Argot Navis

There was this story in the Boston Globe on Wednesday, although I just read it today (via). It's interesting, and I needed a non-automotive reason to ramble today, so I thought I'd give my thoughts on it. I'm not an Egyptologist, and Egypt is not my primary area of interest, so I can only really give an outsider's perspective, but I do know at least a couple things about ancient Egypt.

I'll start off with a minor annoyance. Here's the quote:

'And no whips cracked overhead last week as Myat-Noe-Zin Myint, Rachel Martin, and three other undergraduates stuffed quivering just-mixed “Egyptian” concrete into cobblestone-sized wooden molds marked “King Tut Plywood Co.”'

Tutankhamun did not build a pyramid, nor was he buried in one. Similarly, Queen Elizabeth II's reign has not been marked by very many Viking attacks. I know, it's just a cutesy thing, and it probably wouldn't annoy me much, except that when I was taking intro archaeology, one of the other students in the class was convinced that King Tut had, in fact, been buried in a pyramid. That's a minor complaint, though.

The gist of the article is that a materials science professor at MIT is doing an experiment to determine whether or not the ancient Egyptians could have been making concrete. In this sense, the title of the article, “A new angle on pyramids”, is not very apt. As the article itself points out:

“The idea that some pyramid blocks were cast of concrete-like material was aggressively advanced in the 1980s by French chemical engineer Joseph Davidovits . . .”

Most people, myself included, probably do not consider 20+-year-old “angles” all that “new.”

To start off, there are a couple quotes from Egyptologists in the article. Zahi Hawass had this to say about it:

'”It's highly stupid,” he said via a spokesman. “The pyramids are made from solid blocks of quarried limestone. To suggest otherwise is idiotic and insulting.”'

A little acidic, but I feel like he's generally that way when dealing with any, um, “alternative” notions about the pyramids (this one is certainly more sensible than most).

Kathryn Bard was a bit nicer about it:

'”There is just no evidence for making concrete, and there is no evidence that ancient Egyptians used the stuff,” she said.'

Having spoken several times with Kathryn, I can assure you that she and Zahi are not part of some vast conspiracy of Egyptologists, and there are issues they do not see eye to eye on. I feel like this is true of most disciplines, but I think it's important to remember, given statements like this one:

'”That's the problem, the big archeologists – and Egypt's tourist industry – want to preserve romantic ideas,” said Davidovits . . .'

I guess it's not quite a “conspiracy theory”-type explanation, but it's basically along the same lines. The “big archeologists” just won't accept anything that isn't a mainstream idea. Hobbs, the materials scientist in question, states the same thing, although a bit more cautiously:

'”The degree of hostility aimed at experimentation is disturbing,” he said. “Too many big egos and too many published works may be riding on the idea that every pyramid block was carved, not cast.”'

By the way, apparently these are the “romantic ideas” that “big archeologists” are looking to preserve:

'. . . the ones popularized by Hollywood epics like “The Ten Commandments,” with thousands of near-naked toilers straining with ropes and rollers to move mammoth carved stones.'

This is one of those lines that sounds really great in a newspaper article, but has absolutely nothing to do with how pretty much any archaeologist perceives the construction of the pyramids. Nonetheless, I really don't think these statements about being kept down by the man are very useful. If your theory is valid, it will probably gain acceptance. This line from the beginning of the article kind of points out why:

“Maybe they invented concrete 2,000 years before the Romans started using it in their structures.”

Archaeologists are often quite interested in “firsts.” (That's certainly not the only reason that valid theories will gain acceptance, but it's an important one to note.) The fact that not many mainstream Egyptologists are all that excited about this is suggestive, and not of a conspiracy.

I didn't really touch on the “hostility” before, but I think a lot of it stems from the fact that this is an experiment that doesn't really tell us all that much. I would be much more surprised if they concluded that the ancient Egyptians wouldn't have been technically able to make concrete (I think Davidovits actually argued that making concrete would be easier than cutting and moving the stone in blocks), but, as Bard points out, there is no evidence that they actually did, which, I think, is a more important issue. Which leads me into Barsoum et al.'s paper. It's about a year and a half old right now, so I assume both Bard and Hawass have probably read it, or are at least aware of it. The article gives this from Barsoum:

'Barsoum, a professor of materials engineering, said microscope, X-ray, and chemical analysis of scraps of stone from the pyramids “suggest a small but significant percentage of blocks on the higher portions of the pyramids were cast” from concrete.

He stressed that he believes that most of the blocks in the Khufu Pyramid were carved in the manner long suggested by archeologists. “But 10 or 20 percent [of the blocks] were probably cast in areas where it would have been highly difficult to position [whole stone] blocks,” he said.'

I haven't read the paper, and I don't currently have access to the journal, so I can't comment on it directly. The article doesn't really say anything about why he came to this conclusion, but Dipayan Jana, who did this smaller study last year disagrees with what Barsoum et al. found. From that paper:

'A critical evaluation of major element oxide compositions of all silica-rich microspheres show a clear enrichment of these spheres with calcium and magnesium in the Lauer sample, as previously reported by Barsoum et al. (2006). Contrary to their results, however, the present study clearly shows: (a) the presence of these silica-rich microconstituents not only in both casing stone samples but also in the natural limestone, and hence the ubiquitous
occurrences as a common microconstituent in the studied samples from Giza; and (b) their variable minor element oxide compositions, indicative of incorporation of impurities by the lepispheres. The occurrence of these “impurities” in the silica-rich microconstituents (lepispheres) are quite “natural” and do not indicate a “synthetic” nature of limestone.' (Jana 2007)

The Globe article addresses this:

'To eyes less eager to find concrete, the binders might look just like impurities in an ordinary stone block.'

And, as they say, this makes it a rather difficult position to prove, given that there doesn't seem to be any archaeological evidence of concrete production. This other quote about the same thing is also interesting:

'The present study, however, clearly shows occurrences of silica-rich microconstituents in all samples except the geopolymeric limestone, and their variable chemistry is due to trace amounts of impurities that these phases can accommodate.' (Jana 2007)

So, if I'm reading this correctly, the only sample they weren't found in was the man-made one! Now, granted, Jana's sample was quite small, but the important part is that Barsoum et al. concluded that one of these stones was man-made, and Jana sees no evidence for this. I don't think either side in the materials science argument is convinced, but personally, I tend to agree with the mainstream theory (and, again, remember that I am not an Egyptologist . . . or a materials scientist). To relate it back to the Globe article, I still really don't see what this experiment is going to tell us that we wouldn't probalby assume (ie. that Old Kingdom Egyptians had the technical ability to make concrete, assuming they knew how to do it), but considering it seems to be mostly undergrads working on it, I guess it's a pretty cool project.

References!:
Jana, Dipayan.
2007. “THE GREAT PYRAMID DEBATE: Evidence from Detailed Petrographic Examinations of Casing Stones from the Great Pyramid of Khufu, a Natural Limestone from Tura, and a Man-made (Geopolymeric) Limestone.” PROCEEDINGS OF THE TWENTY-NINTH CONFERENCE ON CEMENT MICROSCOPY QUEBEC CITY, PQ, CANADA MAY 20 -24, 2007.