杏吧原创

Certain ancient Egyptian temples and tombs were indeed oriented towards certain regions of the sky, according to a new analysis.

Many ancient structures are claimed to be aligned to celestial objects,聽such as Stonehenge. However, most studies of this phenomenon are unreliable, says Fabio Silva at Bournemouth University in the UK, because they don鈥檛 use statistical tests to reveal how likely it is that the supposed patterns are coincidences.

Now Silva has developed a statistical method that should help identify genuine patterns.聽Most studies of this nature rely on mapping multiple structures made by a culture, then looking for clusters that may relate to star or planet positions. A 2009 study of 330 ancient Egyptian temples identified seven groups, each supposedly with a different alignment.

Yet the clusters could just be coincidences. 鈥淲hat people were doing was creating visualisations of their data, and then eyeballing frequency peaks in those graphics,鈥� says Silva.

Silva鈥檚 method assumes that the original ground-level data has uncertainties, and introduces more uncertainty when these measurements are extrapolated to the sky. 鈥淵ou then get a region of the sky that is more likely to be targeted by this structure,鈥� he says.

鈥淚 certainly appreciate the attempt to bring a quantitative analysis into a field which seems to me to be somewhat qualitative,鈥� says astronomer Michelle Lochner at the University of the Western Cape in South Africa.

Silva has applied his method to the Egyptian temple data. Of those seven purported groups of sky-oriented structures, four weren鈥檛 statistically significant, and a fifth looks 鈥渋ffy鈥�, he says.聽Only two held up: certain temples in the Old Kingdom (2686-2160 BC)聽and in the Middle Kingdom (2055-1650 BC). For hundreds of years, many pyramids were aligned to the four cardinal points, although the cultural reasons shifted.

In the Old Kingdom, for example,聽pyramids such as the Great Pyramid of Giza were built with their entrances facing north. Ancient Egyptians believed that 鈥渢he north is the place of the ascent the soul of the pharaoh makes to the northern imperishable stars鈥�, says Bernadette Brady at聽the University of Wales Trinity Saint David in Lampeter, UK, who studies astrology as a cultural phenomenon.

In the Middle Kingdom, the sun god Ra became prominent, so some temples faced east to where the sun rises. Other structures like the Karnak temple near Luxor were instead aligned to sunrise on the December solstice. Many cultures have rituals around the solstice, so it鈥檚 possible that the ancient Egyptians of this time had them too.

Silva also re-examined 鈥渞ecumbent stone circles鈥� in Scotland, but couldn鈥檛 find a statistically significant pattern that suggested the circles were aligned to something in the sky. He says the problem may be that previous studies assumed people stood in the centre of the circle and looked over one particular stone. The builders may have had something else in mind.

Such issues around data collection are likely to be crucial, says Lochner. 鈥淭he danger with this kind of work is it can so easily incorporate unconscious bias. This would be a major source of uncertainty that needs to be carefully included into any statistical framework.鈥