Human Tech Tree

Formal Sciences & Matter

Physics

67 points from the earliest roots to the research frontier: 52 researched, 4 current research, 6 unsolved and 5 that become possible once they are solved. State of knowledge: October 2026.

Open the interactive tree →

Antiquity3000 BC – 500 AD

  • Archimedes: Lever & Buoyancy~250 BCResearchedArchimedes founds statics with the law of the lever and buoyancy, the first exact physics with mathematical proof.

Middle Ages & Renaissance500 – 1700

  • Book of Optics (Alhazen)~1021ResearchedIbn al-Haytham's 'Book of Optics' (about 1011-1021) argues from experiment that vision comes from light entering the eye.
  • Falling Bodies & Planet Orbits1609ResearchedKepler finds the laws of planetary orbits (1609) and Galileo the law of falling bodies (1638): physics becomes a measuring science.
  • Law of Refraction (Snell)1621ResearchedWillebrord Snell finds in 1621 the exact law for how light bends at a boundary; Descartes publishes it in 1637.
  • Vacuum Pumps & Gas Laws1643-1662ResearchedTorricelli's barometer (1643), von Guericke's pump and Boyle's law (1662) show that air has weight and pressure.
  • Newtonian Mechanics1687ResearchedNewton's Principia (1687) explain falling apples and planets with three laws of motion and one law of gravitation.

Industrial Age1700 – 1900

  • Achromatic Lens (Dollond)1758ResearchedJohn Dollond's lens of crown and flint glass (patent 1758) cancels colour fringes and makes sharp refracting telescopes and cameras possible.
  • Electric Charge & Coulomb1785ResearchedFrom Gilbert's De Magnete (1600) and Franklin's lightning experiments to Coulomb's inverse-square law (1785), electricity becomes measurable.
  • Wave Optics (Young, Fresnel)1801ResearchedYoung's interference experiments (1801) and Fresnel's theory (1815-21) show that light is a wave.
  • Fraunhofer: Lines & Gratings1814ResearchedJoseph von Fraunhofer maps hundreds of dark lines in the Sun's spectrum (1814), makes top-quality optical glass and builds diffraction gratings…
  • Thermodynamics1824ResearchedCarnot (1824), Joule, Clausius (1850) and Boltzmann explain heat, energy and entropy: why engines have limited efficiency and time has a direction.
  • Electromagnetism1831-1865ResearchedFaraday (1831) and Maxwell (1865) unite electricity, magnetism and light in four equations; radio waves follow in 1887.
  • Abbe's Image Theory (Zeiss)1873ResearchedErnst Abbe shows (1873) that a microscope image is formed by diffraction and that the smallest detail depends on wavelength and numerical aperture.
  • Statistical Mechanics1877ResearchedMaxwell, Boltzmann and Gibbs derive heat, pressure and entropy from the statistics of countless atoms (1860-1902).
  • Michelson-Morley Experiment1887ResearchedTheir interferometer finds no sign of an 'ether wind' (1887), a puzzle that Einstein's relativity resolves.
  • Radioactivity1896ResearchedBecquerel (1896) and the Curies (1898) find that some atoms send out rays by themselves; atoms turn out to be changeable.
  • Discovery of the Electron1897ResearchedJ. J. Thomson shows (1897) that cathode rays are streams of particles far lighter than any atom.

