Geophysics is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment, and the use of quantitative methods for their analysis. The term "geophysics" sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and composition; its dynamics and their surface expression in plate tectonics, the generation of magmas, volcanism and rock formation. However, modern geophysics organizations use a broader definition that includes the water cycle including snow and ice; fluid dynamics of the oceans and the atmosphere; electricity and magnetism in the ionosphere and magnetosphere and solar-terrestrial relations; and analogous problems associated with the Moon and other planets.

Although geophysics was only recognized as a separate discipline in the 19th century, its origins date back to ancient times. The first magnetic compasses were made from lodestones, while more modern magnetic compasses played an important role in the history of navigation. The first seismic instrument was built in 132 AD. Isaac Newton applied his theory of mechanics to the tides and the precession of the equinox; and instruments were developed to measure the Earth's shape, density and gravity field, as well as the components of the water cycle. In the 20th century, geophysical methods were developed for remote exploration of the solid Earth and the ocean, and geophysics played an essential role in the development of the theory of plate tectonics.

1. What is the main topic of this article?
2. When was this term recognized as a separate discipline in the sciences?
3. When was it first studied, though without a name?
4. Do modern geophysics include the water cycle as part of this science?
5. Did earlier ones?
6. What was an important part of earlier versions of the compass?
7. Do modern geophysics include the oceans as part of this science?
8. Do modern geophysics include volcanoes as part of this science?
9. What was one type of scientist that was important in the development of the theory of plate tectonic?
10. Do geophysics include magnetic fields as part of this science?

Provide a numbered list of answers.
1. Geophysics
2. 19th century
3. unknown
4. Yes
5. No
6. unknown
7. Yes
8. Yes
9. Isaac Newton
10. Yes