Answer:
Step-by-step explanation:
There are many laws in physics, that started out as theories and became scientific truths only after an experiment was performed that confirmed that the theory was true.
One of the most famous theories was the guess that the gravitational Force was a constant amount that depended on mass and distance. It was incredibly difficult to prove because the with large masses and small distances, the force is quite small.
Newton proposed the existence of the gravitational force in 1687 and Cavendish found its precise truth in 1798 -- 111 years after Newton said it was so.
Newton proposed a theory. Cavendish proved it to be a law later. Even then, Einstein proposed the modern law.