A mysterious sound recorded in 1949 remained unidentified for 77 years—until scientists realized they'd captured the oldest known whale song, decades before anyone understood these creatures sang at all.
A man’s voice reads a date onto a plastic disc. “The date, 7 March, 1949,” he says, as reported by Smithsonian Magazine. Underneath the announcement there is something else: a low, looping sound with… [+5154 chars]