Important Scientific Discoveries in 20th Century By ayemanmahbub 1900 Max Planck: Emission of Electron Spectrum 1905 Albert Einstein: Theory of Relativity 1911 Ernest Rutherford: Atomic Nucleus 1913 Niels Bohr: Model of the atom 1925 Erwin Schrödinger: Schrödinger equation (Quantum mechanics) 1929 Alexander Fleming: Penicillin, the first beta-lactam antibiotic 1938 Otto Hahn, Lise Meitner and Fritz Strassmann: Nuclear fission of heavy nuclei 1947 William Shockley, John Bardeen and Walter Brattain invent the first transistor 1967 Vela nuclear test detection satellites discover the first gamma-ray burst 1980 Klaus von Klitzing discovered the Quantum Hall Effect.
