Month: July 2008
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Why red dwarfs could reveal first Earth-like planets
Red dwarfs are relatively common, cool stars that are less than half the size of the Sun. Because of their size, it should be easy to spot orbiting planets as they pass in front of the stars. For instance, a planet twice the size of Earth, orbiting in a star’s habitable zone at a distance…
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Can entanglement exist in biological systems?
Can entanglement exist in biological systems? The usual argument against is that physicists have to work hard to produce entanglement in the carefully controlled conditions that exist in the lab. So it’s hardly likely that entanglement will ever be found in systems that are warm, wet and messy, like human bodies for instance. But Sandu…
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Simple mod turns diode into photon counter
Counting photons is a tricky business. They’re slippery beasts that arrive silently, often and in packs, in ways that are almost impossible to count. One of the most widely used of devices that can spot the arrival of a single photon is the avalanche photodiode. These cheap and easy to use devices rely on the…
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The curious kernels of dictionaries
If you don’t know the meanng of a word, you look it up in the dictionary. But what if you don’t know the meaning of any of the words in the definition? Or the meaning of any of the words in the definitions of these defining words? And so on ad infinitum. This is known…
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In case ya missed ’em…
The nacre from this week’s physics arxiv blog: The curious kernels of dictionaries Group theory and spinal injuries Global warming and the climate of fear How many pedestrians can squeeze through a corridor?
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Walkin ‘n’ talkin
The other highlights from the physics arxiv: Magnetic Excitation in Artificially Designed Oxygen Molecule Magnet Pre-launch Estimates for GLAST Sensitivity to Dark Matter Annihilation Signals A Robust Correlation Between Growth Rate and Amplitude of Solar Cycles Evolution of the First Stars with Dark Matter Burning The Borexino detector at the Laboratori Nazionali del Gran Sasso…
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How many pedestrians can squeeze through a corridor?
There’s chaos in the corridors at the labs of Michael Schreckenberg and colleagues at the University Duisberg-Essen in Germany. Schreckenberg specialises in the physics of traffic and transport and has been fascinated by a particular question: how much pedestrian traffic can you squeeze into a shopping mall during the peak shopping hours? This question has…
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Global warming and the climate of fear
“It does, however, seem difficult to believe that our species, that has dominated the planet for a relatively short period of time, could have such a huge impact on our planet’s climate, whilst the Sun, the most massive body in the solar system whose influence dominates our planet, could have such little impact.” So concludes…
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Group theory and spinal injuries
Medical science is stuck in the middle ages when it comes to understanding the causes of back pain and how to prevent it. If you want advice, “bend your knees when lifting” is all you’re likely to get. The standard theory describing spinal injuries is known as the principal loading hypothesis and assumes that any…