It towers over the Giza complex on Cairo's outskirts alongside smaller pyramids for kings Menkaure and Khafre and the Great Sphinx.
"This void was hiddien in the construction of the pyramid".
"In order to understand how Khufu was built, we need to understand the internal structure". Built as a royal tomb around 2560 BC, it's made of an estimated 2.3 million blocks of stone.
Built over 4,500 years ago during the reign of Pharaoh Khufu, the pyramid has been home to thousands of archeological studies.
What is the secret chamber?This count then gives you an idea about the density of the object the muons have travelled through - that's how the researchers found this big void in Khufu's Pyramid - also known as the Great Pyramid of Giza. The newly discovered aspect, which scientists found by using a technique similar to an X-ray, is about the same size as the Grand Gallery, so around 100 or so feet long.
Muons are by-products of cosmic rays that can penetrate stone and distinguish cavities from solid formations.More news: Stunning 'Monster' Planet Discovery Puts Key Theory in Doubt
The Verge laid out a succinct, easy to understand, and extremely radical-sounding explanation of muons: "Muons 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 nearly the speed of light". Scientists say the particles penetrate any material that made them the ideal tool to X-ray the pyramid with.
A rendering from ScanPyramids of the void. "The good news is that the void is there, and it's very big", he said.
The scattering of the muons was recorded on an extremely sensitive photographic medium known as nuclear emulsion film, which had been positioned in the Queen's chamber, inside the pyramid. Every method showed the same result: a large void in the area above the Grand Gallery.
The exact shape and size of the void is fuzzy - its objective and possible contents a mystery. However, some historians are more excited than others about the discovery.
Scientists said yesterday that they have found a hidden chamber in Egypt's Great Pyramid of Giza, in what would be the first such discovery in the structure since the 19th century and one likely to spark a new surge of interest in the pharaohs.
Right now, there are no plans to enter the Great Pyramid to further investigate the void, because there is no way to get to it through the existing network of passages and chambers. The study of the pyramids has been going on for an very bad long time.