In America, the "football field" (ex. the new Airbus jet has wings wider than a football field) is a standard unit of distance. In the rest of the world, they use non-standard "football pitch" (ex. the new Airbus jet has wings wider than a football pitch). Very handy. Well now we now have the "day of MP3 music" as a unit of hard disk space:

When stored in highly compressed form on a computer hard drive, the solution [to the 'Lie group E8' math puzzle] takes up as much space as 45 days of continuous music in MP3 format.

They don't mention the compression ratio, the encoder, or the type of music - so there's bound to be confusion over exactly how large that is. Nonetheless, I'm sure it's an impressive feat. How impressive?

"It's like a Mount Everest of mathematical structures they've climbed now," said Brian Conrey, director of the institute.

Ah, yes, one Mt Everest: the standard unit of difficulty.