Epitomizing the old adage “where there’s smoke, there’s fire,” a group of volunteers and scientists in Finland set out to prove or disprove that the northern lights, or northern lights, make sounds.
For hundreds of years, reports of crackling, cracking or hissing abound, especially from indigenous people living in the Arctic, but also from non-indigenous people living in Canada, Finland, and other northern countries.
A belief among some Canadian First Nations groups is that the aurora consists of the spirits of their ancestors and the noise is their song.
However, there is very little science to suggest that the solar radiation moving in the magnetosphere is capable of producing more than images of the famous green, pink and purple lights.
But just as there is a line of reasoning among people looking for species that are presumed extinct that if so many people report sightings, there must be something there, one scientist reckons that for years people have described sounds that come from the aurora, for which at least is worth exploring the possibility.
A professor of acoustics at Finland’s Aalto University, Unto Laine, who heard faint sounds while observing the Northern Lights in remote Lapland, looked at the mountain of anecdotal reports and tried to construct a hypothesis that might explain them.
In 2016 he came up with the idea that the sounds were electric shocks as a result of a “temperature inversion”, which occurs when cold air, instead of floating above the ground, sticks to the ground, and when hot air, which normally radiates close to the dirt level, rises to cover the cold air at altitudes around 60-400 meters: a reversal of their normal positions.
When this hot air rises, it carries negatively charged electrons to the investment fund. The static electric potential field expands skyward and down to earth, and when the northern lights bombard the magnetosphere with positively charged electrons, they fuse on top of the inversion.
“I tested it with two hours of material I recorded at Fiskars in 2013,” Laine wrote in his university press. “The model fit perfectly with the hypothesis and, at the same time, gave the height of the inversion layer more precisely at 78-80 meters.”
This would at least explain why the sounds are described as “sizzling” by a First Nations photographer, and of the “bursting bubbles” by Laine himself, as well as why many people never hear anything when they are under the aurora, since if there were no temperature inversion, electrical conditions would be absent.
Laine collected the data for nearly two decades with a three-microphone setup recorded during certain periods, but now his research has inspired a new citizen science project at the Hankasalmi Observatory in Jyväskylä, Finland, that will record possible auroral sounds 24 hours a day. day. with four microphones.
The project was funded by 200 different donors, as well as an EU science grant.
“We are trying to hear the same sound with three or four microphones located a few meters away,” said Arto Oksanen, president of the observatory. “By measuring the delay time in each recording, it is possible to calculate the three-dimensional position of the sound source, or at least the direction to the sound source.”
This would allow researchers to establish a distance in the genesis of sound and, in large part, would help prove or disprove Laine’s theory. We will make sure to keep you informed of any eventual findings from this intriguing project.
(HEAR for applause in the Northern Lights video below).
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