Great Pyramid of Giza scanned using cosmic rays, revealing secret corridor

Though over 4,500 years old, the largest of the three pyramids of Giza is still offering up new details about its interior.

In 2016, scientists using cosmic muon rays discovered the pyramid held within it secret voids. Now, another study using cosmic muons has revealed the size and shape of the structure. The function of the corridor is still unknown.

The structure lies on the north side of the pyramid and is named the North Face Corridor, behind the Chevron structures on the pyramid.

Scientists were able to determine the size and shape of the North Face Corridor using a technique called cosmic-ray muon radiography. Essentially, more muons will pass through voids in the pyramid than if they were passing through the solid mass of the structure. By measuring the number of muons that pass through the pyramid at different points, the researchers are able to develop a 3D map of the internal structure of the pyramid without ever having to go inside.

The method allowed them to determine that the corridor is roughly nine metres in length and is two metres by two metres in height and width.

Diagram-on-left-showing-scan-of-pyramid-photo-on-right-of-pyramid-wall
East-West cut view of the Great Pyramid and front view of the North face Chevron area. (a) Subterranean chamber, (b) queen’s chamber, (c) grand gallery, (d) king’s chamber, (e) descending corridor, (f) ascending corridor, (g) al-Ma’mun corridor, (h) north face Chevron area, (i) ScanPyramids Big Void with horizontal hypothesis (red hatching) and inclined hypothesis (green hatching) as published in November 2017. Credit: Procureur et al. in Nature Communications.

Using the same process, scientists discovered another 30-metre chamber in the pyramid in 2017.


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The Great Pyramid is one of the most impressive and recognisable archaeological sites in the world. It was built during the reign of King Khufu, who ruled ancient Egypt between the years 2,509 and 2,483 BCE, during the fourth dynasty of Egyptian pharaohs.

Lying roughly 18 kilometres from  the centre of Egypt’s capital, Cairo, the pyramid is 139 metres tall and 230 metres wide. However, with its smooth outer coating which has since mostly been stripped away, the pyramid would have been 146 metres tall when it was first constructed.

Khufu’s Pyramid was the tallest structure in the world for over 3,800 years until the construction of Lincoln Cathedral in England in 1311.


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The researchers say that the pyramid still holds many mysteries including the role of the Chevron. Such discoveries, they write, will aid in better understanding the function of different parts of these magnificent ancient structures, and even how the pyramids themselves were built.

The discovery is detailed in a paper published in Nature Communications.

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