Slashdot Mirror
Pyramid Stones Were Poured, Not Quarried
brian0918 writes "Times Online is reporting that French and American researchers have discovered that the stones on the higher levels of the great pyramids of Egypt were built with concrete. From the article: 'Until recently it was hard for geologists to distinguish between natural limestone and the kind that would have been made by reconstituting liquefied lime.' They found 'traces of a rapid chemical reaction which did not allow natural crystallization. The reaction would be inexplicable if the stones were quarried, but perfectly comprehensible if one accepts that they were cast like concrete.'"
My dad always used to tell me that when Alexandria was burned, all the publications holding the Roman recipe for concrete went with it. That, he claimed, was why all concrete poured was inferior to the Roman Aqueducts. And why it wasn't until 1948 that the right combination of limestone & other minerals was discovered to be able to resist water and hold that high a level of precision. Cement/concrete are by nature porous surfaces and so often sap water which causes structural problems. The fact that the some of the aqueducts still hold their accuracy within inches of their architectural specifications after 2000 years is nothing to overlook.
If Egyptians (for thousands of years prior to the Romans) had experimented with or refined this process and if an Aristotelean (such as Demetrius of Phaleron) had moved this information to Alexandria, that would explain how the structures like the aqueducts were constructed with such high quality mixtures.
I have one tiny problem with the summary as the article states: While summary uses the word cast: I would like to point out that this is known as forming concrete and not casting concrete. The difference is like the difference between pouring concrete for a foundation of a house and laying brick. Laying brick is casting while pouring concrete (like the article alludes to) is called 'forming.'
This might sound like a small matter but laying brick & forming concrete walls are two entirely different professions.
In all honesty, if you were to ask me to construct a pyramid today--knowing what I know, I would build the core of the pyramid out of laid brick. And then I would, starting from the bottom, form up the angled sides and fill in those areas. If you're wondering why I would take this route, try it with paper. Cut out blocks of paper from a notebook without making marks and try to make a perfect angled edge between them. Pretty difficult. Now try it in three dimensions with 2000 year old tools.
It makes sense that they would have both technologies (like the article states), one quarried for huge bricks and the other formed up ash, salt & lime. It would also explain a lot of technologies the Romans had.
My work here is dung.
because in science, a hypothesis is interesting, but prooving a hypothesis is important. What you heard was the hypothesis. This right now is the information that major strides have been made towards actually prooving it.
34486853790
Connection too slow for X forwarding? Try "ssh -CX user@host"
Go look at a concrete highway sometime, and check whether the concrete is continuous (like asphalt*) or whether it has regular seams. There's a reason for the seams: namely, that concrete expands and contracts with temperature. If we poured roads as once continuous chunk they'd expand in the heat and buckle, or contract in the cold and crack. The seams are there to relieve the temperature-induced strain.
Now, consider the fact that the Egyptions lived in the middle of the desert. One particular feature of such a climate is that there are wide extremes of temperature: it gets really hot during the day, and really cold at night. Once you realize that the Egyptions probably had prior experience with the materials before trying to build the biggest structure in the world out of them, you might expect that they'd realize the same thing current civil engineers do, and put in releases to prevent cracking. In 3D, this would mean pouring the concrete in blocks.
(*note: asphalt can be laid in continuous strips because it's much less brittle than concrete, at least at normal service temperatures.)
"[Regarding the 'cloud,'] ownership was what made America different than Russia." -- Woz
As a student at Drexel, I have had the privilege of hearing about this research firsthand - it is more than convincing. There is no doubt in my mind that he is 100% correct. For those of you in doubt - he is not claiming that all stones were "cast" or "molded" into places. Only the ones at the top and on the outside of most of the "newer" pyramids. The older pyramids do not use this technology. It is believed the egyptians discovered this technology as they were building and their pyramids became more sofisticated as a result. You can just look at the pictures:
r /BentPyramid/EgyptianPoliceman.jpg
r /AllPyramids/StaircaseInsideRedPyramid.jpg
i d.html?ref=science
The Bent Pyramid (an older pyramid), its obvious blocks put into place from a quarry up until where it bends.
http://www.richard-seaman.com/Travel/Egypt/Dahshu
Now, look inside the Red Pyramid (a newer pyramid), tell me they carved 26 million bricks with such perfect precision. They carved Limestone, using copper tools (ahem, softer than limestone), so perfectly together that you can't even fit a playing card between them? I don't think so.
http://www.richard-seaman.com/Travel/Egypt/Dahshu
This article can also be found on the New York Times http://www.nytimes.com/2006/12/01/science/01pyram
The limestones they are talking about used to cover the pyramid to give it flat sides, and the only remains left at Giza can be seen at the very top of the middle pyramid in this photo. (FWIW, this is the pyramid of Khafre (Chepren) - next the the Great Pyramid of Khufu (Cheops), which has had all of its limestone block cladding removed.)
The third large pyramid at Giza (Menkare/Mycerinus, foreground in the group photo) was intended to be covered in granite cladding. ed
Also, the bronze technology of the time was more advanced than anything known to Victorian civilization - Burton writes about the bronze chisel (found inside a pyramid or temple, I forget) that was harder than wrought iron when he's discussing the switch from bronze weapons to iron weapons in The Book of the Sword.
We know that the ancient Egyptians had bronze tools hard enough to work limestone. We have at least one example.
First off, your use of the work mould means you are either British or know nothing about concrete. The walls used to hold the uncured concrete are called forms.
Making adjacent blocks with tight cracks is blindingly easy.
First, pour one block. Start with a corner one. This takes (4) side forms.
Second, strip the forms. Clean them.
Third, set three forms, using the hardened block as the 4th wall. Pour this one.
Repeat steps 2 and 3 ad nauseam.
You could pour every other block, and come back and pour the ones in between.
They even had the technology to make all of the blocks line up straight - string. We use the same technology today.
Besides, making a sort of concrete from powdered stone and lime just to pour it at the bottom seems like a real bad idea - why not just carry the mud and forms to the top and save the effort of moving and aligning the final bricks?
I think I need a new sig here.