Our online world requires us to share private information with others. This is possible thanks to public key encryption, which works because a certain mathematics problem in number theory is…
Is public-key encryption in danger of collapse?
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Is Relativistic Geometry Conventional?
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…
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…
The 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…
Three 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…