Felicity Finch enters the bright, clean and remarkably peaceful world of self-storage, with its windowless metal rooms, numbered padlocked doors and aisles stretching to fill the space the size of a football pitch. They are the 21st-century’s sterilised, standardised, corporatised attics, potting sheds and garages - and just possibly the solution to a problem that has stumped physicists. If the universe is expanding, why is there never enough space to keep your stuff?