If you use a fleet of drones at once, presumably you could get an even larger synthetic aperture (radar from each drone bounches off the ground and is picked up by all other drones)? Contrary to movement-based synthetic aperture this would be movement+many-receivers?
SAR from a drone would be peanuts compared to the aperture available from a space plane. On the other hand, if one is studying a specific area, illuminating with a drone and passive SAR with a space plane might be very effective?
Graham Hancock is a fraud. We certainly underestimate the ingenuity of past peoples, but the way that Hancock frames this discourse is full of shit.
Bad Archaeology is a great resource that explains why a wide array of pseudoarchaeological notions and tropes, including those peddled by Hancock, are wrong. Check it out.
Graham Hancock is always careful to separate his speculations from the facts, and carefully label each.
And, he has turned out to be right (about things that are not completely wacky) remarkably often. Most recently, the Younger Dryas Boundary comet strike, that drove 30+ American genera to extinction and wiped out the Clovis culture, has finally been accepted by mainstream geologists. (Neanderthal gatekeepers on Wikipedia have not caught up yet, and probably won't for five or ten more years, and then will insist they were right to stall.) Furthermore, we now are certain that a large civilization farmed the whole Amazon basin for at least 1500 years before it was wiped out by Spanish-delivered smallpox.
> Most recently, the Younger Dryas Boundary comet strike, that drove 30+ American genera to extinction and wiped out the Clovis culture, has finally been accepted by mainstream geologists.
This statement surprised me because, while I haven't kept any sort of close eye on Younger Dryas research, I had literally never heard of this hypothesis before. A quick search of scholar.google.com for "Younger Dryas impact" focusing on recent papers seems to indicate to me that there is at least an active, ongoing academic dispute between at least two groups over the matter, and I haven't looked at the author lists to figure out if there's only one group on a specific side.
At the very least, I'd be very hesitant to say that it "has finally been accepted by mainstream geologists."
Edit: I should also mention that I did find an r/AskHistorians post on this topic (https://old.reddit.com/r/AskHistorians/comments/du40jl/the_y...) where the archaeologist is clearly not a believer in the hypothesis, linking some articles [including those I found in my aforementioned search] that are critical of the theory. While not gospel truth, it again suggests that "has finally been accepted by mainstream geologists" is not an accurate description of the current status of the hypothesis in the relevant community.
The watershed event was publication of Powell's "Deadly Voyager" this year. Powell is a respected, mainstream geologist. Hancock's most vocal mainstream critics have issued public mea culpas. The book is available on Kindle, free for Prime members, and is a quick and enlightening read.
The opposition for the past 13 years turns out to be a real black eye for geology. One group's failure to discover corroborating evidence was treated as a demonstration of falsehood and possible fraud, rather than what turned out to be a failure to sample the correct stratum. The negative evidence, interpreted correctly, reinforces the Impact Hypothesis by showing that the particles reported occur only in the cited layer, and not in samples straddling the layer.
The most compelling evidence is widespread, very sharp platinum enrichment at the layer, at dozens of sites, and particles that exhibit melting of materials that melt only well over 2000 degrees C, which does not occur in forest fires or volcanic eruptions.
I few trivial searches disqualify your "watershed event":
The "particles" you mention are most probably Highly siderophile elements (HSE) - which indeed only form upwards of 2000°C. That doesn't mean they have to come from outer space, though, as they are also present in earth's upper mantle[0]. Surface HSE presence can therefore also be explained by volcanic activity.
And indeed, a July 2020 publication has shown that the present evidence and thus the Younger Drias Event can also be explained by a series of volcanic eruptions[1].
> The "particles" you mention are most probably Highly siderophile elements (HSE)
From what I saw of some of the articles I was reading, it was nanodiamonds and magnetic microspherules. I'm getting this mostly from [1], which is definitely a strong critical take on the evidence, suggesting that the methodology for identifying these particles is sufficiently subjective that researchers knowing where the samples are to have occurred is biasing their interpretation of the results to find a sharp distinction around the Younger Dryas threshold that isn't corroborated if that context is removed.
You can quibble over this or that equivocal result, but the very sharp platinum concentration results at numerous sites are not so easily dismissed, and are (therefore?) notably not mentioned.
When I first poked at this hypothesis, I came away feeling that the best characterization was that it's an area of academic dispute where both sides have credibility and neither side can be accurately considered fringe or mainstream, in contrast to your initial comment. Nothing you have said has shaken that belief, and I have no relevant scientific expertise to offer in support of one side or the other. I have my personal opinion on which side I feel has the better evidence and prefer on the balance of probabilities, but what that opinion is is ultimately unimportant.
