Dual transitions were defined in [1,2]. Here are examples of them in works of Gallilei:
The Greeks tried to explain natural phenomena without studying them. The explanations were qualitative. Galilei switched from explanations to studying. The studies were quantitative.
In 1602 Galilei started studying the free fall. Initially he thought that the speed of a body in the free fall is proportional to the distance it traveled. But this hypothesis contradicted the results of experiments. Then Galilei switched to a dual hypothesis that the speed is proportional not to the distance but to the time it traveled.
In 1609 Galilei turned a spyglass invented for observing distant objects on Earth (chiefly for military purposes) into a telescope for a peaceful observation of objects in the outer space.
R E F E R E N C E S: