summarize what have learned in Chapter 4 Physics of the Globe topic, specifically the topic of Gravimetry, Magnetism, Geothermic. (150 words)

In Chapter 4 of Physics of the Globe, we delved into the fascinating world of Gravimetry, Magnetism, and Geothermics. Gravimetry, the measurement of the strength of a gravitational field, taught us about the variations in Earth's gravitational field and how these can be used to understand its internal structure. Magnetism introduced us to Earth's magnetic field, its origin, and its importance in navigation and protecting us from solar wind. We learned about the dynamo theory and how the movement of molten iron within Earth's outer core generates this field. Lastly, Geothermics provided insight into the heat within the Earth, its sources, and how it is transferred to the surface. This heat plays a crucial role in plate tectonics and volcanic activity. Overall, these topics gave us a deeper understanding of the complex and dynamic nature of our planet.