That said, there is one thing that mildly concerned me when I read your first comment and that your later comments have only reinforced my impressions. You seem to be approaching this topic from an evangelical perspective, and not a scientific one: that there is a core belief, this needs to be disseminated to as many people as possible, and that anything that challenges that belief needs to be swiftly eliminated. Your rhetoric--"Neanderthal", "black eye for geology"--does not help your argument. I only bring this up because I saw a video over the weekend [1] discussing Flat Earthers and some of the argumentation style they used, and on reflection, it was striking how similar your comments were, just on an acceptable opinion rather than a loony idea.
That [1] really only examines ratios of osmium to platinum-group elements is telling. At only one place in the paper do they admit that the osmium/osmium isotope ratios found in their samples, from the one cave, do, in fact, match a known bolide. They very carefully avoid addressing the extreme Pt abundances found in the YDB layer at dozens of sites. This is akin to others complaining that iridium abundance at the strata is not especially elevated, without addressing platinum, which lacks other explanation.
"Lack of clear consensus" cited in the paper is revealed to mean that certain individuals, like them, have disagreed, without addressing faulty details. Such individuals have made claims that spherules identified as carbon are spores, without having examined any of them, or that they are not present at all, but which turn out to refer to layers that do not coincide with the YDB.
The European volcanic eruption mentioned is known to have occurred some centuries before the YDB.
You can't refute results from dozens of sites with equivocal results from a single site.
Hancock is well-known as more than a bit of a crank. He's interesting (in much the same sense that ancient aliens shows are), but please give disclaimers so you don't confuse the unaware.
A gamer buddy really liked the Distant Origin scenario (Star Trek Voyager episode). https://en.wikipedia.org/wiki/Distant_Origin TLDR: Ancient non-human civilization, prior inhabitant of earth, now long gone.
"Where's the hot spots?"
"Um, what?"
"Any industrial, technical civilization would leave their mark somehow thru their waste and pollution. Even if they left millions of years ago and their cities were built on subduction zones, we'd still detect their nuclear waste dumps."
Long pause.
"Well, ya."
Comparatively, I can kind of imagine groups of humans getting wiped out without a trace. The Sea Peoples didn't leave much behind. It's an accident we know about those lost cities on the steppes, which were completely lost to history. There's 100s (1000s?) of habitats buried under the desert, waiting to be explored. Etc.
But not being anything close to an archeologist: Hancock's notions are a bit far fetched, circumstantial. Like he's fooling himself into seeing stuff that's not there. Like seeing animals in the clouds, faces in pictures of martian soil, illuminating patterns in numbers.
I started reading into these supposed "fringe" theories surrounding Hancock and Robert Schoch and the other people talking about these ideas about a year ago and I find some of their arguments credible and not completely nuts and I honestly think there's something more there than what the official, established story is able to explain.
Some of the evidence Hancock presents doesn't hold much weight in my mind and I think he's just reaching but other pieces do.
For example, I think the Orion Correlation and Sphinx Erosion Hypothesis are interesting to look into. Also Gobekli Tepe.
There also doesn't appear to be any indisputable evidence that officially dates the Great Pyramids and the Sphinx to the purported time period of around 2,500 BC, the age of Khufu.
It doesn't necessarily have to be that Hancock's theories for what actually happened are right and he's not adamant they are either, only theories, but I think he's raised enough issues with what Egyptologists or Archeologists are saying is canonical to lead me to believe what the mainstream majority Egyptologists or Archeologists claim is certain fact may just be a local maxima based on interpretation of found evidence at the time the theories were first recognized and an unwillingness to change their position unless evidence to contradict them becomes so strong they can't deny it with a straight face.
It's also fascinating that many large burial / ancient civilization sites have been discovered even in the last 50 years, e.g., Cerutti Mastodon site, and also Amazon civilization remnants using Lidar, which leads me to hope a lot more could be discovered in the next 50 and greatly change what is purported on wikipedia as true.
>There also doesn't appear to be any indisputable evidence that officially dates the Great Pyramids and the Sphinx to the purported time period of around 2,500 BC, the age of Khufu.
The fact that there isn't any Predynastic pottery at the Great Pyramids severely limits any kind speculation as to when they were built, at least in the backward direction.
Joke's on them. Turns out there really was a big, widespread comet strike, probably multiple air bursts, and it was also responsible for extinctions in South America and Africa. Evidence of the singular event surfaced as far afield as South Africa, Chile, and Syria.
Was there an advanced civilization? First, what do you mean by "advanced"? Any civilization at all preceding known Harappan and Mesopotamian settlements would be a big upset to the current narrative. There are extensively built-up areas known, off the coast of India and south of Harappan sites, that were last above water more than 6000 years ago.
The "current narrative" already includes pre-mesopotamian civilizations like Göbekli Tepe (10000 BC), Ganj Dareh (8000 BC), Mehrgarh (7000 BC), Tell Abu Hureyra (11000BC, first known crop cultivation), ...
