The second-most-used substance on Earth is concrete; the first is water. Enormous volumes of cement and concrete are produced each year, and amounts are rising significantly with population growth and emerging economies. Concrete is a major greenhouse gas contributor to climate change, so reductions in this footprint are critically needed.
How did the ancient Andeans and Egyptians move the massive stone blocks used to build their monumental architecture? With an abundance of human muscle power but only simple hand tools, they needed to be creative. Floating blocks on boats across lakes and along river channels was a possible transport method—but did they have the water and the engineering technology for this?