Particle Physics & The Standard Model: Key Innovations & Milestones
Encyclopedia/1. The Cosmos & The Natural World/2. Physics & Chemistry • Curated by Admin Timeline.sg
This timeline traces the development of particle physics from ancient atomic theories to the discovery of the Higgs boson, highlighting key experiments and theoretical breakthroughs that shaped the Standard Model.
Chronological Storyline (44 Milestones)
400 BCE
Democritus Proposes Atomism
Greek philosopher Democritus proposes that all matter is composed of indivisible particles called atoms. #philosophy #science
Democritus Proposes Atomism By user:shakko - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=5535206
1803 CE
Dalton's Atomic Theory
John Dalton proposes atomic theory based on experimental evidence, stating elements consist of atoms. #chemistry #science
Dalton's Atomic Theory By Thomas Phillips - National Portrait Gallery, London, Public domain, https://commons.wikimedia.org/w/index.php?curid=11727058
1897 CE
Discovery of the Electron
J.J. Thomson discovers the electron through cathode ray experiments, identifying the first subatomic particle. #physics #particlephysics
Discovery of the Electron By Not Mentioned - First World War.com, Public domain, https://commons.wikimedia.org/w/index.php?curid=2969861
1905 CE
Einstein's Photoelectric Effect
Albert Einstein explains the photoelectric effect, proposing light quanta (photons). #physics #quantum
Einstein's Photoelectric Effect By Ponor - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=92684859
1911 CE
Rutherford Discovers the Nucleus
Ernest Rutherford's gold foil experiment reveals the atomic nucleus, leading to the nuclear model. #physics #nucleus
1913 CE
Bohr Model of the Atom
Niels Bohr proposes a model with quantized electron orbits, explaining hydrogen spectra. #physics #quantum
Bohr Model of the Atom By JabberWok at English Wikipedia - Transferred from en.wikipedia to Commons., CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2639910
1919 CE
Rutherford Discovers the Proton
Ernest Rutherford identifies the proton through alpha particle scattering in nitrogen gas. #physics #proton
Rutherford Discovers the Proton By Arpad Horvath - Own work, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=637353
1925 CE
Pauli Exclusion Principle
Wolfgang Pauli formulates the exclusion principle, explaining electron shell structure. #physics #quantum
Pauli Exclusion Principle By Unknown author, Public domain, https://commons.wikimedia.org/w/index.php?curid=333866
1927 CE
Heisenberg's Uncertainty Principle
Werner Heisenberg introduces the uncertainty principle, a cornerstone of quantum mechanics. #physics #quantum
Heisenberg's Uncertainty Principle By Unknown author - This image was provided to Wikimedia Commons by the German Federal Archive (Deutsches Bundesarchiv) as part of a cooperation project. The German Federal Archive guarantees an authentic representation only using the originals (negative and/or positive), resp. the digitalization of the originals as provided by the Digital Image Archive., CC BY-SA 3.0 de, https://commons.wikimedia.org/w/index.php?curid=5436254
1928 CE
Dirac Equation Predicts Antimatter
Paul Dirac formulates a relativistic quantum equation, predicting the existence of antimatter. #physics #antimatter
1932 CE
Discovery of the Positron
Carl Anderson discovers the positron, the first antimatter particle, in cosmic rays. #physics #antimatter
Discovery of the Positron By Carl D. Anderson (1905–1991) - Anderson, Carl D. (1933). "The Positive Electron". Physical Review 43 (6): 491–494. DOI:10.1103/PhysRev.43.491., Public domain, https://commons.wikimedia.org/w/index.php?curid=93111759
1932 CE
Discovery of the Neutron
James Chadwick discovers the neutron, completing the picture of atomic nuclei. #physics #neutron
Discovery of the Neutron By No machine-readable author provided. Harp assumed (based on copyright claims). - No machine-readable source provided. Own work assumed (based on copyright claims)., CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=637381
1935 CE
Yukawa Proposes the Pion
