Timeline of Science and Technology in the 20th Century

A list of major events selected by piero scaruffi

Continued from Science of the 19th Century
(See also: A timeline of Biotechnology)
(See also: A timeline of Artificial Intelligence)
(See also: A timeline of Neuroscience)
(See also: A timeline of Computing)

1900: Max Planck discovers that atoms can emit energy only in discrete amounts or "quanta" and that the energy of light is proportional to the frequency
1900: Ferdinand von Zeppelin builds the first rigid dirigible
1900: Sigmund Freud's "The Interpretation of Dreams"

1901: Guglielmo Marconi conducts the first transatlantic radio transmission (for the first time humans can send sounds to any place on Earth without any wires)

1902: Willis Carrier invents the air conditioner
1902: Clarence McClung discovers the sex chromosomes
1903: Wilbur and Orville Wright fly the first airplane
1903: Konstantin Tsiolkovsky's "The Exploration of Cosmic Space by Means of Reaction Devices"
1903: Valdemar Poulsen invents an arc transmitter for radio broadcasts
1903: William Bayliss and Ernest Starling discover that hormones are chemical messengers
1904: John Fleming uses a diode to detect radio signals
1905: Albert Einstein publishes "The Special Theory of Relativity"

1905: Albert Einstein explains that the photoelectric effect is due to the fact that light is made of packets (later dubbed "photons") that behave like particles and its energy can change only by multiples of Planck's constant proportional to the light's frequency
1905: Albert Einstein explains Brownian motion, and proves the existence of atoms
1905: Alfred Binet and Theodore Simon develop the Intelligence Quotient test
1906: William Bateson names a new discipline, "Genetics"
1906: Robert von Lieben invents the triode, the "vacuum tube" (birth of electronics)
1907: Lee DeForest creates the first electronic amplifier
1907: Hermann Minkowski's four-dimensional spacetime
1907: Leo Baekeland invents "bakelite", the first entirely synthetic plastic
1908: Jacques Brandenberger invents cellophane
1908: Ernst Zermelo founds axiomatic set theory
1911: Heike Kamerlingh Onnes discovers superconductivity
1911: General Electric introduces the first commercial refrigerator
1911: Ernest Rutherford discovers that the atom is made of a nucleus and orbiting electrons, and mostly empty, a miniature solar system
1911: Edward Thorndike founds "connectionism" to explain how the mind learns
1912: Alfred Wegener discovers the continental drift
1912: Joseph John Thomson invents the mass spectrometer
1912: Max Wertheimer founds Gestalt Psychology
1913: Ford installs the first assembly line
1913: John Watson founds Behaviorism
1913: Niels Bohr proves that electrons are permitted to occupy only some orbits around the nucleus of the atom, and the angular momentum of an electron is proportional to Planck's constant, and the energy of an atom changes in discrete quantities

Nov 1915: Albert Einstein publishes "The Theory of General Relativity"
1916: Karl Schwarzschild predicts the existence of black holes
1917: Wolfgang Koehler studies problem solving in chimpanzees
1918: Ronald Fisher founds Population Genetics
1918: Hermann Weyl introduces the concept of gauge field to unify gravitation and electromagnetism
1919: Theodor Kaluza adds a fifth dimension to General Relativity
1920: David Hilbert sets out a program to axiomatize mathematics
1921: Edward Sapir formulates the "principle of linguistic relativity" that the structure of a language affects the ways in which its speakers think
1923: Jean Piaget formulates the theory that the mind grows just like the body grows

1923: Arthur Holly Compton performs an experiment (the "Compton Effect") demonstrating that light cannot be only a wave but must also be made of particles
1924: Louis DeBroglie discovers that matter is both particles and waves, with frequency and wavelength being proportional to energy and momentum
1924: Alexander Oparin formulates the theory of the "primordial soup" to explain the beginning of life
1924: Hans Berger records electrical waves from the human brain, the first electroencephalograms
1924: Otto Laporte formulates the law of conservation of parity
1925: Satyendra Nath Bose and Albert Einstein discover a condensate that exhibits macroscopic quantum phenomena
1925: Wolfgang Pauli discovers that some particles (the "fermions") can never occupy the same state at the same time

1926: Erwin Schroedinger's equation of Quantum Mechanics

1926: Oskar Klein proposes a fourth spatial dimension that is undetectable because it is the size of the Planck length
1926: Films with synchronized voice and music are introduced (talking movies)
1926: Robert Goddard launches the first liquid-fuel rocket
1926: Max Born's probabilistic interpretation of the wave amplitudes in Schroedinger's equation.

