Events honoring the mathematical constant pi (3.14159 ) began at precisely 1:59 on March 14, thus making the date 3/14 1:59.
Coincidentally, March 14 is also Einsteins birthday.
Mathematicians have been fascinated by pi for over 2,500 years.
Defined as the ratio of a circles circumference to its diameter, the infinite series of numbers that form pi have never been shown to form a discernible pattern.
"The number of Pi is incredibly important to all technology," said associate professor of mathematics Steve McKelvey, who, along with four other professors from the math department, submitted to being "pied" by the student body in recognition of the day.
National events also recognize the importance of pi with contests, forums, and projects sponsored by the Goudreau Museum of Mathematics in New York.
For many years the college held a math colloquium on Pi Day, but this changed with the arrival of Luke Anderson 02.
This former St. Olaf student memorized a sequence of the digits of pi and began holding performances on each Pi Day to sing the numbers to his audience.
His last performance was this year.
Along with singing the digits of pi, Anderson composed and sang several songs in honor of pi set to the tune of Jingle Bells, O Christmas Tree, and other popular tunes.
This year the event was combined with the Womens History Month celebrations and the audience was served pie.
While attendance continues to be mostly math and science majors, professors are ever hopeful about spreading "the joy of pi."