Stable isotope analysis is a scientific technique used to study the composition of materials by measuring the ratios of stable isotopes, which are variants of elements that do not decay over time. This method is commonly applied in fields such as geochemistry, archaeology, and environmental science to gain insights into processes like climate change, food webs, and ancient human diets. By analyzing samples from sources like water, soil, or biological tissues, researchers can trace the origins and movements of materials. For example, stable isotopes of carbon and nitrogen can reveal information about an organism's diet and habitat, helping scientists understand ecological relationships and historical changes in environments.