# What is PI?

## What is PI ?

March 14th is celebrated as the “PI” (π) day! As we know, π (PI ) is a mathematical constant, having an approximate value of 3.14159 … The first three significant digits (3, 1 and 4) of π (PI) makes March 14th (3/14 – month/day format) of every year a special day!

We have used PI in our basic math. For instance, we used it in our elementary / middle school math, to calculate the circumference and area of circles. Pi is used for mathematical computations in Engineering, Quantum Physics, Space Research, etc. Let’s see some interesting facts about π (Pi) !

• π (PI) is a mathematical constant and is an irrational number. An irrational number has an infinite number of decimal points. That is, its decimal points do not have a repeating pattern and the number of decimal points tends to infinity. The picture below is a tiny series of decimal points in π (PI) that will keep going without ending. The picture shows only about 488 digits of Pi.
• Emma Haruka Iwao, a google employee set a new world record on this Pi Day (Mar-03-2019) for calculating the value of Pi. She calculated Pi to 31.4 Trillion (31,415,926,535,897) digits using 25 Google Cloud Virtual Machines. The computation required 170 TB (Terabytes) and it took 121 days to find 31.4 Trillion digits.
• If you want to compare the speed of two identitical computers, find out which one calculates larger number of digits of Pi (π) in a specified amount of time.
• π (PI) is a constant (3.14159…), which is the ratio of the circumference to diameter of any circle. In other words, if you divide the circumference of any circle by its diameter, you will get π (PI) (3.14159…) as the result. Whether the circular (or spherical) object is an Atom or Mustard or Wheel or Sun, the ratio of the object’s circumference to its diameter is always 3.14159… That is π. In otherwords, if we divide the circumference by the diameter of an atom or mustard or pupil of our eye or wheel of cart or London Eye or Sun, we will get 3.14159… (π) as a result.
• The visible universe that has the largest size, has a radius of about 46 billion light years. How many digits of Pi do you think, we need to calcaulate the circumference of the visible Universe?
• NASA uses about 40 digits of Pi to calculate the circumference of the visible Universe, with an accuracy equal to the diameter of a Hydrogen atom.
• You know, you can get nice deals on “Pie” in restaurants around the world on “Pi” Day !
• In order to calculate the size of (Area or Circumference) “Pie”, we must use the value of “Pi”. Thus, Pi (π) is there in every slice of our life!

You can find more interesting facts about Pi at the following link: Piday