The twentieth century was a period of rapid advancements in various fields of research, including science, technology, and social sciences. Important discoveries and developments during this time included the theory of relativity, quantum mechanics, the discovery of DNA, the development of computers and the internet, and the rise of modern psychology and sociology. Key research areas in the twentieth century included physics, biology, chemistry, medicine, psychology, sociology, and engineering. Researchers and scientists during this time made significant contributions to our understanding of the natural world, human behavior, and society as a whole. Overall, the twentieth century was a time of great innovation and progress in the field of research, leading to major breakthroughs that continue to shape our world today.