Final answer:
Galileo Galilei was indeed deemed a heretic by the Roman Catholic Church for advocating the Copernican heliocentric system, which opposed the Church's geocentric view. He was tried by the Inquisition, placed under house arrest, and his works banned. The Church only admitted its error in censoring Galileo's ideas centuries later in 1992.
Step-by-step explanation:
Galileo Galilei, a proponent of the Copernican hypothesis proclaiming a heliocentric solar system, faced severe opposition from the Roman Catholic Church. The Church, defending Aristotelian and Ptolemaic geocentric views for both theological and practical reasons, found Galileo's teachings to be radically contrary to its authoritative stance on the cosmos. His outspoken support for these "dangerous" opinions, particularly through his publications in Italian, which made them widely accessible, led the Church to officially label the Copernican doctrine as "false and absurd." In 1616, the church deemed teaching the Copernican model as heretical.
In 1633, Galileo was summoned by the Inquisition and placed under house arrest after being found vehemently suspected of heresy. His works remained banned by the Church until 1836. It was not until 1992 that the Church acknowledged its mistake in condemning Galileo's ideas.
Galileo's legacy persisted through the continued observation and verification of his discoveries by scientists after his death, which ultimately led to the validation and acceptance of his work by the Church and the wider scientific community. His insistence on observation as the determinant of truth laid foundational principles in scientific methodology.