# The Naked Scientists Forum

### Poll

#### Should we replace pi with a new constant with a value equal to two times pi

Yes
2 (33.3%)
Good idea, but leave it alone.
1 (16.7%)
No - it's a bad idea.
3 (50%)

Total Members Voted: 6

### Author Topic: Should we dump pi?  (Read 3815 times)

#### Geezer

• Neilep Level Member
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• "Vive la résistance!"
##### Should we dump pi?
« on: 01/07/2011 17:44:50 »
I read something about a movement to replace pi with another constant that has twice the value of pi.

Personally, I think this is quite a good idea as I always find the relationship between radians and pi to be thoroughly confusing, but what do you think?

#### CliffordK

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##### Should we dump pi?
« Reply #1 on: 01/07/2011 18:56:43 »
Truthfully it would not make a huge difference.  But, if you look at some of your formulas.

For sine & cosine.  π radians for a half cycle, 2π for a full cycle.

Circumference of a circle: πD = 2πr
Area of a circle: πr2
Volume of a sphere: (4/3)πr3

Say you introduced a new value, Π=2π
Then your radians might be simpler, with the new Π radians for a full cycle, although you still have the half cycles, and etc.

Your circumference of a circle would be a wash as you would ignore the diameter, and just calculate everything with the radius.

Your area of a circle suddenly has an additional step: Area would be (Π/2)r2
And, your volume of a sphere would be a wash too...  changing from (4/3)πr3 to (2/3)Πr3

I presume the reason for the choice of π rather than 2π in the past was that multiplication operations were easier than division operations.  So they chose to minimize the division operations by using the current π.

Do math textbooks still have interpolation tables?  [xx(]

Now, everyone either solves equations symbolically, or punches them into a calculator, and thus the multiplication/division distinction is far less important.

Anyway...  since I like Apple pi, Blackberry pi, Rhubarb pi...  well....  I'm just a big pi fan.  Why change a good thing?
« Last Edit: 01/07/2011 18:58:37 by CliffordK »

#### CZARCAR

• Hero Member
• Posts: 686
##### Should we dump pi?
« Reply #2 on: 01/07/2011 23:52:05 »

#### CliffordK

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##### Should we dump pi?
« Reply #3 on: 02/07/2011 00:24:12 »

One of the common measurements of angles in a circle is Radians.

It has been a while since I've used them, but the sine and cosine is easier to deal with when using fractions of π, at least in theory.

sin(0) = sin(π) = sin(2π) = cos(π/2) = cos(3π/2) = 0
sin(π/2) = (-)sin(3π/2) = cos(0) = (-)cos(π) = cos(2π) = 1

#### granpa

• Sr. Member
• Posts: 118
##### Should we dump pi?
« Reply #4 on: 02/07/2011 23:14:03 »
http://en.wikipedia.org/wiki/N-sphere

the equations for an n dimensional sphere are:

#### imatfaal

• Neilep Level Member
• Posts: 2787
• rouge moderator
##### Should we dump pi?
« Reply #5 on: 03/07/2011 10:17:27 »
You're a little late Geezer - tau day was last week 6.28 (June 28th for the colonial overlord types).  Here is the Tau Manifesto http://tauday.com/

All good clean fun - and whilst most physical/calculational engagement with Pi is in terms of 2pi; the reworking of text-books and potential for snafus if we moved to using Tau would be immense.

#### Bored chemist

• Neilep Level Member
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##### Should we dump pi?
« Reply #6 on: 03/07/2011 14:11:54 »
Perhaps we should compromise and use tau before tau day each year and pi afterwards.
That should avoid any confusion.

#### CZARCAR

• Hero Member
• Posts: 686
##### Should we dump pi?
« Reply #7 on: 03/07/2011 19:25:11 »
constancy at dumptime should definitely be considered so which has more fiber?

#### The Naked Scientists Forum

##### Should we dump pi?
« Reply #7 on: 03/07/2011 19:25:11 »