Sound waves that move from one medium to another at an angle change
direction due to?

While unproven, it uses facts to support part of a conclusion. it is still factual and has predictive power, however.

Ithink that the use of creativity in the sciences entails that one produce something out of nothing or from another thing. with this, i think that the he wrote down his results as four parts of the atomic theory is the manifestation of the  creativity of john dalton.