Today, Tuesday is Tau Day


There is a growing movement, started by Dr. Palais of U of Utah, and fronted currently by Dr. Hartl who wrote the Tau Manifesto, to discredit Pi as an un-natural addiction (1). I say an addiction because there are still people endeavoring to claim records. Fabrice Bellard, who spent 131 days in 2009 watching his desktop computer calculate Pi to 2.7 trillion digits, holds the current record (2). It is rumored that he was on hold to his cable supplier.

Now Tau is simply two helpings of Pi. Why is it useful? The first thing that came to mind that what these avid mathematicians and physicists are exercised about is the current trend in western society of our growing rotundity. These occupations require a lot of butt in chair work. Our tape measures give us a circumference and we are informed that it is simpler to divide by Tau and double the answer to get the width of chair that we must order than to divide by Pi and get flummoxed by the lack of factors of 2. I don’t have that problem, I just choose a big-ass chair and wriggle around in it – it helps me think.

They have a better argument when they measure angles in radians rather than degrees. It helps their hard sums to use radians. So going round in a circle, we have turned 360 degrees or Tau radians instead of 2Pi radians. That factor of 2 gets them every time.

The claim is that circles are not about diameters but about radius signifies that they have spent more time with a pair of compasses than a chainsaw. Out here in the Pacific Northwest we like our chainsaws and would never take about trees in terms of the radius of their trunk. I like my diameters, but in the interests of mathematical integration will take my two helpings of Pi today.


  1. http://www.bbc.co.uk/news/science-environment-13906169
  2. http://news.bbc.co.uk/2/hi/technology/8442255.stm

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