Question

what was that suggestion that copernicus proposed in contradiction to the established belief of the order of the universe? that the sun was far too hot to sit still that the sun was the center of the universe, not the earth.

Explanation:

Copernicus proposed the heliocentric model. Before his time, the geocentric model (Earth - centered universe) was the established belief. The heliocentric model stated that the sun is at the center of the universe, and planets (including Earth) orbit around it. The statement "That the sun was far too hot to sit still" is not relevant to his main revolutionary idea about the order of the universe.

Answer:

That the sun was the center of the universe, not the earth.