There’s a 1995 PBS Nova episode in their Secrets of Lost Empires series which includes a segment on drilled granite. The episode features egyptologist Mark Lehner, stone mason Roger Hopkins, and ancient tool expert Denys Stocks.
The episode mainly explores the question of how an obelisk was raised. The team ran out of time before they were able to reach a satisfying conclusion, but they returned to Egypt in 1999 to record another NOVA episode, which includes two competing theories on how to raise an obelisk. I highly recommend both episodes.
> Photograph of a model of the bottom of the drill hole shows that lines are spaced closer together (arrow). This may be due to abrasive having become finer as drilling continued.
Anyone who has drilled brittle materials will know why the lines got closer together. The feed pressure was reduced near the end of the hole to avoid chipping out the back surface.
It's obvious Egyptians could carve granite using stone instruments. What is worth more investigation, is how they carved symmetric granite vases within 1/100th of an inch precision.
nowadays, when people need precision to 1/100th of an "inch" (250μm in modern units) on soft materials like unhardened steel, they can use steel tools
but when they need precision of 1μm or better (in medieval units, 1/25000th of an "inch"), or when they're cutting materials harder than steel, they resort to grinding with stone, typically emery (sapphire) for most of the grinding, followed by polishing. poor people who don't have steel tools also commonly do this for lower-precision work in soft materials; you can find all kinds of videos on youtube of people using angle grinders for things that a well-equipped machine shop would do with a bandsaw or milling machine
similarly, to get the dimensional references to measure to, common shop work can use cast-iron straight edges. but, for more precise work, they resort to granite surface plates
the egyptians of the old kingdom clearly had granite surface plates (they built significant parts of the pyramids' interiors out of them) and grinding, though they were evidently using the inferior quartz sand as their abrasive
as for symmetry, the most likely explanation is that they used lathes; the oldest indisputable records of lathes are from new kingdom egypt, but rotationally symmetric work that seems to have been made on a lathe appears as far back as the old kingdom
with respect to granite, while i don't doubt that you can find a granite vase here and there, most ancient egyptian fine stone carvings are from much softer rocks such as schist, alabaster (gypsum), and "alabaster" (calcite)
so i would say the investigation has already been done and found convincing answers
Ben from UncharteredX has a good video on these drill samples, but does not buy into the mainstream acceptance of how they were made. In fact the granite core samples show continuous grooves and you can calculator the pressure per turn the mechanism was under, and it’s not really able to be done easily.
A discontinuity being an exception from a great majority of surface consisting of spiralling and continuous lines is no proof, nor debunking.
A spiral form being an exception from a great majority of circular lines may be just that, an exception, and would point towards a non-spiraling cut.
The photo with the discontinuity shows one side only. Therefore there is no way of knowing if and how the lines are connected on the obscured side, and no conclusion can be made either way.
Important to distinguish a spiral cut from a spiral ream. It is entirely possible to chip/drill/chisel a hole, and then to ream it out with a spiral tool.
Could someone point to where in the article that is? Figure 5 is not a counterexample in my opinion, for the reasons mentioned in an one of my other comments, namely a single deviation from a spiralling line (if there are such lines) is not proof that all other lines are not spiralling. It is only a counterexample with regards to those particular lines.
They don't need to prove all the lines are not spiraling, only to find counterexamples where the lines (spiraling or not) are discontinuous. One counterexample is enough to disprove a theory. Their explanation of exactly how their theory resulted in the evidence we see is easy to understand. A rebuttal would ideally include a similarly detailed explanation and similar experimentation around how fixed cutting points would have produced the same discontinuities.
Thus, in the interest of scientific advancement, I encourage you to, like here, team up with someone who has no horse in the race, and publish an equal or better rebuttal. After all, science can't advance if we just accept what someone says or limit our disagreement to an internet comment.
It's a pretty old article, maybe an unbiased team already has done this!
The argument between the eminent Egyptologists that opens the article is frustratingly naive to anyone who has real experience in drilling and shaping hard materials. A dentist is, oddly enough, exactly the person I'd expect to write this article - academic enough to bother writing it, but practical enough to see the tool marks and have an insight into how they were made.
The whole thing reads like great literature. There should be a scientific magazine for papers that can be understood by the motivated layman. I accidentally read the whole thing in one sitting.
For more of excellent writing read Derek Lowe's https://www.science.org/blogs/pipeline His "Things I Won't Work With" series is particularly entertaining whilst remaining firmly scientific.
