My dad identifies himself as a fundamentalist Christian. For him, this means that the Bible is the inerrant word of god. When you get down to the details, it means that he believes that the earth was created about 6,000 years ago over a span of 6 days. When I was a kid, I remember a number of times when my dad and I were watching TV when some news report would announce some new scientific discovery; perhaps a new human ancestor or new evidence about the nesting habits of a dinosaur. Inevitably, he would turn to me and say, "Now how do they know that?" It was a rhetorical question. He wanted me to approach these things critically and use common sense to see that they were likely as not just making shit up in hopes that we wouldn't understand or question it.
When I grew up, I thought about those questions occasionally. How do "they" know the things they say they know? So I started to read some books. I was surprised that, unlike the quick news reports I saw on CNN as a kid, scientists were eager to explain exactly how they know what they know. For every time my dad asked me the rhetorical question of how they know what they claim, there was an actual, non-rhetorical answer!
Now, with my kids, I like to do the same thing my dad used to do with me. When we watch a show like Nova or Nature, I ask, "How do you think they know that?" Sometimes, it's an easy question for them to answer, and sometimes it's a bit more challenging. Sometimes, I already know the answer and sometimes I don't. Either way, it's a practice that I've enjoyed repurposing. So, in the spirit of looking for answers to questions about how we know what we say we know, I'd like to share a link to a page on the Smithsonian Museum of Natural History's website: How Do We Know?
I'll add more of these types of sites as I find them. If you know of any others, let me know in the comments!