Episode notes
Around 2600 BC, Pharaoh Khufu's pyramid rose on the Giza Plateau, over 481 feet tall and sheathed in polished white Tura limestone that would have glared under the Egyptian sun. The slave army image comes from Herodotus, writing more than 2,000 years later. Excavated workers' villages instead show conscripted farmers, averaging about 13,200 and peaking near 40,000 during the Nile flood, organized into gangs of about 40 with proud names, fed beef and lamb, and treated for broken bones and amputations. Arsenical copper tools, water, and swelling wooden wedges let four modern workers cut a 2.5 ton block in four days.
Granite blocks up to 80 tons came 560 miles from Aswan on cedar barges braced with rope trusses, and the papyrus logbook of an official named Merer, found in 2013 at a Red Sea harbor, records limestone shipments from Tura in Khufu's 27th year. Inside, the corbelled Grand Gallery spreads the load, the air shafts bend in ways that undercut star alignment theories, and in 2017 the ScanPyramids project used cosmic ray muons to find a sealed Big Void above the gallery at least 30 meters long. Later centuries forgot all of this, calling the pyramids Joseph's granaries, until the caliph al-Mamun tunneled in during 832 AD and found an empty sarcophagus.
- Arsenical copper: why adding arsenic made chisels hard enough for limestone
- How Egyptian barges used tensioned rope trusses to prevent hogging under heavy granite
- Al-Mamun's fire and vinegar tunnel, still the entrance tourists use today
- Radiocarbon dating of ash and charcoal in gypsum mortar confirming Khufu's reign
- The Dixon Relic, a cedar plank dated to 3341 BC, and the old wood problem