You misspelled “terrifying” there. I’ve never practiced chemistry, just got my B.S. and went to med school, but simply reading the names of most of those compounds made my blood run cold.
Gorelik or Gorelick (Russian: Горелик; Belarusian: Гарэлік: Harelik) is a Jewish occupational surname historically denoting a vodka distiller or trader. Its etymology is Slavic, from Belarusian harelka (гарэлка), a calque from Polish gorzałka, itself from German geprant Wein 'burnt wine'.
This is one of the most intriguing ancient mysteries, and is sufficiently well grounded in engineering practice that it can be experimentally validated. Things like the hardness of the cutting edge, the RPM required to mimic the drill markings, the shape and progression of the drill bit etc.
So, it's reasonably clear that the bronze-age Egyptians must have had some drilling rig for boring hard stone - one which operated at 1,000 rpm or similar and could make an impression into something like quartz. All the ancient aliens nonsense aside, this rig in itself must have been quite impressive in itself - probably a composite of pulleys and ropes with a tubular emery-embedded cutting bit. Would have loved to have seen it working!
If the claims of levitation, ultrasonic resonance, and/or lingam electrical plasma stone masonry methods are valid; perhaps the necessary RPMs for core drilling are lower than 1000 RPM.
Given drilled cores of e.g. (limestone, granite,), which are heavy cylinders that roll, when was the wheel invented in that time and place?
> The plasma treatment showed a maximum of 65% and a minimum of 15% reduction in specific cutting energy and was regarded as being dependent on mainly the hardness and size of the samples [and the electrical conductivity of the stone]
E.g. this video identifies electrodes and protrusions in various megalithic projects worldwide: https://youtu.be/n8hRsg8tWXg
Perhaps the redundant doors of the great pyramid were water locks rigged with ropes. There do appear to be inset places to place granite cores for rigging.
Ancient and modern stonemasonry skills; how many times have they been lost and why?
Pure copper is too soft and it has never been useful for most tools.
The widespread use of copper for other purposes than jewelry has begun only after it became possible to produce in a reproducible way various alloys of coppers, now known as bronzes.
The tin bronze, i.e. the alloy of copper with tin, has been discovered relatively late, around 5500 years ago, close to the time when writing has been invented, so we have much more historical information about the civilizations that used tin bronze. (The much cheaper brass has been discovered only long after the method of iron extraction, during the Greco-Roman Antiquity.)
Nevertheless, for several thousands of years before, other copper alloys have been used, e.g. arsenical bronze or antimony bronze, so that is still "bronze age", even if it would be useful to differentiate between the ages of iron, of tin bronze and of other "bronzes". The Egyptian state definitely belongs to the age of the tin bronze.
experimental archaeologists (forget the names, sorry) drilling egyptian granite with egyptian sand† found that copper tube drills work better than bronze tube drills, presumably because copper is, as the machinists say, 'gummier'
so while you're right that copper is much less useful than bronze for most tools, here the tool we're talking about is one of the exceptions
they also tried tubular reeds, with and without water. those didn't work at all
the egyptian state seems to predate not just tin bronze or even arsenical bronze but even copper tools, at least in egypt
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† emery doesn't occur locally and doesn't start appearing in the drilled holes during the first millennium of rock drilling
While you are right about pure copper being the best for such drilling with free abrasive, a few niche use cases for pure copper do not make a "bronze age" into a "copper age".
Even after the much cheaper iron replaced bronze for most uses, bronze remained the best choice for a few purposes, but nonetheless that does not override the transition from the bronze age to the iron age.
While emery does not occur locally, the island of Naxos is closer to Egypt than many other places from which various goods were imported at that time, so that was not a serious obstacle against its use.
The conclusion of the parent article was that emery (with copper cylinders) produced the best matches with the archaeological artifacts, so that was the most probable method used for drilling (the other possible alternatives, like importing diamond dust or corundum dust from India have probabilities far too low to be believable; what we name now as diamonds became known to the Mediterranean world only after the expedition in India of Alexander the Great; the word "diamond" is much older, but it was previously applied to osmium-iridium alloy nuggets, which are found together with gold nuggets in alluvial deposits and which are embedded in the gold of many ancient Egyptian artifacts).
i agree with almost all of your comment. just a few minor points:
- there was a 'chalcolithic' period of copper tools in most places before the advent of bronze, but i believe that bronze tools were already in use in egypt when drilling started
- later investigations did not find emery dust in the oldest drill holes, leading to the conclusion that the abrasive was quartz, so although the egyptians certainly could have been importing abrasives from naxos, they don't seem to have done so until much later
- the identification of plato's 'adamas' with an osmium-iridium alloy is quite dubious; he was certainly talking about a metal, but it could easily have been steel or meteoric iron
- just to clarify, you probably know this, but corundum dust and emery are the same thing (the article was fairly confusing on this point)
Always weird when people correct others with something that is wrong. Its bronze age. And if it was the copper age the correct term would be chalcolithic.
