The Great Pyramid Looks Like It Has Four Flat Faces, but Each One Is Subtly Dished Inwards Down the Middle, Making It Secretly Eight-Sided — a Detail so Slight It Was Really only Spotted From the Air, in a Photograph Caught at the Right Angle of Sunlight.

The Great Pyramid looks like it has four flat faces, but each one is subtly dished inwards down the middle, making it secretly eight-sided — a detail so slight it was really only spotted from the air, in a photograph caught at the right angle of sunlight.

Ask anyone to describe the Great Pyramid of Giza and you get the same shape: four smooth triangular faces meeting at a point, a square base. And that was probably close to how the finished monument looked. Its surviving surface, however, is more complicated. The exposed stone core of each face has an irregular groove running down its centre, from near the summit to the base. In favourable light, that groove can make each triangular face appear d…