The Concrete Pyramids

[TacticalNuke]

Concrete was poured to build the Great Pyramids about 5,000 years ago, according to controversial research, which suggests the ancient Egyptans predated the Romans by thousands of years as the inventors of concrete.

http://dsc.discovery.com/news/2006/12/08/pyramids_arc.html?category=archaeology&guid=20061208120000&dcitc=w19-502-ak-0000

[Antoinette]

Interesting. The chemical analysis of the "limestone" convinces me that the pyramids do contain the earliest known concrete.

It is great to think about topics other than the service academies. Thanks for the distraction!