Group Structural Realism (Part 4)

…in the tower, or the ‘whole shebang.’ This introduces a tower’s worth of ‘lower down’ groups into our ontology, and risks the possibility that a ‘highest’ automorphism group doesn’t exist. Or, if it is possible to fix a structural foundation by promoting the ‘whole shebang’ of higher group structures, then it seems that our ontology is excessively extravagant and uninformative. In summary: structural realism is forced to either risk incoherence (…

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Happy 2009! Five Tutorials for Philosophers of Physics

…torials for philosophers of physics — and anyone else who cares — from the soulphysics archives. Get Started Using Automatic Symbol Insertion in MS Word. Reduce the stress this year. Here’s an easy way to use mathematical symbols without having to deal with LaTeX. Get Started Improving Your Philsci Archive Experience. Broaden your horizons in the new year with everyone’s favorite philosophy of science database. Here are some tricks to ease the exp…

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Get Started Learning General Relativity Online

…to Differential Geometry and General Relativity, by Stefan Waner. A beautifully arranged collection of lecture notes on differential geometry. Approach is highly mathematical, taking the reader from basic point-set topology all the way to Einstein’s field equations. Tensors and Relativity, by Peter Dunsby. A first course in general relativity, beginning with special relativity. Includes an “assignments” section with hints. The layout is ugly and…

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Fundamental Rubik’s Cube Problem Is Nearly Solved

…e cube configurations requiring at least 20 moves to solve; this gave us a lower bound. Then last year, Kunkle and Cooperman proved (pdf) that any cube configuration can be solved in 26 moves; this gave us an upper bound. But in recent months, rapid progress has been made. In March, Rokicki developed and posted a highly effecient solution-finding algorithm, with which he was able to reduce the upper bound to 25 moves. He now says he’s already redu…

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Elegant Desktop ToDo List

…do! Geektool. This beautiful little app is available for free from Tynsoe.org. For more on what it can do, try this tutorial. For our purposes, here’s how to display a TXT file on your Desktop: Create a new Shell geeklet in the Geektool preference pane Enter the command: cat PathToYourList/YourList.txt To synchronize multiple computers, make sure the file is in a Dropbox folder. Quicksilver. This is why I own a mac. It’s free from Blacktree.com….

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