Theorem of the Day



Theorem of the Day and the τ Manifesto In a 2001 article in Mathematical Intelligencer, Bob Palais argued persuasively that the domination of circle geometry by a constant representing half a circle was perverse, obfuscatory and pedagogically unsound. Michael Hartl was inspired to ask whether this domination might not be overthrown. His Tau Manifesto, launched in conjunction with a substitute for the internationally recognised Pi Day, maintained the light touch of Palais but assembled a weighty 'case for the prosecution'. Certainly there seems to be a case for Pi to answer; and its main (although certainly not only) defence seems to be that possession is 9/10 of the law. theoremoftheday is happy to do its bit to promote debate, and that is best done by taking a stand. Accordingly, in all theorem descriptions posted here which involve a circle constant, this constant has been expressed in terms of τ = 6.2831... rather than π = 3.1415.... Such theorems are marked with the above logo (homegrown — it is not official!) Some remarks:
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