Listen to part of lecture in an art history class.

Good morning, ready to continue our review of prehistory art?Today, we will be covering the Upper Paleolithic Period, which I am roughly defining as the period from 35000 to 8000 B.C.A lot of those cave drawings you have all seen come from this period. But We also be talking about portable work of art, things that could be carried around from place to place.Here is one example.This sculpture is called "the lady with the hood" and it was caved from ivory, probably a mammoth's tusk.Its age is a bit of a mystery.According to one source, it dates from 22000 B.C.But other sources claimed it has been dated closer to 30000 B.C. Em, Amy?

Why don't we know the exact date when this head was made?

That is a fair question.We are talking about prehistory here.So obviously, the artists didn't put a signature or a date on anything they did.So how do we know when this figure was carved.

Last semester, I took an archaeology class, and we spend a lot of time on, eh, studying ways to date things.One technique I remember was using the location of an object to dated it, like how deep it was burried.

That would be stratigraphy.Stratigraphy is used for dating portable art.When archaeologists are digging at the site, they make very careful notes about which stratum, which layer of earth they find things in.And, you know, the general rule is that the oldest layers are at the lowest level.But this only works if the site hasn't been touched, and the layers are intact.A problem with this dating method is that an object could have been carried around, used for several generations before it was discarded.So it might be much older than the layer or even the site where it was found.The stratification technique gives us the minimum age of an object, which isn't necessarily its true age.Eh... Tom, in your archaeology class, did you talk about radiocarbon dating?

Yeah, we did.That had to do with chemical analysis, something to do with measuring the amount of radiocarbon that's left in organic stuff.Because we know how fast radiocarbon decays, we can figure out the age of the organic material.

The key word there is organic.Is art made of organic material?

Well, you said the "Lady with hood" was carved out of ivory.That's organic.

Absolutely. Any other examples?

Well, when they did those cave drawings.Did they use like charcoal or maybe colors, dyes made from plants. 

Fortunately they did, at least some of the time. So it turns out that radiocarbon dating works for a lot of prehistoric art.But again, there is a problem.This technique destroys what it analyzes, so you have to chip off bits of object for testing.Ah, obviously where you reluctant to do that in some cases. And part from that, there is another problems.The date tells you the age of the material, say, a bone or a tree, the object is made from, but not the date when the artist actually created it.So with radiocarbon dating, we get the maximum possible age for the object, but it could be younger.OK, let's say our scientific analysis has produced an age range.Can we narrow it down?

Could we look for similar styles or motives?You know, try to find things common to one time period.

We do that all the time.And When we see similarities in pieces of art, we assume some connection in time or place.But is it possible that we could be imposing our own values on that analysis?

Em, sorry, I don't get your point.

Well, we have all kinds of preconceived ideas about how artistic styles develop.For example, a lot of people think the presence of details demonstrates that the work was done by a more sophisticated artist.While a lack of detail suggests a primitive style.But trends in art in the last century or so certainly challenge that idea.Don't get me wrong though, analyzing the styles of prehistoric artifacts can help dating them.But we need to be careful with the idea that artistic development occurs in a staight line, from simple to complex representations.

What your are saying is, I mean, I get the feeling that this is like a legal process, like building a legal case, the more pieces of evidence we have, the closer we get to the truth.

Great analogy.And now you can see why we don't have an exact date for our sculpture "the lady with the hood".