# What is Pi Day? Math, science, pies and more

A freshly decorated key lime pie sits on a counter in a busy bakery kitchen at Michele's Pies, Wednesday, March 13, 2024, in Norwalk, Connecticut. Math enthusiasts and bakers celebrate Pi Day on March 14 or 3/14, the first three digits of a mathematical constant with many practical uses. Around the world, many people will mark this day with a slice of sweet or savory pie. (AP Photo/John Minchillo)

Math enthusiasts around the world, from students to rocket scientists, celebrate Pi Day on Thursday, March 14, or March 14 – the first three digits of an infinite number with many practical uses.

Around the world, many people will mark this day with a slice of pie, sweet, savory or even pizza.

Simply put, Pi is a mathematical constant that expresses the ratio of the circumference of a circle to its diameter. It is part of many formulas used in physics, astronomy, engineering and other fields, dating back thousands of years to ancient Egypt, Babylon and China.

Pi Day itself dates back to 1988, when physicist Larry Shaw began celebrations at the Exploratorium science museum in San Francisco. The holiday didn't really gain national recognition until two decades later. In 2009, Congress designated March 14 as a special day – hoping to spark more interest in math and science. Fittingly, this day is also Albert Einstein's birthday.

Here's a little more about the origin of the holiday and how it is celebrated today.

## WHAT IS PI?

Pi can calculate the circumference of a circle by measuring the diameter (the distance passing directly through the middle of the circle) and multiplying it by the number greater than 3.14.

It is considered a constant number and it is also infinite, which means it is mathematically irrational. Long before computers, historical scientists such as Isaac Newton spent many hours manually calculating decimal places. Today, using sophisticated computers, researchers have found billions of digits for pi, but there is no end.

## WHY IS IT CALLED PI?

It did not receive its name until 1706, when the Welsh mathematician William Jones began using the Greek symbol for the number.

Why this letter? It is the first Greek letter of the words “periphery” and “perimeter”, and pi is the ratio of the periphery – or circumference – of a circle to its diameter.

## WHAT PRACTICAL USES?

The number is essential for accurately pointing an antenna at a satellite. It can determine everything from the size of a huge cylinder needed in refinery equipment to the size of paper rolls used in printers.

Pi is also useful in determining the necessary scale of a tank that serves heating and cooling systems in buildings of different sizes.

NASA uses Pi daily. It is the key to calculating orbits, the positions of planets and other celestial bodies, rocket propulsion elements, spacecraft communication and even the correct deployment of parachutes when a vehicle crashes into Earth or lands on Mars.

Using just nine digits of pi, scientists say they can calculate the Earth's circumference so accurately that they are only wrong by about a quarter of an inch (0.6 centimeter) every 25,000 miles (around 40,000 kilometers).

## IT’S NOT JUST MATHEMATICS, BUT

Every year, the San Francisco museum that invented the holiday holds events, including a parade around a circular plaque, called the Pi Shrine, 3.14 times — and then, of course, festivities with lots of pie.

Across the country, many events are now taking place on college campuses. For example, Nova Southeastern University in Florida will host a series of activities, including a game called “Mental Math Bingo” and an event with free pizza (pies) – and for dessert, the requisite pie.

“Every year, Pi Day gives us a way to celebrate math, have fun and recognize the importance of math in our lives,” said Jason Gershman, chair of the NSU Department of Mathematics.

At Michele's Pies in Norwalk, Conn., manager Stephen Jarrett said it's one of the biggest days of the year.

“We have hundreds of pies on order (Thursday) from businesses, schools and just individuals,” Jarrett said in an interview. “Pi Day is such a fun and silly holiday because it's a mathematical number that people love to turn into something fun and delicious. So people celebrate Pi Day with sweet pies, savory pies, and it's just an excuse for a little treat.

NASA holds its annual “Pi Day Challenge” online, offering people plenty of games and puzzles, some of them straight from the space agency's own playbook, like calculating the orbit of an asteroid or of the distance that a lunar rover would have to travel each day to get there. inspect a certain lunar area.

## AND EINSTEIN?

Perhaps the world's best-known scientist, Einstein was born on March 14, 1879, in Germany. The infinite number of Pi has been used in many of his groundbreaking theories and today Pi Day gives the world another reason to celebrate his achievements.

For the sake of mathematical symmetry, the famous physicist Stephen Hawking died on March 14, 2018, at the age of 76. However, Pi is not a perfect number. He once said this:

“One of the fundamental rules of the universe is that nothing is perfect. Perfection simply does not exist. Without imperfection, neither you nor I would exist.

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