"Constant" is a journey through the social and political histories of measurement. For most of recorded history, the human body was the measure of all things. “Constant” asks what led measurement to depart from the body and become a science unto itself. The film explores three shifts in the history of measurement standardization, from the land surveying that drove Early Modern European land privatization, to the French Revolution that drove the Metric Revolution, to the conceptual dematerialisation of measurement in the contemporary era of Big Science. Each chapter traces the relationship of measurement standardization to ideas of egalitarianism, agency, justice, and power. Cinematic and technical images that begin as products of measurement systems are stretched beyond their functions to describe the resistance of lived experience to symbolic abstractions.