pyramids of giza: Ancient Egypt

 For centuries, the pyramids of Giza in Egypt have puzzled researchers, not only because of their mysterious voids and hidden chambers but because the ancient Egyptians were able to build such magnificent structures without modern technology.

One of the most confusing issues is how perfectly those walls became aligned. Although a bit lopsided, the square sides of the 138.8-meter-tall Great Pyramid of Giza, also known as the Great Pyramid of Khufu, are fairly straightforward.

High accuracy in building the pyramids of Giza

• Archaeologist and engineer Glenn Dash explained in a study published in 2017 in the Journal of Ancient Egyptian Architecture, that the builders of the Great Pyramid of Khufu aligned the great monument with the main points with great accuracy, according to a report published yesterday, Wednesday, on the "Science Alert" website.

• In fact, all three Egyptian pyramids (two at Giza and one at Dahshur) are remarkably aligned, in a way you wouldn't expect to see from an era without drones, blueprints, and computers.

• Also, Dash explained that all three pyramids exhibit the same error method, rotating slightly counterclockwise from the cardinal points.

• While there are many hypotheses about how they do this, such as using the polar star to align the pyramids or the sun's shadow, it has not been entirely clear how these hypotheses work.

autumnal equinox

• In addition, a study by Dash suggested that about 4,500 years ago the Egyptians could have used the autumnal equinox to achieve perfect alignment.

• The equinox is seen as the moment when the equator passes through the center of the sun's disk twice a year, and the length of the day and night are largely equal.

• Dash already ran his own experiment, starting on the first day of the autumnal equinox in 2016 and using a scorpion to cast a shadow.

• He traced the shadow point at regular intervals, creating a smooth curve of the points.  At the end of the day, with a taut piece of string wrapped around the shaft, he crossed two points of the curve and created an almost perfect line running east to west.

What is the strongest evidence for building the pyramids of Giza?

• Also, he showed that the degree of error is slightly counterclockwise, which is similar to the slight error found in the alignment of the pyramid of Khufu and Khafre in Giza, and the red pyramid in Dahshur.

• Although the paper shows that this technique could have been used to align the pyramids, we still don't have any strong evidence for that in fact, according to Science Alert.

• However, this hypothesis makes an interesting point: that something as simple as drawing shadows during the autumnal equinox could be sophisticated enough to line up some of the most famous ancient structures in human history.