How the Pyramids Were (and Were Not) Built, Part 1

by Brian Dunning
May 4, 2021

Few questions divide the world of science from the world of metaphysics as dramatically as that of the origin of Egypt's great pyramids. On the one side we have the Egyptologists, an international army of academics and cross disciplinary scientists who have lived and worked at the site for centuries, who find that the pyramids were built by the ancient Egyptians; and on the other side, we have a small number of very vocal and popular alternative historians who prefer a narrative of intervention by some advanced race, perhaps from the mythical Atlantis, perhaps from an alien planet, or some other whimsical place. Today we're going to look at what we know, and more importantly, how we know, about what is arguably the human race's most monumental achievement.

Because this subject has garnered so much public mindshare over the years, this is going to be a rare two-part episode. In this week's show we're going to lay the basics of what we know about the pyramids that puts to rest any alternative history claims; and in next week's, we're going to have a look at some of the new discoveries, many of which you may not have heard of, that really put an exclamation mark on the entire topic.

The Great Pyramid of Khufu is nearly always the focus of this subject, and it will be today as well. It is the tallest pyramid anywhere in the world, and the largest by volume in Egypt — both the Great Pyramid of Cholula in Mexico and the Mausoleum of Qin Shi Huang in China are larger by volume, though substantially lower. Once it was built, it became the world's tallest structure, a title it held for 3,800 years. It was the first of the three great pyramids at the Giza Necropolis, and it is the finest built anywhere in Egypt, in both the quality of its stonemasonry and finish work, and the complexity and precision of its engineering. Later pyramids were actually built to lower standards, probably for economy's sake since the construction of the Great Pyramid constituted a project of such unprecedented and enormous resources, which we'll discuss.

Predictably, it is this exceptional nature of the Great Pyramid that has drawn the wild conjectures from some modern alternative historians, who suggest that Egyptians alone were incapable of such a project, and thus must have had help. It's worthwhile to hear this quote from Mark Lehner, who has for 40 years been one of the most active and most published Egyptologists representing the side of science, talking about when he first came to Giza while he was still a student in the 1970s:

I came with so-called New Age ideas about the pyramids, believing that they had something to say about the Lost Continent of Atlantis, and so on... and when I encountered bedrock reality at the Giza plateau, it didn't add up to those ideas.

Despite its incremental superiority to other pyramids, the Great Pyramid did not just pop into existence thanks to some supernatural assistance. The single most important thing to understand about it is its context within ancient Egypt's long tradition of pyramid building. Before Pharaoh Khufu began construction on his Great Pyramid, there was about a century of research and development into pyramid construction. Much of this was the product of Khufu's father and predecessor, the Pharaoh Sneferu.

Note: Strictly speaking, Egyptian kings were not called Pharaohs until much later, in the 18th dynasty. None of the kings in this episode would have been called Pharaoh in their time; however it's common practice for us to retroactively apply the title, so I've gone with common practice here. —BD

Sneferu built three great pyramids during his reign, each using different designs and construction methods, each refining the process a bit more and solving a few more of the problems. The first, the Meidum Pyramid, he probably inherited from his predecessor, the 3rd dynasty Pharaoh Huni, for whom this was his fifth pyramid. Huni had designed a step pyramid with five levels, but Sneferu tried to complete it by encasing it within a smooth sided conventional pyramid. Unfortunately, Sneferu built his extension on a foundation of sand, and it was built against Huni's smooth-sided step pyramid. Neither offered adequate support, and it collapsed. Today only about 3 levels of Huni's step pyramid, surrounded by debris from Sneferu's pyramid, survive.

Sneferu started his next pyramid at the same time his engineers were having the problems at Meidum. The Bent Pyramid was on a proper foundation and was a steep, 54° pyramid. Halfway up, there's an angle and the rest of it is only at 43°. The instability of such steep sides taught Sneferu not to use quite so aggressive an angle.

Sneferu's third pyramid, the Red Pyramid, was Egypt's first truly successful smooth-sided pyramid and incorporated all the lessons learned to date. It refined the engineering techniques and also laid the groundwork for planning the massive supply chains needed to keep such a project moving.

So it was with a wealth of experience building pyramids and supplying their construction that Pharaoh Khufu set out to construct the Great Pyramid. We have a detailed history of the development of that experience, and that historical record is inconsistent with the modern conjecture of some unknown advanced civilization suddenly stepping in and doing everything for the Egyptians.

