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Engineer: Egyptians built pyramids by piling rubble and attaching bricks later (mirror.co.uk)
79 points by seferphier 1374 days ago | hide | past | web | 63 comments | favorite

Not passing the sniff test for me. Three flaws at first glance…

At the end he describes lowering blocks into place by incrementally removing bladders. This does not work. As soon as you are fully submerged and displacing with bladders you are unstable. As your depth increases, pressure increases, and your displacement goes down making you sink even faster. The good news is if you get neutrally buoyant you could poke the blocks down into place and they wouldn't weight much so you could move them around then remove the bladders.

Also not covered was how the water gets to the top. Each lock load of blocks and bladders requires at minimum the same mass of water to be lowered (to fill the lower lock chamber). In practice it will be at least several times this in order to keep the blocks from jamming in the chamber. So each ton of block effortlessly floated to the top will take several to many tons of water laboriously hauled to the top. Hauling water is probably lower friction than stone, compared to the volume multiplier, I can't say who wins.

The inner lower lock door is also a problem. It has to contain water at something like 10 atmospheres and be loose enough to move. Plus, if shaped like the video, it needs to weigh 150lbs/in^2 to keep from being blown out when raised. That makes it about 120 feet tall if made from limestone.

What if the channel was vertical an placed at the center of the pyramid?

     /| |\
    / | | \
   /  | |  \
  /===/ \   \
blocks surface at the center of the floor while it's being built.

The entering tunnel is gently sloped but doesn't have to reach the top of the pyramid.

I guess it would be easier to build since the the walls of the channels are kept in place by the weight of the whole structure.

I don't know about the bladders though.

Your sniff test doesn't matter. There was a recent episode of 99% Invisible talking about an architect in NYC who proposed building a skyscraper out of a steel internal skeleton but all the best engineers of the day scoffed at him. He built it, it still stands, and it changed out skyscrapers have been built since.

Point is, I'm skeptical too but the fellow has made some more videos that go into more detail. They even directly answer some of your questions.

Don't immediately write something off without doing some due diligence first. The more I'm learning about this, the more practical it seems.

He explains it better in the second part, including how they got the water to the top, water pressure, water proofing ect. http://youtu.be/C1y8N0ePuF8 and of course in the actual book

Interesting idea, and maybe one worth investigating further. I've always liked the internal ramp theory: https://www.youtube.com/watch?v=Ws4O5LOCI68

In the end, lets all at least agree that it was human innovation and not alien technology that built the pyramids.

1. People, in general, are smarter than the ancients and civilization has progressed since then.

2. We don't know how they built the pyramids.

Either aliens built the pyramids, or we're dumber than the ancients.

Hmm, Poe's law? I'll bite.

When it comes to engineering, domain knowledge is often far more important than any kind of inherent "smartness," and ancient Egyptians had thousands of years of block-stacking domain knowledge that we don't. While modern society has billions of tricks up our sleeve that would completely befuddle ancient Egyptians, I'm sure they had a handful of tricks that would catch us by surprise. Knowledge isn't strictly ordered.

Also, just because we aren't sure precisely which strategy they used doesn't mean that we didn't think of it, it just means that we can't find evidence to overwhelmingly support a single one of our hypotheses.

Umm, modern humans are perfectly capable of building pyramids or even much more complicated structures. You may have noticed that 21st century civil engineering is much more advanced than ancient Egyptian civil engineering. However, what we don't have is the level of experience with their tools that they had.

There are more smart people today than x years ago != The smartest people today are smarter than the smartest of x years ago.

I spent a bit of time over the past few years really old text (some 2000 years+). Nothing in those writings suggest we are smarter than those people.

I don't know how it would be surprising that we could be dumber than the ancients at something. How about the dark ages? A good chunk of Europe lost touch with the accomplishments of the Roman empire. It took a long time to recover and it would not surprise me if some good ideas were never picked up again.

Or even take today's technology. We are in many ways coasting on the accomplishments of prior generations and very likely some of these would be difficult to recreate from scratch. I recall some rhetorical question: say we wanted to do it tomorrow, how much would it cost us in R&D to once again figure out how to get to the moon? Or, since most of us know tech, I can put it this way: how many folks on HN talking about js or ruby know how to write a kernel, or design a CPU, from scratch?

We don't know what the architects of the pyramids discussed in the pub either, but that is not because we are worse at conversation.

> 1. People, in general, are smarter than the ancients and civilization has progressed since then.

All it really takes is one genius with influence in the right ears to achieve something remarkable.

I am not convinced that the Egyptians could build watertight channels at this scale, especially those shown climbing up the slope of the pyramid which would have to be watertight at the top too, and under great pressure. Also one or two packages could easily get stuck in the "pipe" jamming the whole thing. Finally, the video likely downplays the number of floaters necessary to lift a block of stone.

Yes. I thought the same exact thing. Also, I was wondering exactly how the water was magically moved around a the top of the pyramid? I can see evacuating sections, but then you would have to wait for the next rains to refill them. That would take an incredibly long time. Imagine how much work would be required to bring more water to the top of that pyramid to refill the sections AND the leaking flotation columns. Heck, imagine the PSI of water at the bottom of the pyramid columns when they were reaching a hundred feet high?

