In this overview of radiation's many great benefits and as yet untapped potential, Dr. Alan E. Waltar, past president of the American Nuclear Society, explains how this important energy source has been harnessed to serve a plethora of humanitarian functions. Through the use of anecdotes, Waltar provides numerous examples of radiation's many uses in agriculture, medicine, electricity generation, modern industry, transportation, public safety, environmental protection, space exploration, and even archeology and the arts. Estimating the total financial contribution of all these varied uses, Waltar comes to the revelation that radiation technology now contributes more than $420 billion to the US economy and provides over 4.4 million jobs. In the future, Dr. Waltar foresees continuous improvement in many areas of science, industry, and medicine through tapping the incredible potential of Marie Curie's initial insights.