INVENTING ROOT LOCUS: HOW ONE MAN REPLACED CHAOS WITH CLARITY

INVENTING ROOT LOCUS

ABOUT THIS SITE:

This forthcoming book will tell the extraordinary story of Walter R. Evans, whose 1948 invention of Root Locus and the Spirule revolutionized control system design, shaping the methodologies taught in classrooms and employed by engineers worldwide. Root Locus stands as one of the most significant contributions of the post-war aerospace industry, profoundly impacting national security and advancing technology.

Drawing from Walter Evans' original notes, hundreds of letters, and firsthand accounts from his colleagues at North American Aviation’s Aerophysics Laboratory—later known as Autonetics—this biography offers unparalleled insight into the life and legacy of a pioneer whose work changed the course of engineering history.

Yet, this is more than a story of technical genius. It is also a deeply human narrative of resilience, love, and partnership. When a devastating stroke struck Walter at the age of 60, his wife, Arline—whom colleague Bob Cannon affectionately called “Saint Arline”—dedicated herself to his recovery and well-being. Together, they overcame immense challenges, proving that triumph can emerge even from life’s greatest adversities.

This contents page previews chapters from the forthcoming book Into Stability: Walter R. Evans and the Story of Root Locus, written by his son, Greg.