Stars tell the age of the pyramids, researcher says By Alex Dominguez
Associated Press Writer
posted: 11:18 am ET
17 November 2000
BALTIMORE (AP) -- Just how old are the pyramids? The answer may lie in the stars.
Current estimates for the construction of the pyramids, based on surviving lists of the pharaohs, are believed to be accurate to within about 100 years.
But Cambridge University Egyptologist Kate Spence said that by analyzing the relative position of Earth and two stars, she has dated the construction of the Great Pyramid at Giza -- one of the Seven Wonders of the Ancient World -- to within five years of 2478 B.C.
The sky in ancient Egypt: Builders may have used the vertical alignment of two bright stars to align the pyramids north-south.That means the Great Pyramid is 4,478 years old -- or 75 years older than one commonly accepted estimate.
Spence's estimate comes from her proposed solution to another mystery: How did the ancient Egyptians align their pyramids so that two sides ran so precisely north-south? She suggests that they used a pair of stars found in the Little and Big Dippers.
But because Earth wobbles on its axis, those two stars would have given different indications for "north'' over the centuries. So by calculating when that pair of stars would have been in a northern alignment, Spence said she can figure out when the pyramids were built.
In Thursday's issue of the journal Nature, Spence said the two-star method could explain the various degrees of inaccuracy in the orientation of pyramids built at different times.
Today's North Star, or Polaris, was in the wrong position in those days to help the pyramid builders. Spence instead employs the stars Mizar, found in the Big Dipper's handle, and Kochab, in the bowl of the Little Dipper.
When the pyramids were built, these stars circled nightly around a point over the North Pole. So, when one star appeared directly over the other, the Egyptians could have used a plumb line to find north, Spence said.
It's not clear whether the Egyptians really did that, but "the technique she argues for seems very reasonable'' and deserves further study, said Edwin Krupp, director of the Griffith Observatory in Los Angeles. The paper could provide "several pieces of a very intriguing puzzle.''
The ancient Egyptians aligned their pyramids and temples to the north because they believed their pharaohs became stars in the northern sky after they died. Aligning the pyramids, in which the pharaohs were buried, was believed to give the deceased direct access to the northern sky.
Betsy Bryan, a professor of Egyptology and the chairwoman of the department of Near Eastern Studies at Johns Hopkins University in Baltimore, said Spence's method seems reasonable, and if it proves to be correct, will further refine the timetable of ancient Egypt.
"That's important because there have been arguments made that the pyramids and the Sphinx were built thousands and thousands of years earlier than that,'' Bryan said. "This is yet another piece of evidence that our view that these are monuments that belong to the middle of the third millennium is right.''
http://www.space.com/scienceastronomy/planetearth/stars_pyramids_wg_001116.html
