A small Roman transport from the second century AD carrying an onboard fish tank. At least that’s the interpretation of a team of marine archaeologists from the University of Venice. The tank would have used a hand driven piston pump to keep the water oxygenated.
Filed under Archaeology, Technology
That’s the theory advanced by physicist named Paul A. LaViolette. I was quite intrigued when I first saw the news story about LaViolette’s proposal. Happily, the story included a download link to a preprint of the paper (which was published in Radiocarbon). My evaluation, therefore, can be based on the paper itself and not just the summation given in the story.
I’ll admit I had some reservations right from the beginning, when I saw mention in the story that LaViolette had written a book in 1997 arguing that certain themes found in mythologies worldwide are references to intense solar activity at the end of the Pleistocene. I’m not an expert in solar physics, but I do know something about oral traditions. If the book is what the story claims, then LaViolette makes the same mistake that Von Daniken and Velikovsky made: treating myth as a distortion of history, which it is not. Mythology is not bad history, or mistaken history, because it’s not history at all, but something very different. This is a peripheral issue, however, as there is no mention of any oral traditions in this particular paper.
Although, as I said, I am not an expert in solar physics, I do have enough of a physics and chemistry background to follow LaViolette’s argument. Basically, he uses evidence from isotope analysis of seafloor layers called varves from the Cariaco Basin (off the coast of Venezuela) to argue for a massive solar flare between 12,957 and 12,760 years ago. This would be near the beginning of a period of rapid global cooling called the Younger Dryas. In addition to the Cariaco varves, LaViolette also uses data from Greenland ice cores to bolster his argument.
LaViolette goes on to argue that the magnitude of this flare – he estimates it as about 125 times more powerful than a similar type of flare observed in 1956 – would have overpowered the Earth’s magnetic field and allowed animals at ground level to receive at least 3 sieverts of radiation, in the form of high energy protons, which would be close to a lethal dose. He bases this on the presumption that the flare would have lasted about 50 hours, similar in length to the 1859 Carrington Event, and he takes into account the shielding effect of the atmosphere. He also suggests that the partial collapse of the magnetic field due to the flare would have allowed some of the interplanetary dust that surrounds the planet to fall to earth, and argues that this explains the extraterrestrial dust markers that have been found in some sediment cores.
I’m not qualified to evaluate whether or not a solar flare is the best explanation for LaViolette’s isotope data; he may very well be right about that. I was surprised to notice, however, that his estimate of the radiation dosage assumes that the animals on the ground were exposed for the entire 50 hours, even though the sun would have been on the opposite side of the planet for roughly half of this period. Also, the amount of atmosphere through which the protons would have to pass would logically depend upon the angle of the sun in the sky, which obviously varies throughout the day.
A second problem is that LaViolette nowhere addresses the geographically uneven nature of the terminal Pleistocene extinctions. While a large majority of North American species larger than 100 kg went extinct, very few African or South Asian species did. Extinction rates on the other continents lie between those two extremes. It is certainly conceivable that some mechanism might exist that could cause a solar flare to produce this effect. However it is not immediately obvious what that mechanism might be. Some discussion of this problem, I believe, ought to have been included.
Of course, the question of whether the Pleistocene extinctions occurred very rapidly or over a period of several thousand years is far from settled. However, this is not necessarily a problem for LaViolette’s hypothesis. It is easily conceivable that a short burst of intense radiation could eliminate or severely reduce the populations of a few keystone species and thereby have a long term destabilizing effect on an entire ecosystem. If this were the case, identifying those keystone species and showing that they were, in fact, the first to become extinct, would be a primary step in building a chain of supporting evidence.
Although, as I said at the beginning, this is an intriguing idea, as presented it has some significant problems. Until those are addressed, I believe a skeptical approach to LaViolette’s model is warranted.
Filed under Archaeology, Space
In Baltimore a mikvah, or Jewish ritual bath, dating from 1845 has been found by archaeologists. This is the oldest known mikvah in the United States.
From an archaeological standpoint, the trash that was thrown in the mikvah when it was filled in in 1860 might well prove to be more important than the bath itself. Trash reveals a great deal about the ways in which people live. And in this case, it has the advantage of all having been deposited in a very short period of time and at a known date.
One more interesting detail is that after the building was used as a synagogue, it became a Catholic church for a while, and then was turned back into a synagogue again. That’s a very American pattern of religious building use, and not at all what you would be likely to find in many other parts of the world.
Filed under Archaeology
It looks like the article is not available online yet, so all I have to go on is this press release. Basically, iron oxide was being mined as a pigment in Chile as far back as 12,000 years ago. It doesn’t say if that date is calibrated or uncalibrated, but either way it’s a pretty impressive date for early mining, especially so far south.
