pi for all, tau more than ever

Cover of A History of Pi

A few links for pi day:

A brief history of pi | TechHive: "Everybody knows the value of pi is 3.14…er, something, but how many people know where the ratio came from?"

And the always lively Petr Beckmann, author of the History of Pi, whose book I enjoyed, here on why the Dark Ages were such an improvement on the Romans.  A review:

The history of pi, says the author, though a small part of the history of mathematics, is nevertheless a mirror of the history of man. Petr Beckmann holds up this mirror, giving the background of the times when pi made progress -- and also when it did not, because science was being stifled by militarism or religious fanaticism. 

Whatever happened in Roman times, here in the US, politicos did try to change pi by legislative fiat:

New Math: The Time Indiana Tried to Change Pi to 3.2 | Mental Floss: "The very notion of legislatively changing a mathematical constant sounds so crazy that it just has to be an urban legend, right? Nope. As unbelievable as it sounds, a bill that would have effectively redefined pi as 3.2 came up before the Indiana legislature in 1897." 

My Pi day post from 2011 looked at tau and I am including more today.

Tau Day: An Even More Fundamental Holiday Than Pi Day | TechHive: "We all know about Pi Day, that tasty holiday on March 14 where celebrations include reciting digits of Pi and eating pie. At MIT, we ate pizza pie, pine nuts, and dined on dozens of types of sugary and fruity pies. Today, on what’s usually called “2 Pi Day” (do you bake twice as many pies as you usually would?) we’re seeing headlines about “pi being under attack” and the movement to replace pi with another constant... tau?"

It looks like Khan is onboard, too

    Tau versus Pi: Why Tau might be a better number to look at than Pi