The spread of scientific ideas from Europe was almost entirely by conquest.

Only in a very literal sense. Nobody said "let's conquer everyone in order to spread the atomic of theory of matter" and once they conquered they didn't execute people who didn't believe in atoms or decide that people who don't believe in atoms are not permitted to testify in court.

Try being openly creationist at a major university, you'll quickly discover the kind of social pressure science can bring to bear.

That's not the same kind of social pressure. I'm referring to one's personal life, not one's professional life.