Filed under Archaeology, Mining
For fun recently, I’ve been reading Isabel Kelly’s 1932 Ethnography of the Surprise Valley Paiute (yes, I’m aware that I have strange tastes in reading). In the late 19th and early 20th centuries, both amateur and professional anthropologists raced to document the cultures of what were considered to be “vanishing races.” Most of those peoples, obviously, did not vanish. Instead, they adapted to new circumstances, just as people have been doing throughout human history. The anthropological work of that era, however, has nevertheless proved in many cases to be invaluable, in that it gathered and preserved cultural information at a time when many indigenous peoples were under tremendous pressure to abandon their traditions and assimilate completely into American society.
Most of this work was not the “participant observation” that we tend to think of as stereotypical anthropology; where the scientist goes to live among an unfamiliar group of people, observing and taking notes on their day-to-day activities. Rather, anthropologists like Alfred Kroeber, John Peabody Harrington, and Isabel Kelly conducted extensive interviews with people old enough to remember the ways in which people had lived half a century or more earlier.
Apart from simply being fascinating to read, much of this material, if carefully used, is also invaluable to an archaeologist. One of the biggest caveats, or course, is time. In most cases, the interviews were conducted late enough that the informants would have had no personal memory of any time before contact with Europeans; they were born into societies that had already undergone profound changes. And, of course, these were human beings and not computers. They did not have perfect recall of events they had experienced decades earlier. It should also be considered that some informants may not have been completely forthcoming with information they considered private, and that some of what they reported might have been misunderstood by the anthropologist. But even after these and other limitations have been taken into account, these early ethnographies are often very helpful in interpreting what remains in the archaeological record, particularly from period shortly after European contact.
But mainly, I read old ethnographies because I enjoy it. They provide a fascinating glimpse into the past as it was actually experienced by some of the people who lived it.
Filed under Anthropology, Archaeology
A recent article in the Daily Mail reports that genetic testing has indicated that the first group to reach North American may have numbered around seventy people. I’m always happy to see the press reporting on archaeological matters, but I have to admit I’ve got some reservations about this story.
My first question is why the Mail is publishing this as “stunning new” research when the study they refer to, by Dr. Jody Hey of Rutgers University, was published in 2005. There’s a download link for the paper, titled On the Number of New World Founders: A Population Genetic Portrait of the Peopling of the Americas, on Dr. Hey’s web site. I don’t have the background in genetics to critique the work, but I will note, as Dr. Hey himself does, that the date he came up with for the initial entry into North America is somewhat younger than is suggested by archaeological evidence.
I admit I am a little puzzled by Hey’s choice to sample people who spoke Amerind languages. The Amerind family, proposed more than twenty years ago by Joseph Greenberg, has never been widely accepted by linguists specializing in North American languages. In other words, there are no linguistic grounds for thinking that the people Hey studied are all descendents of the same group of early migrants, although that possibility certainly not ruled out.
Beyond all this, the Daily Mail then goes on to claim that, “the accepted wisdom among archaeologists is that the first people to colonise America were called the Clovis.” This, of course, has not been true for some time now. I’m not sure where this error originated, but it didn’t come from Dr. Hey, who mentions the pre-Clovis Monte Verde site in his paper. New evidence since 2005, including the incredible find of human coprolites at Paisley Cave, have placed the pre-Clovis occupation on even firmer ground. It appears that the reporter at the Mail neglected to do even the most basic homework. Like checking Wikipedia. Or even reading Dr. Hey’s paper before writing a story about it.
Filed under Archaeology
I recently stumbled across an interesting discussion on Steve Wilson’s blog, of the various definitions of space archaeology (in two parts, here and here). The focus is mostly on three intersecting subcategories of space archaeology: aerospace archaeology – the archaeological study of flight and space exploration, exoarchaeology – investigation of archaeological sites located off the Earth, and xenoarchaeology – the archaeological study of past non-human cultures. (He illustrates the overlapping nature of these three sub-fields with this chart.)
Xenoarchaeology, arguably the most interesting of the three, is obviously purely speculative at the moment, as no confirmed evidence of non-human cultural activity has yet been found. (The study of stone tools and other artifacts manufactured by hominids other than Homo sapiens could presumably be considered xenoarchaeology, but in practice the term is not used in that way.)
Of course, the lack of any actual evidence has not kept vast numbers of trees from being killed to promote wild theories involving alien visitors, both ancient and modern. As far as I’m aware, William Doleman’s excavation at the putative UFO crash site near Roswell, New Mexico remains the only legitimate xenoarchaeological field investigation. A few very speculative papers have appeared (usually using the term SETA: Search for Extraterrestrial Artifacts), but I am not aware of any that have been authored by archaeologists.
However, the other two sub-fields, aerospace archaeology and exoarchaeology, have become mainstream enough to be discussed in a space archaeology symposium at the recent SAA conference. The focus of the symposium was on the preservation of our aerospace cultural heritage, rather than investigating aerospace sites, which is perfectly understandable. Most of the questions that space archaeologists could address involve unique events (i.e., why and how did a particular space vehicle malfunction), rather than the patterned cultural behavior that is more properly the subject of archaeological investigation. In addition, on site investigation of archaeological remains located off Earth is likely to remain prohibitively expensive for the foreseeable future.
