Physical geodesy is a branch of geodesy that mainly focuses on the measurement of gravity and the shape of the earth. It is a highly technical and specialized field that requires advanced knowledge and skills. There are several synonyms for the term physical geodesy, such as geodetic physics, mathematical geodesy, geodetic surveying, and physical surveying. Each of these synonyms emphasizes different aspects of the same field of study. Geodetic physics, for example, emphasizes the use of physics to understand the earth's shape and gravity field, while physical surveying focuses on the practical measurement techniques used to collect data about the earth's physical properties.