Schlagwort-Archive: North Pole

Two stars form an astral hand and pointed to True North

Astral hand to True NorthTwo of the recognized eight circumpolar stars, Alderamin (10,8°) und Kocab (43,6°), were crossing formerly the meridian nearly at the same time, when they were positioned almost vertically on top of one another. They form an astral hand that could have shown the True North. Kate Spence, University of Cambridge, has proposed a surprising simple theory, which provides the key to the mysterious orientacion of the pyramids. … the Egyptians could have observed two stars, which were lying approximately in one line to the northern skypole, at that time.
The North was where the extension of their connecting line hit the horizon vertically at night.

 

„The sky was the limit for the Pyramid builders
Dinah Ashman explains how modern astronomy may have put a new date on the building of the Great Pyramid at Giza.

A new theory of how exactly the ancient Egyptians oriented the pyramids according to the stars could put a date on the construction of the Great Pyramid at Giza near Cairo that is accurate within 5 years.
Builders probably got started between 2485 and 2475 BC, Kate Spence of the University of Cambridge, UK, proposes in Nature. Previous estimates have been accurate only to within 100 years. Spence’s idea could enable Egyptologists to refine their chronologies for all the reigns of the Old Kingdom — the middle of the third millennium BC.
“Spence has come up with an ingenious solution to a long-standing mystery,” says Owen Gingerich of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts.
The new theory is inspired by the subtle deviations in the alignment of the eight pyramids at Giza from true north. The bases of the earliest-built pyramids point slightly east of north and those of the later-built ones, slightly west. The most precisely aligned pyramid is that of King Khufu or Cheops, also known as the Great Pyramid.
The pyramid builders, Spence suggests, used a pair of fairly bright stars, which in 2467 BC lay precisely along a straight line including the celestial north pole. Each star was about 10 degrees from the pole.
One is Kochab (ï-Ursae Minoris) in the bowl of the Little Dipper (Ursa Minor), the other Mizar (zeta-Ursae Majoris) in the middle of the handle of the Big Dipper (Ursa Major).
“In 2467 BC an Egyptian astronomer could wait while the heavens slowly pivoted around the unmarked pole until a plumb line exactly intersected both stars, one about 10° above the invisible pole and the other 10° below it,” Gingerich explains. The sight line to the horizon point directly below the plumb line would then point straight to north.
Because of the Earth’s precession — the revolving axis of the Earth is unstable and rotates like a gyroscope with a period of 26,000 years — the celestial north pole was exactly aligned between Kochab and Mizar only in the year 2467 BC. Although given the precision of the measurements of the time, the ‘accurate’ period was effectively a few years.
The orientation errors of earlier and later pyramids faithfully track the slow drift of Kochab and Mizar with respect to true north. Because the error in the Kochab-Mizar alignment can be readily calculated for any date, the error in each pyramid’s orientation reveals its construction date [1].” [2]

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[1] Spence, Kate. Ancient Egyptian chronology and the astronomical orientation of pyramids. Nature 408, 320 – 324 .2000
[2] http://www.nature.com/news/2000/001116/full/news001116-10.html    Dinah Ashman

The Star Clock – a quarter turn of the visible starry sky or 6 hours on our time scale, 90 degrees …

On the Nebra Sky Disc facing south we see our Winter Hexacon and a triangle constellation.On the Nebra Sky Disc facing south, two large constellations form a triangle and a star at the edge on the right, as well as from a hexagon and two stars on the upper edge are depicted.

On the Nebra Sky Disc facing north we see eight circumpolar star circling an invisible North Pole..

Looking north, eight circumpolar stars circle an invisible North Pole whose position on the Sky Disc is determined by three independent clues. The distances between the parallel circles of these stars proportionately fit the altitude angles of some of the brightest circumpolar stars.

The meridian is an imaginary great circle which runs through the North Pole and the South Pole; 90° to the horizon.

In the star clock three of the circumpolar stars discovered in the meridian are located almost vertically above one another, while at the same time the constellation from the Winter Hexagon with Deneb, and Vega at the northerly point, could be seen. Exactly six hours later two more circumpolar stars form an astral hand, when Altair had risen at the eastern point and thereby the triangular constellation occupied the eastern quarter of the sky, while Procyon from the Hexagon was located near the western point, shortly before setting. Another six hours later the first astral hand reached his upper culminacion in the meridian and another six hours later the stars of the second hand had changed their places. Two astral hands in their lower and upper culmination.

One of two astral hands had reached his lower culmination on the meridian.
Six hours later respectively one star of another hand was standing on each side of the North Pole.
After another 90 dedrees sky turn the first reached his upper pinnacle.
And again after a quarter turn of the visible starry sky the second had turned, as well, while Procyon was just rised and had reached the east point. This astral hand form an exactly 90° angle with Procyon in the east.

As the two stars Procyon and Altair moved parallel to the equinoctial line, one could see them performing a quarter astral course when they were positioned above the southern point.