Introductory remarks

Abstract

Liquid crystals have been recognized as such for just about 100 years. The pure substances known to exhibit one or more liquid crystal phases are numbered in thousands: Professor Gray will probably update us on the present score. The liquid crystals give us a very fine object lesson in the interaction of science and application. Their general nature has been well understood since Georges Friedel’s great review article in 1921. There was not much written about them in English before the Faraday Society discussion of 1933 - the meeting at which Sir William Bragg brilliantly overnight perceived the geometrical origin of the focal conic texture of smectics, unaware that Friedel had explained it all a dozen years before. After that, most scientists closed the book. The liquid crystals were scientific curiosities, basically understood, and no one had a use for them. Chemists gradually discovered more mesomorphic substances but, on the whole, knowledge of their physics went backwards rather than forwards. The history of the science of liquid crystals is marked with repeated rediscovery of things forgotten. When, in 1958, I published a paper about liquid crystals I was advocating renewed study of them as a source of information about molecular interactions. However, for one thing, that was not too easy, except in terms of severely simplified simulation models; for another, scientific curiosity alone was not sufficient incentive.