# Dr. Daniel Orr Finds Pi in Surprising Places

March 5, 2020

As we approach 3.14 (at 1:59 am?), we are preparing to celebrate all things π.

In anticipation of the day, Professor Andy Norton interviewed Professor Daniel Orr on suprising appearances of π. Did you know that π isn't just about circles and geometry? Dr. Orr explains how π pops up in a probability problem about prime numbers.

Question: what is the probability that two whole numbers will be relatively prime (share no common factors)?

Answer: 6/π^{2}

As Dr. Orr explains, this solution comes from the Riemann zeta function.