Hideki Yukawa predicts the existence of mesons as carriers of the strong nuclear force. #physics #nuclear
Yukawa Proposes the Pion By Nobel Foundation archive - nobelprize.org [1], Public domain, https://commons.wikimedia.org/w/index.php?curid=6182205
1937 CE
Discovery of the Muon
Carl Anderson and Seth Neddermeyer discover the muon in cosmic rays, initially puzzling physicists. #physics #muon
1947 CE
Discovery of the Pion
Cecil Powell and colleagues discover the pion in cosmic rays, confirming Yukawa's prediction. #physics #pion
Discovery of the Pion By No machine-readable author provided. Harp assumed (based on copyright claims). - No machine-readable source provided. Own work assumed (based on copyright claims)., CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=637403
1950 CE
Fermi's Theory of Beta Decay
Enrico Fermi formulates a theory of beta decay, introducing the weak interaction. #physics #weakforce
Fermi's Theory of Beta Decay By Inductiveload - Own work, Public domain, https://commons.wikimedia.org/w/index.php?curid=2859203
1955 CE
Discovery of the Antiproton
Emilio Segrè and Owen Chamberlain discover the antiproton at the Bevatron. #physics #antimatter
Discovery of the Antiproton By en real life identity: SHA-1 commitment ba62ca25da3fee2f8f36c101994f571c151abee7 - Self created using Inkscape from File:Quark structure proton.svg as a template., CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=24105730
1956 CE
Discovery of the Neutrino
Clyde Cowan and Frederick Reines detect the neutrino, confirming its existence. #physics #neutrino
Discovery of the Neutrino By Argonne National Laboratory - Image courtesy of Argonne National Laboratory, Public domain, https://commons.wikimedia.org/w/index.php?curid=10949136
Parity Violation in Weak Interactions By Smithsonian Institution - Flickr: Chien-shiung Wu (1912-1997), No restrictions, https://commons.wikimedia.org/w/index.php?curid=18759827
1961 CE
Gell-Mann's Eightfold Way
Murray Gell-Mann proposes the Eightfold Way, organizing hadrons into patterns based on symmetry. #physics #quarks )
Gell-Mann's Eightfold Way By Laurascudder - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2379550
1964 CE
Higgs Mechanism Proposed
Peter Higgs and others propose the Higgs mechanism to explain mass generation via spontaneous symmetry breaking. #physics #higgs
Higgs Mechanism Proposed By Cush - Own work using: PBS NOVA [1], Fermilab, Office of Science, United States Department of Energy, Particle Data Group, Public domain, https://commons.wikimedia.org/w/index.php?curid=4286964
1964 CE
Quark Model Proposed
Murray Gell-Mann and George Zweig independently propose quarks as fundamental constituents of hadrons. #physics #quarks
1967 CE
Electroweak Unification
Steven Weinberg and Abdus Salam unify electromagnetic and weak forces into the electroweak theory. #physics #standardmodel
1968 CE
Deep Inelastic Scattering at SLAC
Experiments at SLAC reveal point-like constituents inside protons, providing evidence for quarks. #physics #quarks
Deep Inelastic Scattering at SLAC By E2m - Own work, Public domain, https://commons.wikimedia.org/w/index.php?curid=1796747
1970 CE
GIM Mechanism Predicts Charm Quark
Glashow, Iliopoulos, and Maiani propose the charm quark to explain absence of flavor-changing neutral currents. #physics #quarks
GIM Mechanism Predicts Charm Quark By Blibla - Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=50058727
Simultaneous discovery of the J/ψ meson at SLAC and Brookhaven confirms the charm quark. #physics #quarks
Discovery of the J/ψ Meson By https://commons.wikimedia.org/wiki/User:Harp - File:Quark_structure_pion.svg, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=46504895
1975 CE
Discovery of the Tau Lepton
Martin Perl discovers the tau lepton at SLAC, the third generation charged lepton. #physics #lepton )
Discovery of the Tau Lepton By user:MissMJ - File:Standard Model of Elementary Particles.svg, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=24692629
1977 CE
Discovery of the Upsilon Meson
Discovery of the upsilon meson at Fermilab reveals the bottom quark. #physics #quarks
