Clearly the idea of pi and tau are both wrong, since they make the 2d circle the reference instead of the 1d circle.
Notice the formula for the volume of an n-ball is proportional to pi^(n/2)r^n! Define tau properly, and could become (tau r)^n!!
Also notice how many other cases outside of 2d geometry uses sqrt(pi) or sqrt(2pi). The gamma function, normal distribution, stirling approximation etc. are all full of it, and when you rarely need pi or tau, adding a ^2 is much nicer than always having to draw a big ugly sqrt.
I don't mind tau especially, but it is seems the wrong battle to fight. Sqrt(pi) also has mythical powers: http://www.squarerootofpi.com/
I'm not against being open to things like ancient aliens, but I think the fact that squarerootofpi references that and astrology, etc puts it on completely different footing from tau, which the post we are discussing right now mentions being included in programming languages and scientific papers. [edit: obviously this says nothing about square root of half tau and its uses!]
I put tau into my math-related code last year, and I have enjoyed the results (which are much the same as before, of course).
Also notice how many other cases outside of 2d geometry uses sqrt(pi) or sqrt(2pi). The gamma function, normal distribution, stirling approximation etc. are all full of it, and when you rarely need pi or tau, adding a ^2 is much nicer than always having to draw a big ugly sqrt.
I don't mind tau especially, but it is seems the wrong battle to fight. Sqrt(pi) also has mythical powers: http://www.squarerootofpi.com/