1927: First vaccines for tuberculosis and tetanus
1927: Philo Farnsworth invents the television
1927: Werner Heisenberg discovers the uncertainty principle

1927: Louis de Broglie discovers a "hidden-variables" interpretation of Quantum Mechanics

1927: Fritz London introduces the first successful gauge theory (phase invariance of electromagnetism)
1928: Paul Dirac discovers antimatter

1928: Fritz Pfleumer invents magnetic tape for audio recording
1928: Alexander Fleming discovers penicillin
1928: Umberto Nobile's dirigible flies over the North Pole
1929: Edwin Hubble discovers that the universe is expanding
1930: Karl Lashley discovers that functions are not localized but distributed around the brain
1930: Paul Dirac proves that the vacuum is not empty
1930: Wolfgang Pauli derives theoretically the existence of the neutrino, a particle that does not interact with ordinary matter
1931: Kurt Goedel's theorem of incompleteness

1932: Fredrick Bartlett formulates the theory of Reconstructive Memory

1932: James Chadwick discovers the neutron
1933: Edwin Armstrong invents FM radio
1933: Fritz Zwicky speculates that the universe must be full of "dark matter"
1933: Otto Stern discovers that the (electrically neutral) neutron has a magnetic field, an ndication that it must have an internal structure
1933: Ernst Ruska builds an electron microscope that exceeds the resolution attainable with an optical microscope
1935: Wallace Carothers invents nylon
1935: Robert Watson-Watt builds the first RADAR
1935: AEG introduces the first magnetic tape recorder
1935: Albert Einstein, Boris Podolsky and Nathan Rosen discover an apparent paradox of Quantum Mechanics (the EPR paradox)
1935: Schroedinger's cat, the most famous thought experiment of Quantum Mechanics, and the first use of the term "entanglement"
1935: Arthur George Tansley introduces the concept of the "ecosystem"
1936: Technetium, the first human-made element
1936: Alan Turing's Universal Machine

1936: Heinrich Focke flies the first helicopter
1937: Chester Carlson invents the photocopier
1938: Otto Hahn, Fritz Strassman and Lise Meitner demonstrate nuclear fission
Dec 1938: Otto Hahn and Fritz Strassmann carry out the nuclear fission of uranium
1938: Chester Carlson invents xerography
1939: Niels Bohr and John Wheeler describe the mechanism of nuclear fission
1939: Walter Schottky explains how the interface between a semiconductor and a metal works
1943: Enrico Fermi achieves a nuclear reaction

1943: Tommy Flowers and others build the Colossus, the world's first programmable digital electronic computer
1944: Oswald Avery discovers that genes are made of DNA
1945: Howard Florey and Ernst Chain develop the first antibiotics
1945: John Von Neumann designs a computer that holds its own instructions, the "stored-program architecture"

1945: The first atomic bombs are exploded by the USA
1947: John Bardeen and William Shockley invent the transistor
1947: Einstein coins the expression "spooky action at a distance" to describe entanglement
1947: Edwin Land invents Polaroid, the first instant camera
1947: Norman Wiener's Cybernetics

1947: Dennis Gabor invents the hologram
1948: Claude Shannon's Theory of Information

1948: Hendrik Casimir shows how the zero-point energy can be detected ("Casimir effect")
1948: Georgiy Gamow develops the Big Bang theory

1949: Donald Hebb's neural selectionism

1949: John von Neumann computes pi to 2,037 decimal places using the ENIAC computer
1950: James-Jerome Gibson argues that biological systems pick up information from the environment
1950: "Human calculator" Shakuntala Devi tours Europe
1951: Carl Djerassi and others invent the oral contraceptive pill
1951: William Wilson Morgan discovers the structure of the MilkyWay galaxy
1951: David Bohm hypothesizes that Quantum Mechanics requires a fifth dimension

