Karl Benz invented the first automobile, which improved transportation by making it faster than walking. Medicine has advanced significantly over the centuries, from early Egyptian breakthroughs to 20th-century improvements in science, technology, and disease treatment. The atom bomb was developed in the early 20th century by scientists like Robert Oppenheimer, opening up understandings of atomic structure. Technology from the 20th century like radios, TVs, and refrigerators profoundly impacted lives for better and worse, with the refrigerator evolving from early iceboxes to today's varied designs. The document ranks technology as the best 20th-century improvement, enabling communication, education, disease treatment, and a better world.