Rovelli won the second prize in the 2013 FQXi contest "It From Bit or Bit From It?" for his essay about "relative information". His paper, Relative Information at the Foundation of Physics, discusses how "Shannon's notion of relative information between two physical systems can function as [a] foundation for statistical mechanics and quantum mechanics, without referring to subjectivism or idealism...[This approach can] represent a key missing element in the foundation of the naturalistic picture of the world."Carlo Rovelli, Relative information at the foundation of physics (Marseille, CPT & Toulon U.). October 31, 2013. 3 pp.; Published in "It from Bit or Bit from It? On Physics and information", A Aguirre, B Foster and Z Merali eds., 79-86 (Springer 2015)- Carlo Rovelli, Relative information at the foundation of physics, Arxiv.org. Retrieved 2019-10-01. In 2017, Rovelli elaborated further upon the subject of relative information, writing that: In nature, variables are not independent; for instance, in any magnet, the two ends have opposite polarities. Knowing one amounts to knowing the other. So we can say that each end “has information” about the other. There is nothing mental in this; it is just a way of saying that there is a necessary relation between the polarities of the two ends. We say that there is "relative information" between two systems anytime the state of one is constrained by the state of the other. In this precise sense, physical systems may be said to have information about one another, with no need for a mind to play any role. Such "relative information" is ubiquitous in nature: The colour of the light carries information about the object the light has bounced from; a virus has information about the cell it may attach, and neurons have information about one another. Since the world is a knit tangle of interacting events, it teems with relative information. When this information is exploited for survival, extensively elaborated by our brain, and may be coded in a language understood by a community, it becomes mental, and it acquires the semantic weight that we commonly attribute to the notion of information. But the basic ingredient is down there in the physical world: physical correlation between distinct variables. The physical world is not a set of self-absorbed entities that do their selfish things. It is a tightly knitted net of relative information, where everybody's state reflects somebody else's state. We understand physical, chemical, biological, social, political, astrophysical, and cosmological systems in terms of these nets of relations, not in terms of individual behaviour. Physical relative information is a powerful basic concept for describing the world. Before “energy,” “matter,” or even “entity.”"What scientific term or concept ought to be more widely known? - Relative Information", Edge.org, 2017. Retrieved 13-9-2019
