March 14: 3/14 or 3/14 if we read it in English nomenclature. Saying “three fourteen” quickly paints a number reminiscent of high school in our minds.

Moreover, it is quite possible, when listening to it, to follow the letter: fifteen, ninety-two, sixty-five … as long as our memory reaches us to remember the numbers of the unique number Pi. The US Congress in 2009 officially announced that on this day, March 14, It will be day π.

It was a huge success from the start, and the idea grew until in 2019, UNESCO declared it World Mathematics Day. Since then, more and more people join the celebration every year, with π as the symbol for those of us who love math.

Pi is not really a number

Let’s start by clarifying something, Pi is the sixteenth letter of the Greek alphabet (π) and in mathematics we use it to represent something more interesting than a number (which I am not saying that numbers are not). So the first anomaly of Pi is that This is not a number. But then, if it’s not a number, then what is Pi?

Pi represents the ratio of the circumference’s length to its diameter. A ratio that has its own peculiarity (here is its second rarity) to be steadyi.e. always have the same value no matter how small or large the circumference.

In particular, in Euclidean geometry – which we owe to Euclid (325-265 B.C.) and which assures us things like that one straight line passes through two points – the constant value of Pi is distinct (and now there are three) as to be irrational.

Not that he’s out of his mind, but although it is the result of dividing the circumference by the diameter, it can never be expressed as dividing two integers. If the diameter of the wheel was a “min” value, without decimal numbers, then the area it would cover in one revolution wouldn’t be. But then how much will it be? We’re approaching a major question, the value of Pi…but let me finish with another rarity, the fourth already.

with me transcendent. Not that it’s too important to transcend (also) but transcendent, without n. This mathematical property assures us that Pi will never be the solution to any polynomial.

polynomial? I’m sure you remember him from your math studies. Polynomials are equations in which the unknown is raised to one or more natural numbers, for example x2 + x + 3 = 0.

Well it doesn’t matter what exponent and numbers are used, there is no polynomial where x equals Pi. It is also worth noting that this is a characteristic that does not match many numbers, so at this point already the Pi has proven to be a rarity but the best is still missing. Now yeah, let’s talk of its worth.

The elusive value of Pi

As we said at the beginning, the constant value of Pi (in Euclidean geometry) is 3.141592 … but, precisely, because it is irrational, we know that it will have infinite decimal places. Infinite, it seems, is infinite, and to make matters worse, in this case it is not only infinite but does not follow any pattern.

They appear randomly, with an equal chance of appearing for all numbers from 0 to 9. In fact, its values can be used as a random number generator and among them can be searched for any sequence of numbers, even anyone’s ID number, which is sure to exist somewhere.

However, the most important thing about this Pi property is that it has become Inspiration To work for many people.

Since early times (there are indications that Pi was already known to the Babylonians in 2000 BC), efforts have been made to determine its value as accurately as possible. In particular, Archimedes of Syracuse (287 – 212 BC) was the first to bear fruit, devising a method for reducing the value of this rare constant.

Archimedes used inscribed (those within the perimeter) and constrained (those with the inner perimeter) polygons. In this way, the perimeter value of the perimeter will always be between the perimeter of the patterned polygon and the perimeter of the given polygon.

By adding more and more sides to the polygons, Archimedes was able to give a set of values for Pi, which had a maximum error of 0.040% over the true value…come, close, close.

Archimedes’ idea was followed by many others of a very diverse nature, some even from the point of view of probability and statistics, as was the case with Georges-Louis Leclerc (1707-1788), Count of Buffon.

In particular, Leclerc found the number Pi while trying to determine how likely it was that throwing a needle at a set of parallel lines would cause it to land transversely on one of the lines. After various calculations, he concluded that if the lines are separated by the same distance as the length of the needle, Said probability was 2 divided by Pi.

In this way it was easy to approximate the Pi by throwing several needles in, noting the proportion of these that actually cut the parallel lines and comparing it to the exact probability.

However, with the arrival of the computer age, the fifth anomaly of Pi appeared, being a calculated number. In particular, Alan Turing specified, in 1936, that a number is computable if there is an algorithm that allows us to round its value to a predetermined number of decimal places.

Calculated 63 trillion decimal places for Pi

Following this premise, in 1949, the ENIAC machine was able to break the record set by humans to date and calculate the first 2037 decimal places of Pi, given Starting a $63 billion race (European) from figures calculated in 2021 by a team from the University of Applied Sciences in the Swiss canton of Graubünden.

But Pi is not just a strange mathematical entity that has mobilized threads of human thought since ancient times. Pi, as Rhett Alain assures us, is an astonishing number that appears naturally where we least expect it: in estimating our location by GPS, in the movement of a wall clock pendulum or even in the way an assistant uses a voice, it is able to recognize that the user wants, on Example, to be told a joke.

But, above all, Pi is the perfect excuse for us to celebrate mathematics and all it has to offer us every March 14th. Happy International Mathematics Day!

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