International Pi Day is celebrated on March 14th. Pi is one of the most recognized numbers in mathematics, and mathematicians all around the world celebrate it. This week, our Maths Ambassadors are doing an assembly all about pi.
What is Pi?
Pi is the symbol used in maths to represent a constant. The perimeter around the edge of a circle is called the circumference. The diameter is the length of the line from side to side passing through the centre. Pi is the ratio of the circumference of a circle to its diameter. This is approximately 3.1416.
More about Pi
The decimal places of the number for pi goes on to infinity. The pattern of the numbers never repeats and so it is called an “Irrational Number”. You would get the same number for pi regardless of what size the circle is. So, a penny coin or the Millennium Dome all have the same value of pi.
The History of Pi
The existence of pi dates to the Babylonians about 4,000 years ago. At that time, a figure of “3 times the square of the radius” of the circle was used to find the circumference. In those days, the exact number was not known. Egyptian mathematicians approximated pi with a bit more accuracy using 3.1605 in 1,650 B.C.
The Greek mathematician Archimedes, who was born in 287 B.C. used the geometry method to approximate the value of pi. His method uses the area of two shapes. Imagine a shape having so many sides that it resembles a circle. With a lot of patience and grit, the area of such a polygon can be used to get a more accurate value of pi.
Today, pi has been calculated to over 50 trillion digits beyond its decimal point.
Why is International Pi Day such a great occasion?
The celebration of Pi Day began on March 14, 1988, at the San Francisco Exploratorium, where physicist Larry Shaw organised a big festive occasion to make mathematics more relatable and fun. March 14, 1879, also happens to be the birthday of Albert Einstein, one of the most influential scientists of the 20th century
How does Pi help us in our everyday lives?
Firstly, pi allows us to communicate to satellites. For example, to get Wi-Fi to work on planes, engineers use trigonometry, which uses pi, to calculate the direction that the antenna has to be facing. Without pi, we wouldn’t be able to predict the weather, track cargo ships, or even use google maps on our phones.
Pi is also used widely in the field of architecture. Bridges, mosques, and many buildings all share the characteristic of using arches. Since arches are semicircles, pi helps in determining the perimeter which in turn helps in calculating the amount of material required for construction.
Finally, while pi is used for crucial calculations that affect our daily lives, it can also be used for smaller scale needs, like barcode printers. These printers, which are employed in hospitals, warehouses, power plants, and other locations, print on a wide range of materials, including paper and polyester, each of which requires a distinct roll length. If the rolls are built too large, they won’t fit in the printer and so a formula is made that finds the maximum roll length of a material using pi.
In conclusion, pi is a significant number that allows scientists, engineers, architects and more to form calculations that help them in their field of work. While we usually don’t give the value a second thought, without pi, we wouldn’t be able to put on our favourite tv show, we wouldn’t be able to escape on a plane to a tropical island, and we wouldn’t even be able to message our family on our phone.
