There's a sort of radio wave that bangs its way around Earth, knocking around electrons in the plasma fields of loose ions surrounding our planet and sending strange tones to radio detectors. It's called a "whistler." And now, scientists have observed bursts like this in more detail than ever before. Whistlers, typically created during certain lightning strikes, usually travel along Earth's magnetic-field lines. Humans first detected them more than a century ago, thanks to their ability to make a "whistling" sound (really more like a ghostly recording of laser blasts in a "Star Wars" movie) when picked up by a...