>That would take an incredibly long time.

Note that Egypt was a lot wetter when the pyramids were built (circa 2500 BCE). http://www.pbs.org/wgbh/nova/next/ancient/climate-change-may...

>Heck, imagine the PSI of water at the bottom of the pyramid columns when they were reaching a hundred feet high?

A column of water 100 feet high exerts 43 psi at its base.

OK. So, the great pyramids were nearly 500ft tall. At the top, the pressure below would have been around 200psi. Even the most stalwart modern plumbing fixtures have trouble past 72psi. 100psi is the upper limit before things start to fail. I don't think that there would be a mechanical problem with stone holding back that pressure, it's the leakage that would be the killer.

Modern plumbing stuff is designed to be economical. (Which just limits the usefulness of extrapolating from there)

If the mechanics of using the stonework to hold the water were well worked out I would think clay would work well to seal small cracks (and for the scale we are talking about, the 'plumber' could just crawl on in). Or pitch or other sticky stuff.

The theory mentions multiple shafts, not a single contiguous one.

How feasible is it to even float massive stone blocks by attaching animal skin balloons to them as is done in the video? I would have figured that you would need many more than are shown. Also, how would you protect the balloons from pushing out of their restraints as they rub against the upper diagonal wall of the near-vertical channels?

(I have no idea what I'm doing...) how much does 1 cu-foot of water weigh compared to 1 cu-foot of limestone? water is about 63Lbs / cu-foot. limestone is 163 Lb / cu-foot. So, 1cuf stone in water is 163-63=100Lb (it's already partially buoyant because it's IN water). Then you need to evacuate water using air bags that are ABOUT 1.5 times the blocks size. So, the whole payload would be 1 unit block with 1.5 units of air. or 2.5 units total. Much bigger than the video suggested. But not unreasonable.

It's much easier if you work in metric units (as usual).

The density of water is 1,000 kg/m³.

The density limestone is around 2,500 kg/m³ (it can actually go down to around 2,100 kb/m³).

This means that you'd need to displace more than 2 to 2.5 times the volume of water in order to float a limestone block. Keep in mind that volume goes up (roughly) as a cube of the increase in linear dimension, so the difference won't be quite as dramatic as it first seems, but that's still a lot of flotation required. Certainly much larger than the floats shown in the video.

The animal-skin bladder theory is particularly problematic, because the volumetric efficiency of spheroid animal-skin bladder floats isn't particularly good. Water would fill in the space between bladders, requiring much larger float assemblies than if they were able to construct larger, single-chamber bladders. The video depicts float assemblies that aren't even as large as the blocks they were transporting. I found that rather disappointing for an engineering-driven theory.

Yeah. So, the "hats" of bladders on the block can't be too high because the depth of water would be impossible to maintain. Therefore, they would have to be wide. That would limit the number of floating blocks you could have at any given time. It would also present a problem with the gravity conveyor to the top of the pyramid.

As it certainly doesn't need to be proven further, Egyptians were quite an ingenious people. All of the things you're suggesting as obstacles would probably be trivial to deal with for them at their advancement level. A commenter (seferphier) posted this link that may provide a glimpse into additional possible cues, I suggest to have a look http://www.youtube.com/watch?v=C1y8N0ePuF8&feature=youtu.be&.... I particularly liked the part where it is suggested that it would be relatively easy for them to move 600 litres of water in a single minute. With virtually unlimited water and such a capacity to move it, I think the theory might be plausible and merits further investigation.

Density of limestone is about 2.5, so the volume of floats would be about 2.5 times the blocks.

I'm tired but isn't that just 1.5 times?

Tied together, a 1m³ block of limestone and a volume of 1.5m³ of floats displace 2.5m³ of water. Assuming the mass of the floats themselves isn't much then already that would lift 2.5 tons off from the bottom of the water pool.

Yeah, I got it wrong.

Shouldn't that be 1.5X instead? Unless you are factoring in that limestone's permeable.

Are you taking into account the surrounding water (density=1) in your calculations?

For the sake of the argument, let's accept "The structural engineer reckons that would be impossible as the ramps would have had to have been at least a quarter of a mile long" and ""If that happened, there would still be signs that the ramps had been there, and there aren't any."

This idea replaces that quarter mile ramp by a waterway with a difference in water level of 150+ meter and thus with 150+ meter high watertight walls that can withstand the pressure. Where are the signs that that waterway was there?

Also, how do you get the water up in that lock? Ships can move up through locks, but water only flows down.

There's a second video that addresses this that's linked elsewhere in the comments. Basically he outlines some evidence for a high pressure natural spring underneath the pyramid, and that some of the branches off the main burial chambers that have never been adequately explained were used to fascilitate water movement. For the last few levels, he proposes a regular old bucket line. Over all, not implausible. In some ways, more so than the standard heave-ho theory.

A natural spring in the desert that fountains water up 100+ meters, and they decide to put a huge pyramid-shaped stop on it, presumably to get rid of the luscious oasis that must have been there? And that fountain somehow, in thousands of years, didn't find a new way out through the limestone, which is water soluble?

