Galileo Galilei

Galileo Galilei is the father of modern observational science, physics, and the scientific method. He championed Copernican heliocentrism through groundbreaking telescopic discoveries: the moons of Jupiter, the phases of Venus, sunspots, and lunar mountains, providing concrete evidence against a perfect, Earth-centered universe. In physics, he formulated the law of falling bodies and the principle of inertia, directly challenging Aristotelian physics and paving the way for Newton's laws. Most importantly, he insisted that the Book of Nature is written in mathematics and must be read through experiment, measurement, and observation—establishing the empirical foundation of modern science. His conflict with the Catholic Church symbolizes the struggle between scientific inquiry and doctrinal authority. His work marked the decisive turn from philosophical speculation to evidence-based scientific practice.