Galileo Galilei was an influential Italian scientist whose contributions laid the groundwork for modern physics and astronomy. Born in 1564, he initially studied medicine at the University of Pisa but soon shifted his focus to mathematics and natural philosophy. His pioneering work in the early 17th century on the mechanics of motion challenged longstanding Aristotelian beliefs and promoted the scientific method of experimentation. One of his most significant achievements was the improvement of the telescope, enabling him to make groundbreaking astronomical observations. He discovered the four largest moons of Jupiter, examined the phases of Venus, and studied sunspots. These findings supported the heliocentric model proposed by Copernicus, which placed the sun at the center of the solar system, contradicting the widely accepted geocentric view. Galileo's support for heliocentrism led to conflicts with the Catholic Church, culminating in his trial and subsequent house arrest. Despite this, his work inspired future generations of scientists and cemented his legacy as the father of modern observational astronomy and a key figure in the scientific revolution. Galileo Galilei was a pivotal figure in the scientific revolution, contributing to the development of modern physics and astronomy. His innovations, particularly in telescopic observations, transformed our understanding of the cosmos. Despite facing persecution for his beliefs, his legacy continues to influence science today.