Something that might bear on this is in Proverbs (26:4-5):
"Do not answer a fool according to his folly, lest even you become like him.
Answer a fool according to his folly, lest he be wise in his sight."
Noting the obvious contradiction, the Talmud (Shabbos 30b) points out that the first statement is referring to "worldly matters," the second to Torah issues. According to that, then, one should correct others' misconceptions (or even deliberate mockery) when it comes to Torah (so that they don't walk away thinking that they've beaten you), but ignore them in other areas (where if they think so, it's not as critical).
There are other ways of explaining these two verses, though. Some of the commentaries say that it means: don't answer the fool with invective of your own, because that will put you on his level, but do answer him in a way that will help him (or, at least, the audience) realize his lack of knowledge. (Ralbag, specifically, comments that it would be wrong to leave him with his mistaken notions; "it is appropriate to remove stumbling blocks from people's way, [even] forcibly.") So perhaps indeed this would require you to correct their scientific misconceptions, although perhaps one might argue that there's a difference between those that have practical and immediate repercussions vs. those that are more theoretical.
(Also, most people aren't "fools" in the sense used here; Malbim points out that this term means someone who knows he's wrong but is trying to twist the truth in order to rationalize his improper behavior.)