One of the lessons of General Relativity is supposed to be that gravitation is the science of geometry. John Wheeler characterised it as, “a geometrodynamical universe”: a world whose properties…
Read moreIs Relativistic Geometry Conventional?
Curie’s Principle: Not a theorem, Not even for Ismael
Twenty years ago now, Jenann Ismael wrote a fascinating little article called “Curie’s Principle” (1997 Synthese), which discussed a symmetry principle due to Pierre Curie: “When certain effects show a…
Read moreThe physics of the 2015 Supertide in Western Europe
The causes of tides The tides are caused by two things. The moon’s gravitational force pulling on the oceans. The sun’s gravitational force pulling on the oceans. An eclipse does not…
Read moreThree merry roads to T-violation
Last year I had a back-and-forth Abhay Ashtekar. It was during a lively conference organised by Emily Grosholz and hosted by the Center for Gravitaiton and the Cosmos where Ashtekar is director. Our discussion…
Read moreBohmian Indeterminism
Bohmian mechanics is not just an “interpretation” of quantum mechanics. It is a radical revision. In this note, I’d like to point out one reason that it’s an implausible revision:…
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