Productivity is our economic measure for how far our work goes, as individuals and as a society over all. It plays an important role in determining our quality of life, the prices of our goods and services, and, to some extent, the amount of free time we have. Today, we explore how thousands of years of productivity advancements transformed something now so standard that we take it for granted: light. | At this Summer School, phones ARE allowed during class... Check out this week's PM TikTok! | Listen to past seasons of Summer School here.