[logfromblammo]

Human activity weathers stone monuments faster than desert winds. If I recall correctly, the original sheathing stones and capstones of the pyramids were gradually stolen. The Sphinx was used for target practice.

Water, on the other hand, will tear through your stones much more quickly. In a wet, temperate climate, the weak acid falling from the sky will wear limestone. The moisture invading cracks and freezing will widen those cracks. Lichens will bore tiny holes into the rock, and plant roots will cause fissures to expand. Additionally, moisture that penetrates to metallic structural reinforcement will oxidize and swell that reinforcement to pop bits off of the stone (observable from earlier attempts at restoration at the Parthenon, where the replacement anchor pins weren't coated in lead correctly, and they started to crack the rock blocks--now they use non-corroding titanium pins). Sometimes mortar does not swell or expand at the same rate as whatever it binds, and something will crack, admit water, and generally deteriorate from there.

Water is the enemy of preservation. They pyramids didn't survive just because they are stone, but because they are also dry.

And on a long enough geological timescale, every potential building site will eventually experience every climate, including being entirely immersed in salt water.

[eric_h]

> The Sphinx was used for target practice.

This was the first I've heard that assertion, so it sent me down a bit of a rabbit hole.

Turns out it's a common story that Napoleon used the Sphinx for target practice, hence the lost nose. It also turns out that that is most certainly not true. Napoleon, being wholeheartedly in favor of the enlightenment, would never have destroyed antiquities (only plundered them for his own profit -- lets not forget that the Rosetta Stone was discovered during a Napoleonic campaign).

Further, a 15th century Arab historian notes that the nose was missing in his era and "attributes the loss of the nose to iconoclasm by Muhammad Sa'im al-Dahr—a Sufi Muslim from the khanqah of Sa'id al-Su'ada—in AD 1378, upon finding the local peasants making offerings to the Sphinx in the hope of increasing their harvest. Enraged, he destroyed the nose, and was later hanged for vandalism."[0]

0) https://en.wikipedia.org/wiki/Great_Sphinx_of_Giza#Missing_n...

P.S. thanks for sending me down that rabbit hole - I haven't idly done some armchair egyptology since I was a teenager

[logfromblammo]

The way I heard it, the target practice was responsible for the loss of a piece of an ear. Not having been there to see it myself, I suppose I am not a reliable source for this. Thanks for the fact-checking, as I didn't think to do it myself.