The popping and crackling sounds associated with Aurora borealis (or the Northern Lights) are born when the related geomagnetic storm activates the charges that have accumulated in the atmosphere’s inversion layer causing them to discharge, according to researchers at Aalto University, Finland. Aalto University scientists find explanation for auroral sounds. Image credit: Unto Laine / Aalto University. In 2012, Prof. Unto K. Laine of Aalto University...