Deep time

Deep time is the concept of geological time that spans billions of years, far beyond the scale of human experience. It provides the temporal framework for understanding the formation and evolution of Earth, the development of life, and the slow-moving processes that shape planetary change. First developed as a scientific idea in the 18th century and popularized in the 20th century by writers such as John McPhee,^[1] the concept of deep time has influenced fields ranging from geology and evolutionary biology to climate science, philosophy, education, and environmental ethics. Today, deep time is increasingly used in science communication and public engagement, offering a powerful lens for understanding human impact during the Anthropocene.