Final answer:
Nicolaus Copernicus is credited with developing the heliocentric theory, suggesting that the Sun is at the center of the universe, which was a pivotal departure from the geocentric model of Ptolemy. His work, published in 1543, laid the foundations for future scientific explorations and was validated by later astronomers.
Step-by-step explanation:
The scientist who developed the heliocentric theory, proposing that the Sun is at the center of the universe rather than the Earth, is Nicolaus Copernicus. His revolutionary idea, detailed in his seminal work, De Revolutionibus Orbium Coelestium (On the Revolutions of the Celestial Spheres), was published in 1543. This theory was a significant shift from the prevailing geocentric theory established by Ptolemy, which had been widely accepted for over a millennium.
Copernicus, a polymath rooted in the Renaissance era, employed interdisciplinary knowledge encompassing theology, medicine, law, language, and mathematics to inform his astronomical work. Copernicus' theory turned the tide of cosmological thought, which was further built upon by subsequent scientists like Galileo Galilei and Johannes Kepler. Although his heliocentric model did not include planets beyond Saturn, and he couldn't definitively prove the Earth revolves around the Sun at the time, his compelling arguments laid the groundwork for the future confirmation of the theory.