Discovery of the Upsilon Meson By Unknown author, Public domain, https://commons.wikimedia.org/w/index.php?curid=1570293
1979 CE
Discovery of the Gluon
Experiments at DESY's PETRA collider provide direct evidence for gluons via three-jet events. #physics #gluon
Discovery of the Gluon By Joel Holdsworth (Joelholdsworth) - Non-Derived SVG of Radiate gluon.png, originally the work of SilverStar at Feynmann-diagram-gluon-radiation.svg, updated by joelholdsworth., Public domain, https://commons.wikimedia.org/w/index.php?curid=1764161
1983 CE
Discovery of W and Z Bosons
CERN's UA1 and UA2 experiments discover the W and Z bosons, carriers of the weak force. #physics #weakforce
1989 CE
LEP Collider Begins Operation
The Large Electron-Positron Collider at CERN starts operation, precisely testing the Standard Model. #physics #collider
LEP Collider Begins Operation By Juhanson - Image taken by Juhanson during CERN 50 Years OpenDay, using Canon EOS 10D camera, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=197318
1995 CE
Discovery of the Top Quark
Fermilab's CDF and DØ experiments discover the top quark at the Tevatron. #physics #quarks
Discovery of the Top Quark By user:MissMJ - File:Standard Model of Elementary Particles.svg, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=24657343
Neutrino Oscillations Discovered By Lucas Taylor / CERN - http://cdsweb.cern.ch/record/628469, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1433671
2000 CE
Discovery of the Tau Neutrino
Fermilab's DONUT experiment directly detects the tau neutrino, completing the lepton family. #physics #neutrino
Discovery of the Tau Neutrino By user:MissMJ - File:Standard Model of Elementary Particles.svg, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=24692631
2008 CE
LHC Starts Operations
The Large Hadron Collider at CERN begins operations, designed to explore the TeV scale. #physics #collider
LHC Starts Operations By Arpad Horvath - Drawn by Arpad Horvath with Inkscape., CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=679693
Jul 4, 2012 CE
Discovery of the Higgs Boson
ATLAS and CMS experiments at the LHC announce the discovery of a Higgs-like particle, confirming the Higgs mechanism. #physics #higgs
Discovery of the Higgs Boson By CERN for the ATLAS and CMS Collaborations - https://cds.cern.ch/record/1630222, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=29737816
2013 CE
Nobel Prize for Higgs Mechanism
François Englert and Peter Higgs receive the Nobel Prize in Physics for the Higgs mechanism. #physics #higgs
Nobel Prize for Higgs Mechanism By Design of the medal: The Nobel Foundation. Sculptor and engraver: Erik Lindberg (1902). - Source of this work Photographer: David Monniaux (2005, 2006, 2007) Edited by: hidro 21:17, 28 July 2008 (UTC) Design of the medal: The Nobel Foundation. Sculptor and engraver: Erik Lindberg (1902)., Cc-by-sa-3.0, https://en.wikipedia.org/w/index.php?curid=18622921
2015 CE
LHC Run 2 at Higher Energy
The LHC resumes collisions at 13 TeV, searching for new physics beyond the Standard Model. #physics #collider
2016 CE
Discovery of Pentaquarks
LHCb experiment at CERN confirms the existence of pentaquarks, exotic hadrons with five quarks. #physics #hadrons
Discovery of Pentaquarks By Headbomb - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=41591193
2017 CE
Observation of Double Charm Baryon
LHCb observes the Ξcc++ baryon, containing two charm quarks, confirming predictions. #physics #baryons
2018 CE
Tetraquark Discoveries
Multiple tetraquark candidates observed at LHCb and other experiments, expanding hadron spectroscopy. #physics #hadrons
2021 CE
Muon g-2 Anomaly
Fermilab's Muon g-2 experiment confirms a discrepancy with Standard Model predictions, hinting at new physics. #physics #muon
Muon g-2 Anomaly By Reidar Hahn - https://vms.fnal.gov/asset/detail?recid=1950114, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=58326280
2022 CE
LHC Run 3 Begins
The LHC starts its third run at record energy, aiming to collect more data for precision measurements. #physics #collider
