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
Science of Education: Its General Principles Deduced from its Aim and the Aesthetic Revelation of the World Science of Education: Its General Principles Deduced from its Aim and the Aesthetic Revelation of the World Science of Education (full title: Science of Education: Its General Principles Deduced from its Aim and the Aesthetic Revelation of the World) is a book written by the German empiricist Johann Friedrich Herbart. It was first published in German in 1806 and the first English printing was in 1902. Herbart emphasized education as the way for an individual to fulfill his potential and created a scientific method to help him do so. The Science of Education advocated a five-step methodology that appeals to