How many people did it take to build the Great Pyramid?
spectrum.ieee.org
spectrum.ieee.org
1. It's easy to underestimate what is possible when you limit thinking to a short timescale. I think of the cathedrals, temples, mosques, etc. that have been built all over the world, where the people who started the work knew they wouldn't live to see it finished, but that didn't dissuade them.
Or conversely, it's easy to overestimate the difficulty of something if you are too constrained by thinking in terms of finishing it relatively quickly.
2. Building things does make it easier to build things - and conversely, not building things makes it harder. There is a lot of architectural stuff in our world today, particularly fine masonry and woodwork, that is still common because so much of it was made up through the 1930's or so, but which is actually quite difficult to produce today because most of the skilled labor and the industry that supported it is gone.
This also reminded me of an article about scientific glasswork, which is similarly dying out[1], and of course more familiar to the HN crowd we know about old technology that was once common and now is difficult to replicate or maintain.
Lots to think about.
1: https://www.latimes.com/local/education/la-me-caltech-glassb...
That's mind-boggling. Why would building a cathedral/mosque/temple take longer than a lifetime (or half)?
There's also likely an element of not really wanting it to be done since the construction itself is a big part of the draw of the building for tourism.
When you see it, the timeline starts to make sense.
Even pre-industrial London could crank out enough churches in a dozen years to keep a celebrated architect booked solid. But that’s an exceedingly dense urban era, capable of supporting a large array of skilled labor.
Furthermore cathedrals were often build iteratively - e.g. someone finances a new tower to add to an existing centuries old building.
Our society has managed to write down some things like math for example so our knowledge as species won't be lost if mathematicians suddenly died. But it's harder to find permanent storage for the more skills based human activities like the woodworking you mention.
To give another example, the Saturn V rockets were built by a generation of metalworkers who had honed their skills in the manufacturing plants of world war 2. The plans for the rocket engines are still preserved but back then a plan was just a rough guideline. In the details, each single engine was hand-tailored to the individual rocket. Nowadays, stuff is far more automated and plans are highly precise. Thus Nasa couldn't just get the plans out of the cabinet and build new Saturn V rockets or even just put their engines into new rockets.
I wonder if we are better in preserving our heritage than we used to be. Which information about the manufacturing process of one of today's cars will be usable in 100 years? Will they be able to build computer chips like we did?
But even so, I think it's clear that with more broad documentation, we are in a better position to pick up the expertise of the past.
So in the future, all the wonderful, nutty youtubers that keep alive old arts and give demos would be especially invaluable. Not just in clarifying specific techniques and knowledge, but by demonstrating a general approach to problems that existed at the current time.
I've been watching all sorts of things the past couple of months like this: People making vacuum tubes, repairing vacuum tube equipment, older mainframe technologies like ancient versions of MVS, machining parts on equipment from the '30's.
None of it is how-things-are-done in a cutting edge factory or step by step directions on how to reproduce an important cultural artifact, but from the perspective of future people, it will be a valuable aid to gathering that context.
One I'm particularly reminded of is Clickspring on youtube who is building an antikythera mechanism. Even though we have the partial artifact, so little is known concerning metal working technologies of the time that it seems to be an anachronism completely alien to its time of origin.
His approach is to explore what technologies would make sense to a working craftsman of any era (which also could be surmised to have existed in the era). It's interesting to watch and it has apparently born fruit in terms discovering academically important information about the device.
Archive the channels you care about - they might otherwise be impossible to find in a few decades, or a few years. Youtube-dl is one of my favorite pieces of software.
Digital artefacts could be, paradoxically, less durable going in the future - if you write and publish a physical book, it might get forgotten in a library somewhere and rediscovered 200 years after you die.
If you publish an ebook on your website and die and no one cares, the probability of anyone discovering it by happenstance 200 years later goes down to 0.
Certainly, we can and should individually archive what's important to us, but more generally (archiving information for the next 1000 years say), I dunno. I hope someone will figure it out.
This seems overly pessimistic given the existence of archive.org (they accept donations!).
If archival institutions keep existing and improving their search and accessibility, it seems very possible that random websites will be accessible for a long time to come; 200 years is definitely within the realm of feasibility.
Hardcovers from the 19th century are pretty common. Tons of low-value ones (textbooks, fiction by at-the-time very popular authors who've been forgotten) floating around at a couple dollars a piece in flea markets here in the US, and I bet even older books are somewhat common in Europe. Lots by famous authors but of course those are usually more expensive. Most of those weren't finely-printed on modern archival paper or anything like that, and haven't been kept in archival conditions, but often have a few years of hard-reading life left in them (and much more well-shelved), so 150-200 years is a fairly easy age to achieve for gently-read hardbacks using cheap (but not the very cheapest) materials. Maybe more if you re-bind them once or twice, or they're very rarely read.
