Phiala Shanahan Is Seeking Fundamental Answers About Our Physical World

February 28, 2023

In 2010, Phiala Shanahan was an undergraduate at the University of Adelaide, wrapping up a degree in computational physics, when she heard of an unexpected discovery in particle physics. The news had nothing to do with any of the rare, exotic particles that physicists were searching for at the time. Rather, the revelation revolved around the mundane, ubiquitous proton.

That year, scientists had measured the proton’s radius and discovered that the particle was ever so slightly smaller than what previous experiments had reported. This new measurement threw into question what physicists had assumed was well-understood: What exactly was the size of the proton?

What would then be coined the “proton radius puzzle” immediately drew Shanahan’s interest, prompting a more fundamental question: What else don’t we know about this seemingly straightforward particle?