In 1897, Joseph Thomson discovered that atoms contained electrons. He proposed a change in the atomic theory of that time, and t
he theory was modified because of his discovery. Since Thomson's discovery, atomic theory has been further modified. What is the best explanation for why scientific theories are modified?
The best explanation for why scientific theories are modified is simply because it is a theory. Theories are created as a set of suppositions that help humanity understand something that would otherwise be unexplainable. Since they are not proven through scientific facts but instead are more of ideas that help further our understanding of a phenomenon, they tend to be modified as new ideas are introduced and others are proven to be false/wrong.