Is information everything?
Physics World · 1990
Whoever it was who first contracted the words 'binary digit' to form 'bit' can hardly have realised that he (she?) was coining a term not only for the smallest unit of information but also for the smallest unit of 'being' – or so the general relativist John Archibald Wheeler would have us believe. 'It from bit' is his declamation of the ultimate fount of significance of every physical quantity: all we can know about photons, fields, black holes – you name 'it' – depends at root, he emphasizes, on yes-or-no indications. Pursuing the implications of this observation through quantised strings, quantum measurement theory, computational representations of physical laws, information theory, thermodynamic entropy, evolution... those, he says, are routes to that happy state of perceived simplicity and beauty when we finally know the Final Answer to the question: 'How come existence?'