In this interview, David Zierler, Oral Historian for AIP, interviews Ephraim Fischbach, professor of physics at Purdue University. Fischbach recounts his childhood in Brooklyn and the role of Judaism in his upbringing. He discusses his undergraduate work at Columbia University, and he describes a number of humorous adventures in the lab that convinced him to switch to physics from chemistry. Fischbach describes his graduate work under the direction of Henry Primakoff in theoretical particle physics at the University of Pennsylvania, and his first job after Penn at SUNY-Stony Brook. He discusses his work on the strength of gravitational interactions, weak interactions, algebraic computing, and he describes his time at the Niels Bohr Institute in Copenhagen. Fischbach describes the circumstances leading to his hire at Purdue and he discusses his collaboration with Sam Aronson and the fundamental work on the Fifth Force, and the popular interest this work engendered. Fischbach explains the underlying mysteries of the Fifth Force and its ongoing influence in both cosmology and particle physics. He describes his ongoing interests in complex calculations, radioactive decay, and neutrinos, among many projects, and in the last part of the interview, Fischbach explains his goal to protect electrical grids from solar storms, which he sees as one of the greatest threats facing modern society.