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.'"

Comments

Casting Vs Forming

[eldavojohn]

I've poured a lot of concrete with my dad over the years. So I will share with you some of the useless knowledge I acquired before college. He has only a high school degree so it's not like he was a scholar on this material.

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:

The Ancient Egyptians built their great Pyramids by pouring concrete into blocks high on the site rather than hauling up giant stones, according to a new Franco-American study.

While summary uses the word cast:

The reaction would be inexplicable if the stones were quarried, but perfectly comprehensible if one accepts that they were cast like concrete.

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.

Re:It has to be said

[jimstapleton]

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.

A little insight

[Anonymous Coward]

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:

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/Dahshur /BentPyramid/EgyptianPoliceman.jpg

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/Dahshur /AllPyramids/StaircaseInsideRedPyramid.jpg

This article can also be found on the New York Times http://www.nytimes.com/2006/12/01/science/01pyrami d.html?ref=science

Just FYI...

[PhineusJWhoopee]

Just FYI, the limestone blocks in question are *not* the stones you see at the base of the pyramids (for example, all the stones in this photo). These are made of granite.

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