The owner of a local store I frequent is a talkative fellow, a delightfully cynical guy, someone with a lot of common sense who thinks about the words that come out of his mouth. We always chat for a few minutes even if that means the cash register has to stop ringing. He didn’t know much about what I do, but when he found out the other day I’m a “scientist” (I corrected him, since I’m a journalist … we often get lumped together, which is really unfair to the scientists), he had a question for me: “C’mon,” he says, “if the moon is supposedly 5 billion years old, how come there isn’t more dust on the surface?”

I didn’t really understand the question, but it was clearly one of those “scientists might be smart, but that doesn’t mean they’re always right” questions. I was surprised to hear it from him, because I knew the question’s basic genesis and where this conversation was heading: How do scientists know things are as old as they say things are? We’ve never been to the far corners of the universe, so how do we know the big house is really 13.7 billion years old?

The subtext, of course, goes something like this: Maybe Earth and everything else is only 6,000 years old, created in 6 days — a literal interpretation some make of the Bible.

And there’s another great flat-Earth question that goes with it: How do we know the dinosaurs are really millions of years old? A preacher who writes a weekly column in a local paper here loves to tackle this question. He cites beasts mentioned in the Bible that could be dinosaurs, and holds that we humans must have walked with them. So he accepts the evidence that dinosaurs existed, just not the part that makes them too ancient for his belief system. I don’t get that logic, if that’s what it is.

Anyway, my store-owner friend made me think about this resistance to scientific theory (he puts his fingers in the air to apply quote marks to that word) in a whole new way. He’s not anti-science, mind you, but he’s doubtful about some things and genuinely wary of complex theories and what seems to him like sketchy evidence.

To my friend, I offered the analogy of a tree. If I plopped you down in a forest of trees you knew nothing about, I said, and asked you how old a certain tree was, you could gather some visual evidence and probably make a good estimate. In fact, once you’d learned a lot about the forest and how it works and examined the trees by various methods (tree rings being your greatest discovery), you could accurately estimate the age of any tree in it and even confirm your estimates beyond question. He granted me that seemed reasonable.

“But you can’t touch the stars,” he says. I knew that was coming. And frankly, here is where I stumbled. Astronomers have smart and accurate ways of estimating the ages of stars and the universe itself. They analyze light and chemistry, they look across space and therefore back in time. They analyze motions and groupings, spin time backward from what’s known to be modern toward what’s known to be ancient, and out of all this come theories about the age and evolution of the cosmos that are tested by various methods. But to be honest, the methods are complicated, and for most of us, a little trust is involved in accepting most scientific findings because, indeed, we’ve never employed the methods ourselves, never actually touched (or any many cases even seen) the objects in question, and probably don’t even want to know the details of the data. And of course those crazy scientists are always changing their stories. The universe’s present “precise” age is put at 13.7 billion years. But just 5 years ago,  — blink of an eye in cosmic time! — the estimate varied by billions of years and was revised and debated often.

Anyway, I’m into this conversation 30 minutes now and it’s close to dinnertime (and several customers are getting poor service as our friendly debate plays out) so I opt for short answers on a handful of lines of evidence and methods, not the oodles of details that are in my head (or, to be honest, that I often have to look up over and over again). He’s not buying any of it. To him and many other people, this scientific stuff is all about estimates and assumptions, and it could all be wrong. As my stomach growls, a light bulb goes off in my head. For many people who are busy raising kids and working seven days a week and barely finding time to read a little news now and then, science is like art: It can be really interesting, but it’s not reality. It’s something to look at and enjoy, maybe even ponder, perhaps argue about a little, but never let it get in the way of what you believe. And my next thought is: Do scientists and journalists do even a halfway decent job explaining the wonders of the universe to the average person? Or are we all so wrapped up in our view of things, so loaded with assumptions and jargon, that we fail to resonate with those who could most benefit from a little scientific understanding.

As for the moon, I finally tell my friend I have no idea why there isn’t more dust. Nor do I know why there isn’t less. I don’t even know how much dust there is, and tell him that I suspect his question stems from a “theory” developed by someone with a serious agenda based on some serious beliefs and a serious lack of evidence. I also say that I suspect a lunar expert somewhere has figured out that there’s just about the amount of dust you would expect from a 4.5-billion-year-old satellite of that size and composition and circumstance. If that’s true, it’d be just one of many lines of evidence that support this longstanding, well-tested and undisputed age estimate, all of which stack up against precisely zero evidence for it being 6,000 years old. And in this case, as with the study of Earth and dinosaur bones, we have touched it, and the Apollo astronauts even brought some back for study, for age-dating and all that. [By the way, here's how radiocarbon dating is done, in case you ever need to look it up in the middle of an argument.]

“You choose to believe the scientists,” is what I hear. Ah, yes, I have to do a little of that. And I’ll continue to do that until somebody uncovers a cave painting of my ancestors dancing with dinosaurs.