Archaeologists examine artifacts and ancient sites to understand historic periods. Anthropologists study past and present human cultures, drawing on knowledge to examine and analyze cultural growth over time. Linguists study human language in terms of form, meaning, and social context, and are skilled in multiple languages. Political scientists and economists analyze governments, public affairs, goods, services, and important economic figures to understand their fields. Oceanographers use chemistry and earth science to study the physical properties and currents of the oceans.