PBS Space Time addresses the memory question in a really accessible way here. The key insight is (briefly) that one end of a particular object’s history is highly correlated with the environment along which its duration extends (i.e. you can infer information about other parts of the environment by examining the object at that end if its duration). The other end is not so correlated. The degree to which this correlation exists at a particular point along the object’s duration is its “memory” at that particular “moment in time”.
PBS Space Time addresses the memory question in a really accessible way here. The key insight is (briefly) that one end of a particular object’s history is highly correlated with the environment along which its duration extends (i.e. you can infer information about other parts of the environment by examining the object at that end if its duration). The other end is not so correlated. The degree to which this correlation exists at a particular point along the object’s duration is its “memory” at that particular “moment in time”.