That's without even getting into really nice material and binding, or very expensive non-paper for the pages if you're very serious about keeping a book in good shape for centuries. Not even tape comes close—we don't have a really good archival format for digital stuff yet, let alone one that normal people may have a bunch of in their houses (like books). Maybe one of the several long-lived storage formats under development will take off one of these days and our digital storage will get a bit less risky. Right now it's pretty bad, only saved by being extremely cheap compared to other options.
Skills like hand fabrication and fitting aren't something that you can store. You can record videos or interview skilled tradesmen as much as you want, but the real skill is something that is learned through experience, it's muscle memory and intuition, not theoretical knowledge.
It was quite natural to think of enhancing the successful Ariane 4 design instead of building Ariane 5. From the conversations I remember from that time this was not considered a viable path - mostly because the supply chain of the Ariane 4 parts had already gone dry and it was not considered realistic to rebuild them.
For me as a young engineer this was very surprising, but a few years later I understood two things much better:
1. The knowledge to build projects of this scale is very distributed. There were subcontractors over subcontractors (spread over several countries) and every one had some tacit knowledge viable for the project.
2. Setup cost for parts production is relevant, even for the small series productions common in aerospace.
[EDIT:] maybe this: https://mathoverflow.net/questions/43690/whats-a-mathematici...
Losing knowledge like this was much easier in earlier eras when fewer people were literate. Trade knowledge would be passed down via apprenticeships and rarely written down. So it only takes one generation of the apprenticeship system breaking down for the knowledge to be lost entirely.
(Also, for anybody unfamiliar with r/AskHistorians, it's one of the best corners of the internet! Professional historians provide in-depth answers to random questions about history.)
[0] https://old.reddit.com/r/AskHistorians/comments/gntlr8/how_d...
The thing is, there are many aspects to doing things which can’t be written down. So even today, the one generation concept is meaningful. There is a deep “use it or lose it” spirit in biological systems. We might think of ourselves in primarily literate/rational terms, but that’s far from the truth.
"Sorry, we lost all knowledge of how to build those during the great content-id wars of 2029."
I wonder whether that's not really more the exception rather than the rule - some famous cathedrals just took a long time. But lots of huge projects were completed in one or two decades or less - the pyramids, the Coliseum, the Taj Mahal, the Pantheon, Hagia Sophia, etc.
I've always wanted to find a community that collaborates to determine as much as possible the rough range of the total cost, either in man hours, dollar amount or other metrics, of things we see, know, and interact with every day. I think it is even more interesting if you try to estimate the cost of the research the thing depends on (which greatly scales up the complexity but also the fun of the exercise).
For instance, what is the manhour cost of google.com historically? You can approach it in so many different ways - revenue analysis, # of employees in google search team over the years, or just guess at how much you would need to build google.com yourself today.
Subreddit suggestions for different styles of this kind of activity:
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/r/resetPrice
Imagine that the infrastructure of the world has reset to the stone ages but we still retain all modern knowledge. What's the price, in man hours, of rebuilding things that we use every day and take for granted?
What is the reset price of google.com?
What is the reset price of Seattle?
What is the reset price of a mechanical pencil?
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/r/CTMH
Cost in Total Man Hours
What's the CTMH of the NY philharmonic orchestra playing for one evening?
What's the CTMH of developing the entire iPhone phone line series, from original to current model?
Also similar - /r/ETEB - Estimated total effort to build
Also there doesn't seem to be any consideration of logistics time. Were the 900 men always perfectly positioned to apply their energy to the project? Did they not spend time and energy moving around the building site? Did they ever make a mistake and have to redo a section?
This is a good starting estimate. As anyone who's ever worked on any project knows, the estimate is going to be way too optimistic.
Also: I've been to Giza. It's hot and dry as all hell. Humans are going to be far from perfect labor machines in that climate.
The climate 4500 years ago was very different in this area, and the world in general. For Egypt and the middle east it was generally a little cooler, but much wetter.
When we are looking back into history, even only a couple of hundred years it is important to remember that the climate, and geography was different. Climate shifts, rivers and coastlines move etc.
The conclusion is that it took 900 men 20 years to lift one 2.6t cubic meter of stone to a specific height again and again. Does anyone considers this to be realistic for any construction project?
Like estimating the Mona Lisa took 5s to paint based on the surface of 0.4 square meters. Or the Sistine Chapel ceiling took a couple of days and a really big brush.
The fact that someone with such a CV [0] came up with this for the IEEE page as anything more than an exercise of imagination is very surprising for me.
900 to lift the stones 900 to place and finish them (horizontal movement?) 1500 to cut the stone 3300 design/support (logistics?)
The details are below the fold.
Has the author ever done physical labor?
His calculations just say it probably couldn't have taken less. But more? Just add a few more of those variables that he completely overlooked and the effort easily increases by one order of magnitude. The worst project managers I've met made better assumptions that this author.
