Pi Day Celebrates Math Constant's Ubiquity in Science

From rockets to cancer research, the number pi is embedded in our lives in countless ways.

Mar. 14, 2026 at 4:08pm by Ben Kaplan

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Every year on March 14, math enthusiasts and dessert lovers unite to celebrate Pi Day, commemorating the first three digits of the mathematical constant pi. While pi is best known for its use in calculating the area of a circle, its applications extend far beyond the classroom, touching fields from aerospace engineering to biomedical research. Experts discuss how pi is fundamental to everything from spacecraft propulsion to COVID-19 testing, highlighting the pervasive role this irrational number plays in the cutting edge of science.

Why it matters

Pi Day celebrates the ubiquity of this mathematical constant, which underpins countless scientific and technological advancements that impact our daily lives. By recognizing pi's far-reaching influence, the holiday invites the public to engage with and appreciate the joy of mathematical learning.

The details

Pi, representing the ratio of a circle's circumference to its diameter, is used in a wide range of scientific applications. In aerospace engineering, pi is integral to calculations for spacecraft motion, materials science, and propulsion systems. Biomedical researchers leverage pi's role in fluid dynamics to develop innovative diagnostic tools, such as a new 20-minute Lyme disease test. Even the reception of signals from distant space probes relies on pi-based computations.

  • Pi Day is celebrated annually on March 14, the date representing the first three digits of pi (3.14).
  • The celebration at the Exploratorium science museum in San Francisco begins at 1:59 p.m., signifying the next three digits of pi (3.141).

The players

Larry Shaw

A physicist at the Exploratorium science museum in San Francisco who created Pi Day in 1988.

Sam Sharkland

Program director of public programs at the Exploratorium, who worked with Larry Shaw before his death in 2017.

Artur Davoyan

A professor of mechanical and aerospace engineering at the University of California, Los Angeles, who researches new propulsion systems for space exploration.

Dino Di Carlo

Chair of the bioengineering department at the UCLA Samueli School of Engineering, who conducts research on using tiny fluid droplets to study cells and develop new diagnostic tools.

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What they’re saying

“He had a very open and expansive view of the world and saw an opportunity with this number, mathematical concept, to invite people into the joy of mathematical learning.”

— Sam Sharkland, program director of public programs at the Exploratorium (WRAL)

“As an engineer and scientist, (pi) is just a part of life. Maybe I've taken it for granted.”

— Dino Di Carlo, chair of the bioengineering department at the UCLA Samueli School of Engineering (WRAL)

What’s next

The Exploratorium in San Francisco will host its annual Pi Day celebration on March 14, 2027, featuring a procession where hundreds of visitors march around the pi shrine, each carrying a digit.

The takeaway

Pi Day highlights the profound impact of this mathematical constant, which is woven into the fabric of scientific advancement, from space exploration to medical diagnostics. By recognizing pi's ubiquity, the holiday invites the public to engage with and appreciate the power of mathematics in our everyday lives.