# Thread: π=3.14 (Pi) where does it get that name?

1. ## π=3.14 (Pi) where does it get that name?

Inspired by pi computation i wondered where pi was given it's name.I came up with this result(that was questioned however by a member of this forum)

Pi has taken that name because of the greek(of course) word περιφέρεια (=circumference)

How did pi get it's name

That is completely justified,because (as you may know) if you select a random circle and you calculate the fraction of the circle's circumference to it's own diameter you will get the number π (=pi=3.14).

I also read that π is given it's name by the greek word προσευχή (=pray) but it do not believe it.This idea stands at this
Code:
```Αεί ο Θεός ο Μέγας γεωμετρεί, 	3, 1 4 1 5 9
το κύκλου μήκος ίνα ορίση διαμέτρω, 	2 6 5 3 5 8
παρήγαγεν αριθμόν απέραντον, 	9 7 9
και ον, φεύ, ουδέποτε όλον θνητοί θα εύρωσι. 	3 2 3 8 4 6 2 6```
which is considered to be a pray by some people,but this is wrong.This was a mnemonic way in order that greek students of the mathematical uni of Athens were able to remember the first digits of π,and it was invented by a greek mathematician named N.Chatzidakis(1872-1942).The special about the above is that the amount of the letters of every word is equal to the corresponding digit of π.Αεί has three letters and first digit of π is 3,and so on.But π was named by the ancient greek mathematicians so this can not be true.(that π was given it's name by word pray( =προσευχή).
pray .At this link is also stated that π was given it's name by the word περιφέρεια( =circumference)

However i also found a link(i found only one for some reason..) that states that if the name was given by the ancient times,then it was not given by the Greeks but by the Egyptians.
What Is the History of Pi?
But,it happens that i have traveled to Egypt,and i remember that at the pyramids,there was something in these structures that was equal to 2*π.So this has done to us a big surprise.However experts and archaiologists from there said to us that this was just a coincidence,because no clue that Egyptians knew about π .And that is ok to me,because if they knew about this,why don't they wrote algorithms about it's calculation as Greeks did?In any way i believed(of course) the experts and not just a link.What the experts said to us at our travel,i did found it also on the net.

However the fact that a user of this forum questioned that π(=pi) comes from the greek word περιφέρεια made me post here,in order to let you tell us what you think about it

2. Thanks for the information. It is all Greek to me

3. I tried to write everything in English,only one link is in greek and the pray is written in the old fashioned way(too old i would say) so i could not translate it with 100% accuracy.However if you have some question about some word ask me.In general though what would you think?Do you agree that pi comes from circumference as i stated above,or have another theory?

4. Wikipedia says that William Jones was the first in 1706 who used the symbol π for the constant 3.1415...
That's also what the link What Is the History of Pi? says, so it seems the old egyptians and greeks didn't have a special word/symbol for pi.

Bye, Andreas

5. But Archimedes wrote algorithm(s) about it and ,believe me, he lived a looong ago from 1706.As for the links of wikipedia,the other links (e.g. wiki-answers) said that greeks gave the name to it.I gave an explanation above,where i stated that π was given it's name by greek word περιφέρεια.The idea of W.Jones to introduce the letter π for it is not justified to me.I mean we was not even Greek!How does he came up with this?

6. Originally Posted by std10093
But Archimedes wrote algorithm(s) about it and ,believe me, he lived a looong ago from 1706.
That doesn't prove that he used a word/symbol for the value 3.1415...
Here you can find an English translation of his work "On the measurement of a circle" where he explains his approximation. I cannot say anything about the original greek version but the translation never mentions pi or π, only that the constant is between 3 10/71 and 3 1/7.

Originally Posted by std10093
As for the links of wikipedia,the other links (e.g. wiki-answers) said that greeks gave the name to it
Frankly I believe wikipedia more than an anonymous answer on wiki-answers.

Originally Posted by std10093
The idea of W.Jones to introduce the letter π for it is not justified to me.I mean we was not even Greek!How does he came up with this?
It doesn't matter if he was Greek or not. He just gave it it's name and I guess Greek letters were popular back then (and still are in mathematics). Also read the wikipedia article where it says:
He may have chosen π because it was the first letter in the Greek spelling of the word periphery.
Just because constants have names and symbols nowadays doesn't mean that they also had them thousand years ago. You can calculate with the value of pi without naming it.

Bye, Andreas

7. It is all Greek to me
*groan*

Exactly this is why we need a dislike button.

*shrug*

I've always just assumed it was notational jargon.

Soma

8. Originally Posted by AndiPersti
Just because constants have names and symbols nowadays doesn't mean that they also had them thousand years ago. You can calculate with the value of pi without naming it.
Wasn't it Shakespeare who said, "A pi by any other name would taste as delicious"?

9. ^_^

And now I'm thinking about all the times politicians, and obviously bad mathematicians, have tried to "simplify" π by defining it to be something other than π.

So thanks for this thread.

Soma

10. @ANdreas,yes greek letters were and are popular among all over science because everything (almost) started in greek.But it is not reasonable to me that this Jones gave that name without a reson.However we did limited into two answers i think.Into the greek word and into that Mr.Jones

@soma,glad that you thanked for the post

11. Originally Posted by phantomotap
Exactly this is why we need a dislike button.
I agree. This standard "like", without a dislike is like yang without yin.
The only argument I've heard against it, is that it would cause problems. Which is poor, considering people already do when they feel like it, and don't need a dislike button to do so.

12. O_o

You do realize I was just poking at laserlight because of such a terrible "groaner", right?

Soma

13. lots of sites have buttons to vote up or down on something. it's a pretty straightforward concept.

14. Originally Posted by phantomotap
You do realize I was just poking at laserlight because of such a terrible "groaner", right?
Not sure what you mean by "groaner", but I wasn't commenting on your comment towards laserlight. Rather, I was commenting on your statement of having a dislike option.

I hope my assumption that the two thoughts were meant separately wasn't in error.

15. Originally Posted by std10093
@ANdreas,yes greek letters were and are popular among all over science because everything (almost) started in greek.But it is not reasonable to me that this Jones gave that name without a reson.However we did limited into two answers i think.Into the greek word and into that Mr.Jones
We can't ask Mr Jones any more for his reason, but the wikipedia article suggests he used π because that's the first letter of the Greek word for periphery(περιφέρεια) which is another word for the circumference of a circle. So why do you think there are two answers? :-)

BTW: Wolfram MathWorld (a trustworthy source for mathematics IMHO) also mentions William Jones as the first user of the symbol π.
On this page you can also find many references if you really want to dig deeper.

Bye, Andreas

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