Geophysics to every area of the Earth sciences. To provide a clearer idea of what constitutes geophysics, this section describes phenomena that are studied in physics and how they relate to the Earth and its surroundings. The gravitational pull of the Moon and Sun give rise to two high tides and two low tides every lunar day, or every 24 hours and 50 minutes. Therefore, there is a gap of 12 hours and 25 minutes between every high tide and between every low tide. Gravitational forces make rocks press down on deeper rocks, increasing their density as the depth increases. Measurements
Sun and Moon (Middle-earth) an immense island of fire. The Moon was described as an immense island of crystal. It was also said there that the youth Tilion, who guided the Moon, was said to secretly be in love with Arien, the maiden who guided the Sun, and that because he steered the Moon too close to the Sun the Moon was burned, causing the darker spots on the Moon (the Lunar maria). Aulë devised "vírin", a crystalline material from which he made a cup wherein the flower was set. The markings on the moon are caused as Lórien tried to pluck the "Rose