The scientist credited with the heliocentric model of the universe is Nicolaus Copernicus. In the early 16th century, he proposed that the sun, not the Earth, was at the center of the universe, fundamentally challenging the long-held geocentric view supported by Ptolemy and the Catholic Church. Copernicus published his ideas in "De revolutionibus orbium coelestium" in 1543, which marked the beginning of the Scientific Revolution. His model laid the groundwork for future astronomers, including Galileo and Kepler, to further develop the understanding of celestial mechanics. Copernicus's work ultimately transformed the field of astronomy and contributed to the shift towards modern science.