I decided to purchase this book after seeing some of the material presented as part of a history/science program on TV. The information there was impressive enough that I decided to read the book written by two of the guest commentators. Bond and Hempsell's book, A Sumerian Observation of the Köfels' Impact Event, is not a light weight read by any means. In places, it was definitely over my head, but the general concepts were apparent.
First let me say that I do not have nearly the scientific background that the authors do, but I do have a broad background which definitely suits me to evaluating the topic. I don't have a degree in mechanical engineering as does Mr. Bond, nor degrees in physics, astronomy and astronautics as does Mr. Hempsell. I do have a rudimentary understanding of physics and astronomy and a nearly complete degree in geology, with a primary focus in earth history, paleontology, and structural geology (primarily sedimentary formations, since my intention was to pursue paleontology at a graduate level). I also have a masters degree in ancient history for which I took basic course work in both Sumarian and Akkadian, though I do not claim anything like authority and expertise in either. (Frankly I was better at Egyptian hieroglyphics, which I found more interesting at the time.) That given, I will attempt to critique the book for prospective readers.
A Sumerian Observation is not for those who do not have a strong interest in history, particularly ancient Mesopotamian history, and a basic understanding of physics and astronomy. This is primarily because the topic is a complex one, bridging science and social science. One might be able to plow through it without this knowledge, but I'm not sure the average reader would find it either edifying or satisfying. This really is a special interest type of book, which is why it is rather expensive. It attracted me because I have these interests and thought I might gain better insight into what I saw on the TV program. If this doesn't sound like you, you would be better off spending the money on something you might enjoy and understand more.
For those who do have these interests, I think you will find what I did, and what the authors themselves admit from the very beginning, the arguments are very circular. The authors use what they want to prove as part of the argument. They want to show that the Köfels' formation near the village of Köfels' in Austria was an impact crater rather than a slide or volcanic structure, that it occurred in the period from 3500-2000 BC, and that Sumerian disk shaped object K8538 in the British Museum's cuneiform collection, generally referred to as the "Planisphere," depicted this event. They then proceed to adjust the data of all sides until it fit's their proposal. Data which does not agree with the theory is discredited or reread. Their basis for this is generally acceptable research by others, but the research results are by no means consensual among the field's professionals. This doesn't mean that the results are "wrong," only that they have not withstood the scrutiny of time and further study. In fact, the reports the authors use, are just that: "further study" and part of the scientific "scrutiny" in the field.
They also assume that uncertainties can be added to produce defining limits for the value of the actual data, but in general, individual uncertainties tend to be multiplicative rather than additive, which makes the defining limits of the data far less flexible with each added poorly defined detail than the authors suggest. This is what makes meteorology such a difficult science and computer simulations of it difficult to build. Each assumption with its +/- degree of certainty makes the equations more and more insubstantial. In dealing with the data of the planisphere, this is particularly noticeable.
First the document is damaged, sometimes in places where significant data might be located. Despite the attractive and oft quoted statement that "absence of evidence is not evidence of absence," for a scientific study, it might as well be. You can't make solid statements on what "might" or "should" be there.
Secondly, the document is probably not the original but a copy; in fact, it's very likely a copy of a copy of a copy, etc., which would be typical of cuneiform documents considered important, as Sumerian documents often were by their political descendants in the area. The possibility of the introduction of simple copiest's errors is significant, given that there may have been more than one of them to introduce them over the period of 700 BC to 3100 BC that the author's believe took place between the Sumerian observation and the Assyrian preservation.
Thirdly, as the authors themselves note, the content of the document, if it is actually as old as they believe it to be, was probably originally written in pictographic characters at a very nascent stage of literacy, a very pliable period in the history of the written word. Pictographic signs came to have set meanings only with the expansion of a shared symbol system and literacy over a wide area. Not only that but Sumerian was a language which has unknown parentage; it is not just another one of several Semitic languages from the area. Concepts, precepts and cultural point of view are therefore unique. Furthermore, by the time the Planisphere we possess was made, the Sumerians had ceased to exist over 1200 years earlier, their culture and language long buried. Lexicons were kept by later Semitic speakers specifically for translation of Sumerian documents, but the language of the Sumerians was as foreign to these people as ancient Japanese might be to English speakers. It might be translatable for a specialist in the field, but the possibility of mistranslation from early Sumerian pictograms into Assyrian Akkadian cuneiform was enormous even for such a person. The authors' discussion of the cuneiform signs and the language of the document reveal just that. In some places the redactor of the document was a little confused about the meaning of the Sumerian. Now add the fact that Akkadian is also an ancient and long dead language, which must be translated by experts, and whose concensus on the meaning of the signs is belabored in professional journals still, we add yet another layer for confusion. So the question remains, do we really have and can we really know what the Sumerian astronomer intended at all?
Even the assumption that the bowl shaped object was designed to be an erasable surface easily held in the hand by the observer or his assistant, while probably true, is based on an object that may not be an absolute copy of the original at all, but perhaps a design known to be useful by astronomers of the contemporary redactor of the object and therefore imposed upon the object we possess because it "made sense" and therefore "must have been." In short, just as the authors interpret the object from 700 BC in terms they believe "must have been," so too might a 700 BC translator interpret an earlier document. When you accept that there may have been a number of such translators between the one who provided the author's with their document and the scientist who created the observation, that makes for a lot of interpretative changes that "made sense" to somebody in between them.
These points made, I will say that I agree with the authors' assessment. Not because their argument is "logical," but because I know that the Sumerians were avid celestial observers. Though they were primarily interested in prediction and interpretation and in correlation between events in the sky and those on earth, they were more observational scientists than we often give them credit. They were also capable mathematicians for their time, basing their manipulations on a sexigesimal system. Our 360 degree circle, 60 second minute and 60 minute hour were bequeathed to us by the Sumerians. Part of the purpose of the ziggurat was the observation of the sky, just as they probably were for the pyramid builders of South and Central America. That they might observe an actual celestial event and maintain a record of their findings I find entirely credible. I therefore have no difficulty believing that the original document recorded astronomical data believed significant enough to have been preserved through the ages. Exactly what the event was, where it might have left its mark, is difficult to say for sure, but it is as likely to be Köfels' as any; but again, this is not a scientific observation based on proof, but an opinion.
The concept that the Köfels' site is impact rather than volcanic is not really proved so far as I was able to ascertain from the book. The mention of dykes and sills suggest melting not uncommon in volcanic areas, and certainly the Alps themselves were created by a major and probably ongoing subduction event that has closed the Tethys Sea, leaving the Mediterranean, the Caspian, and the Baltic Seas as residual representatives. Volcanism would not be unexpected here. The authors themselves mention studies that suggest that what has been interpreted as impact evidence might actually be evidence of landslide activity which is very much in evidence in the area. Furthermore, they also mention dates nearly 10,000 years before the present that may place the event, volcanic or other, beyond the desired date of 3123 BC. So now we have an impact event that isn't necessarily real which is "supported" by a document that isn't necessarily in the form its original creator intended.
I think the idea is brilliantly conceived. I think it's not unlikely to be true, because bizarre accidents of fate just do happen, and this one appeals to me. But that's still not solid evidence.