Archaeology is the study of buildings and objects that people made a long time ago. Archaeologists take a look at how people lived before writing was invented. They examine their daily life and what they left behind. They also try to find out why cultures and civilizations fell apart or why people of the time hunted certain animals. Because history is such a vast field, archaeologists mostly concentrate on certain periods of history, for example ancient Greece, or ancient Egypt. An archaeologist has many different tasks to do. Besides fieldwork they excavate objects and try to reconstruct historical sites. They also examine their findings and try to learn more about a certain period in history. Fieldwork is the discovery of sites that are worth studying. Sometimes archaeologists know where to look for, however, at other times they make such discoveries by chance. Some objects are close to the surface and can be found easily while others can only be traced with the help of satellite images or other advanced methods. For archaeological sites under the earth's surface or under water they use sound technology and radar. After fieldwork is completed an archaeologist starts to excavate the site. They use various instruments like shovels and picks, but must be careful not to damage or destroy valuable objects and findings. Architects use special brushes to scrap away soil and set objects free. The objects they discover are called artefacts. They are labelled and often covered with chemicals so that they can be preserved. Sometimes field laboratories are set up in order to catalogue the objects that are found. When finished with digging out ancient objects archaeologists must interpret what they have found. They try to determine how old artefacts are and from which period they come. Sometimes scientists from other fields help with their work. An archaeologist can date an object by comparing it with the other objects that have been nearby. Artefacts are compared with rock layers in order to figure out their approximate age. Other methods use the rings of the trees, which proves to be highly accurate. Radiocarbon dating is the most accurate method of finding out how old something is. Every living object has traces of radioactive carbon in them. The amount of carbon decreases after a living thing dies. Archaeologists can compare the carbon in artefacts to living objects and calculate their age. This method is very accurate for objects that go back thousands of years. Archaeology first emerged during the Renaissance period of the 1400s. At that time many people were curious about older things. They found pleasure in the classics and were anxious to find out how the ancient Greeks and Romans lived. In the 18th century excavations began in Italy. During that time the historic sites of Pompeii and Herculaneum were set free. Scientists found streets, baths houses as well as paintings and statues from the old Roman towns. In the 1870s Troy and other sites on Greek islands were excavated. The most exciting finding of modern archaeology occurred in 1922 when the British archaeologist Howard Carter found the tomb of Egyptian pharaoh Tutankhamen in the Valley of the Kings. Inside the tomb was a mummy in a gold coffin which was virtually untouched. Later on other parts of the world became the centre of archaeological interest. In 1940, caves with prehistoric wall painting were found in southern France. Other important sites include the Aztec civilisation in Mexico and the Terracotta Army of ancient China. Today most archaeologists work at universities or government departments, which also provide funds for their work. Sometimes they get money from museums or private organisations.