The mistake of all regular scientists is to believe that everything will have a scientific explanation. Top scientists knows that this is not the case.
https://arstechnica.com/science/2022/01/study-1960-ramjet-design-for-interstellar-travel-a-sci-fi-staple-is-unfeasible/
https://arstechnica.com/science/2022/01/study-1960-ramjet-design-for-interstellar-travel-a-sci-fi-staple-is-unfeasible/