1951: Electricity is generated by a nuclear reactor at Arco in Idaho
1952: Harold Urey and Stanley Miller recreate the conditions of early Earth in a laboratory and show how aminoacids may have formed
1953: Eugene Aserinsky discovers "rapid eye movement" (REM) sleep that corresponds with periods of dreaming
1953: Francis Crick and James Watson discover the double helix of the DNA

1953: Taiichi Ohno invents "lean manufacturing" (or "just-in-time" manufacturing)
1953: Roger Sperry studies the "split brain" and discovers that the two hemispheres are specialized in different tasks

1954: George Devol designs the first industrial robot, Unimate
1954: Chen Ning Yang and Robert Mills generalize Maxwell's electromagnetism
1954: The Obninsk Nuclear Power Plant in the USSR became the first nuclear power plant to generate electricity for a power grid
1954: Bell Labs' Gerald Pearson, Calvin Fuller and Daryl Chapin build the first silicon solar cell
1954: The first transistor radio ("Regency")
1955: John McCarthy's Artificial intelligence

1955: Jonas Salk develops the first polio vaccine

1955: Niels Jerne proposes a natural-selection theory of antibody formation

1956: Charles Ginsburg builds the first practical videotape recorder
1956: The first flying car, the Aerocar, is certified in the USA
1956: Chien-Shiung Wu, Chen Ning Yang and Tsung-Dao Lee prove the violation of parity
1957: Frank Rosenblatt conceives the "Perceptron", the first artificial neural network
1957: Albert Sabin develops the oral polio vaccine

1957: The Soviet Union tests the R-7 Semyorka, the first intercontinental ballistic missile (ICBM)
1957: John Bardeen, Leon Neil Cooper, and John Robert Schrieffer provide a theory explaining superconductivity

1957: Hugh Everett introduces an interpretation of Quantum Mechanics without uncertainties, the multiverse
1957: Noam Chomsky's theory of grammar

1957: the Soviet Union launches the first artificial satellite, the Sputnik, mostly designed by Sergei Korolev
1958: Boeing introduces the long-distance jet
1958: Jack Kilby invents the integrated circuit
1958: Jim Backus invents the Fortran programming language, the first machine-independent language
1959: Eveready (later renamed Energizer) introduces the alkaline battery
1959: Michel Jouvet discovers that REM sleep is generated in the brain stem

