This issue has recently generated comments.  The answer is “no”.  As explained by the Supreme Court in Diamond Rubber:

“A patentee may be baldly empirical, seeing nothing beyond his experiments and the result ***. It is certainly not necessary that [the inventor] understand or be able to state the scientific principles underlying his invention ***.”

Diamond Rubber Co. v. Consol. Rubber Tire Co., 220 U.S. 428, 435–36 (1911)

(citations omitted)