Asked by: Tom Storey, by email
Nothing physical can exist with literally zero thickness, as its atoms have a finite size. But there are many examples of so-called ‘monolayers’ just one molecule – or a few tens of billionths of a metre – in thickness. The most familiar are monolayers of oil in puddles, which are so thin they split light into its constituent colours.
Robert is a science writer and visiting professor of science at Aston University.