My point was that once you learn the basic physics underlying this, you should be able to come to the proper conclusion about the vitamin D question easily enou

My point was that once you learn the basic physics underlying this, you should be able to come to the proper conclusion about the vitamin D question easily enough. Every person going through the US school system is required to take a basic physics course, as far as I know. So every child who receives a HS diploma in the US should know this basic concept and, if they actually thought about it, should be able to figure it out. I think you're confusing the underlying theory with us encountering the question on the day we learned it and then dismissing the fact that we were primed with the current conversation to know the answer. What I'm saying is that once we had that knowledge about the underlying physics, the same question(s) could have been posed weeks or months later (with no priming) and we should have been able to figure it out.