Which model places Earth at the center of the Universe?

• A. Geocentrism
• B. Heliocentrism
• C. Copernican principle
• D. Stellar parallax

Answer: (A)

Geocentrism is the model that places Earth at the center of the universe. This view was the dominant framework in ancient astronomy, with the Ptolemaic system explaining planetary motions by having celestial bodies move on epicycles around Earth. In this picture, the Sun and stars orbit a fixed Earth. Heliocentrism, by contrast, puts the Sun at the center and explains planetary motions from that vantage point. The Copernican principle is the idea that Earth is not in a privileged location in the cosmos, which underpins heliocentrism, not geocentrism. Stellar parallax is an observational effect used to measure distances to stars and provided evidence against a fixed-Earth model once measured, but it’s not a cosmological model itself.