[SlowBoat407]

I’ve thought for a long time that the blocks were cast in place. Still working out how to make a sandstone concrete, though.

[KarlInOhio]

Could be? Concrete doesn't look like natural rock. Give some geologist a magnifying glass and sixty seconds and you'll have an answer.

[ZX12R]

Some of the chambers and other internal structures are lined with enormous granite slabs, and I don’t think those could be cast. So, if you can carve out large granite slabs, it should be pretty simple to cut limestone ones, and do so faster and easier. I don’t see the need for them to even consider casting.

[Red Badger]

http://www.macraesbluebook.com/search/company.cfm?company=402249

[uncbob]

Ya mean at this late date in history they don’t know

[SpaceBar]

Materials scientist, archaeologists, chemical engineers. They throw around a lot of high powered degrees in the article without mentioning the one discipline most qualified to make the determination, e.g. a geologist. Specifically one specializing in igneous petrology.

[19th LA Inf]

I remember seeing a clipping about 20 years ago on our department’s Trivia bulletin board stating that the pyramids were made of cast concrete blocks. The proof? The grain pattern of the plywood used for the molds.

[FreePaul]

...would mean the ancient Egyptians were great materials scientists as well as great civil engineers.

And still couldn't make drawings depicting people in 3D.

[JeanLM]

Not a new theory as Davidowitz said in his book, and as another poster has said. Story I heard from some German R&D people was that the blocks are synthetic zeolite castings. Story is when Napolean was stranded in Egypt, he had some of his engineers take a look at ancient Egyptian artifacts. They found a finely made hollow quarzite vase, which by any then known (18th century) technology couldn’t be fabricated because the material was too hard.

They took it back to France and gave it to Lavoisier who pronounced that it had been cast not cut by some unknown technique.

Smart folks those ancients. The natural ores used for the zeolite were supposedly mined to exhaustion, and they didn’t know how to make more.

Lavoisier also lost his head because he supported freedom of thought. Would have been a freeper for sure.

[TexGuy]

Archaeologists say there is no evidence the pyramids are built of any synthetic material ...

But that doesn't stop the scientists from putting forth any theories to the contrary.

[jonrick46]

Just my theory (play some Twilight Zone music): An Alien mothership dropped off a huge pile of concrete mix for a landing strip, the Egyptians found it and used it for their pyramids.

[PzLdr]

From Jersey. They got a good price. Capice?

[fishtank]

I’m surprised that the Egyptians would not want to re-cover the pyramids with smooth limestone, as they were originally built.

[RetSignman]

The world has been waiting with bated breath for the answer to this one, I, personally, think they were made from camel dung.

[Little Bill]

To make concrete you have to burn limestone with additives, is that where all the trees in Egypt went?

[kidd]

Elvis built the pyramids.
Ask Mojo Nixon

[maine-iac7]

http://www.aeraweb.org/khufu_quarry.asp

http://www.theglobaleducationproject.org/egypt/studyguide/6stone.php

[fso301]

According to Barrack Hussein Obama’s pastor, they were cut with high speed diamond wet saws then lapped to a mirror finish, transported to the job site where stationary and mobile cranes hoisted them into place.

[True Republican Patriot]

ping

[wendy1946]

The basic pyramid blocks had to have been poured; way too much work and you’d waste more than half the available stone material otherwise.