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) for the Moon was the Silver Flower, and Gollum referred to it as the White Face. The Moon was more highly valued than the Sun by the Elves, both because it came from the Elder Tree, and because it rose first. In the universe of Middle-earth, the Moon was generally regarded as masculine, in recognition of Tilion. This gender corresponds with Máni, the personified moon in Norse mythology. In the early versions of "The Silmarillion" as described in "The Book of Lost Tales 1", a part of The History of Middle-earth series, the Sun was described in great detail as