Final answer:
Geologists use fossil evidence, volcanic activity, seismic data, and modern technology like GPS to deduce that the Earth's plates are moving. Physics aids in understanding these plate movements and the Earth's geological history.
Step-by-step explanation:
Geologists have deduced that the plates were moving based on several key pieces of evidence. These include the fossil evidence of ancient sea life found on dry land far from oceans, supporting the idea of continental drift. Volcanic activity, such as the creation of the Hawaiian island chain, and seismic data from earthquakes, also provided insights into the dynamic nature of the Earth's surface. Additionally, geoscientists have utilized modern technology, like GPS and VLBI, to measure the rate and direction of plate motions directly.
Physics plays a role in predicting the motion of tectonic plates and understanding how processes such as mountain building shape the Earth's surface. When considering changes over time, geologists also look at relative dating techniques to determine the geological ages of fossils and calculate the rate of speciation of early organisms.