1959: Robert Noyce co-invents the integrated circuit
1959: Min Chueh Chang invents in-vitro fertilization
May 1960: Theodore Maiman demonstrates the first working LASER
1960: Wernher von Braun spearheads development of NASA's Mercury and Apollo space programs
1961: Charles Bachman develops the first database management system
1961: Marshall Nirenberg and Heinrich Matthaei discover how the 4-letter genetic code gets translated into the 20-letter language of proteins
1961: Fernando Corbato builds the first time-sharing system that allows users to remotely access a computer
1961: Yuri Gagarin becomes the first astronaut
1961: Marshall Nirenberg cracks the genetic code
1961: Jacques Monod and Francois Jacob discover gene regulation
1962: Telstar, the first telecommunication satellite
1962: Texas Instruments introduces what will be come known as LED (Light-emitting diode) technology, invented by James Biard and Gary Pittman
1962: The first Search for Extraterrestrial Intelligence (SETI) takes place with, among others, Frank Drake and Carl Sagan
1963: Murray Gell-Mann's theory of quarks, Quantum Chromodynamics
1963: The touch-tone phone
1963: Douglas Engelbart builds the first "mouse"
1963: Ivan Sutherland demonstrates "Sketchpad", the first program with a graphical user interface
1964: American Airlines' SABRE reservation system is the first online transaction processing
1964: John Young proposes a "selectionist" theory of the brain (learning is the result of the elimination of neural connections)
1964: John Stuart Bell solves the EPR paradox
1964: IBM introduces the first "operating system" for computers
1964: Japan inaugurates the first "bullet train", the Shinkansen
1964: Peter Higgs proves the existence of a mass-giving boson
1965: DEC introduces the first mini-computer based on integrated circuits, the PDP-8
1965: Robert Holley discovers transfer RNA
1965: Arno Penzias and Robert Wilson discover the cosmic microwave background radiation
1966: Hironari Miyazawa proposes a supersymmetry relating mesons and baryons
1966: Rene Thom formulates catastrophe theory
1967: Jack Kilby develops the first hand-held calculator
1967: The first pulsar is observed
1967: Christian Barnard performs the first human heart transplant
1967: Ilya Prigogine shows that biological systems are dissipative systems which self-organize far from equilibrium
1968: Barclays Bank installs networked "automated teller machines" or ATMs
1968: Andries van Dam introduces the "Undo" command
1968: The Arpanet (Internet) is inaugurated
1968: Gabriele Veneziano discovers that a string can describe the interaction of strongly interacting particles
1969: Neil Armstrong is the first human to walk on the Moon
1969: The Concorde, a supersonic passenger airplane
1969: Paul MacLean proposes the theory of the "triune brain"
1969: Yoichiro Nambu introduces string theory
1970: The first practical optical fiber is developed by glass maker Corning Glass Works
1970: Michael Gazzaniga and Joseph Ledoux discover the left-brain "interpreter"
1971: Ananda Chakrabart develops a genetically engineered organism, a new species of Pseudomonas bacteria
1971: Sony introduces the U-matic, first commercial videocassette recorder (VCR)
1971: Ted Hoff and Federico Faggin build the first universal micro-processor
1971: Pierre Ramond introduces the first supersymmetric theory
1972: Ray Tomlinson invents e-mail
1972: Robert Moore and Irving Zucker discover that the suprachiasmatic nuclei is the site of the circadian biologic clock
1972: Hamilton Watch introduces the Hamilton Pulsar P1, the first electronic digital watch and the first using a digital LED display
1972: Raymond Damadian builds the world's first magnetic resonance imaging (MRI) machine
1972: Godfrey Hounsfield and Allan Cormack invent computed tomography scanning or CAT-scanning
1972: Theodore Friedmann and Richard Roblin's "Gene Therapy for Human Genetic Disease?"
1972: Paul Berg's team synthesizes the first recombinant DNA molecule
1972: The Global Positioning System (GPS) is launched
1972: Magnavox introduces the first videogame console, "Odyssey"
1973: Sharp develops the LCD technology for display monitors
1973: Stanley Cohen and Herbert Boyer create the first recombinant DNA organism (the birth of "biotechnology")
1973: Brandon Carter introduces the "anthropic principle" in cosmology
1973: Martin Cooper invents the cellular telephone
1973: Jean-Pierre Changeux discovers neural Darwinism
1974: Ed Roberts invents the first personal computer, the Altair 8800
1974: Sam Hurst invents the touch-screen user interface
1974: Stephen Hawking discovers the radiation of black holes
1974: John Schwarz suggests that string theory is a theory of gravity (superstring theory)
1974: Howard Georgi and Sheldon Glashow propose a grand unification theory (GUT) to unify weak, strong and electromagnetic forces
1975: Benoit Mandelbrot presents a theory of "fractals"
1975: Wilson Edward Osborne founds Sociobiology
1976: Martin Hellman, Ralph Merkle and Whitfield Diffie describe the concept of public-key cryptography
1976: Julian Jaynes introduces the theory of the "bicameral mind"
