Final answer:
An archaeologist discovers physical remains known as artifacts and fossils, which are crucial for understanding past civilizations through the scientific process of archaeological excavation.
Step-by-step explanation:
The physical remains, which an archaeologist discovers, are also referred to as artifacts and fossils. Artifacts are objects made by human beings that reveal evidence of ancient cultural activity, such as stone tools, pottery, or bones with carvings. Fossils, in the broader sense used by biological anthropologists, are the preserved remains of plants and animals, but in archaeology, they usually refer to human or animal bones that survive the environmental conditions over time. Archaeological excavation is the scientific process that uncovers these artifacts and fossils, aiming to understand the history and culture of past civilizations. This excavation involves meticulous grid-system mapping, careful removal of earth, and detailed cataloging of finds, often bringing in specialists to analyze ecofacts, such as seeds or animal bones, which can also provide insight into the relationship between ancient peoples and their environment.