You clearly lack background knowledge about contemporary archaeological understanding of the palaeolithic and neolithic periods in southwest asia and anatolia.
First off, referring to 'civilizations' as basic entities or units of analysis is just nonsense. Sure, there has been some talk about 'social complexity' up to the mid-90s, but (a) that discourse is largely outdated since it tends to be based on justifying prior presumptions regarding the nature and boundaries of societies that were already assumed to be 'civilizations' without adequate reason, (b) that perspective is being replaced by more bottom-up approaches that model various kinds of behaviours and interactions, including possibilities and limits thereof, and as guided by the archaeological evidence, and (c) even when we do talk about so-called 'civilizations', that is typically limited to a period starting around 4000 BCE. You are clearly ignoring (what I consider to be) the most exciting topic of archaeological research, the pre-pottery neolithic. As bildung points out, coherent models about this period have been formulated by drawing on evidence accumulated from dozens of PPN sites.
Yes, it is true that Gobekli Tepe has no habitation associated with it, but we do not consider this an unresolved puzzle. Gobleki Tepe is commonly accepted as a great example of the ingenuity of nomadic peoples. Why do you assume that it would be necessary for its builders to have been sedentary?
Please omit swipes like "You clearly lack background knowledge" and "Umm what?" from HN comments. They just add poison to the community.
If you know more, that's wonderful, but please share what you know in the spirit of helping everybody learn, not putting other people down.
Getting frustrated like at https://news.ycombinator.com/item?id=24473147 and going into a flamewar style is definitely not going to help. Of course it's frustrating to encounter wrong comments on the internet, but the fix is to respectfully provide correct information and explain the problems with false claims.
> the fix is to respectfully provide correct information and explain the problems with false claims.
This is precisely what I did in the post you are referring to.
> If you know more, that's wonderful, but please share what you know in the spirit of helping everybody learn, not putting other people down.
I wasn't aware that these discussions are meant to be records for collective learning. I have been framing my replies as responses to particular positions, held and presented by particular people. In almost all situations I target the ideas presented and not the individuals, the exception being the comment you highlighted above. I definitely should have been more respectful in that instance. But I disagree with the notion that I've been trolling or making pointless personal attacks (even in that one case, I expanded upon my reasoning in lots of detail).
For it to count as respectfully providing correct info, you have to omit the personal swipes. Fortunately that's not hard, though it sometimes requires an editing pass or two (that's how I do it).
I do not assume it would be necessary for its builders to have been sedentary.
Neolithic behaviors differing from the modern familiars are all interesting, but when we use the word "civilization", we are definitively talking about cities. Associating onset of civilization with 3-4000 BCE is a conclusion from present evidence, not a definition, and would need to be changed in the face of new evidence of cities.
Hints at civilization pre-4000 BCE typified by GT are as interesting as other neolithic phenomena. To be clear: while it is possible, in principle, that GT builders invented all their stonework methods de novo, it is clearly much more likely that they drew on a long history of gradually more sophisticated stonework not yet unearthed, possibly elsewhere. What we know about sea level changes allows that much of such evidence may now be under water, although it could also be found in the Tepes yet to be excavated.
We have absolutely no reason to believe that areas now deluged were unoccupied, or that the people who lived in those places chose to stay there and drown. They would have brought their culture uphill with them.
The entire Persian Gulf was recently dry land. Australians retain oral records of the social upheavals when people who lived in the Sahul region between present Australia and New Guinea were obliged to move uphill, to where other people already lived. Similar upheavals must have occurred on the present Indonesian islands and nearby peninsulas, absorbing influx from the hundreds of thousands of square miles of the the now deluged Sundaland.
People 6000 years ago, or 11,000 years ago, were no more clever than 20,000 years ago. What was evidently done 6000 years ago could have been done longer ago, given only population density and surplus food production. Undiscovered civilizations are certainly possible: the huge Amazon basin civilization was entirely unsuspected only decades ago.
> when we use the word "civilization", we are definitively talking about cities. Associating onset of civilization with 3-4000 BCE is a conclusion from present evidence, not a definition, and would need to be changed in the face of new evidence of cities.
The term 'civilization' is not really used at all among archaeologists, to be frank. You are correct in recognizing the link between the notion of civilization and the notion of cities, since both of these terms are ambiguous, co-dependent and ultimately useless. What evidence is needed to call something a city? Many settlements have been excavated dating to times before 4000 BCE which include features that would be classically referred to as characteristics of cities. If you were to follow the evidence, as you claim to do, the distinction between cities and settlements and between civilizations and whatever is associated with settlements (which is ambiguous as well!!) becomes meaningless. Only cranks really lean on this distinction as having any sort of significant meaning, which tends to be upholding a truly arbitrary notion of what constitutes a civilization (i.e. circular logic, with conclusions leading the parameters of reasoning).
