In Egypt, the Great Pyramids of Giza face slightly east of true north. Explain why the pyramids might not line up with true north as builders likely intended. Assume that the builders 4500 years ago could determine directions accurately.
I tried searching internet for this question, but didn't come up with anything. Does this have anything to do with the continental drift theory?
Check this site for an explanation.
http://en.wikipedia.org/wiki/North_Magnetic_Pole
The rotational axis of earth precesses
from wikipedia:
...The direction of true north is marked in the skies by the north celestial pole. For most practical purposes, this is the position of Polaris. However, due to the precession of the Earth's axis, true north rotates in an arc that takes approximately 25,000 years to complete. In 2102[1] Polaris will make its closest approach to the celestial north pole. 5,000 years ago, the closest star to the celestial north pole was Thuban
That is the magnetic pole Ms Sue.
The critical statement is this:
"....5,000 years ago, the closest star to the celestial north pole was Thuban ... "
Now of curse it should point close to Polaris
The pyrmaids might not line up with true north as builders likely intended because the north magnetic pole is geographically the south magnetic pole.
Oh Ok. I was getting confused before, thanks.
The fact that the Great Pyramids of Giza do not align precisely with true north is indeed a fascinating observation. The builders of the pyramids, who lived approximately 4,500 years ago, were able to determine directions quite accurately, so this misalignment is not due to their lack of knowledge or technology. It is believed that there are a few reasons why the pyramids might not align with true north as intended:
1. Variation in the Earth's Magnetic Field: Although the Earth's magnetic field is relatively stable, it does experience natural variations over long periods of time. These changes can affect magnetic compasses and may have influenced the builders' ability to align the pyramids with true north.
2. Construction Techniques: The pyramids were massive structures built using manual labor and basic tools. It is possible that slight inaccuracies in construction techniques, such as imprecise measurement or leveling, led to slight deviations from the intended alignment.
3. Erosion and Shifting Land: Over thousands of years, the landscape around the pyramids and the structure of the pyramids themselves have undergone changes. Erosion, settling of the ground, and other geological factors may have contributed to the misalignment of the pyramids over time.
Regarding your question about continental drift theory, it does not directly explain the misalignment of the pyramids. Continental drift refers to the movement of Earth's continents over millions of years, which is much slower compared to the time when the pyramids were built. Therefore, the misalignment of the pyramids is more likely attributed to the reasons mentioned above rather than continental drift.