Your most interesting fact about Pi

In summary: Expand ##\frac 1 {x-1}## in a (geometric) series and integrate to get ##\sum...##. Multiply the two series and compare coefficients of ##x^n##. Part of the coefficient of ##x^n## will be ##\sum \frac 1 {k^2}##, part ##\sum \frac 1 {k}##. The latter is ##\zeta(1)##, the former ##\zeta(2)##. So the integral is ##\zeta(2)\zeta(1)##. The identity is probably more easily proven on a calculus level, but it's interesting how the zeta function sneaks in there... .
  • #1
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Pi day is tomorrow! 3.14!

What is your most interesting fact or insight about the number Pi?
 
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  • #2
That ##\tau (= 2\pi)## would have been a better choice :-p
 
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  • #3
Greg Bernhardt said:
Pi day is tomorrow! 3.14!

What is your most interesting fact or insight about the number Pi?
Beside the fact that ##e^{i\pi}+1=0##, it is that it took so unbelievably long until its transcendence has been proven. I have a vague memory of the proof, and it wasn't that complicated.
 
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  • #4
[tex]\frac {\pi^2} 6= \sum_N \frac 1 {n^2} = \prod_P(1-\frac 1 {p^2})^{-1}[/tex]

(where P are primes and N are natural numbers)
 
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  • #5
A pie pi wide is pi square round.
 
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  • #6
I got married on Pi Day 3.141987... . :smile:
(BTW, Greg... thanks for the reminder)

Still married to the same one, two too... . :biggrin:
Pi Day 3.142018 is also the day the great physicist Stephen Hawking died, at age 76... . :frown:

.
 
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  • #7
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Be Rational, Get Real - NEW Funny Humor Joke POSTER
 

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  • #8
Q. What is the volume of a pizza with radius z and thickness a?

A. pizza
 
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  • #9
39f4bf13efa51c1eee9f5c145ba6035f.jpg
 

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  • #10
fresh_42 said:
Beside the fact that ##e^{i\pi}+1=0##, it is that it took so unbelievably long until its transcendence has been proven. I have a vague memory of the proof, and it wasn't that complicated.

At what level would one have to be for it to be 'not that complicated'? I first read about it quite young, still at school, in Eric Temple Bell's book on the great mathematicians, in the chapter on Hermite by which time, well into the 19th-century It was all getting rather intimidating and oppressive, everything above one's head. But Temple Bell (funny name) had a knack of phrases which somehow stuck in the mind. Even when they were, as in this case, not his.

Charles Hermite was first to prove the transcendence (? transcendentiality?) of a 'naturally occurring' number, i.e. one not invented for the purpose of proving transcendence, i.e. .I suppose for proving existence of such numbers. The number was ##e##. The memorable phrase I still remember without having the book by me was when he said, someone should be able to prove the trancendence of π "but believe me, dear friend, it will not fail to cost them some efforts.'

Having written that, I was curious to trace the original quotation, which today the miracle of Internet allows me to do from home, allows me to do at all.

Je ne me hasarderai point à la recherche d’une démonstration de la transcendance du nombre π. Que d’autres tentent l’entreprise. Nul ne serait plus heureux que moi de leur succès. Mais, croyez m’en, mon cher ami, il ne laissera pas que de leur en coûter quelques efforts.

(Some phrasing there sounds slightly antique to me, can someone confirm?) But if one of the most famous mathematicians of all time said that of one of most famous problems (impossibility of squaring the circle in Euclidean geometry depends on it), it's not sounding "wasn't that complicated". But maybe somebody has discovered a simpler way? Accessible to ordinary mortals? Is there a standard way of doing it?
 
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  • #11
epenguin said:
At what level would one have to be for it to be 'not that complicated'?
It had been at the end of a lecture script of Linear Algebra. I just don't remember whether it was at the end of the first semester or at the end of the first year.
 
  • #12
You can remember the first 8 digits of pi by counting the letters of each word in the sentence "May I have a large container of coffee".