You make bad assumptions you get bad conclusions. And saying them "with certainty" just makes one sound even more ignorant. Imagine what his calculations would say about La Sagrada Familia. Certainly not 150 years.
"All archaeologists have their own methods of calculating the number of workers employed at Giza, but most agree that the Great Pyramid was built by approximately 4,000 primary labourers (quarry workers, hauliers and masons). They would have been supported by 16-20,000 secondary workers (ramp builders, tool-makers, mortar mixers and those providing back-up services such as supplying food, clothing and fuel). This gives a total of 20-25,000, labouring for 20 years or more."
[1] http://www.bbc.co.uk/history/ancient/egyptians/pyramid_build...
While the analysis is interesting, I think the 300 working days a year is too long. Likely, work on these types of public projects was mostly done during the flood season, which was around 4 months (120 days [0]) so maybe 100 work days at best, so the calculations for required workers should probably be multiplied by 3.
Weekends didn't exist until the Industrial Revolution, which was ~4300 years after the pyramids were finished.
Archaeologists are accustomed to this "pyramidomania" that almost always forgets to examine the facts before building up theories.
Suppose they took 600 years, instead; then it's one per hour.
Which is harder to imagine, cutting, moving, lifting and placing 30 blocks in every waking hour for 20 years, or placing one per waking hour, non-stop, for 600 years? Each seems less possible than the other.
I don't know of any firm evidence for when any of the pyramids were built. We can guess that the bent and red pyramids were built first, but they could just as easily be poor copies attempted a thousand years later, or ten.
There is a fluorescence technique to discover when a cut limestone face that has been covered for centuries was last exposed to sunlight, but I don't know of it being used on any Great Pyramid block. One would not expect Egyptologists to advocate for such a test, because only two outcomes are possible: they were far enough off to be embarrassed; or not, and it was useless. (Either way, better not.)
They built these things with perfectly straight, slanting tunnels a few inches wide running from inner chambers almost to the surface, for no known reason. Some people say they point at certain mythologically important stars on equinoctal days, but I have not been able to get confirmation of that.
One thing well established is that none of them were tombs. When somebody finally battered their way into each, maybe 4300+ years later, all the chambers were empty and unmarked. (Except one has an empty stone box in it big enough to be a coffin or bathtub.)
There are lots of examples of 20-, 30-, 60-ton basalt boxes cut from living rock with perfect right-angled inside corners, and moved through funerary complex tunnels barely big enough. Take off the (10-ton) lid and they're empty. It's anybody's guess what they were for.
But to imagine, make plans, adhere to them is hard.
It includes a date from the Mykerinus (Menkaure) pyramid, the smallest on the Giza plateau, and presumed youngest, of 3450±950 BC, or 4400-2500 BC, compared to current estimates of 2613-2494 BC. A sample from the Valley Temple, presumed contemporaneous with the Great Pyramid, says 3060±470 BC, or 3530-2590 BC, with the same estimated age. One could interpret the measurements as corroborating the estimates, but only by squinting.
It just seems notable that more work hasn't been done on, e.g., the Great Pyramid itself.
Wikipedia says: https://en.wikipedia.org/wiki/Great_Pyramid_of_Giza#Casing_s...
> Casing stones
> At completion, the Great Pyramid was surfaced with white "casing stones"—slant-faced, but flat-topped, blocks of highly polished white limestone.... Visibly, all that remains is the underlying stepped core structure seen today.[citation needed] In 1303 AD, a massive earthquake loosened many of the outer casing stones, which in 1356 were carted away by Bahri Sultan An-Nasir Nasir-ad-Din al-Hasan to build mosques and fortresses in nearby Cairo.[citation needed] Many more casing stones were removed from the great pyramids by Muhammad Ali Pasha in the early 19th century to build the upper portion of his Alabaster Mosque in Cairo, not far from Giza.[citation needed] ...
When someone claims that "by appealing to simple physics" they can say "with confidence" how many people were involved in a construction from almost 5000 years ago I have to doubt anything that follows is more than pure speculation.
The problem is too complex for simple physics to provide any relevant answer. The same simple physics would have us believe 14000 strong men could throw a tiny 1Kg object straight into orbit.
Don't think that was the case
If you're only counting energy needed to raise stones, then you're costing at zero a piece of stone, cut and transported to ground level near the pyramid. But that is hard work.
In "Lost Technologies of the Great Pyramid" (2010) and "The Great Pyramid Prosperity Machine: Why the Great Pyramid was Built!" (2011), Steven Myers contends that the people who built the pyramids were master hydrologists who built a series of locks from the Nile all the way up the sides of the pyramids and pumped water up to a pool of water on the topmost level; where they used buoyancy and mechanical leverage by way of a floating barge crane in order to place blocks. This would explain how and why the pyramids are water tight, why explosive residue has been found in specific chambers, and why boats have been found buried at the bases of the pyramids.
https://www.amazon.com/dp/B0045Y26CC/
There are videos: http://www.thepump.org/video-series-2
https://www.youtube.com/playlist?list=PLt_DvKGJ_QLYvJ3IdVKXU...
