Ancient Egypt City Aligned With Sun on King's Birthday

[Mark]

http://www.livescience.com/23994-ancient-city-alexandria-sun.html

The Egyptian city of Alexandria, home to one of the seven wonders of the ancient world, may have been built to align with the rising sun on the day of Alexander the Great's birth, a new study finds.

The Macedonian king, who commanded an empire that stretched from Greece to Egypt to the Indus River in what is now India, founded the city of Alexandria in 331 B.C. The town would later become hugely prosperous, home to Cleopatra, the magnificent Royal Library of Alexandria and the 450-foot-tall (140 meters) Lighthouse of Alexandria, one of the wonders of the ancient world. Today, more than 4 million people live in modern Alexandria.

Ancient Alexandria was planned around a main east-west thoroughfare called Canopic Road, said Giulio Magli, an archaeoastronomer at the Politecnico of Milan. A study of the ancient route reveals it is not laid out according to topography; for example, it doesn't run quite parallel to the coastline. But on the birthday of Alexander the Great, the rising sun of the fourth century rose "in almost perfect alignment with the road," Magli said.

The results, he added, could help researchers in the hunt for the elusive tomb of Alexander. Ancient texts hold that the king's body was placed in a gold casket in a gold sarcophagus, later replaced with glass. The tomb, located somewhere in Alexandria, has been lost for nearly 2,000 years. [8 Grisly Archaeological Discoveries]

Building by the stars

Magli and his colleague Luisa Ferro used computer software to simulate the sun's position in the fourth century B.C. (Because Earth's orbit isn't perfect, there is some variation in the sun's path through the sky over centuries.) Alexander the Great was born on July 20, 356 B.C. by the Julian calendar, which is slightly different than the modern, Gregorian calendar, because it does not have leap years to account for partial days in the Earth's orbit around the sun. On that day in the fourth century B.C., the researchers found, the sun rose at a spot less than half a degree off of the road's route.

"With a slight displacement of the day, the phenomenon is still enjoyable in our times," Magli told LiveScience.

A second star would have added to the effect, Magli said. The "King's Star" Regulus, which is found on the head of the lion in the constellation Leo, also rose in near-perfect alignment with Canopic Road and became visible after a period of conjunction with the sun near July 20. Earth's orbit has changed enough that this Regulus phenomenon no longer happens, Magli said.

Sun as a symbol

Architecture-by-astronomy was common in the ancient world, Magli said. The Great Pyramid of Giza, for example, is aligned with amazing precision along the compass points, which would have required the use of the stars as reference points. The Egyptians, whom Alexander conquered, had long associated the sun god Ra with their pharaohs.

"Aligning the city [of Alexandria] to the sun in the day of birth of Alexander was a way to embody in the architectural project an explicit reference to his power," Magli said. The King's Star would have only added to the mystique, he said.

The researchers reported their work online Oct. 9 in the Oxford Journal of Archaeology. They are now examining other cities founded by Alexander and later rulers to see if the solar pattern holds. The hope, Magli said, is that an understanding of Alexandria's astronomical layout will give researchers a better idea of where Alexander's tomb might be.

[Jim Webster]

How much of this would be 'hey, the way the road goes, we can tweak it a few degrees and.....' rather than 'Obviously we'll have to design the city around the alignment with Alexanders birthday'

It would be interesting to look at the alignment of streets in the other Alexandrias

Jim

[Mark]

How much of this would be 'hey, the way the road goes, we can tweak it a few degrees and.....' rather than 'Obviously we'll have to design the city around the alignment with Alexanders birthday'

It would be interesting to look at the alignment of streets in the other Alexandrias

Jim

Or, e.g. Hellenistic Antioch i.e. was it something always done or something only done for Alexander or only done in Egyptian culture (alternative example, Antinopolis, which would presumably have followed Hellenistic conventions in Egypt).

[Sharur]

One should always be slightly wary about such astronomical "alignments" generally.

For instance, what exactly is being aligned, given that the sun is a disc half a degree across, not a single point? Which part of the terrestrial object must one use to achieve said "alignment"? A road too is not a single precise point or line, but an object occupying an angular area. An "alignment" also requires a specific viewing point, so how should that be determined?

Overall, this tends to mean a solar "alignment" doesn't just happen on a single day, but can be seen (depending on the time of year, latitude, size of terrestrial object, distance from terrestrial object's sighting point to the observer, etc.) for several days or weeks around then.

Luckily, it wasn't in Britain this time, where additionally we have to pray it's not cloudy on the horizon at the key point on each day, of course! Oh well, try again next year...