Our current lives are a result of scientific evolution to which many geniuses in science have contributed. This book describes the lives of great scientists from Galileo to Einstein who made remarkable discoveries in science. By focusing on their stories, the reader will understand that the common trait shared by them in their scientific journey was a genuine enthusiasm to scholarship.The Progress of science is surveyed as follows: Galileo called the father of modern science, expressed natural phenomena with quantitatively measurable quantities, such as weight and length for the first time. Kepler discovered Kepler's laws that explained the movement of celestial bodies. It was however not understood why celestial bodies moved according to Kepler's laws. This problem was elucidated by Newton founding Newtonian mechanics. Electromagnetic phenomena experimentally discovered by Faraday, were theoretically unified by Maxwell who founded electromagnetic theory, constituting the two greatest theories in classical physics together with Newtonian mechanics until the end of nineteenth century.At the end of nineteenth century, two experimental results could not explained by classical physics. The one was the result on the black body radiation. For elucidating the result, Planck in 1900 derived Planck's formula, discovering the concept of "quantum." The other was Michelson-Morley experiment's result supporting relativity principle. For elucidating the result, Einstein developed relativistic theory, constituting the two greatest theories of twentieth century together with quantum mechanics.The readers can understand the progress in physics from classical physics to modern physics, impressed by the lives of geniuses with a genuine enthusiasm to scholarship.