Narrator Listen to part of a lecture in an archaeology class. Professor: So, last class we talked about the Bronze Age in Europe and the kinds of artifact we have from, from that time period. One of the most famous prehistoric sites in the world was built during the Bronze Age. The monument I’m talking about is Stonehenge. Stonehenge is a circular setting of huge standing stones located on the Salisbury Plain in southwest England. Now there’s still a lot of debate over what the purpose of the structure actually was. We generally accept that Stonehenge had some sort of astronomical significance. Its stones can be used to track the movements of the sun and moon along the horizon, but beyond that, we can’t know much for sure. The first thing we should ask is what the stones themselves can tell us. The ones in the outer ring are mostly a local type of sandstone, but the builders also used foreign stones called blue stones, these tend to be smaller and make up Stonehenge’s inner ring, or smaller than the sandstones, that is, but still massive. The blue stones each weighed around 4 tons, and because of...Oh, is there a question?
Student：Yeah, sorry. You said foreign stones? If they are foreign, where did they come from? And how did they get there? Professor: OK, well, there’s actually a debate there too. It’s long been believed that the Stonehenge blue stones come from the Preseli Hills. The Preseli Hills are in South Wales. The most widely held view is that the builders of Stonehenge transported the stones all the way from Preseli over a hundred miles. It’s often accepted as fact actually. Many think that the Preseli Hills were considered sacred and its blue stones were believed to have healing properties. In fact, some supporters of this human-transport hypothesis think that this was one of Stonehenge’s primary functions: that Stonehenge was a healing site, attracting travelers because of the stone’s supposed health benefits. And there’s evidence that many of the ancient people buried nearby were actually travelers. Debris at the site also includes many small pieces of blue stones that had been chipped off, which would make sense if people wanted bits of the stone as lucky amulets or healing charms. Student: Wait, but about this human-transport hypothesis, aren’t those rocks like really heavy? And it’s not like they had trucks or anything, so... Professor: Right, that’s a good question. Actually, many archaeologists doubt whether Bronze Age peoples had the technical capacity to move such massive stones across that distance. Even if it was possible, there’s not much evidence to justify such a huge effort. And there are other problems. Researchers have found multiple ax heads that were made from the blue stone, which could mean that Bronze Age cultures didn’t actually value the blue stone that highly. After all, why would you use a sacred material to make an ordinary tool? Student: But if the blue stone wasn’t special, why would the builders transport it so far? Professor: Precisely, the competing hypothesis that’s emerged claims that instead of humans moving the blue stones, glaciers picked up the rocks from the Preseli Hills. Over time, the ice could’ve carried them to Salisbury where they would’ve been easily available to the builders. One problem is that while glacier remnants have been found in southwestern England, there’s little evidence of glacier activity near Stonehenge itself. There are, however, blue stones on the Salisbury Plain that actually predate Stonehenge. They were there before the builders even began construction, which makes glacier seem more likely. But some recent research has provided new information about the origin of the blue stones. Geologists analyzed the rocks at Stonehenge and outcrops of rock in the Preseli Hills. This
new research pinpoints the exact location in the hills of the source of this type of blue stone. But why would glaciers move stones from only one source? I mean glaciers would pick up rocks at random, you’d expect to find rocks from other places that were also displaced by glaciers, but we haven’t. On the other hand, we haven’t seen signs of digging or tools, so we don’t know if humans were there. With all these contradictions, why do so many people accept the human-transport hypothesis? It’s often accepted as fact. Well, for one thing, it’s a good story. I mean, we like to feel empowered, to see evidence that teamwork can achieve anything. And this is an explanation that has been repeated over and over, don’t underestimate the power of repetition. Of course, eventually, we may find out how the blue stones got there. But for the time being, these are the theories and the evidence we have to work with.