YouTuber breaks down how to timestamp a call using just the background hum

If you were ever in any doubt as to just how mind-bogglingly impressive science can be, just watch this video of a linguistic expert time-stamping phone calls using the background hum on a line. The video, from YouTuber Tom Scott, features University of York research associate in the Department of Language and Linguistic Science, Amelia Gully, using a technique called Electrical Network Frequency analysis (ENF) to match background hum recordings with data from the UK's power grid (it's broken do...