09172010, 08:58 AM  #1 
The Grand Mouse 高貴的老鼠
Posts: 39,522
Karma: 112209871
Join Date: Jul 2007
Location: Norfolk, England
Device: Kindle Paperwhite 3

Why Tau is better than Pi
I can across an interesting idea today. Put simply, the idea is that the ratio for relating the size of a circle to its circumference has been badly chosen.
That is to say, Pi (π), the ratio of the Circumferences to the Diameter of a circle is an awkward choice. The argument goes that using the ratio of the Circumference to the Radius instead would make many things simpler and more obvious. The proposed symbol for this is Tau (τ). All is explained at the Tau Day website. http://www.tauday.com/ I found it very persuasive. What do others think? 
09172010, 09:39 AM  #2 
Wizard
Posts: 2,737
Karma: 635747
Join Date: Nov 2009
Location: Northeast Ohio, USA
Device: PRS900

I didn't read the entire article in detail, it's been a few years since I've done math at those levels, but it makes sense to me and I have to agree on a few of the points. I agree that using the radius is more intuitive than the diameter, you very rarely hear someone referring to the diameter of a circle.
My problem with it though is that "pie are square(d)" rolls off the tongue much more easily than "two tau are square(d)" 
09172010, 09:41 AM  #3 
Happy Holidays!
Posts: 32,667
Karma: 78812947
Join Date: Feb 2009
Location: Durham, NC
Device: Every Kindle Ever Made & To Be Made + Kobo Aura + Nexus7.2!

tau for two and two for tau,
mu for ... sorry  couldn't resist! 
09172010, 09:46 AM  #4 
Wizard
Posts: 4,395
Karma: 1358132
Join Date: Nov 2007
Location: UK
Device: Palm TX, CyBook Gen3

I'm afraid I had to respectfully decline the author's kind invitation to "consider integrals over all angles in polar coordinates", because I have no idea what he's going on about.

09172010, 10:45 AM  #5  
The Grand Mouse 高貴的老鼠
Posts: 39,522
Karma: 112209871
Join Date: Jul 2007
Location: Norfolk, England
Device: Kindle Paperwhite 3

Quote:
‘Tau are’ is simpler than ‘two pi are’. Of course, we could also say ‘pi dee’ but then for consistency we ought to use ‘one quarter pi dee squared'. Ugh... The ½τr² is also exactly analogous with lots of other equations that deal with the integration of an equation with a constant of proportionality. The link gives the example of objects falling in a uniform gravitational field. (i.e. on Earth, to a close approximation). The speed of dropped item is directly proportional to the time it has been falling (neglecting air resistance and changes in the gravity field). v = gt The distance fallen is the integral of this: d = ½gt² I must admit that the more I consider this, the more pleased I am with it. Although I would hold out for tau day to be celebrated on the 6th of February, not the 28th of June! And celebrations ought, of course, to reach a climax at exactly 53 seconds past 3:33 pm (or am if you're on night shifts). Because, of course, the ratio 333/53 approximates tau to three decimal places. Alternatively we could have an ‘approximate tau lunch’ on 7th October, at 1:13 pm, since 710/133 is tau to six decimal places. 

09172010, 11:31 AM  #6 
FUBAR!
Posts: 1,946
Karma: 15018767
Join Date: Mar 2010
Location: Woodstock, IL
Device: Kindle 3, Samsung Galaxy Note 10.1 S

I like popcorn.

09172010, 12:58 PM  #7  
The Grand Mouse 高貴的老鼠
Posts: 39,522
Karma: 112209871
Join Date: Jul 2007
Location: Norfolk, England
Device: Kindle Paperwhite 3

Quote:


09172010, 02:17 PM  #8 
Man Who Stares at Books
Posts: 1,725
Karma: 10606558
Join Date: Mar 2010
Location: 50th State, USA. Also, PA, NY, CA, and elsewhere.
Device: All of the Above

I disagree most vehemently with the concept of Tau day. First, I am too old to learn new math. Second, Pi makes sense to the elders. Consider a hat maker or brassiere seamstress. How do they set the diameter of a hat or bra? They take a tape measure and wrap it around the object of interest. With a single factor (1/Pi), they take that circumference and turn it into a diameter. Of course, I am so learned that I can just look at/feel a breast and tell you the correct cup size. (It is a complex process, involving volumetric estimation, and my sensitive hand). Lastly, why give up another Greek letter for a constant that is already been spoken for? I want to reserve Tau for a constant of nature that I may discover, such as the perfect shape of a breast (in 3D), or the dimension of the universe.

09172010, 03:52 PM  #9 
Guru
Posts: 618
Karma: 493394
Join Date: Jun 2008
Location: Seattle, WA
Device: iRex iLiad, Onyx Boox 60

Fat Abe makes a very persuasive argument...

09172010, 05:04 PM  #10 
Evangelist
Posts: 404
Karma: 546196
Join Date: Mar 2009
Location: UK canal boat
Device: sony prs505, prs650 liseuses

An entertaining article! Given that there is a simple conversion between pi & tau, one can just use whichever is most convenient for the purpose in hand. I like the more sensible radian measures of fractions of a circle and the pleasing conformity with other integration equations  I shall have to try running a few calculations in parallel and see how the tau versions 'feel'.

09182010, 05:16 AM  #11 
Country Member
Posts: 9,056
Karma: 7676767
Join Date: Feb 2010
Location: Denmark
Device: Liseuse: Irex DR800. PRS 505 in the house, and the missus has an iPad.

What the f***, I haven't got used to decimal currency yet, and you want to start messing with pi. No way.

09282010, 10:37 PM  #12 
The Dank Side of the Moon
Posts: 32,434
Karma: 74014603
Join Date: Sep 2009
Location: Denver, CO
Device: Kindle2; Xoom; Kindle Fire

e is the best.

09282010, 10:38 PM  #13 
The Dank Side of the Moon
Posts: 32,434
Karma: 74014603
Join Date: Sep 2009
Location: Denver, CO
Device: Kindle2; Xoom; Kindle Fire


09292010, 01:45 AM  #14 
Enthusiast
Posts: 48
Karma: 160
Join Date: Jun 2010
Location: UK
Device: Sony PRS505, Lenovo X61 tablet PC, Advent Vega Android tablet

ask me taumorrow

09292010, 04:15 AM  #15 
The Grand Mouse 高貴的老鼠
Posts: 39,522
Karma: 112209871
Join Date: Jul 2007
Location: Norfolk, England
Device: Kindle Paperwhite 3


Thread Tools  Search this Thread 
