Is the universe made of information?
Previous work has suggested deep connections between statistical mechanics and certain aspects of both information theory and statistical inference, based primarily on the shared concept of entropy. In this talk I go beyond familiar information theoretic treatments of entropy to develop purely information-based interpretations of both the 1st and 2nd laws of thermodynamics. This allows us to ask and answer a question that has gone begging until now: What is the analogue of temperature (T) on the information/inferential side? I argue that the physical quantity T has a familiar, but surprising, interpretation as statistical evidence. Moreover, this formulation provides a template for measuring evidence on an absolute (Kelvin) scale for the first time. This has far reaching implications for bioinformatics, since the measurement and interpretation of statistical evidence is a critical element of how we make scientific use of bioinformatic results. In a more speculative vein, this work also raises the question of whether our physical theories require us to posit the existence of matter. If fundamental physical laws can be interpreted in purely informational terms, perhaps it is mathematically cogent to say that the universe is in fact made of information.