Galileo Galilei is known as the "father of modern science" due to his groundbreaking contributions to physics and astronomy in the early 17th century. He championed the scientific method and emphasized observation and experimentation as the basis for scientific inquiry. His telescopic discoveries, such as Jupiter's moons and the phases of Venus, challenged prevailing geocentric theories and supported the heliocentric model proposed by Copernicus. Galileo's work laid foundational principles for future scientific research and has had lasting impacts on both science and philosophy.