Explore the transformative impact of high-performance computer simulations on scientific understanding in this comprehensive lecture. Delve into the history of scientific modeling before examining modern applications in various fields, including crystallography, materials science, and molecular dynamics. Learn about genetic algorithms for crystal structure prediction, the significance of Lawrence Bragg's bubble raft model, and cutting-edge simulations of nanostructures and nanoparticles. Discover how computer modeling contributes to the development of high-energy density batteries and consider three major challenges facing the field. Gain insights into how these advanced simulations are revolutionizing scientific research, from testing hypotheses at planetary scales to developing personalized approaches in the fight against COVID-19.