Saturday, March 08, 2008

Singing cosmos

How cool is this? The northern lights sing:

It's safe to say that the majority of scientists who do research in this field are skeptical of the notion that the aurora's dazzling light show has its own built-in soundtrack, but while visiting Lapland, Hill worked closely with a geophysicist who does: Esa Turunen of the SGO, whose research focuses in part on scientifically establishing the audibility of the phenomenon. Certainly the aurora borealis produces sounds in space, and those sounds are monitored and recorded regularly by observatories all over the globe, including the SGO. But the sounds heard on Earth are probably more local in origin.

Field instruments are finally sensitive enough to capture these weird sounds for empirical analysis, hampered a bit by the fact that the sounds only occur during the most intense geomagnetic activity. The Helsinki University of Technology (HUT) has an Auroral Acoustics program that statistically analyzes field recordings of auroral acoustics and compares them to a "control group" of recordings from nights when there was no geomagnetic activity. It's an ongoing project, but to date, findings support the anecdotal evidence: the sounds are real, they strongly correlate with particularly intense auroral displays, and they are produced locally, although scientists remain mystified by the exact mechanism doing the producing.

Northern lights
(Click image for full view.)

More here.

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