Legendary pyramids have occupied scholars, not only for their secret voids and hidden chambers, but also for the fact that the ancient Egyptians managed to build such impressive monuments using the technical means of the past. So one of the greatest mysteries is the impressive alignment of the pyramids. In particular, the Great Pyramid of Giza has highly accurate lines at 138.8 metres on each side and is aligned with the cardinal points, north, south, east and west. Accuracy is close to 4 minutes arc or if you want 1/15th of a degree. Something extremely difficult in an age without drones and computers.
There has been much speculation about how they did this, using for example the North Star or the shadow of the Sun, but it is not yet clear how they calculated them. The latest method, published in 2017, suggests a much simpler way.
Experimenting with the first day of the autumnal equinox in 2016, they used a rudder to create a shadow. They marked the peak of the shadow at regular intervals during the day, forming a curve. At the end of the day, using a rope tied to the rudder, they saw where the curve intersected, joined them, and created a nearly perfect straight line from east to west.
So all the Egyptians had to do to align their pyramids was have a sunny day. Although this method looks like it could be used, unfortunately we still don’t have evidence of the technique that eventually followed.
The Egyptians have unfortunately left us very little information. No mechanical documents or architectural drawings with technical explanations have been found to prove how the ancient Egyptians aligned the pyramids.
The research was published in The Journal of Ancient Egyptian Architecture.