I vote -1 on this idea because the name "TAU" is used in a number of =
fields to represent a wide variety of things:

=
http://en.wikipedia.org/wiki/Greek_letters_used_in_mathematics,_science,_a=
nd_engineering#.CE.A4.CF.84_.28tau.29

For example, tau as also used as a constant representing the golden =
ratio (1.618...).

The names "PI" and "E" are used far more consistently across fields.  =
Giving special preference to one (proposed!) use of the name "TAU" seems =
unfair to the other (established!) uses.

How about making a "twopi" gem that defines Math::TAU and BigMath.TAU?  =
If it is as useful as its proponents claim, it will undoubtedly become a =
very popular gem and the public outcry to add it to the core of the =
language will be deafening.

Dave

On Feb 26, 2013, at 9:54 PM, drbrain (Eric Hodel) wrote:

>=20
> Issue #4897 has been updated by drbrain (Eric Hodel).
>=20
> Status changed from Feedback to Assigned
> Assignee set to matz (Yukihiro Matsumoto)
>=20
> The patch is fine.
> ----------------------------------------
> Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle =
constant, Tau=3D2*Pi. See http://tauday.com/
> https://bugs.ruby-lang.org/issues/4897#change-37135
>=20
> Author: sbaird (Simon Baird)
> Status: Assigned
> Priority: Low
> Assignee: matz (Yukihiro Matsumoto)
> Category: Joke
> Target version: Next Major
>=20
>=20
> Firstly please read the Tau Manifesto at http://tauday.com/ . It's =
quite long but essential to understanding why this is a good idea.
>=20
> Here is a patch on trunk that implements this:
> http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html
>=20
> Allow me to anticipate and respond in advance to some common =
objections:
>=20
> 1. It's easy to define it yourself so why put this in core.
> Possibly correct, but I think this is the right thing to do. Tau is =
important. And it's a pretty small patch.
>=20
> 2. If this constant goes in then pretty soon someone will want every =
other math constant and there are hundreds of them. (Slippery slope =
argument).
> The circle constant is one of the two most important numbers is =
mathematics. It's not just another math constant. We already define Pi.
>=20
>=20
> --=20
> http://bugs.ruby-lang.org/
>=20