From Paul Dormer
Paul Mander takes Feedback to task for saying cubic litres involve nine dimensions as this implies cubing a cube and the cube of 3 is not 9 (19 April, p 17). He should check his maths. The cube of a number n is n × n × n. Cubing this gives (n × n × n) × (n × n × n) × (n × n × n) which is quite clearly n to the power 9.
Guildford, Surrey, UK
