why were the discoveries of astronomer like Galileo seen as radical and a threat to the church authority? what was the new idea that they proposed?

They were seen as a threat because they went against the teachings of the Church. The new idea was that the Earth revolved around the sun instead of the sun and the whole universe revolving around the Earth

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saltywhitehorse saltywhitehorse · Answer 2 · 2021-12-09T11:26:12+01:00

The discoveries of astronomer like Galileo seen as radical and a threat to the church authority as it challenged their teachings and believes.

Galileo theory was denied by the Church when he started the Earth revolves around the Sun.
His opinions were very distinct from the church education.
The Church believed that the Sun revolves around the Earth.
Church authority feared that if the theory given by Galileo were true, then the Church will lose its stand.
Astronomers were declared heresy by the Church authority.

Therefore we can conclude that the Church Authority declared heresy to those astronomers like Galileo whose finding about earth and universe were different from the Church.

Learn more about Galileo here:

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