Albert Einstein was born on March 14 (Pi Day).

The first 6 digits of pi appear in order 6 times (I think it's 6) in the first ten million digits of pi.

I know the thread title said "your most interesting fact", but can you tell I like pi? I have memorized all of the digits of pi (right now I'm just working on getting them in order :smile: :wink:).
 
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  • #13
Fig Neutron said:
"May I have a large container of coffee"

- this is stronger than coffee :
How I want a drink, alcoholic of course, after the heavy lectures involving quantum mechanics :skullXbones:
 
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  • #16
You are right.It is pointless.But still quite impressive what the human mind can do.
 
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  • #17
To better than 0.5%, a year is ##\pi\times 10^7## seconds.
 
  • #18
Ibix said:
To better than 0.5%, a year is ##\pi\times 10^7## seconds.

Aliens!
 
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  • #19
Borek said:
Aliens!
Even worse - numerologist aliens.
 
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  • #20
fresh_42 said:
Beside the fact that ##e^{i\pi}+1=0##, it is that it took so unbelievably long until its transcendence has been proven. I have a vague memory of the proof, and it wasn't that complicated.
##\pi = - i \ \ln(-1)## or ##\pi = - 2 \ i \ \ln(i)##

There you have it. :)
 
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  • #22
PeroK said:
Changing to ##\tau = 2\pi## would be worthwhile just to highlight the pointlessness of that if nothing else.
On the other hand, two pies are better than one.

Is there a constant called cookie?
 
  • #23
Borek said:
[tex]\frac {\pi^2} 6= \sum_N \frac 1 {n^2} = \prod_P(1-\frac 1 {p^2})^{-1}[/tex]

(where P are primes and N are natural numbers)
Just found
$$\int_0^1 \frac{\log x}{x-1} \,dx = \frac{\pi^2}{6}$$
I don't like this Pythagorean numerology in me, but I can't escape its fascination. What is it with this ##\pi^2/6\,##?
 
  • #25
fresh_42 said:
Just found
$$\int_0^1 \frac{\log x}{x-1} \,dx = \frac{\pi^2}{6}$$
I don't like this Pythagorean numerology in me, but I can't escape its fascination. What is it with this ##\pi^2/6\,##?
Expand ##\log(x)## in a Taylor series and integrate to get ##\sum \frac{1}{n^2}##
 
  • #26
TeethWhitener said:
Expand ##\log(x)## in a Taylor series and integrate to get ##\sum \frac{1}{n^2}##
Sure. I just wanted to emphasize the visual beauty of the three different expressions by ##\sum\; , \; \prod\; , \;\int##
 
  • #27
How about a modern version?

The following sentence about ##\pi## has been stable under Google-Translate transformations:
"Pi is not included in any Galois extension of rational numbers."
 
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What is the most interesting fact about Pi?

The most interesting fact about Pi is that it is an irrational number, meaning it cannot be expressed as a finite decimal or fraction. It has infinite digits and has been calculated to over 31 trillion digits.

Why is Pi important?

Pi is important because it is a mathematical constant that is used in many calculations and formulas in mathematics, physics, engineering, and other scientific fields. It is also a fundamental concept in geometry, as it represents the ratio of a circle's circumference to its diameter.

Who discovered Pi?

The concept of Pi has been studied and used by many ancient civilizations, including the Egyptians, Babylonians, and Greeks. However, the first calculation of Pi was done by Archimedes of Syracuse in the 3rd century BCE. The symbol "π" was later introduced by mathematician William Jones in 1706.

Can Pi be written as a fraction?

No, Pi cannot be written as a fraction because it is an irrational number. However, it can be approximated by fractions such as 22/7 or 355/113.

What is the current world record for calculating Pi?

The current world record for calculating Pi is held by physicist Peter Trueb, who calculated Pi to 31 trillion digits in 2020. However, with the help of powerful computers, Pi has been calculated to over 50 trillion digits.

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