I'm starting to think we should think of the pre-historic times as the "simple machine age". When I see the artifacts I'm left with the impression that these people had plenty of labor and they were exploiting and learning the use of simple machines.
Everything they did could be explained by mastery of use gravity, ropes, and levers. If the materials used were primarily organic in composition the tooling would be long gone by now.
> (Note: Emery is a granular rock composed mainly of corundum—a crystalline compound of silicon and carbon—magnetite and spinel. Here, `emery’ and `corundum’ are used for the abrasive powders derived from these rocks.)
Corundum is Aluminium Oxide (not clear if this is part of the original article?)
For what seems like every 100 YouTube channels that speculate on everything from lost civilizations to aliens there are some mundane channels that actually set out to demonstrate and reproduce technologies and works like the ancients.
One of the more well known channels is scientists against myths, here is a link to one of their videos reproducing granite drill holes how the Egyptians might have: https://youtu.be/yyCc4iuMikQ?si=oUkmF122iHIklvuz
I really like their videos making granite and diorite vases, while the YT algo will tend to take you down the must have been lost technology/lost civilization/alien rabbit hole, sometimes you get lucky and they suggest other channels doing amazing work. The comments are fun too, no matter how well done anything is there’s always someone demanding demanding the small channels recreate the great pyramids at scale.
People want to believe in something more when it comes to ancient Egypt even if they know it is not reality. To me, it is obviously linked to the beauty and other worldly feel of the ancient Egyptian iconography and art.
If you just had the pyramids in the desert with the entire civilization lost, while impressive there wouldn't be other worldly explanations that sounded palatable. It would obviously just be the engineering of a lost civilization.
It is really a testament to the power of ancient Egyptian art that it can still inspire the imagination to such a degree thousands of years later and across cultures.
I think for some that it is the opposite. Most people are able to understand that due to the extensive evidence of centuries of advanced civilization, including extensive surviving writings and evidence of mathematics knowledge, the Egyptians were able to coordinate the construction of the pyramids using advanced, but not anachronistic technology. However, due to the disproportionate vastness and majesty of the pyramids and some of the other surviving ancient Egyptian works, many people can still be led to believe that there was something more at work than practical engineering with ancient technology.
I'm getting a bit off topic here but regarding the pseudo-archaeology that's popular on YouTube: Graham Hancock (who had a 10 part Netflix series called Ancient Apocalypse about an advanced global civilization during/before the last glacial maximum) recently appeared on Joe Rogan's podcast alongside Flint Dibble who is an archaeologist that does public communication on YouTube.
At least according to my own YouTube bubble it seems we are in a pretty big moment for pseudo-archaeology! Here's an informal discussion about it from Stefan Milo who I highly recommend for anyone intereated in prehistory: https://youtu.be/rWugM4XRPuc?si=EkO5PEAKRAIYYRJD
I have seen another good quality video summarising the debate on the podcast but annoyingly I cannot remember it to share, maybe someone else can share a fun resource (unfortunately the Joe Rogan podcast is way too long for me to actually listen to)!
Graham has been appearing on Rogan’s podcast for years now. It’s Grahams exposure from Rogan that actually got Graham his Netflix show not the other way around.
In terms of proliferation of “pseudo archeology” - whatever that is - yes, lots of people are realizing they can profit from this, so more content than ever is being created to monetize the attention capture. It’s not unlike flat earth content that people have been able to successfully monetize.
It’s not all bad, Graham is no doubt responsible for getting people interested in history, archeology, and even geology. It’s really not societies fault they are ill equipped to exercise independent and critical thinking, much less the not having the skill sets, tools and resources to evaluate the existing archeological record.
Though for the people that want to make a career out of it, I’d rather see them obtain formal educations and contribute in meaningful ways in lieu of the majority of the grifting type social media content…most people probably have the capability to become educated about the actual science and they’d also learn pretty quickly there is no vast conspiracy to hide history/prehistory as much of the monetized social media promotes.
