Yury Kronn, Ph.D. (1935-2021), was a world-renowned scientist, inventor, and leading theoretician in physics. He earned his doctorate at Russia’s prestigious Gorky University and was awarded a Doctor of Sciences degree by Lebedev Physical Institute of Moscow. The coauthor of Resonant Nonlinear Interactions of Light with Matter, as well as the author of more than 80 scientific articles, he was involved in subtle energy physics research for the last 30 years of his life.