The Mystery of Space (1919) belongs to the strange, earnest moment when the fourth dimension escaped the mathematicians. Robert T. Browne surveys the hyperspace movement — Riemann and Lobachevsky on one side, theosophy and ‘new psychic faculties’ on the other — and argues that the geometry of higher dimensions marks a stage in the evolution of human consciousness itself.
As mathematics it is a period piece; as intellectual history it is fascinating — the fourth dimension as the Edwardian age actually imagined it. Download the free EPUB for a guided tour of geometry’s most mystical detour.