Investigation of exoarchaeological sites using remote sensing* is a more practical approach, and some types of projects have already been carried out. (Phil Stooke’s tracing of the path of the Lunokhod 2 rover last March being one example.) More ambitious projects may be able to piggyback on future space missions. If a sufficiently compelling research question can be devised, it might even be possible to fund a space mission specifically for an archaeological purpose (although the current state of the economy makes that appear unlikely in the near term).
As I stated, aerospace heritage preservation was the primary focus of the speakers at the SAA conference. This mainly involves legal and political action right here on Earth, and significant work can be done at a much lower cost than even the cheapest space mission. It is also somewhat urgent, given the potential that space tourism and other private space ventures have to damage irreplaceable heritage sites.
Presently, NASA’s concept of space archaeology is largely limited to the use of satellite remote sensing to study archaeological sites on Earth. This is itself a fascinating and important subject, but I hope that within the next few years they will also develop an interest in some of the other aspects of archaeology in, or involving, outer space.
* Please don’t confuse remote sensing with the paranormal practice of remote viewing.
Filed under Archaeology, Space
According to a paper recently published by an archaeologist in the U.K. the Panathenaic Games, one of the most important festivals in ancient Greece, was timed to begin just when the constellation Draco appeared in the evening sky. Unreported Heritage News has the story.
One of the things I love most about archaeology is the incredible diversity of skills used: physics, geology, architecture, animal butchering, and just about anything else. In this case, Dr. Boutsikas needed a knowledge of both astronomy and mythology to figure out not just what the citizen of Athens were seeing in the night sky, but why it was important to them.
Filed under Archaeology, Space
Got back home yesterday. I’m still feeling a little wiped out from taking two trips close together (first the SAA conference, and then this one), so I’m just going to post some archaeology porn. All of these pictures were taken last December at Petrified Forest National Park. (Click to embiggen.)
This is at Puerco Pueblo, a structure of about 100 rooms dating from around AD 1250-1300. Just to the right of center is what looks to me like a giant bird holding a struggling person in its beak. It’s probably meant to be just a regular sized bird holding a frog though.
Another panel from Puerco Pueblo. This one features several anthropomorphic figures that may be dancers.
A short distance from Puerco Pueblo is Newspaper Rock. I had to zoom way in for this picture because the Park Service doesn’t allow people to get very close.
Unfortunately, we were only able to spend a few hours in the park. Next time I get down to Arizona I’ll try to go back and spend more time there.
Filed under Archaeology, Rock Art
Some of my readers may not be aware that Nevada (actually the entire Great Basin) used to be quite a bit hotter and drier than it is now. Donald Grayson writes in Great Basin Natural History* that the Ruby Marshes, which currently make up the heart of the Ruby Lake National Wildlife Refuge near Elko, Nevada, was dry or nearly dry between about 6,800 and 4,500 years ago. Owens Lake dried up as well, while at Lake Tahoe trees were growing on land that is now 13 feet below the level at which the lake flows into the Truckee River. Summer temperatures at Pyramid Lake were around 9° F warmer than they are at present.
This is not an odd or controversial claim. The climate over much of the planet during the Middle Holocene period, sometimes called the Altithermal, was significantly warmer than today. Many places, including the Great Basin, were also quite a bit drier. So dry, in fact, that large portions of the Great Basin appear to have been completely abandoned by the people who had lived there during earlier periods.
Other instances of climate change have also impacted human societies in various ways. To pick just one example, the Medieval Climate Optimum had a profound impact throughout much of the western part of North America. Both the Puebloan peoples in the Southwest and the Chumash along the coast of California seem to have undergone significant social change during this time, although exactly how much of that was a direct response to climate stress will likely remain a subject of vigorous archaeological debate for some time to come. Thousands of miles to the southeast, along the west coast of South America, Michael Moseley, in The Incas and Their Ancestors: The Archaeology of Peru, interprets much of the cultural development in this part of the world as a series of responses to climactic stress. Many more examples could be given, but I think this is enough to make the point.
Understanding relationships between human societies and their surrounding natural environments has been a major focus in archaeology at least since the advent of processualism in ca. 1958. It therefore seems more than a little bit strange that archaeologists have not been major participants in current debates about climate change. Of course, I’m well aware that a few of the most shrill voices out there have already decided, usually for ideological reasons, what must be done. Those people have no real desire to hear from anybody except other true believers. But I think they are very much a minority (although a loud one). For the rest of the crowd, those who seriously want to understand what is going on and, just as importantly, make the best possible decisions about what, if anything, should be done, I think archaeology has the potential to offer some critical insights about adaptive strategies that have been used in the past.
I have a lot more to say about this, but it’s dinner time and I’m hungry, so it will have to wait until a future post.
Filed under Archaeology