Are you saying there’s not ancient technology or civilization that’s lost to us? That seems extremely unlikely to me.
The name “scientists against myths” makes me wary of this channel. They clearly have an agenda, and I as a laymen have no way to identify when they’re letting that agenda cloud their judgment.
As a laymen I can at least evaluate the trustworthiness of other humans, and framing the debate as “science vs myth” when history is rife with examples of myths later being explained by science sets off alarm bells.
‘Ancient technology that’s lost to us’ is one of those phrases that is used to construct a motte and bailey argument which opens a gap through which some crazy theories get inserted, so it’s worthy of being treated with skepticism.
Are there ancient structures where we are unsure what technologies were used to make them? Yes, absolutely.
Does the existence of such artifacts imply the existence of certain precursor technologies and tools used to build them? Yes, but we must proceed cautiously. Without direct evidence of the tools and technologies used we are speculating based on the results we observe, about what the means used to produce them must have been. The same result, though, can be produced in many different ways. Problems we look at today and say ‘surely that would require a machine or a powerful engine to do?’ might be solved instead by just throwing manpower at the problem, or by taking much more time to execute than we might initially assume is reasonable. And the existence of doubt about which of several historically plausible theories as to how something was constructed does not automatically mean that historically implausible theories are equally valid.
And, most importantly, does the fact that we have ‘lost’ the precise techniques used in ancient constructions leave open the possibility that those ancient techniques were actually superior to what we have today? Theoretically, but in general, no, of course not. Be very wary whenever you see someone say something like ‘the precision of these stone blocks exceeds what we can do today’. These are nonsensical claims made from ignorance about what modern engineering is capable of. Take a look just at how modern kitchen counters are cut, let alone how precisely engineered something like a modern tunnel, or the LIGO gravity wave detector was constructed.
> The name “scientists against myths” makes me wary of this channel. They clearly have an agenda[...]
myth: an unfounded or false notion [0]
Given that definition of "myth" I find the name "scientists against myths" to be rather redundant, wouldn't you? In what version of reality is that not the agenda of every scientist?
You say Troy was considered a myth as if it were an absolute, it wasn’t, it was debated among scholars.
Fact is German archaeologist Heinrich Schliemann was one of those learned people that didn’t think it was a myth, and in fact did locate and excavated a city matching the descriptions.
That’s how science works, things generally tend not to exist until there is proof or record of their existence, science doesn’t default to things existing until record of their non-existence emerges.
The scientists who considered it a myth were completely, utterly wrong. I think it is perfectly healthy to have skepticism about scientists who wage war against "myths".
See also the long fight against the "myth" of lead poisoning, amongst dozens if not hundreds of other examples.
>Are you saying there’s not ancient technology or civilization that’s lost to us?
Archeology is based on the record, so we only know as much as we have of the record. Like most sciences the archeological record is subject to new discoveries.
The problem is the way “lost civilization” and “ancient high technology” are most often used disingenuously.
For example we don’t have the exact formulas to replicate Greek fire nor Roman concrete as they were valuable secrets of the times. The equivalence of me arguing “Greek fire and Roman concrete is proof of a ‘lost high technology’ and evidence for older ‘lost civilization’ from the before the ice age, lost to a cataclysm, and mainstream archeology rejects my theories because of a vast conspiracy against amateur archeologists” then placing the burden of proof on “academics” to find evidence no such civilization exists.
I think respecting the cutting depth per rotation would give better clues and would make the the assumption actually comparable to "what they did" back then
An initial undersized hole was drilled using any of the methods they suggest which produce no concentric rings. Then a single point boring tool was used to machine the hole to its final dimension. The hole tapers 1 cm over its length. 0.5 cm of wear of the single point tool in use would account for the decrease in diameter.
From the perspective of a person living in the US, it is technically correct that ancient aliens were responsible for all the ancient Egyptian artifacts.
They were ancient in that they lived a long time ago and they were aliens in that they were not citizens or residents of the US.
