Two previously unknown cavities have been detected inside the Great Pyramid of Giza. Using muography, thermography and 3D simulation, researchers said they had found new "voids" in the structure, which was built in about 2560BC as a tomb for the Egyptian pharaoh Khufu.Scan Pyramids, a collaborative project involving a number of universities, companies and scientific institutes, has been using the three techniques to discover more about the pyramid.Describing muography, researcher Mehdi Tayoubi said: "Just like X-rays pass through our bodies allowing us to see our skeleton, these elementary particles, muons, weighing around 200 times more than electrons, can very easily pass through any structure, even large and thick rocks, such as mountains."One of the newly detected voids is on the northeastern edge of the pyramid.More results will be made public later this month.The team is also continuing to acquire muon data from inside the Queen's Chamber in the pyramid."We expect to have the results of the analysis of the data generated by those instruments during the first three months of next year," the researchers said.Scientists overseeing the project have recommended that it be extended by at least a year for the collection of more data. ..