The pyramids of Egypt tower over the desert sands where they have stood for thousands of years. And the largest of them, the Great Pyramid of Giza, is the most age-old of the Seven Wonders of the Ancient World. Thought to have been studied for many hundreds of years, the incredible monuments that are Giza’s pyramids still hold many mysteries, though – and yet now an archaeologist believes he has the answer to one of them.
The three pyramids of the Giza pyramid complex are probably the best known of all ancient Egyptian constructions. The structures are located in the Western Desert, roughly eight miles southwest of Cairo. And, in addition to the pyramids, the archaeological site also contains the Great Sphinx, a village and a handful of cemeteries.
Latest estimates put the Giza pyramids’ ages at nearly 4,500 years old. It is believed that they were built as tombs for the Egyptian pharaohs. What’s more, they once held not only the pharaohs’ mummified remains, but also supplies needed for the afterlife. Unfortunately, though, both mummies and treasures were removed years ago.
Of the three Giza pyramids, the first to be constructed was the Great Pyramid of Khufu (also known as Cheops). It stood 481 feet tall when it was built but now measures 455 feet. Southwest of this is the Pyramid of Khafre (Chephren), rising to 448 feet. And still farther southwest is the Pyramid of Menkaure (Mykerinos), the smallest, at 215 feet originally – now 204 feet.
Given their age, it’s not surprising that there are disputes about many aspects of the Giza pyramids. For instance, while it was once assumed that they were built by slaves, new evidence makes paid labor a much more likely scenario. Meanwhile, there is still not a complete consensus on how the stone blocks were transported and put into place after being quarried.
Exactly how the architects of the pyramids made their measurements is also debated. Some researchers say the builders may have used mathematical concepts such as the golden ratio, the Pythagorean theorem and Pi when planning their structures. But no one knows for certain.
Another intriguing question is how the Giza builders managed to get the three pyramids to align so accurately. All of the pyramids line up at their southeastern corner in a diagonal that can be followed to the Temple of Heliopolis on the opposite side of the Nile. This is known as the “Pyramid Diagonal.”
Now, archaeologist and engineer Glen Dash thinks he may have come up with an answer to this mystery. Connecticut-based Dash has 45 years’ experience in archaeology and in 1996 founded the Glen Dash Foundation of Archaeological Research. Moreover, much of his work to date has been in Giza.
As part of his Giza research, Dash has explored techniques that may have been used by the ancients to achieve the Pyramid Diagonal. And after looking into several theories, he now believes he has found the answer. The secret, according to the engineer, is a simple approach called the “Indian circle method.”
The Indian circle method has been around for millennia. It is so named because the first known record of it comes from an Indian text written between 400 and 300 BC. However, it is conceivable that the method was being used by the Harappan civilization of India, and in other places, even earlier. Dash believes this geographical range included ancient Egypt.
The method traditionally involves a wooden rod, known as a gnomon, and a piece of string. First, the rod is planted upright in the ground outdoors. Then as the sun changes position, so does the rod’s shadow. By marking the progress of the shadow at half-hourly intervals during the day, it’s thereby possible to draw a curved line through the marks.
Once the shadow line has been drawn, the piece of string is tied around the gnomon. The string is next pulled taut and dragged in a circular motion around the rod. And as it moves, the string passes through two positions on the shadow line. A straight line made between these points will then accurately mark an east-to-west diagonal.
Dash modified this method by trying it on the autumn equinox. As the position of the sun changes during the year, so does the curvature of the shadow line. And during the equinox, the line plotted along the shadow’s movements will be almost straight. This means that the string is no longer required, as the marks will already be aligned from east to west.
The length of the line drawn by joining these points depends on the height of the platform and gnomon. “To lay in a baseline for a pyramid,” Dash wrote in The Journal of Egyptian Architecture, “the Egyptians would have had to extend the line formed by these two points for hundreds of meters with little error.”
Dash further writes that there are several methods the pyramid builders might have used to accurately extend their east-west line. Alternatively, they may have employed a bigger rod and platform in each case. For his part, the engineer-archaeologist built a platform at his home in Connecticut. The base measured 3 feet by 20 feet, and the top of the gnomon was raised 2.7 feet above it. This in turn produced a line 16 feet in length.
In the case of the architects at Giza, Dash believes they had a much larger, and suitably flat, platform conveniently available. “The platform around the Great Pyramid is leveled to within a few centimeters over its entire 920-meter periphery,” he said. With this larger base, then, the ancients would have been able to also use a taller gnomon and get a longer line.
Yet while Dash thinks there’s a good chance that the Giza complex builders used the equinoctial method to line up their pyramids, it isn’t possible to know for sure. “No engineering documents or architectural plans have been found that give technical explanations demonstrating how the ancient Egyptians aligned any of their temples or pyramids,” he wrote.
Over the years, many other methods that may have been used to align the pyramids have been proposed. In November 2000, for example, the journal Nature published an article by Kate Spence of Cambridge University. In it, Spence theorizes that the Giza pyramids are in fact built along a north-south axis which the builders plotted using two stars: Kochab and Mizar.
Another controversial but popular hypothesis is known as the Orion correlation theory. Published in 1989, this notion suggests that rather than aligning with cardinal points, the positions of the pyramids correlate to the constellation Orion. However, while this theory was the subject of a BBC documentary and several esoteric books, it is rejected by many researchers.
According to Dash, what makes his theory stand out from the rest is its relative simplicity and workability. “It produces results that match the actual alignments of the largest pyramids of the pyramid age in magnitude and direction,” he stated. “It is hard to imagine a method that could be simpler either conceptually or in practice.”