Happy Pi Day!

Even if it’s a Sunday one 🙂 Yesterday all lovers of mathematics celebrated Pi Day, and we successfully missed it. But as is well known, good holidays can be celebrated with a delay – especially if they are connected with infinite numbers.

This holiday is unofficial. It was invented by physicist Larry Shaw in 1987. While working at the popular science museum Exploratorium in San Francisco, he noticed a funny coincidence: in the American date format March 14 looks like 3/14 – exactly like the first digits of the number π. And if you add the time 1:59:26, you get an almost perfect sequence: 3.1415926. For a person who loves mathematics, it is roughly like seeing perfectly matched gears in a mechanism.

That is how the idea of a small humorous holiday was born. In the first year the museum staff organized a symbolic “parade in a circle” – participants walked around the building, representing a circle. After that they ate pies. The English word pie sounds exactly like pi, so the tradition caught on instantly. Sometimes the strongest traditions start exactly like this – with a joke, a walk and a piece of pie.

Over time Pi Day spread far beyond the museum. Universities, schools, scientific centers and simply lovers of mathematics around the world began celebrating it. Lectures are held, mathematical quizzes are organized, competitions for memorizing the digits of Pi take place, popular science talks are given and even unusual “mathematical marathons” are arranged where participants try to recall as many digits after the decimal point as possible.

The number π itself is one of the most famous mathematical constants. It is the ratio of the circumference of a circle to its diameter. It is the same for any circle, whether it is a bicycle wheel, a planet or a microscopic particle. Its approximate value is known to almost everyone: 3.14. But in reality the number is infinite and irrational, which means that its decimal representation never ends and never repeats.

People have been trying to calculate it for more than two thousand years. The ancient Greek mathematician Archimedes was one of the first to obtain a fairly accurate approximation using inscribed and circumscribed polygons. In ancient China and India mathematicians also calculated increasingly precise values. Today supercomputers calculate trillions of digits after the decimal point – more out of sporting interest and for testing computing systems than out of practical necessity.

But the most amazing thing about Pi is that it is everywhere. We rarely think about it, but this constant is literally embedded in the technologies we use every day.

It is used in computer graphics and animation when programs calculate rotations, circles and curves. It is involved in image and video processing algorithms. Without it it would be impossible to accurately calculate satellite orbits and the operation of GPS navigation. The number Pi is used in wave physics, in engineering calculations and in modeling the movement of liquids and air.

Even in medicine it plays an important role. In computed tomography and magnetic resonance diagnostics complex mathematical algorithms use π to reconstruct images of human internal organs. In other words, when a doctor looks at a CT scan, somewhere deep inside the calculations the same ancient number from school geometry is quietly at work.

The result is a curious thing. This mathematical constant arose from a very simple task – measuring a circle. But over time it turned into one of the fundamental tools of modern science and technology.

So Pi Day is not just a reason for jokes and pies. It is a reminder that sometimes the most important things begin with a simple question. For example, how many times the diameter of a circle fits into its circumference.

And yes, if today you suddenly feel like eating a piece of pie “in honor of science”, mathematicians definitely will not object. After all, the number Pi has an infinite number of digits. Which means it can be celebrated infinitely long.