Tim Maudlin.mp3's guest appearances

Tim Maudlin.mp3

Cosmology Group Podcasts

Tim Maudlin

Michael Strevens

David Albert

David Albert.mp3

Barry Loewer

Sheldon Goldstein

OwlTail

Lecture 13; Sheldon Goldstein, David Albert and Tim Maudlin.mp3

David summarizes his distinction between inference by prediction/retrodiction and inference by measurement, and reiterates that this can make plausible the claim that the special status of the Past-Hypothesis can ground the asymmetry in our epistemic relations to the past and future. He goes through some objections to this view that came up in the class before, which he and Tim then discuss. David relates this epistemic asymmetry to the time-asymmetries in causation, counterfactual conditionals, and our apparent ability to elicit change in the world. He argues that the very facts that make the past epistemically more accessible than the future also makes our causal handle on the future far far weaker than our handle on the past. There is a discussion of how this is supposed to fit with our pre-theoretic intuition that we have NO causal handle on the past.Tim weighs in on some of these points, criticizing David's desire for a "mechanical" explanation for temporal asymmetries. He argues that our notion of a mechanical explanation already presupposes a substantive temporal asymmetry. David discusses the relation between the Mentaculus (which he takes to be the source of mechanical explanations) and the notion that time passes/has a direction. Tim responds and puts some pressure on David's claim that these two are largely independent. There is a lengthy discussion of this point.

David summarizes his distinction between inference by prediction/retrodiction and inference by measurement, and reiterates that this can make plausible the claim that the special status of the Past-Hypothesis can ground the asymmetry in our epistemic relations to the past and future. He goes through some objections to this view that came up in the class before, which he and Tim then discuss. <br>David relates this epistemic asymmetry to the time-asymmetries in causation, counterfactual conditionals, and our apparent ability to elicit change in the world. He argues that the very facts that make the past epistemically more accessible than the future also makes our causal handle on the future far far weaker than our handle on the past. There is a discussion of how this is supposed to fit with our pre-theoretic intuition that we have NO causal handle on the past.<br>Tim weighs in on some of these points, criticizing David's desire for a "mechanical" explanation for temporal asymmetries. He argues that our notion of a mechanical explanation already presupposes a substantive temporal asymmetry. David discusses the relation between the Mentaculus (which he takes to be the source of mechanical explanations) and the notion that time passes/has a direction. Tim responds and puts some pressure on David's claim that these two are largely independent. There is a lengthy discussion of this point.

Lecture 12; David Albert and Tim Maudlin.mp3

Tim opens with a brief point about the postulation of a very low entropy past state. He contrasts the claim that, if this state is not the initial state of the world, that the entropy profile of the universe will be symmetric (intuitively, with a global minimum at the moment of the past hypothesis) and the claim that the macroscopic profile of the universe will be symmetric in the same way. David takes some time to respond to this point.David then turns the discussion to the inferential role of the past hypothesis. He starts by identifying two kinds of inferences that can be used to determine the state of the world at times other than the present: Inference by Prediction/Retrodiction (in which one takes facts about the present and applies the laws to determine facts about the past or future) and Inference by Measurement (in which one takes facts about the present plus facts about certain past events and determines facts about the past or future). Inference by Measurement is, David points out, much stronger, but its appeal to certain past events is in need of justification. David argues that the event postulated by the past hypothesis is precisely the privileged past state that can do this inferential work. Tim asks whether these inference types really exhaust the relevantly available inference procedures. He also wonders whether the sorts of inferences David wants to call inferences by measurement really always have to appeal to facts about states other than the present, specifically the past hypothesis. There is a long discussion of the predictive centrality/fundamentality of the past hypothesis and of the nature of records.

Tim opens with a brief point about the postulation of a very low entropy past state. He contrasts the claim that, if this state is not the initial state of the world, that the entropy profile of the universe will be symmetric (intuitively, with a global minimum at the moment of the past hypothesis) and the claim that the macroscopic profile of the universe will be symmetric in the same way. David takes some time to respond to this point.<br>David then turns the discussion to the inferential role of the past hypothesis. He starts by identifying two kinds of inferences that can be used to determine the state of the world at times other than the present: Inference by Prediction/Retrodiction (in which one takes facts about the present and applies the laws to determine facts about the past or future) and Inference by Measurement (in which one takes facts about the present plus facts about certain past events and determines facts about the past or future). Inference by Measurement is, David points out, much stronger, but its appeal to certain past events is in need of justification. David argues that the event postulated by the past hypothesis is precisely the privileged past state that can do this inferential work. Tim asks whether these inference types really exhaust the relevantly available inference procedures. He also wonders whether the sorts of inferences David wants to call inferences by measurement really always have to appeal to facts about states other than the present, specifically the past hypothesis. There is a long discussion of the predictive centrality/fundamentality of the past hypothesis and of the nature of records.