Why was the first scientists to dispute Ptolemy's model of a geocentric or earth-centered universe?

The first scientist to significantly dispute Ptolemy's geocentric model was Nicolaus Copernicus. In the 16th century, Copernicus proposed a heliocentric model, placing the Sun at the center of the universe and suggesting that the Earth and other planets revolve around it. His ideas challenged the long-held belief in an Earth-centered universe by providing a simpler explanation for the observed motions of celestial bodies. This shift laid the groundwork for modern astronomy and ultimately led to the scientific revolution.