> while it is possible, in principle, that GT builders invented all their stonework methods de novo, it is clearly much more likely that they drew on a long history of gradually more sophisticated stonework not yet unearthed, possibly elsewhere. What we know about sea level changes allows that much of such evidence may now be under water, although it could also be found in the Tepes yet to be excavated.
Where is your evidence for this wild claim? How is this clearly much more likely, when there is literally nothing but speculation to base this on?
> the rest
So much cherry picking and mental gymnastics going on here, I truly don't know where to start.
We have extensive evidence of incremental development of technology, throughout all of history and pre-history. Thus, suggesting that any sophisticated development, such as is seen in the stonework at GT, would follow less sophisticated work is no kind of "wild claim". The term smacks of name-calling and bad faith, so I leave you there.
Great book, highly recommend. Even if you say 90% of it is pseudo-scientific bs, fine, read it like you would fantasy or sci-fi and there's still easily 10% of mind-expanding possibilities in here. I've read many critiques of Hancock's work and there are always arguments and evidence left over that critics don't address. The only way to decide for yourself is to read his work with an open mind. Or don't!
Fantasy stories about archaeology do serious harm. I've mapped dozens of burials looted by people who had bought into similarly fanciful tales of lost treasures and empires. That fantasy didn't make them any richer, but it did desecrate hundreds of graves and destroy a lot of cultural heritage.
Please be careful with giving recommendations you know are inaccurate. Not only does it mean archaeologists have to go back and correct those misunderstandings, it contributes to the destruction of the very things we're trying to protect.
Ok I will stop recommending his books. Thanks for the heads up. I did not know his ideas were causing such destruction. I will still read all his books with an open mind but you don't have to worry about me looting any sites. :)
I will not stop recommending Hancock's books. In many cases they are the only source of excellent photography of ancient constructions.
Furthermore, Hancock is always very careful to separate factual exposition from his speculations.
Finally, he has remarkably often turned out to be right, and his critics badly wrong. The Younger Dryas Boundary comet strike is now mainstream pre-history, supported by excavations as far afield as Chile, South Africa, and Syria. A culture cultivating the whole Amazon basin for at least 1500 years before being wiped out by smallpox 500 years ago is now well established fact, supported by LIDAR surveys revealing hundreds of miles of major earthworks.
I'm with you. I tried to find that keen edge of sarcasm in my comment but I missed the mark. And really it was childish and I shouldn't have even attempted it. Apologies to AlotOfReading for not replying in earnest, and since I think they upvoted me. Yes I will continue to recommend Hancock's books, along with recommending critiques of his books. Hancock is pretty tame compared to other books I recommend ;). Free flow of information and especially the freedom to be wrong is vital and Hancock is a great expression of this.
>I've read many critiques of Hancock's work and there are always arguments and evidence left over that critics don't address.
It is much easier to generate nonsense than to debunk it. That is why we have the notion of "burden of proof". If someone overwhelmingly writes pseudo-scientific BS, the correct course of action is to dismiss all their writings as potential cognito-hazards - it is certainly not to read them "with an open mind". You know what we call people who let known bullshit artists tinker with their brain? Gullible.
Just open one of his books. He travels the world with his partner and takes incredible photographs, scuba dives submerged ruins, interviews locals and mainstream archaeologists like Klaus Schmidt, digs very deep into mythology and cross references with science, gives almost exhausting levels of citations and references. Not to mention dealing with incredible levels of vitriol and threats while doing so. Not so easy to generate such nonsense! :)
Gullible means believing something. Believe nothing. This is what an open mind is.
Klaus Schmidt, who died around 5 years ago, was the director of excavations at Gobleki Tepe. I highly doubt he would have allowed Hancock to perverse the legitimacy of his work. To read more about how Gobleki Tepe has been abused by pseudoarchaeologists, check out the Tepe Telegrams blog, which is produced by archaeologists who actually work at the site: https://www.dainst.blog/the-tepe-telegrams/
> Gullible means believing something. Believe nothing. This is what an open mind is.
Umm what? If you can't believe anything is true then you can't retain or formulate any knowledge at all. Seriously, this is a really bad take.
Hancock has at least one transcribed interview with Klaus. Look it up for yourself. They had an interesting relationship. Klaus definitely did not agree with many of Hancock's ideas. It's admirable, an open exchange of ideas with people you disagree with. Just like we're doing here! Good on us.
> It's admirable, an open exchange of ideas with people you disagree with. Just like we're doing here! Good on us.
Well there are disagreements stemming from different perspectives or opinions, and then there is the distinction between proper research and conclusions drawn from wilful ignorance, cherry picked data and wild presumptive leaps of imagination that masquerade themselves as legitimate research. Graham Hancock's work is pseudoscience, period. My disagreement with you is not a matter of exchanging perspectives, it's a matter of exposing lies.