Machine Age1900 – 1945

  • Planck's Quantum of Action1900ResearchedTo explain heat radiation, Planck assumes (December 1900) that energy is exchanged in discrete packets E = hf.
  • Theory of Relativity1905ResearchedEinstein shows that space and time are relative (1905) and that gravity is curved spacetime (1915).
  • Nucleus & Bohr Atom1911ResearchedRutherford's scattering results (1911) reveal a tiny dense nucleus; Bohr (1913) adds quantised electron orbits.
  • Superconductivity1911ResearchedKamerlingh Onnes finds in 1911 that mercury at about 4 K conducts current without any resistance.
  • X-ray Crystallography1912ResearchedLaue and the Braggs (1912-13) use X-ray diffraction to see how atoms are arranged in crystals.
  • Noether's Theorem1918ResearchedEmmy Noether proves (1918) that every continuous symmetry of nature's laws implies a conserved quantity.
  • Quantum Mechanics1925ResearchedPlanck, Einstein, Bohr, Heisenberg and Schrödinger discover that at small scales energy and matter behave in discrete, probabilistic ways.
  • Expansion & Big Bang1929ResearchedLemaître and Hubble show that the universe expands (1927/1929); the cosmic microwave background (1964) confirms a hot beginning.
  • Electron microscope1931-1933ResearchedMax Knoll and Ernst Ruska built the first electron lens in 1931 and a two-stage electron microscope in 1933 that out-resolved light microscopes.
  • Solid-State Physics & Bands1931ResearchedBloch and Wilson explain with quantum mechanics why some solids conduct, insulate or semiconduct: the band model.
  • Antimatter1932ResearchedDirac's equation (1928) leads him to predict the antielectron (1931); Anderson finds the positron in 1932, the first antiparticle.
  • Particle Accelerators1932ResearchedCockcroft and Walton (1932) split nuclei with artificially accelerated protons; Lawrence's cyclotron scales the idea up.
  • Nuclear Physics1938ResearchedFrom radioactivity (1896) and the atomic nucleus (1911) to nuclear fission (1938): the discovery of the energy inside atoms.
  • Fusion Powers the Stars1939ResearchedBethe shows (1939) that stars shine by fusing hydrogen into helium, explaining the Sun's energy.
  • Manhattan Project1942-1945ResearchedThe US-led wartime programme (1942-45) built the first nuclear weapons, tested on 16 July 1945 and used in August on Hiroshima and Nagasaki.

Atomic & Space Age1945 – 1990

  • Quantum Electrodynamics1948ResearchedFeynman, Schwinger and Tomonaga make quantum field theory calculable (1948) and predict the electron's magnetism to many digits.
  • CERN1954ResearchedTwelve European states found CERN (1954), the model of international big science.
  • Atomic Clock1955ResearchedEssen and Parry's caesium clock (1955) counts the vibrations of atoms and is far more stable than any pendulum or quartz clock.
  • Laser1960ResearchedMaiman builds the first laser in 1960 from Einstein's idea of stimulated emission (1917): light of a single color, perfectly in step.
  • Bell Test of Entanglement1964ResearchedBell's theorem (1964) and experiments from 1972 on show correlations that no local hidden-variable theory can explain.
  • CO2 Laser1964ResearchedKumar Patel at Bell Labs builds the carbon-dioxide laser in 1964: an efficient infrared laser that reaches kilowatts of power.
  • Cosmic Microwave Background1964ResearchedPenzias and Wilson find (1964) a faint radio glow from every direction: the afterglow of the hot early universe.
  • Evidence for Dark Matter1970ResearchedZwicky (1933) and Rubin and Ford (1970) find that galaxies move as if they hold far more mass than we see.
  • Excimer Laser1970ResearchedBasov, Danilychev and Popov build the first excimer laser (1970); krypton- and argon-fluoride versions give deep-ultraviolet light.
  • Standard Model of Particles1973ResearchedQuarks, leptons and three forces in one symmetry-based theory (1960s and 1970s), confirmed by collider experiments for 50 years.
  • Black Hole Thermodynamics1974ResearchedHawking (1974) shows that black holes radiate and have a temperature, linking gravity, quantum theory and thermodynamics.
  • Multilayer EUV Mirrors1981ResearchedUnderwood and Barbee (1981) stack alternating thin layers so that many weak reflections add up and mirrors work for extreme UV and soft X-rays.
  • Scanning Tunnelling Microscope1981ResearchedBinnig and Rohrer's microscope (IBM Zurich, 1981) senses a tunnelling current between a sharp tip and a surface and resolves single atoms; Nobel…

