Gatesnotes, the blog of Microsoft founder Bill Gates, recently discussed the role of materials such as concrete, steel and plastics and how they made modern life possible. He discusses these materials, and their role in the developing world, by way of a book review: Making the Modern World: Materials and Dematerialization by historian Vaclav Smil. Smil argues that the most important man-made material is concrete.

"The most important material in terms of sheer mass is concrete," says Smil in a video interview that accompanies the blog. "To me, this is the most stunning number in the whole book,  that the Chinese poured into their buildings and roads and highways as much concrete in three years as the United States in one century."

"Concrete is the foundation (literally) for the massive expansion of urban areas of the past several decades, which has been a big factor in cutting the rate of extreme poverty in half since 1990." writes Gates. "In 1950, the world made roughly as much steel as cement (a key ingredient in concrete); by 2010, steel production had grown by a factor of 8, but cement had gone up by a factor of 25."