you don't see it in common parlance I think one of the factors for that is the fact that most high-level scientists learn to be cautious about the claims they

you don't see it in common parlance I think one of the factors for that is the fact that most high-level scientists learn to be cautious about the claims they make. You're much more likely so hear a layman make strong claims about X or Y than you are to hear the same from a PhD physicst, on average. What a lot of people who didn't go through the grinder of Academia seem not to understand, is that when one says "I don't know", it doesn't mean "I know nothing about this". If I say "I don't know", chances are I could discuss the subject at length, but my comprehension is not satisfactory to answer the question on a deep level, or I don't really grok the subject enough to feel confident to give my opinion. This is less present in laymen and can lead to some friction in discussions.