Final answer:
The heliocentric theory defines the Sun as the center of our solar system with the planets orbiting it, contrasting with the earlier geocentric Ptolemaic model. It gained acceptance through the works of Copernicus and Newton, offering a more scientifically substantiated view of the universe.
Step-by-step explanation:
The heliocentric theory is best described as the theory that identifies the sun as the center of our solar system, with planets revolving around it. This conceptual framework is opposed to the geocentric (Earth-centered) models of the universe, such as the Ptolemaic model.
The Ptolemaic view, which dates back to the second century AD, proposed Earth at the center of the universe with the Moon, planets, the Sun, and stars revolving around it. This geocentric model increased in complexity as more circles were added to explain planetary motions, but it lacked any causative explanations. As scientific understanding progressed, notably through the works of Copernicus, Galileo, and Newton, the heliocentric model gained acceptance. Nicolaus Copernicus' work De Revolutionibus Orbium Coelestium laid the foundation for the heliocentric view, showing that Earth and other known planets revolve around the Sun, with the closer planets moving faster in their orbits. This model is underpinned by laws such as Newton's universal law of gravitation, offering a simple, coherent, and quantifiable explanation for celestial phenomena.