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
What Shall We Do Now? with D minor and A minor chords. Where the album's main character, Pink's question about how he should fill out the gaps in his wall was of a rhetorical nature in "Empty Spaces", "What Shall We Do Now?" lists the diversions, possessions, and vices of a rock star (""Shall we buy a new guitar / Shall we drive a more powerful car / Shall we work straight through the night / Shall we get into fights / Leave the lights on / Drop bombs ..."") in response. The two tracks are easily confused. The tape speed for "Empty Spaces" was