Hi all, next week's group meeting will take place on *Tuesday* at 4pm. Joseph Emerson from the University of Waterloo will be visiting and give a short presentation. Additionally, on Wednesday at 11am in E41.1 Chiara Marletto from the University of Oxford will give a talk entitled "The Constructor Theory of Information". See the abstract below: "Constructor theory is a new mode of explanation, where theories of physics are expressed solely in terms of which transformations of physical systems are possible and which are impossible. In this seminar I explain how it can be applied to address fundamental problems in physics, particularly those related to 'information'. The Constructor Theory of Information is a theory of information expressed entirely in constructor-theoretic terms. It proposes conjectured laws of physics that are directly about information. Indeed, it does not regard the latter as an a priori mathematical or logical concept, but as something whose nature and properties are determined by the laws of physics alone. The constructor-theoretic approach allows one to cure the circularity at the foundations of existing information theory (namely that information and distinguishability are each defined in terms of the other); and to explain the relationship between classical and quantum information, revealing the single, constructor-theoretic property that underlies the most distinctive phenomena associated with the latter." Best, -joe