If you’re a mathematician, engineer or simply techy enough to appreciate Pi, then this day is for you. March 14th is the official Pi Day. Pi, also known by the Greek letter π, is a constant value used in math that represents the ratio of a circumference of a circle to its diameter. While Pi is an infinite number, you usually see it shortened to two decimal points—3.14. That’s why March 14 (3rd month, 14th day) is the official Pi Day!

### Taking a Bite Out of History

Pi Day is a holiday which is celebrated annually on March 14th throughout the world. This day was created solely to celebrate the mathematical constant π. The day was founded in 1988, which is the earliest known large-scale celebration of Pi Day. It was organized by a physicist named Larry Shaw at the San Francisco Exploratorium. The story goes that he, his staff and surrounding public marched around one of its circular spaces, then ate fruit pies. Today, many people who celebrate Pi Day also feast on a baked pie, sometimes even pizza pie. Pie for Pi.

### Engineers Use Pi Daily

So, how does Π=3.141592 6535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164 0628620899 8628034825 3421170679….. fit into today’s world?

It does, in fact, in many ways. The mathematical constant Pi has a big role in virtually every industry. Take aerospace for example. Engineers in the aerospace industry use Pi for what is known as actuators. Actuators control the flaps that move on aircraft wings and tails or the parts that open and close valves on jet engines. Controllers send signals to electric motors, telling them how fast they need to spin to make the actuators move.

NASA Engineers use Pi to put spacecraft into orbit around other planets. To do this, they have to slow down the spacecraft just enough and at exactly the right time for it to get pulled into orbit by the planet’s gravity.

In the search for planets outside of our solar system, Pi is used in the equations that would help us characterize these foreign planets. These exoplanets are characterized by their density, which gives us an idea if a planet is mostly made of gas or rocks and the formula for density just happens to have Pi in it.

#### The constant is also used with the following in various industries:

- building and construction
- quantum physics
- music theory
- medical procedures
- talking to satellites
- electric motors
- sizing up vessels at refineries
- measuring a roll of paper
- determining the capacity hot water storage tanks and heaters
- and much more!

Whatever your engineering or mathematical preferences are, enjoy Pi Day. It might give something to sink your teeth into.