I'm not aware of other explanations for how friction could have been overcome in setting the blocks such that they are watertight (in the later Egyptian pyramids).
AFAIU, the pyramids of South America appear to be of different - possibly older - construction methods.
Certainly, water played a role: much of the stone was shipped from quarries some distance away.
It's also imaginable that they used canals to bring the blocks further inland, closer to the pyramid construction site.
However, the near-vertical water tower and lock system would be a challenge to build today, let alone with the technology of the era. The pyramids were built before the widespread use of the wheel, and with soft copper tools, not bronze. They predate the invention of nails, as in the type used to join wood. For example, the planks of Khufu's ship were bound together with knotted ropes and its sails were moved without the aid of block and tackle, as this would have required wheels and axles! It's a sight to behold...
The ship was incredible, to my eyes at least. My partner wasn't interested, but she never studied engineering! To my eyes it looked almost modern, yet absolutely bizarre to the point of being nearly alien, but only in the details. The joinery. The rope work. Things like that.
I liken it to seeing a jumbo jet fly over for the first time. It's huge and impressive, like the pyramids. But to me, seeing an airport was the real wonder. All those planes with the engine nacelle covers open, showing the intricate tubing and turbine housings. The bizarre low trucks and specialised equipment that's used nowhere else. The fuel pump trucks that suck up jet fuel from underground pipes. The strange land of endless concrete. People waving glowing sticks. And so on and so forth. It's an entire "world" that's different from the normal world outside. You get to see the inner workings of the technology up close, not just a superficial end product from a distance. That's what it felt like to see Khufu's ship for me. I felt like I had stepped into the era of the Pharaohs.
I'd like to visit the Pyramids, but I'm more interested in the insides. Khufu's ship sounds fascinating, will definitely take a look if we go.
https://www.geopolymer.org/archaeology/pyramids/are-pyramids...
The current theories are joke, this numbers don’t add up. Don’t be afraid to challenge the “academic” theories, as you see, there is no math behind them.
Combining your results with the scientists' we can only conclude that the Ancient Egyptians had some technology available to them that has been lost to time. Even modern cranes can't do that. Therefore the only other option is aliens!
Some inner chambers seems to point at the Osiris star cluster.
Kidding..
I wonder if an ancient engineer discovered a more useful purpose for the pyramids. Like channeling salt water into the chambers, to create a battery somehow, in order to create an electric field, which was used to power some kind of light bulb at the top. So the pyramid ended up becoming some type of light tower, to illuminate the darkness. This indeed, would be fascinating stone aged technology, that can last for a few millennia.
Note, we can’t find the light bulb at the top, to support this fictional theory, because it got looted at some point in history. Maybe it was a precious diamond or something. LOL..
For one easy reason, you don't just build one from scratch without a lot of experience. A lot of artifacts of that period are -way- too impressive for the same reason. Where's the evidence for prior art of that calibre?
And when will the chemistry of the blocks be analyzed? Were they cut (how) or manufactured (how)? I haven't seen the book delineating these studies; if it doesn't exist, how long should the present fairy tales?
You seem to be implying some kind of "aliens did it" conspiracy theory but there is ample evidence that empires lasting thousands of years are easily able to build such structures. There's nothing all that complicated about it and we don't need aliens to explain it.
It did take decades of years for pyramid-building to improve (possibly longer), but the date of the Great Pyramids is known with pretty high confidence and aligns with particular dynasties and rulers.
The big ambiguity is around the actual techniques that were used to transport the material and build the pyramids, not around the timeline.
There's also about a century of prior art demonstrating the evolution of pyramid construction from Djoser through Khufu.
It's fine to question popsci narratives, but it seems a bit premature to call them fairy tales before you've looked at the relevant wiki page.
Snefru, who was the Pharoah before Khufu (which is the one that build the Great Pyramid) provides a nice example of failure and progression.
He first started with the Meidum Pyramid. This pyramid collapsed during construction.
The he did the Bent Pyramid. This is like it's name in that the angle changes as you go up the pyramid.
Finally, he did the Red Pyramid which looks like what we think of when we think of a pyramid.
So yes, even right before the Great Pyramid, you can see evidence of a learning process.
This article, https://en.wikipedia.org/wiki/Sneferu#Building_projects provides a nice summary with pictures.
The closer you look at the evidence, that far back, the more slippery it gets. Tour groups want a nice, simple story, and the pros are happy to provide one, but the support is very limited, subject to interpretation, opinion, out-and-out guessing, and fraud.