Orreries are mechanical devices that show positions and motions of the planets and moons in a heliocentric model of the solar system. Shown here is a device constructed in 1766 by Benjamin Martin, used to teach astronomy at Harvard University.
Historically, geocentrism was popular in religious circles, which placed the Earth at the center of the universe. Heliocentrism is the astronomical model in which the Earth and planets revolve around the Sun at the center of the universe. In the sixteenth century this model was presented by the Renaissance mathematician and astronomer Nicolaus Copernicus. Later, Johannes Kepler introduced elliptical orbits, and Galileo Galilei presented supporting observations made using a telescope. Later still it was realized that the Sun was not at the center of the Universe.
The understanding that the Earth is not the centre of the universe, and that it is not orbited by other planets and stars, changed people’s perception of their place in the universe forever. Copernicus’ theories helped to inspire a total rethink of our understanding of physics, influencing the concepts of gravity and inertia. These ideas were more fully articulated by Sir Isaac Newton, whose Principia formed the basis of modern physics and astronomy.
Beyond science, the discovery that the Earth was not at the centre of everything made many people question the very nature of their existence, and that of religion - earning scientists the ire of the Church in the process.