The Great Pyramid, or Khufu’s Pyramid, was built on the Giza plateau in Egypt during the fourth dynasty by the pharaoh Khufu (Cheops)1, who reigned from 2509 bc to 2483 bc. Despite being one of the oldest and largest monuments on Earth, there is no consensus about how it was built2,3. To understand its internal structure better, we imaged the pyramid using muons, which are by-products of cosmic rays that are only partially absorbed by stone4,5,6. The resulting cosmic-ray muon radiography allows us to visualize the known and any unknown voids in the pyramid in a non-invasive way. Here we report the discovery of a large void (with a cross-section similar to that of the Grand Gallery and a minimum length of 30 metres) situated above the Grand Gallery. This constitutes the first major inner structure found in the Great Pyramid since the nineteenth century1. The void, named ScanPyramids’ Big Void, was first observed with nuclear emulsion films7,8,9 installed in the Queen’s chamber, then confirmed with scintillator hodoscopes10,11 set up in the same chamber and finally re-confirmed with gas detectors12 outside the pyramid. This large void has therefore been detected with high confidence by three different muon detection technologies and three independent analyses. These results constitute a breakthrough for the understanding of the internal structure of Khufu’s Pyramid. Although there is currently no information about the intended purpose of this void, these findings show how modern particle physics can shed new light on the world’s archaeological heritage.
This experiment is part of the ScanPyramids project, which is supported by NHK, La Fondation Dassault Systèmes, Suez, IceWatch, le Groupe Dassault, Batscop, Itekube, Parrot, ILP, Kurtzdev, Gen-G and Schneider Electric. Measurement with nuclear emulsions was supported by the JST-SENTAN Program from the Japan Science and Technology Agency and JSPS KAKENHI (grant JP15H04241). The CEA telescopes were funded partly by the Région Ile-de-France and the P2IO LabEx (grant ANR-10-LABX-0038) in the framework ‘Investissements d’Avenir’ (grant ANR-11-IDEX-0003-01) managed by the Agence Nationale de la Recherche (France). The detectors were built by the ELVIA company and the CERN Micro-Pattern Gaseous Detector workshop. We thank the members and benefactors of the ScanPyramids project, and in particular: T. Hisaizumi, the members of Cairo University, the members of the F-laboratory in Nagoya University, Y. Doki, the Aïn El Shams University 3D scanning team, the members of the Egyptian Ministry of Antiquities, K. El Enany, M. El Damaty, T. Tawfik, S. Mourad, S. Tageldin, E. Badawy, M. Moussa, T. Yabuki, D. Takama, T. Shibasaki, K. Tsutsumida, K. Mikami, J. Nakao, H. Kurihara, S. Wada, H. Anwar, T. de Tersant, P. Forestier, L. Barthès, M.-P. Aulas, P. Daloz, S. Moignet, V. Raoult-Desprez, S. Sellam, P. Johnson, J.-M. Boursier, T. Alexandre, V. Ferret, T. Collet, H. Andorre, C. Oger-Chevalier, V. Picou, B. Duplat, K. Guilbert, J. Ulrich, D. Ulrich, C. Thouvenin, L. Jamet, A. Kiner, M.-H. Habert, B. Habert, L. Gaudé, F. Schuiten, F. Barati, P. Bourseiller, R. Theet, J.-P. Lutgen, R. Chok, N. Duteil, F. Tran, J.-P. Houdin, L. Kaltenbach, M. Léveillé-Nizerolle, R. Breitner, R. Fontaine, H. Pomeranc, F. Ruffier, G. Bourge, R. Pantanacce, M. Jany, L. Walker, L. Chapus, E. Galal, H. A. Mohalhal, S. M. Elhindawi, J. Lefaucheux, J.-M. Conan, E. M. Elwilly, A. Y. Saad, H. Barrada, E. Priou, S.Parrault, J.-C. Barré, X. Maldague, C. Ibarra Castenado, M. Klein, F. Khodayar, G. Amsellem, M. Sassen, C. Béhar, M. Ezzeldin, E. Van Laere, D. Leglu, B. Biard, N. Godin, P. der Manuelian, L. Gabriel, P. Attar, A. De Sousa, F. Morfoisse, R. Cotentin, C. Delache and G. Perrin.