Galileo’s Manuscripts: Still Learning the Lesson

…tute has done us the extraordinary service of putting the whole manuscript online. I first spent a few days assembling my own interpretation of this manuscript page. Then I took a look at how other people interpreted it. Surprisingly, two features of the manuscript that I thought were significant seem to have been completely ignored by scholars. And no wonder — it turns out that the only available English reproductions of the document omit a signf…

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Can Time Unfold in the Wrong Direction?

…f spatial regions. However, William and the astronaut will agree about the order in which time-like separated events occur: first Harold is crowned, and then Harold is slain. Figure 1: An observer on Earth and an astronaut traveling away with velocity c/2 will describe two different foliations of spacetime into space-like hypersurfaces of simultaneity. On the other hand, an accelerating observer will not generally agree about the order in which th…

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How Time Really Passes

…stness of this experience suggests it reflects an objective feature of the world. Physical theory describes passage by describing a state’s evolution: given an initial state, we determine the past states as well as the future ones. This is a fact about our physical theories. The empirical confirmation of these theories suggests that they too reflect something objective about the world. This does not mean that our apprehension of passage can be red…

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Special Relativity and the Bell Theorems

…— see below. Signal/Information Transfer. These terms are a bit vague, and people disagree about how to explicate them. However, as the chart suggests, I think that what’s really important is whether or not you think there are consequences for the statistical behavior of distant regions. Statistical Correlation. This seems to be the heart of the problem. If you think that Special Relativity implies an upper limit on the “speed” at which statistica…

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Accuracy, Applicability, and Tarskian Semantics

…which seems to be far and away the most popular formal theory of semantics used to construct particular accounts of the semantics of scientific theories, no matter what else the philosopher using it thinks about semantics I. Scientific Semantics as Based on Notions Like Truth Carnap, in the Introduction to Semantics (ch.B, §7, p.22) concisely expresses the seductive intuition that grounds essentially all contemporary thought on the semantics of sc…

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