Pi is the ratio of the circumference of any circle to the diameter of that circle. This holds true for circles of any size. Greek letters are used to denote different values in Mathematics. The Greek letter for Pi is π. Pi is often rounded to 3.14 to make things simpler and help ease certain calculations, but the digits of Pi go on forever and they do not have any apparent repetition in their pattern.

The origins of π are not known for certain however, we know that the Babylonians approximated π around 1800BC and Archimedes calculated π around 250 BC. Archimedes made approximate calculations of the area of a circle by using the Pythagorean Theorem to find the areas of two regular polygons. Archimedes knew that he did not find the actual value of Pi, but only made an approximation. He showed that π is between 3 1/7 and 3 10/71. Following Archimedes’ approximation, many mathematicians followed similar approaches to find the value of pi. Indian mathematician and astronomer Aryabhata, approximated π in c. 500 C.E., with the fraction 62,832/20,000, which is 3.1416.

## Pi Day

Pi Day is widely celebrated among students, teachers, science fans and math lovers. On March 14th (or 3/14 in U.S. date format where the month is written before the date) in 1988, a physicist at the San Francisco Exploratorium held what is considered to be the first official Pi Day celebration, which smartly included fruit pies. Math teachers quickly realized the potential benefits of teaching students about pi while they ate pies, and it gained so much popularity that in 2009, the U.S. Congress officially declared March 14 as Pi Day.

Considering π’s connection with circumferences of circles, scholars were inspired to use it as a measure of angle distance. Since space is full of circular and spherical features, engineers at NASA built spacecrafts that make elliptical orbits and guzzle fuel from cylindrical fuel tanks, and measure distances on circular wheels. Apart from measurements and space travel, pi has other uses. It can be used to help us understand what planets are made of and Pi is also used in calculating the depth of alien oceans.

Such is the love of pi that there is an entire language made from the number Pi called “Pi-lish”. The number of letters in each word match the corresponding digit of pi. This first word has three letters, the second has one letter, the third has four letters, and so on. Software engineer Michael Keith wrote an entire book, titled ‘Not a Wake’ in Pi-lish.

## On this Pi day let’s look at some interesting facts about Pi and some daily life examples:

### In Medicine

Pi has great importance in medicine as doctors use it to study the structure of the eye. Pi is critical in the process of rectifying eye related issues and prescribing appropriate medicines such as eyedrops.

### In Designing Clocks

Clock designers who design pendulum clocks, use pi to design the clock pendulums. Pi is used to ensure the clock arms move the correct degree with the passage of time.

### In Navigation

Pi helps us figure out how to point an antenna toward a satellite under any circumstance. Pi also plays a vital role in GPS navigation.

### In the Construction of the Pyramids

The construction of the Pyramids of Giza, one of the oldest wonders of the world shows another use for Pi. The ratio of the hypotenuse of the Great Pyramid to its half base is the Golden Ratio of Pi!

Even though some believe that tau (which is 2 times π) is better suited to circle calculations, pi is loved by many math enthusiasts. Many mathematicians have successfully calculated the value of Pi to over 50 trillion digits beyond its decimal point. Since the value is an irrational and transcendental number, it will continue infinitely without pattern or repetition. While only a handful of digits are considered for typical calculations, pi’s infinite nature makes it a fun challenge to memorize, and to computationally keep calculating more and more digits.

*“Pure mathematics is, in its way, the poetry of logical ideas”*

– Albert Einstein