Crust (geology) enriched compared to the underlying mantle. Although the continental crust comprises only about 0.6 weight percent of the silicate on Earth, it contains 20% to 70% of the incompatible elements. All the other constituents except water occur only in very small quantities and total less than 1%. Estimates of average density for the upper crust range between 2.69 and 2.74 g/cm and for lower crust between 3.0 and 3.25 g/cm. Earth formed approximately 4.6 billion years ago from a disk of dust and gas orbiting the newly formed Sun. It formed via accretion, where planetesimals and other smaller rocky bodies
The Future and Its Enemies Edward Younkins, a professor at Wheeling Jesuit University, wrote for the journal "Free Life" praising the book as a "brilliant, bold, and compelling new work". He also referred to it as "a must-read for anyone interested in commerce, technology, public policy, and the search for truth in a dynamic world." The Future and Its Enemies The Future and Its Enemies: The Growing Conflict Over Creativity, Enterprise, and Progress is a 1998 book by Virginia Postrel where she describes the growing conflict in post-Cold War society between "dynamism" – marked by constant change, creativity and exploration in the pursuit of progress