Digital Age1990 – 2015

  • Cold Atoms: BEC & Laser Cooling1995ResearchedLaser cooling (Nobel 1997) chilled atoms to microkelvin; in 1995 JILA made the first Bose-Einstein condensate, 2,000 rubidium atoms below 170 nK…
  • Accelerating Universe1998ResearchedDistant supernovae are dimmer than expected (1998): the expansion of the universe is speeding up, which points to dark energy.
  • Neutrino Oscillations1998ResearchedSuper-Kamiokande (1998) shows that neutrinos change type in flight, so they have mass: a first crack in the Standard Model.
  • Higgs Boson Discovered2012ResearchedOn 4 July 2012 ATLAS and CMS at CERN announce the Higgs boson at about 125 GeV, the last missing piece of the Standard Model.
  • High-Energy Neutrino Astronomy2013ResearchedIceCube, a cubic kilometre of Antarctic ice with light sensors, reported high-energy cosmic neutrinos in 2013; Halzen won the 2026 Physics Nobel.

Present2015 – Oct 2026

  • Gravitational Waves Detected2015Current researchLIGO measures gravitational waves from merging black holes for the first time on 14 September 2015; over 200 events are now cataloged.
  • First Black Hole Images (EHT)2019ResearchedThe Event Horizon Telescope imaged the shadow of the black hole in galaxy M87 (released 10 April 2019) and of the Milky Way's Sagittarius A* (12 May…
  • DESI: Evolving Dark Energy?2025Current researchThe DESI survey maps 14 million galaxies and hints that dark energy weakens over time (2.8 to 4.2 sigma).
  • Muon g-2: Final Result2025Current researchFermilab measures the muon's magnetic anomaly to 127 parts per billion (June 2025); new lattice calculations bring theory into line.
  • Neutrino Mass Below 0.45 eV2025Current researchKATRIN limits the neutrino mass to below 0.45 eV in April 2025, under a millionth of the electron mass; cosmology pushes the sum below 0.064 eV.
  • Quantum Tunneling in a Circuit2025ResearchedNobel Prize 2025 for Clarke, Devoret and Martinis: quantum effects in hand-sized superconducting circuits, the basis of qubits.

Research Frontier · Todayunsolved as of Oct 2026

  • A theory of turbulenceopenUnsolvedTurbulence statistics cannot be derived from the flow equations; engineers use models tuned to data and simulations that stop far below real…
  • Dark Energy & Hubble TensionopenUnsolvedThe universe expands at an accelerating rate (1998), caused by 'dark energy', and two ways of measuring the expansion rate disagree.
  • Dark MatteropenUnsolvedAbout 27% of the universe is invisible matter that shows up only through its gravity; nobody knows what it is.
  • Matter-Antimatter AsymmetryopenUnsolvedThe Big Bang should have made matter and antimatter in equal amounts; why did only matter remain?
  • Quantum GravityopenUnsolvedHow do gravity (Einstein) and the quantum world fit together? There are candidate theories but no measurement that decides between them.
  • Quantum Measurement ProblemopenUnsolvedWhy does a measurement always show a definite result although quantum theory allows superpositions? Where does quantum behavior end?

If Solvedbecomes possible

  • Fate of the Universe Known2030s?If solvedWhether dark energy stays constant or changes decides if the universe expands forever, tears apart or collapses.
  • Physics Beyond Standard Model2030s?If solvedNew particles and forces are discovered that explain dark matter and the surplus of matter.
  • Superposition of Large Objects2030s?If solvedMicroscopic crystals or nanodiamonds are put into controlled quantum superposition: a lab test for collapse and gravity.
  • Predictable Turbulence2040s?If solvedTurbulent flows in engineering and nature are predicted from a theory or from models with proven accuracy and error bars.
  • Theory of EverythingopenIf solvedOne consistent theory that describes all four fundamental forces, all particles and spacetime itself.