The outlines of an empty cavity inside the Great Pyramid at Giza in Egypt have been revealed thanks to a bath of subatomic particles. Dubbed the “Big Void”, scientists don’t know what this large open space is, nor why it exists, but its the first cavity to be discovered in almost two hundred years. Even after millennia, the dark interiors of the pyramids jutting out of Egypt’s Giza plateau remain mysterious. The hope is that this newly discovered cavern might help solve the mystery of how an ancient civilization built a monument this size 4,500 years ago.
The space stretches nearly 100 feet long near the center of the pyramid, and is located just above the Grand Gallery, a huge internal corridor. It’s one of the many passages that connect the two large rooms inside the pyramid, called the Queen’s chamber and the King’s chamber.
Using a technique similar to an X-ray, researchers have discovered an empty cavity inside the largest pyramid, the Great Pyramid. It was built for the pharaoh Khufu between 2509 and 2483 BCE. The discovery, described today in the journal Nature, is the latest finding from the ScanPyramids mission, an international effort to spy inside these ancient stone structures without drilling any holes.
The research team found it by tracking particles called muons, which are produced when the cosmic rays that permeate our Universe and pummel our atmosphere break down — creating a kind of subatomic confetti that rains down on Earth at almost the speed of light. These particles drift through air more easily than they pass through solid objects like stone. Scientists can detect internal gaps and spaces by analyzing how many muons travel through a massive object like a pyramid. The method has been used to see inside volcanoes, nuclear reactors at Fukushima, and now, the Great Pyramid at Giza.
The technique is pretty low resolution, however, so many questions remain. The researchers don’t know whether the Big Void is perfectly horizontal, or tilted, or if it’s even a single big empty space or several smaller, adjacent rooms.
“What we are sure about is that this big void is there, that it is impressive, and that it was not expected by any kind of theory,” said study co-author Mehdi Tayoubi from the Heritage, Innovation, and Preservation Institute, in a press briefing. Tayoubi suspects that the Big Void’s presence is no accident of construction or decay; it was built intentionally. “This pyramid is perfect,” he said. “Maybe that’s why people are still dreaming about this pyramid.”
Next, the researchers plan to design a robot that could somehow squeeze into the pyramid to explore this new space. “This mission is about better understanding the pyramids,” Tayoubi said. “But above all, it’s about innovation.”