Probably with similar techniques. If you can spin a round thing against the same spot to make a hole you can certainly use the same materials and rub them in a straight line or along a curve. Hand woodworking involves painstakingly rubbing a little material off the work and then checking it, or shaving it off or cutting it off depending on where you are in the process. And you can also strike a soft metal against the stone to chip out a rough area before finishing and polishing. Inferior tools just have to be sharpened more often is all
If you're like me and want to some actual evidence,
here's a video where they scanned and uploaded STL files from pre-dynastic Egyptian vases.
https://youtu.be/QzFMDS6dkWU?feature=shared
This video is really frustrating. It spends the first 10 mintues trying to convince the viewer that these vases are not fake, yet has no evidence other than "There is no possible way these are fakes, just look at them!". Then he actively offers up that they have not performed this analysis on any museum piece vase which has been confirmed to come from an Egyption tomb or pyramid.
...so it wasn't ancient aliens, with laser-cutting and other amazing technology? That's disappointing. I mean, if I couldn't imagine how it possibly could've been done, then it had to be the aliens, right?
You snark, but please note the "[1983]" in the title. This article's points have since been expounded on, with new evidence both archaeological and experimental.
Namely:
> The concentric lines were not always perfectly parallel.
1. What the article calls "concentric circles" are, in fact, series of spirals. That is, a cutting point ploughing through the granite, round and round.
And indeed the fine abrasive circles that this article manages to reproduce (image 7b) look nothing like the original fairly well-spaced, deep-cut grooves of the original hole (image 1a, all the way at the top).
Petrie himself documented spiral grooves that span many drill rotations, sometimes totaling over 6 metres in a single continuous groove. This is well established and not disputed because the physical evidence is so plain.
Why the OP failed to mention spiral grooves and talks about "concentric circles" instead is unclear, given they otherwise quote Petrie extensively.
> [the hole] diameter on the outside is 5.3 cm. and tapers to 4.3 cm. on the inside.
> …a tubular copper drill creates a more parallel drill hole since it cannot wear beyond the internal diameter of the drill.
2. By all accounts, the tubular drills were fairly thin. We know this because there are thin (overdrilled) circles at the bottom of discovered tube holes, up to 0.5cm in thickness of the tube wall max. There you can see the actual narrow width of the tube because the bottom wasn't sawn off as in the case of OP's particular sarcophagus.
Again well documented by Petrie and others, supported by overwhelming physical evidence, so not a point of contention.
The OP does not go into how the observed difference of 1cm compares to the wear of the (presumably thinner) "internal diameter of the drill". See for example [0] for a clearer, updated exposition.
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To be clear, none of this is of course evidence for any "aliens". But reading your snark reminded me of those internet fly-by experts who deride honest work of others because "The science is settled bro, I saw a documentary on NBC! Aliens lol these other people are cretins!"
I'd recommend turning off sound if Youtube amateur commentary irks you, but the breadth of physical evidence (photos and videos of actual stone artefacts, not theories around them) they display is astounding. Reading scientific papers (or watching NBC…) alone won't build you enough intuition and nuance for fly-by snarks. It is a complex topic, and not all amateurs are cretins. A bit of humility helps.
I agree that they're misusing the word "concentric". However, I'd be very surprised if they truly overlooked the grooves being continuous spirals, as that would be extremely meaningful. Accepting your citation of Petrie, I'm actually surprised that the grooves were spirals, as that implies a cutter which makes significant progress in a single rotation, which seems unlikely in any stone, let alone granite.
Well yes, that's my point – the process is not trivial, with surprising technical details.
For a more in-depth take on grooves – at least more in-depth relative to "concentric circles" or Lehner's "wet sand" video) check out my link above, https://antropogenez.ru/drilling/. Specifically on Petrie's testimony they offer this:
> Of course, Petrie’s Core#7 does not bear any regular helices or a thread cut in granite with a fixed jewel point with a pitch of 2.0 mm, as it has been described by him. There is only a series of grooves, the formation mechanism of which is described above in detail. Their pitch, being very irregular, is not related to the advance movement of the tool cutting edge.
Most importantly, they ran actual experiments on actual stones.
And their theory for those grooves is a sort of emergent property of the accumulated effect of corundum grains falling into the same crest/trough pattern along the tube wall while drilling downward, leading to the observed series of (irregular) cut spiral grooves.
The episode mainly explores the question of how an obelisk was raised. The team ran out of time before they were able to reach a satisfying conclusion, but they returned to Egypt in 1999 to record another NOVA episode, which includes two competing theories on how to raise an obelisk. I highly recommend both episodes.
https://www.pbs.org/wgbh/nova/lostempires/obelisk/cutting08....
https://youtu.be/qeS5lrmyD74
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