World Wars and the AtomScience & Math First nuclear reactor 1942Major Enrico Fermi's team achieves the first controlled nuclear chain reaction. ▲ MattersSaveShareTrace roots Longest chain: The Big Bang → First stars ignite → Supernovae seed heavy elements → The Sun forms → Earth forms → First oceans → First life → Photosynthesis evolves → Great Oxidation Event → Complex cells (eukaryotes) → Multicellular life → First animals → Cambrian Explosion → First vertebrates → Jawed fish → Fish walk onto land → The amniotic egg → The Great Dying → Dinosaurs appear → Asteroid ends the dinosaurs → Early primates → Apes split from monkeys → Human line splits from chimpanzees → Walking upright → First stone tools → Genus Homo appears → Homo erectus → Control of fire → Habitual fire and cooking → Homo sapiens appears → Complex language → Natufian villages → Oldest known bread → Agriculture begins → Irrigation → Uruk and the first cities → Cylinder seals → Writing (cuneiform) → Babylonian mathematics → Babylonian astronomical diaries → Thales and natural philosophy → Trial and death of Socrates → Plato's Academy → Aristotle's Lyceum → Alexander's conquests → Alexandria founded → Library of Alexandria → House of Wisdom → Ibn al-Haytham's Book of Optics → Bacon's Novum Organum → Royal Society → Papin's steam digester → Newcomen steam engine → Watt's steam engine → Thermodynamics → Entropy → Quantum hypothesis → Special relativity and E=mc² → Nuclear fission → First nuclear reactor Community notesLoading notes… Learn more ranked by votesDocumentbritannica.comChicago Pile No. 1 (Britannica) ↗Editor's pickDocumentenergy.gov10 intriguing facts about the world's first nuclear chain reaction (U.S. Department of Energy) ↗Editor's pickBookRichard RhodesThe Making of the Atomic Bomb ↗Editor's pickBookDavid N. SchwartzThe Last Man Who Knew Everything: The Life and Times of Enrico Fermi ↗Editor's pickVideoSearch on YouTubeChicago Pile-1 first nuclear reactor ↗Editor's pick