Tuesday, June 28, 2011

Happy Tau Day

Lord, grant me the serenity to accept the things I cannot change, Courage to change the things I can, And wisdom to know the difference.  Reinhold Niebuhr

Bob Palais wants to make math easier to learn, as does Michael Hartl.  They are both advocates of eliminating Pi.

When I first read this, I was excited.  I recalled my early days of geometry when the idea that the circumference of a circle divided by its diameter is always the same number regardless of the size of the circle was a kinda neat rule.  Then, how confused I was to find that the constant, Pi, couldn't be determined.  Surely, something as absolute and precise as math must have a precise number for the ratio of a circle's circumference and diameter!

Much as I was disappointed by learning of the existence (or non-existence) of Pi, it turns out I have been disappointed by Palais and Hartl's argument for eliminating it.

They propose that Pi be replaced by Tau.  Tau is the ratio of a circle's circumference to its radius.  If your geometry is a bit rusty, that means that Tau is exactly 2 times larger than Pi.  Yes, if you multiply Pi by 2, you still get a number that continues on forever after the decimal place.  That number is 6.28something.  Making June 28 Tau Day.

In fairness to Palais and Hartl, their proposal would actually make learning math easier.  You were taught to use radians instead of degrees to perform calculations on a circle and that one 'trip around' the circle is 2Pi radians.  Palais and Hartl argue that it would be a lot easier to understand if that same trip around the circle were Tau radians.  This then makes it easier to visualize cosine, tangent, lots of calculus stuff and more.

If that doesn't make sense to you, you can read the Tau Manifesto or Pi is Wrong or you can simply take my word for it.  Either way, realize that while it would make understanding math easier, it can never change.

Consider what it would take to replace Pi with Tau.  Thousands of editions of math text books would need to be changed.  Tens of thousands of high school math teachers would need to change their lesson plans (and learn how to teach it).  Hundreds of thousands of editions of physics, chemistry, biology and computer science texts would need to be modified.  Hundreds of thousands of science teachers would need to learn a new way.  And an entire generation of of old folks like me will need to die off because we will never make the effort to change.  Finally, the math professors who could drive such a change have to actually want to drive such a change.

Tau is a classic example of a better design that can not replace an entrenched dominant design.  It is a frequent problem in innovation and change.  It is never enough that the new product, system, approach, or process be better then the existing.  It must be so much better that it overwhelms the cost of change.

So happy Tau Day....it could BE different....but we will calculate just how different using Pi not Tau.

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