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POPSPyramids packed with fossil shells. They say that seashells prove that the rock was quarried, instead of cast in moulds. I can't imagine how making their own 10 tonne bricks in moulds would have made things any easier. Maybe just adding another stage to a process that was already a huge undertaking. I also heard once that after something is build it hasto 'settle' into into it's foundations, Very few builders or architects have been able to find a way to overcome this, but with their weight, and perfect seams with no mortar, the pyramids have only settled a fraction - perhaps a few inches, over thousands of years. Something that seems much more likely with solid rock than bricks. If only the library in Alexandria hadn't burned down with all of the blueprints.
7
POPSMars canyon in HD Hebes Chasma is a very prominent Mars feature just north of the huge Valles Marineris system (a.k.a. the "Grand Canyon of Mars"). Hebes is described as an enclosed trough, with a high, flat-top mountain range right in the centre. The canyon is over 8 km deep in places, and the central mountain ascends to this height, at the same level as the surrounding plains
7
POPSAppalachian Trail: Maine to Georgia...Could It Be Extended? 
Benton MacKaye was convinced that the pace of urban and industrial life along the East Coast was harmful to people. He convened the first Appalachian Trail "conference" in Washington, D.C., in 1925. That gathering of hikers, foresters, and public officials embraced the goal of building the A.T. Currently, the A.T. goes from Maine to Georgia, but there is a movement to extend the A.T. to attach to the existing Alabama Pinhoti trail. Such a move would require an act of Congress: to change the wording of the National Trails System Act of 1968 to include Alabama. But --- it is not that easy when you take into consideration Georgia. An extension could siphon hikers and their tourist dollars away. I think that an extension would carry on Mackaye's original vision: He envisioned the A.T. as a path interspersed with planned wilderness communities where people could go to renew themselves. An extension into Alabama would only expand this wilderness escape and national treasure.
16
POPSClever Inventions Most of these would have started as serious inventions by earnest people. Hope they can laugh at them as easily as I did.
2
POPSTalc keeps killer quakes at bay Talc is a watery mineral composed of magnesium, silicon and oxygen. But it is not a major component of the earth's crust. But when present in sufficient quantity it can, at sufficiently high temperatures, forestall a dangerous build-up of pressure, say geologists Diane Moore and Michael Rymer from the US Geological Survey. Talc has a hardness rating of 1, the lowest possible, while diamonds have a rating of 10. Talc is held together by weakly-bonded microscopic platelets that slide past one another, giving talc its soft, almost oily feel. The mineral is used in the production of ceramics, paint, paper and a number of building materials, and is also present is some food and pharmaceutical products.