Cadet Competition Written Practice Exam

Who developed the heliocentric theory that positioned the sun at the center of the universe?

1. Galileo Galilei

2. Nicolas Copernicus

3. Isaac Newton

4. Johannes Kepler

The correct answer is: Nicolas Copernicus

The heliocentric theory, which proposed that the sun is at the center of the universe with the planets, including Earth, revolving around it, was developed by Nicolaus Copernicus. Copernicus published his groundbreaking work, "De revolutionibus orbium coelestium" (On the Revolutions of the Celestial Spheres), in 1543. This theory was a significant departure from the geocentric model, which placed the Earth at the center, a view that had dominated for centuries. The importance of Copernicus’s contribution lies in the fact that it laid the foundational groundwork for modern astronomy, challenging the prevailing perspectives of his time and ultimately paving the way for future astronomers, such as Galileo and Kepler, who built upon and provided further support for the heliocentric model. Copernicus's insights transformed the understanding of the structure of the cosmos, marking a major shift in scientific thought.