In my years of media and science literacy I’ve repeatedly encountered cases where people have failed to question their premises and simply forged ahead without bothering to make sure that the assumptions were grounded in fact. Premises often seem self-evident—and who wants to waste time verifying or fact-checking something that’s obvious?

About six or seven years ago I was contacted by a man who wanted me to look at his research on Stonehenge. He wasn’t an archaeologist or historian, and from what I could tell had little formal training. What he did have, in apparent abundance, was enthusiasm and free time. He was interested in so-called ley lines, real or imagined—depending on your New Age inclinations—lines that connected important man-made sites around the world, including the Ghiza Pyramids, Macchu Picchu, and so on.

I’d encountered his type before, usually in the context of being asked to carefully read and offer comments on (that is, praise) his theories and discoveries. And not a few paragraphs but instead reams of what might charitably be called crank literature: diagrams, explanations, and so on.

I reluctantly agreed to chat with him for a few minutes to get an overview, and he began explaining how he’d always been fascinated by the stones and he showed me meticulously drawn diagrams of the exact positions of the stones and the precise angles that, he claimed, corresponded perfectly with other mysterious or significant sites on other continents and across the globe. Two particular east-facing stones, for example, just happen to point to other monuments elsewhere in Europe. He proudly noted that he’d visited Stonehenge many times over the years and kept discovering new aspects to the formation. The idea that Stonehenge was aligned in some way with celestial bodies seems perfectly plausible, but how in the world could the ancients have known about, and carefully aligned their standing stones with the exact coordinates of, the Egyptian pyramids, for example?

I’d written some about Stonehenge, and later visited the site myself. I wouldn’t exactly call myself an expert on the topic, but I was conversant with the basic facts and theories.  I listened to him and looked at his maps and charts linking all the stones’ positions. Finally I asked him, “You know they moved the stones, right?’

“They moved Stonehenge?” he asked incredulously.

“Well, the ancient builders moved the rocks to whereStonehenge now sits, of course. But what you see today isn’t the original formation. The standing stones have been moved around several times. There are early drawings and photos of it.” I mentioned a painting by John Constable of the stones from 1835 that showed a significantly different arrangement than what appears today. Over the millennia some stones have fallen into the soft earth, and it’s not known whether they fell straight back or twisted slightly at an angle, and so on. At least a dozen of the stones were straightened and re-erected between 1900 and 1960, and early depictions of Stonehenge (such as Constable’s painting) look quite different than what is seen today. Those restoring the area made an effort to give a sense of what Stonehenge might have been like thousands of years ago, but in fact no one really knows what it originally looked like—or was supposed to look like.

He looked stunned. His years of work had apparently been based on calculations of the precise positions of the stones as they are today—each angle down to the degree and minute—which is not necessarily where they were when first erected. He must have known about the various reconstructions over the years but seemed to have for whatever reason assumed that each time the stones were replaced precisely as they were found. The workers were more concerned about preservation and restoration than historical accuracy; even if that were not the case, the soft Wiltshire earth had caused many of the stones to sink and shift over the thousands of years. There is simply no way to know with any certainty exactly how the stones were first arranged—at least not with the precision needed to link them with other monuments or sacred places on the same meridian around the world.

Seeing his stunned deflation, I awkwardly excused myself so as not to further embarrass him, and I never heard from him again. I wasn’t trying to mock him or debunk his elaborate theories, and I’d honestly wished he’d asked me years earlier before he spent untold time and energy pursuing his analysis based on mistaken assumptions. His was an extreme example, of course, but the error of making assumptions instead of checking them is common.

Because the restoration work at Stonehenge is not hidden yet not widely known, it has generated conspiracy theories. Some have even suggested that the monument dates back less than a century, created to spur tourism profits or for other unknown—and possibly nefarious—reasons. Mick West, author of Escaping the Rabbit Holeand creator of the Metabunk web site, has visited the site several times and investigated such conspiracy claims. West said “The idea that Stonehenge is a relatively modern construction is appealing to a certain type of conspiracy theorist who has fallen far down the rabbit hole. Images appearing to show the construction of Stonehenge with cranes and concrete are an intellectual delight to them. No particular reason is needed for Stonehenge to be faked, because in their mind everything is faked, and this is simply pleasant circular confirmation that they were right all along.” Stonehenge fell out of use around 1500 B.C., and has stood as a mute mystery ever since.