Even with the Great Pyramid, Khufu and his team didn't get everything right. This is plainly evident at a glance: almost all of the smooth outer casing of fine white limestone is gone. Where did it go? Most of it broke up, fell apart, and tumbled down the sides (mostly triggered by earthquakes), where it was picked up by people and taken away to be reused on other projects. This breakage was caused by thermal expansion. By the time Sneferu built the Red Pyramid, they'd refined their stonework with sharp copper tools to make casing stones that fit together very well and looked beautiful. But what they didn't yet know was that without gaps between the stones, thermal expansion would destroy those lovely flat surfaces over the centuries. This is why both the Red Pyramid and the Great Pyramid have almost no casings left, while the older Bent Pyramid and Huni's step pyramid have those smooth outer casings almost entirely intact: they weren't built to as high a standard and thus had some give. This is also the case with pyramids built after the Great Pyramid when they took the construction standards back down a notch to economize the project: the pyramid of Khafre — the son of Khufu, whose monument is the second largest and sits beside his father's on the Giza plateau — still has much of its casing remaining up near the top. Quicker construction, larger gaps, more room for thermal expansion, thus an accidentally more durable casing. Aliens or Atlanteans would have known about that, and done Khufu's right.

(Note: It is a myth that thieves climbed 100m up the pyramids to schlep the gigantic casing stones all the way back down that treacherous slope — an obviously implausible task. They did steal them, but mostly only after the thermal breakup and earthquakes brought them safely down to the desert floor.)

There are, still, plenty of things we don't know about the construction of the pyramids, but these uncertainties are in the details, not the major facts. The largest single question — literally the largest — is what type of ramps were used. As the pyramids grew during construction, ramps had to grow along with them. A 6-10° construction ramp for the Great Pyramid would have been immense, and would have required nearly as much material as the pyramid itself contains. Was it a spiral ramp? Was it a single long straight ramp? There simply aren't very many places on the plateau where any one type of ramp would have fit. We do know the ramp existed, because we've found the material it was made from. The great bulk of the pyramids' mass was common limestone quarried right there on the site just south of the pyramids, and those quarries are now filled with the ramp debris: millions of tons of limestone chips and gypsum. This debris itself provides a wealth of knowledge; clues like that it contains no mud bricks, that it is stratified telling us what types of material were dumped there and when, and lets us build at least a partial picture.

Ramps were diverse. There are over 100 ancient pyramids throughout Egypt, and some of them still have their construction ramps in place. Some were left unfinished; others they just didn't bother to clean up very well. Every imaginable type of ramp was used; there is no one type of ramp used to build a pyramid. It's likely that this same practice of ad-hoc ramp usage was employed at Giza. Most likely one main ramp would have started at the quarry and gone straight to the pyramid; this would have facilitated placing the bulk of its volume, while the rest could have been done with smaller spiral roadways supported by extra stones that today still project nearly a meter farther out from the pyramid than most. There are a number of possibilities, and that we don't really know which is correct doesn't mean that we're forced to consider alien intervention.

Even the perfect ordinal alignment of the pyramids — plus many other constructions throughout the ancient world — was well within the ancients' abilities. You can do it yourself. Twice a year, on the equinoxes, place a pebble at the tip of the shadow cast by any stationary object every hour or so. That line of pebbles will be absolutely perfectly aligned east and west. This was well known to humanity as far back as records go, and it was used all the time. Considering that the life path of a Pharaoh was closely tied to that of the sun, the real surprise would be if the pyramids were not aligned as well as they are.

What many people may not know is just how fast and exciting the field of Egyptology is. New discoveries — many of them profound — are being made all the time, improving our knowledge and expanding its scope, and forcing new editions of the books to come out practically every year. The best known of these new discoveries is the workers' city south of the pyramids, where more than ten thousand workers lived — we don't know how many because so much of it is underneath the modern city of Cairo. Multiple lines of evidence date the city to the construction of the pyramids, but one of these is carbon dating of the organic matter in the enormous amount of pottery recovered from the site. This city's discovery and analysis was the final nail in the coffin of the old Judeo-Christian myth that Egypt's great works were built by slaves. They were built by well fed and well paid workers, many of them greatly skilled, who were housed in comfort with every contemporary convenience. One analogy you hear a lot is that to the United States' Apollo program. It was a source of tremendous national pride that employed a significant chunk of the population. People wanted to work on the Great Pyramid. People wanted it to succeed. It was the very symbol of their national identity.

The discovery of the workers' city was major, and it did all the remaining heavy lifting needed to shift our understanding of the workers and of the project overall. It was not a project of whips and slaves and cruelty; it was one of pride and motivation and patriotism and cooperation. The workers' city was also only the vanguard of a slew of recent work throughout Egypt that is truly adding color to this new, larger sketch of the 4th dynasty — today — and in next week's show, we're going to see all that that means.

By Brian Dunning
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