I think it is more likely to claim there was an oil well there.

Edit: it wasn't a desert at the time they built the pyramids, but blocking a natural spring never was a good idea over there.

The spring theory is really the only theory that answers the 'why' part of the equation. I mean, in the presence of a high pressure spring, it would be natural for people to kind of just stumble upon a building technique like this. People would first make a pool by laying rocks to form walls, then they will start making the walls higher, then realize that they can use buoyancy to lift heavier rocks. Then engineer comes along and realizes that they can make a huge building, and thinks: 'why not?'

buckets + donkeys

Why not test this theory with a smaller pyramid replica. I think that a lot of people would volunteer to spend a couple of weeks of their summer working on a project like this.

Good theorie, but now i wonder how they got the water up. There must be evidence of pump or large amounts of buckets :D

I was wondering too. This video explains in more detail how they used pressure to move the water up


The video says that they toke the water from springs under the pyramid. If the spring has enough pressure to make the water climb to 150 m, then just opening a vertical hole you must get a 150 m water jet. (Really, the water in the jet moves faster, so it has more internal frictions with the spring wall.) In Yellowstone, Old Faithfull has 50 m water jets, but it’s a geyser, not a cold spring with a lot of water.

Archeologists would be able to find evidence of these water piping from springs underneath the pyramid.

I agree, they say that they should have found evidence of ramps... well they should have found evidence of this water structure if it was used.

They had thousands of slaves.

Were they slaves? I've often seen reference that they were citizens working on the pyramid as payment of taxes in the form of manual labour, add to that your boss and the building were being built for, who to them was, a God.

I'd say whatever the most simple explanation is the answer I could see either rubble or ramps.

They were slaves. Calling them something else doesn't make them less exploited.

The pyramids were actually not built by slaves. There's quite a bit of evidence that would suggest this.

Wouldn't the water ramp have immense pressure at the bottom?

Not that much, 150m of water means about 15 atm of pressure.

Did the Egyptian know about water weels at that time?

My favorite theory is that the blocks where cast in place.

The part where they float the blocks up the side seems dubious to me.

Interesting idea.

Romans used water for mining too.

Why do effort when nature does it for you?

Two problems people raise:

Water pressure from 150m+ water column is too much. In the video they talk about dividing the hight slope channel into sections This way leaks will be also smaller.

Putting water inside. This probably is the weaker point of all.

But overall it makes sense. It will be great for a kickstarter to try to replicate it at a small scale.

OK. How about if they also built a large water tower on top of the pyramid? The seasonal rains would be trapped in the basin(s) and used to refill channels and replace water lost due to leakage?

Questionable source imo.

Check out the video first. It is a fascinating theory

Other sources: http://www.dailymail.co.uk/sciencetech/article-2526467/Were-...

Well, the Mail's a cheap tabloid too...

I'm no Egyptologist, but I think I'm right in saying that this guy is arguing against something (the whole long-ramp thing) that's been at least thought unlikely, if not wholly disproven, for some decades now.

neither the mirror, nor the dailymail are particularly reliable sources.

Why would an archaeologist be more qualified to guess how they built the pyramids than an engineer who studied the pyramids for years?

Or are you saying we should just dismiss all of the content because you don't like the organization that published it?

I question your belief that you can evaluate information based on the organization that provides it. Or at least that some popular or well-respected organization can be trusted to provide good information. In fact, oftentimes the most widely trusted organizations have the most invested in maintaining the status quo, which makes facts subservient to that core need to sustain the venerable order of things.

Do you treat all P=NP proofs as of equal worth and spend time carefully checking them to see if they might be accurate? Or do you apply some filtering first - reputable journal etc?

Discounting stories in the Mirror and Mail is a totally reasonable tactic.

UK papers do not have fact checkers like US publications. UK papers very carefully report what someone says, even if most people agree that person is a wingnut and talking nonsense.

Looking at the UK tabloid newspapers we see some deeply nasty methods where blatant lies are told and nonsense peddled.

If the Daily Mail told me that grass is green I'd have to go out and check.

Sure tabloids are an extreme case and they do often print lies and garbage. Still, since you bring scientific journals into it, the scientific publication system has been shown to stifle new scientific theories that correct old ones in favor of maintaining the status quo or most popular theories of the time. So journal reputation can also be a negative qualifier.

Centralized, authority-driven worldviews are very destructive and outdated.

i love this - even if it turns out to be not fully correct in the end. one thing i was wondering was if any evidence had been found about about the balloon floatation devices, and, along similar lines, if they modeled the idea that small barges atop the blocks might have worked instead of balloons.

fwiw : someone else posted this more detailed youtube video ..which has a good discussion of the rationale of the floats -- wood vs animal skin and papyrus.


This entire website looks like a cheap tabloid.

That would be because the mirror is a cheap tabloid.

looks like a classic case of Egyptian sand in the va....

What if a pre-human civilization made them and the egyptians just found them?

What, like some really smart Gomphotheres in the Pliocene maybe?

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