Looking At How Pyramids Were Built Using Their Casing Stones

As one of the most famous Ancient Egyptian pyramids, the Pyramid of Khafre on the plateau of Giza has been a true wonder of the Ancient World ever since its construction around 2570 BCE. Today, well over 4,500 years later, we are still as puzzled as our ancestors over the past hundreds of years how exactly this and other pyramids were constructed. Although many theories exist, including ramps that envelop the entire pyramid, to intricate construction methods from the inside out, the only evidence we have left are these pyramids themselves.

This is where the jokingly called [History for Granite] channel on YouTube has now pitched some new ideas, involving the casing stones that used to fully cover the Pyramid of Khafre, prior to widespread theft and vandalism.

Bonding stones within the casing stones on the Pyramid of Khafre. (Credit: History for Granite, YouTube)
Bonding stones within the casing stones on the Pyramid of Khafre. (Credit: History for Granite, YouTube)

Despite the pyramids of Giza in particular being a veritable tourist trap, said tourists are heavily discouraged from climbing onto the pyramids, or even set up high-powered camera gear on tripods near them. Even with drone footage available, it was necessary to get a zoomed-in look on the casing stones that remain on the pyramid of Khafre near its top at well over 100 meters. Working within these limitations, it was possible to take detailed photos of three sides of the pyramid, which revealed interesting details.

In the top screenshot from the video the top of the pyramid is visible, which gives some indication of just how much the pyramid may have shifted out of alignment due to earthquakes over the millennia. This turned out to be not significant enough to account for some purported ‘gaps’ between the casing stones, with supposed ‘filler material’ from scaffolding holes explainable as just broken off sections of these casing stones. What was more interesting was that a pattern could be found in so-called bonding stones.

Pattern of bonding stones on the north face of the pyramid of Khafre. (Credit: History for Granite, YouTube)
Pattern of bonding stones on the north face of the pyramid of Khafre. (Credit: History for Granite, YouTube)

These bonding stones have a slanted end, so that they can be lifted slightly above a matching slanted stone, before being lowered to complete a row of bricks or stonework. After analyzing the three faces of the still mostly intact casing stones, a clear pattern emerged, such as that on the north face, pictured here.

What this suggests is that each row of casing stones were laid down by multiple groups of workers, each starting at a specific point before coming together where those sections would be joined with a bonding stone. This lends credence to the theory that the pyramid was constructed layer by layer, including the outer covering. To further examine these clues, the even older Bent Pyramid at the royal necropolis of Dahshur with mostly intact casing stones will be examined in more detail next.

If anything this series shows just how much there still is that we don’t know about these massive construction projects that are really only preceded by the works of the Sumerian and Akkadian people.

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Magic Pyramids Blink Eternal With The Power Of The Sun

Without knowing it, we’ve spent years watching [Jasper Sikken] piece together an empire of energy harvesting equipment, and now he’s putting the pieces together into wonderful creations. His recently finished solar harvesting pyramids are mesmerizing objects of geometric perfection we’d love to see glinting in the sun.

These solar harvesting pyramids are well described by their name. Each one contains a PCBA around 30mm on a side with a solar energy harvester built around the dedicated AEM10941 IC, a single solar cell, and a very bright green LED. [Jasper] calculates that the solar cell will charge the super capacitor at 20uA at with just 200 lux of light (a level typical for casual indoor spaces) letting it run indefinitely when placed indoors. Amazingly with the LED blinking for 15ms every 2 seconds it will run for 21 days in complete darkness. And that’s it! This is a software-free piece of hardware which requires no input besides dim light and blinks an LED indefinitely.

Small PCBA, large capacitor

What about that super capacitor? It’s called a Lithium Ion Capacitor (LIC) and is a hybrid between a typical rechargeable lithium battery and an electrolytic capacitor, offering extremely high capacity in a convenient two leg through hole form factor. This one is a whopping 30 Farad at 3.8 V, and we first saw it when [Jasper] won the Hackaday Earth Day contest last month. Check out that link if you want to know more about their uses and how to integrate them.

