Can physics reveal the secrets of Egypt’s pyramids?

By James Dacey

“Just because a mystery is 4500 years old doesn’t mean it can’t be solved.” That is the tagline of a major new project to uncover the secrets of Egypt’s pyramids without damaging a single stone.

Study locations. (Courtesy: Scan Pyramids)

Scan Pyramids – launched by the Egyptian Ministry of Antiquities – will deploy an arsenal of non-invasive technologies to probe the structure of four pyramids from Egypt’s Fourth Dynasty (from 2575 BC to 2465 BC). On the Giza plateau, about 20 km south-west of Cairo, it will study the Pyramid of Khafre, along with the Pyramid of Khufu, aka the “Great Pyramid of Giza”, the oldest of the Seven Wonders of the Ancient World. Meanwhile, on the site of Dahshur, around 40 km south of the Egyptian capital, it will investigate the North and South pyramids. (Click to expand the map.)

Despite their global fame and familiarity, these ancient monuments still hold many mysteries. Chief among them is the question of how the ancient Egyptians managed to build these huge edifices. The Great Pyramid of Giza was originally 150 m tall and weighed 5 million tonnes, yet it was constructed in just 25 years. Egyptologists also believe that these pyramids could be concealing hidden chambers, which could house tombs and secret treasures.

Scan Pyramids will be co-ordinated by the engineering faculty at Cairo University and the French HIP Institute (Heritage, Innovation and Preservation). To search for gaps just behind the pyramid faces, which could be tunnels or chambers, the researchers will use two different methods of infrared thermography, basically a fancy version of the technology used in homes to test for heat loss in poorly insulated buildings.

Then, to search deeper inside the structures, Scan Pyramids will deploy a modern version of a technique first used at the Egyptian pyramids in the early 1970s by Luis Alvarez, who won the 1968 Nobel prize for his work in particle physics. Alvarez looked for hidden structures within the Pyramid of Khafre using muon radiography – a technique that exploits the muons that shower the Earth after they are produced when cosmic rays hit the atmosphere.

Muons react very little with air but they can rapidly lose energy and change direction when interacting with more dense matter. So, a muon detector located beneath or behind a pyramid can be used to reconstruct an image of the building’s interior structure. It’s a technique that has been applied recently to the Sun Pyramid in Mexico, as we reported in or recent podcast “Inside the particle pyramid“.

For this latest project in Egypt, a team has been called in from the Japanese high-energy-physics laboratory (KEK) and Nagoya University. Japanese researchers have finessed muon radiography in recent years and even applied a version to monitor the reactor cores at the Fukushima Daiichi nuclear power plant.

“Our goal is to use techniques to get concrete results. Then, the Egyptologists will interpret them,” says Hany Helal, an engineering researcher at the University of Cairo and the project’s co-ordinator. “In the longer term, given the archaeological wealth of Egypt, we imagine applying these techniques to other monuments.”

For more information on the different technologies being deployed in Scan Pyramids, check out the project website.