The document identifies the five most important scientific advancements of the 20th century as flight, radio, psychology, DNA structure, and the personal computer. It summarizes that flight revolutionized transportation and international relations. Radio expanded communication globally. Psychology challenged existing ways of thinking and treating mental disorders. DNA structure explained genetics and revolutionized medicine and biology. The personal computer assimilated all prior advancements by allowing easy access to travel, communication, study and more from one device.