The major scientific breakthrough that enabled mass production during the industrial age was the development of the assembly line technique, particularly popularized by Henry Ford in the early 20th century. This innovation allowed for the efficient production of goods on a large scale by dividing labor into specific tasks carried out simultaneously in a continuous flow. It drastically reduced the time and cost of manufacturing items, making products more accessible to the public. Additionally, this practice led to an increase in employment opportunities and contributed to the overall economic growth associated with the Industrial Revolution.