Gravitational wave detectors have a sorry history of disappointing results. Joseph Weber at the University of Maryland first claimed to have spotted these waves in 1969. He did it by listening to the way a giant cylindrical bars vibrate, thinking that passing gravitational waves would cause them to ring like a bell. Nobody has been…
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The day the solar wind disappeared
It happened on 11 May 1999…nobody knows why and the event was not related to well known drivers of solar weather such as coronal mass ejections or large flares. According to Durgess Tripathi at the University of Cambridge, UK, and pals, the cause seems to be linked to the appearance a few days earlier of…
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Musical relativity
Here’s a neat idea for a concert that’s going to blow a few minds if it ever takes to the stage. A combination of three or more notes played together is called a chord. We know that certain musical chords sound happy while others sound sad (although nobody knows why). The mood of a piece…
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The science of the Grateful Dead
Good to see that Deadheads are alive and well at Los Alamos National Laboratory in New Mexico. In the heart of one of the world’s most secret weapons labs, these guys are hard at work developing a science of the Grateful Dead, the 60s psychedelic band that played together until 1995. Today, they take the…
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How to build a warp drive
Is faster than light travel allowed by the laws of physics? There’s no harm in speculating, right? In 1994, Michael Alcubierre, a physicist at the National Autonomous University of Mexico in Mexico City, put warp drive on a firm (-ish) theoretical footing for the first time. His thinking was that what relativity actually prevents…