The document summarizes several scientific breakthroughs that occurred between 1921 and 1930, including: 1. The discovery of insulin in 1921 and vitamin E in 1922. 2. Advances in immunization in 1923 and theories about the Earth's core in 1924. 3. Understanding of genetic inheritance in 1925. 4. The discovery of penicillin in 1928, which revolutionized medicine. 5. Developments in physics included Einstein's theory of relativity in 1921 and the discovery of other galaxies in 1929.