Which attempt by Galileo to support Copernicus is modern science considered a significant scientific error?

Answer

His theory explaining tides as resulting from Earth's motion.

Galileo incorrectly theorized that tides were caused by the sloshing motion resulting from the Earth's rotation and orbit, when tides are primarily caused by gravitational forces from the Moon and Sun.

Which attempt by Galileo to support Copernicus is modern science considered a significant scientific error?
GalileosunEarthrotationProof