Okay, I’ll bite: What is the difference? News from Denver brings us back to an old chestnut: What is the difference between young-earth creationists and other dissident-scientists such as flat earthers? Certainly, there are differences in political power—we have a young-earther in the White House these days—but is there anything more than that? Or is it all just an accident of history?

The story from Denver’s flat-earth community points out some of the obvious superficial differences. At least in Denver, flat-earthers tend to be far more about government conspiracies than biblical hermeneutics.

And prominent creationists have always insisted that their beliefs have nothing to do with a flat earth. Back in the 1920s, for example, fundamentalist leader William Bell Riley fumed and fussed that his anti-evolution activism had nothing to do with “‘a flat earth’ . . . ‘an immovable world’ . . . [or] ‘a canopy of roof overhead.’” Those outdated scientific ideas, Riley insisted, were only used to poke fun at people who rejected the false science of evolution.

These days, too, young-earth creationists at Answers In Genesis insist that their scientific ideas have nothing to do with a flat earth. AIG’s Danny Faulkner admits that there are some similarities between the two views, since both have been ridiculed by people who don’t understand them. In the end, though, Faulkner concludes that most flat-earthers are either kooks or insincere.

Officially, AIG contends that since the spherical nature of the earth can be observed directly, the question of the earth’s shape belongs in the realm of “observational science.” That is, we can trust the mainstream facts in this case, even if we can’t trust scientists who speak ignorantly about “historical science.”

For those who know the history, though, the idea of a flat earth has had a remarkably similar history to the notions of a literal worldwide flood and a six-day creation.

As creationist-history guru Glenn Branch has described, in the 1920s the two movements had enormous similarities. Back then, most anti-evolution activists did not believe in a literal six-day creation. They did not insist that the earth was only about 6,004 years old. But a vocal minority did. Spearheaded by the indefatigable activism of George McCready Price, the ideas of a young earth and “flood geology” grew until they became in the 1960s key litmus tests for fundamentalist faith. (For more on that story, check out Ron Numbers’s masterpiece, The Creationists.)

As Branch describes, back in the 1920s flat-earthers also represented a small minority of the anti-evolution crowd. Like the young-earthers, flat-earthers could claim an energetic and charismatic spokesperson, Glenn Voliva. Voliva crusaded against the notion of a spherical earth. Like George McCready Price, Voliva insisted that he had the Truth, a truth evolutionists and round-earthers were too prejudiced to admit.

At the time of the Scopes Trial, Voliva hustled to Dayton, Tennessee to help prosecute John Scopes. Voliva’s hope, according to author Christine Garwood, was to “eliminate the twin heresies of evolution and a spherical earth.”

But that’s where the two ideas went their separate ways. Whereas the outlandish notion of a literally young earth came to be accepted as true by large minorities of Americans, the outlandish notion of a flat earth became an internet quirk adopted by basement-dwelling conspiracy theorists.

So I ask again: What is the difference? I have a few ideas that I’m including in my current book about American creationism. In short, I think the answer lies not in dissident science, but in the mainstream world. By the 1960s, fundamentalist Protestants faced a new choice: Embrace mainstream evolutionary thinking and find a way to reconcile it with evangelical belief, or reject mainstream evolutionary science utterly and create a new creationist science.

When it came to evolution, the choice seemed simple, to many fundamentalists at least. Either kowtow to secular science or remain steadfast to young-earth beliefs.

Flat-earthers, though, never offered such a stark and simple choice. Belief in a flat earth (or a geo-centric solar system, for that matter) had always been embraced by some Biblical conservatives, but it never became a litmus test of orthodoxy.

At least, that’s the argument I’m trying to make in my new book.

What do you think?