What's Pi Day all about? Math, science, pies and more

FILE - Manager Stephen Jarrett displays their National Pie Championships 1st spot winning state pome pastry astatine Michele's Pies, Wednesday, March 13, 2024, successful Norwalk, Conn.

John Minchillo/AP

FILE - A state pome pastry is sliced astatine Michele's Pies, Wednesday, March 13, 2024, successful Norwalk, Conn.

John Minchillo/AP

WEST PALM BEACH, Fla. (AP) — Math enthusiasts astir the world, from assemblage students to rocket scientists, observe Pi Day, which is March 14 oregon 3/14 — the archetypal 3 digits of an infinite fig with galore applicable uses.

Many radical volition people the time with a portion of pastry — sweet, savory oregon adjacent pizza.

Simply put, pi is simply a mathematical changeless that expresses the ratio of a circle’s circumference to its diameter. It figures into galore formulas utilized successful physics, astronomy, engineering and different fields, dating backmost thousands of years to past Egypt, Babylon and China.

Pi Day itself dates to 1988, erstwhile physicist Larry Shaw began celebrations astatine the Exploratorium subject depository successful San Francisco. The vacation didn’t truly summation nationalist designation until 2 decades later. In 2009, Congress designated each March 14 to beryllium the large time — successful the hopes of spurring much involvement successful mathematics and science. Fittingly enough, the time is besides Albert Einstein’s birthday.

Here’s a small much astir the holiday’s root and however it’s celebrated today.

What is pi?

Pi tin cipher the circumference of a ellipse by measuring the diameter — the region consecutive crossed the circle’s mediate — and multiplying that by the 3.14-plus number.

It is considered a changeless fig and it is besides infinite, meaning it is mathematically irrational. Long earlier computers, historical scientists specified arsenic Isaac Newton spent galore hours calculating decimal places by hand. Today, utilizing blase computers, researchers person travel up with trillions of digits for pi, but determination is nary end.

Why is it called pi?

It wasn’t fixed its sanction until 1706, erstwhile Welsh mathematician William Jones began utilizing the Greek awesome for the number.

Why that letter? It’s the archetypal Greek missive successful the words “periphery” and “perimeter,” and pi is the ratio of a circle’s periphery — oregon circumference — to its diameter.

What are immoderate applicable uses?

The fig is cardinal to accurately pointing an antenna toward a satellite. It helps fig retired everything from the size of a monolithic cylinder needed successful refinery instrumentality to the size of insubstantial rolls utilized successful printers.

Pi is besides utile successful determining the indispensable standard of a vessel that serves heating and aerial conditioning systems successful buildings of assorted sizes.

NASA uses pi connected a regular basis. It’s cardinal to calculating orbits, the positions of planets and different celestial bodies, elements of rocket propulsion, spacecraft connection and adjacent the close deployment of parachutes erstwhile a conveyance splashes down connected Earth oregon lands connected Mars.

Using conscionable 9 digits of pi, scientists tin cipher the Earth’s circumference truthful accurately it errs by lone astir a 4th of an inch (0.6 centimeters) for each 25,000 miles (about 40,000 kilometers).

It's not conscionable math, though

Every twelvemonth the San Francisco depository that coined the vacation organizes events, including a parade astir a circular plaque, called the Pi Shrine, 3.14 times — and then, of course, festivities with tons of pie.

Across the country, galore events present instrumentality spot connected assemblage campuses. At Florida Atlantic University successful Jupiter, Florida, students successful the Jupiter Mathematics Club are hosting a Pi Day Extravaganza with a raffle to deed mathematics professors with a pie, on with a contention for who tin memorize the astir digits of pi.

Restaurants crossed the country, including immoderate pizza chains, besides connection $3.14 specials connected Pi Day.

NASA holds its yearly Pi Day Challenge online, offering plentifulness of games and puzzles, immoderate straight from the abstraction agency’s ain playbook, specified arsenic calculating the orbit of an asteroid oregon the region a satellite rover would request to question each time to survey a definite lunar area.

What astir Einstein?

Possibly the world’s best-known scientist, Einstein was calved connected March 14, 1879, successful Germany. The infinite fig of pi was utilized successful galore of his breakthrough theories and present Pi Day gives the satellite different crushed to observe his achievements.

In a spot of mathematics symmetry, famed physicist Stephen Hawking died connected March 14, 2018, astatine property 76. Still, pi is not a cleanable number. He erstwhile had this to say:

“One of the basal rules of the beingness is that thing is perfect. Perfection simply doesn’t exist. Without imperfection, neither you nor I would exist.”

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Associated Press newsman Stephany Matat contributed to this study from West Palm Beach, Florida.