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Engineer: Egyptians built pyramids by piling rubble and attaching bricks later

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Re: Engineer: Egyptians built pyramids by piling rubble and attaching bricks later

#61

Post by asveikau »

skylan_q wrote: post #40
thearn4 wrote: post #8

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.

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?

Re: Engineer: Egyptians built pyramids by piling rubble and attaching bricks later

#62

Post by Someone »

geuis wrote: post #54
Someone wrote: post #45

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 water…

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…

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.

Re: Engineer: Egyptians built pyramids by piling rubble and attaching bricks later

#63

Post by gus_massa »

seferphier wrote: post #3
Freestyler_3 wrote: post #2

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 http://youtu.be/C1y8N0ePuF8?t=15m20s

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.

Re: Engineer: Egyptians built pyramids by piling rubble and attaching bricks later

#64

Post by bradleyland »

FrankenPC wrote: post #24
allochthon wrote: post #20

Earlier quoted context omitted.

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…

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.

Re: Engineer: Egyptians built pyramids by piling rubble and attaching bricks later

#65

Post by Geee »

geuis wrote: post #54
Someone wrote: post #45

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 water…

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…

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?'

Re: Engineer: Egyptians built pyramids by piling rubble and attaching bricks later

#66

Post by kamaal »

dhughes wrote: post #19
ye wrote: post #13

Earlier quoted context omitted.

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.

Re: Engineer: Egyptians built pyramids by piling rubble and attaching bricks later

#67

Post by FrankenPC »

bradleyland wrote: post #64
FrankenPC wrote: post #24

Earlier quoted context omitted.

(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…

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'…

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.
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