Joaquina Salgado
8. Philip Ball
From The Quantum Origin of Time, BBC, 2016… we can regard retrocausality as a kind of fuzziness in the “crystallisation of the present” — Ellis has argued that the past is not always fully defined at any instant. It is like a block of ice that contains little blobs of water that have not yet crystallized. Even though the broad outline of events at a particular instant has been decided, some of the fine details remain fluid until a later time. Then, when this “fixing” of the details happens, it looks like they have retrospective consequences.