For more detail about all of the components of the solar pyramid we need only turn to the Hackaday archives. In December 2019 [Tom Nardi] wrote about building a cheap degassing system for making some very familiar looking resin pyramids. And before that [Donald Papp] brought us another familiar piece of the pyramid when he wrote up a different 1″ x 1″ solar harvesting system that [Jasper] designed.

Check out the video after the break to see what one of these gems looks like from all sides. And for many more experiments leading up the final pyramid check out the logs on the Hackaday.io page.

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Fidget Pyramid With Help From A 2500 Pound Robot

Depending on whom you ask, fidgeting is an unsightly habit or a necessity for free-form ideation. Fan of the latter hypothesis? Well, why aren’t you making yourself a fidget pyramid?

[lignum] sculpted his fidget toy out of a chunk of 2000 year old bog-oak using hand tools and a little precision help from a Kuka KR 150 industrial robot arm. A push button, a toggle switch, a ball-bearing, and a smooth side provide mindless distraction on this piece.

Two plates of 1.5mm aluminium — also cut using the robot arm — are used to attach the button and toggle to the tetrahedron, while the ball bearing is pushed onto a cylindrical protrusion left during the cutting process for the purpose. The build video makes it look easy.

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Code Like An Egyptian

[Marcelo Maximiano’s] son had a school project. He and a team of students built “The Pyramid’s Secret“–an electronic board game using the Arduino Nano. [Marcelo] helped with the electronics, but the result is impressive and a great example of packaging an Arduino project. You can see a video of the game, below.

In addition to the processor, the game uses a WT5001M02 MP3 player (along with an audio amplifier) to produce music and voices. There’s also a rotary encoder, an LCD, a EEPROM (to hold the quiz questions and answers), and an LED driver. There’s also a bunch of LEDs, switches, and a wire maze that requires the player to navigate without bumping into the wire (think 2D Operation).

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Brazillian Class Creates Digital Board Game

A class in Brazil was given the assignment to make a board game. [Marcelo], presumably, heard his son lamenting how lame it was going to be if the board was just cardboard with some drawings on, and came to the rescue.

 fusion between Operation and one of those disease transmitters at the doctors office
A match meant to be.

Working with the class, they came up with the rules of the game. We’re not certain what those are, but it involves a regular game board, a flashing light circle with numbers, and a fusion between Operation and one of those disease transmitters commonly found at the doctor’s office. You can try to puzzle them out from the video after the break.

The brains of the board is an Arduino with an external EEPROM for all the sound effects and other data needed for this construction. Everything is laid out on a beautifully done home etched PCB. It’s too bad the other side of the board isn’t visible.

We’re sure the kids learned a lot working with [Marcelo]. It would have been nice if a traveling wizard came to some of our earlier classes in school and showed us just how much cool stuff you can do if you know electronics.

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Glimpses Of A 3D Volumetric Display

Custom displays are a lot of fun to look at, but this one is something we’d expect to see at a trade show and not on someone’s kitchen table. [Taha Bintahir] built a 3D volumetric display and is showing it off in the image above using a 3DS file of the Superman logo exported from Autodesk. In the video after the break you can see that the display is a transparent pyramid which allows a viewer to see the 3D object inside from any viewpoint around the display. Since first posting about it he has also added a Kinect to the mix, allowing a user to control the 3D object with body movements.

There’s basically no information about the display hardware on [Taha’s] post so we asked him about it. It works by first taking a 3D model and rendering it from four different camera angles. He’s using a custom designed prism for he display and the initial renderings are distorted to match that prism’s dimension. Those renderings are projected on the prism to give the illusion of a 3D object floating at its center.

We’re hoping to hear more details about how this was designed and what hardware is being used. We’ll post a follow-up if [Taha] shares more information.

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