1976: Sergio Ferrara, Daniel Freedman, and Peter van Nieuwenhuizen introduce the first supersymmetry that included gravity.
1977: The Voyager unmanned probes are launched to explore the solar system and beyond
1977: Fritz-Karl Winkler and others produce the first crystallographic X-ray structure of a virus, the tomato bushy stunt virus
1977: The World Health Organization (WHO) announces the eradication of smallpox
1977: Frederick Sanger invents a method for rapid DNA sequencing and publishes the first full DNA genome of a living being
1978: Louise Brown is born through Robert Edwards' technique of in-vitro fertilization, the first "test-tube baby"
1979: Smallpox is eradicated
1980: Douglas Hofstadter publishes "Godel Escher Bach"
1980: Humberto Maturana publishes "Autopoiesis and Cognition"
1980: Ilya Prigogine publishes "From Being to Becoming"
1980: Alan Guth's inflationary model of the universe
1981: Gerd Binnig and Heinrich Rohrer build the scanning tunneling microscope, an instrument for "seeing" the atomic level
1981: Sony introduces the video camera Betacam, the first camcorder
1982: Richard Feynman proposes a universal quantum simulator that can simulate any physical object
1982: Andrei Linde's chaotic inflationary multiverse
1982: Sony and Philips introduce the CD (compact disc)
1983: Kary Banks Mullis develops the polymerase chain reaction for DNA sequencing
1984: Psion introduces the first personal digital assistant
1984: Barry Marshall and Robin Warren show that ulcers are caused by bacteria
1985: David Deutsch's universal quantum computer
1984: Fujio Masuoka invents flash memory
1984: Michael Green and John Schwarz demonstrate that superstring theory can only work in ten dimensions
1986: The Soviet Union launches the permanent space station MIR
1986: Ernst Dickmanns demonstrates the self-driving car "VaMoRs"
1986: Karl Muller and Johannes Bednorz discover the first high-temperature superconductor
1986: Abhay Ashtekar founds quantum loop theory
1987: Applied Biosystems introduces the first fully automated sequencing machine
1989: Magellan Corporation introduces the first hand-held GPS receiver
1989: Christof Koch discovers that at, any given moment, very large number of neurons oscillate in synchrony and one pattern is amplified into a dominant 40 Hz oscillation
1990: The Hubble space telescope is launched
1990: The first Internet search engine, "Archie"
1990: Tim Berners-Lee invents the HyperText Markup Language "HTML" and demonstrates the World-Wide Web
1990: Dycam introduces the world's first digital camera
1990: William French Anderson performs the first procedure of gene therapy
1992: Calgene creates the "Flavr Savr" tomato, the first genetically-engineered food to be sold in stores
1992: The first text (SMS) message is sent from a phone
1993: Gerard 't Hooft develops the holographic theory
1993: William Wootters and others discover how to achieve quantum teleportation using entanglement
1995: The MP3 standard is introduced for digital video
1995: The top quark, the last missing quark, is finally observed at Fermilab
1995: Edward Witten introduces M-Theory
1995: Eric Cornell and Carl Wieman produce the first Bose-Einstein condensate
1995: Ward Cunningham creates WikiWikiWeb, the first "wiki"
1995: Michel Mayor and Didier Queloz discover an exoplanet, "51 Pegasi b"
1995: Sony and Philips introduce the DVD in Japan
1996: Nokia introduces the first "smartphone"
1996: Giacomo Rizzolatti discovers that the brain uses "mirror" neurons to represent what others are doing
1997: Ian Wilmut clones the first mammal, the sheep Dolly
1997: The Mars Pathfinder is the first rover robot on Mars
1997: Toyota begins selling a hybrid car, the Prius
1998: Saul Perlmutter, Brian Schmidt and Adam Riess discover that the expansion of the universe is accelerating (dark energy)
1998: James Thomson and others grow human embryonic stem cells in cell culture
1998: The first handheld devices to read ebooks
1998: Jeff Kimble and others teleport a photon for about one meter
1998: George Mitchell employs hydraulic fracturing or "fracking" to extract natural gas from the shale rock of Texas' Barnett Shale
1999: The first social networking platform, Friendster, is launched by Jonathan Abrams
1999: John Pendry discovers a way to create metamaterials
2003: The Human Genome Project is completed, having identified all the genes in human DNA
2003: A NASA probe finds that one side of the universe is hotter than the other
2004: Andrei Geim and Konstantin Novosolev, isolate individual graphene planes
2005: Rice is the first cereal crop to be sequenced (by the International Rice Genome Sequencing Project)
2007: James Thomson's group and Shinya Yamanaka's group discover a way of converting skin cells into embryonic stem cells
2007: Knome introduces the first commercially available human genome sequencing
2010: Craig Venter and Hamilton Smith reprogram a bacterium's DNA
2010: Autonomous vehicles drive 13,000 km from Italy to China, the first intercontinental trip ever by autonomous vehicles
2012: Markus Covert simulates an entire living organism (Mycoplasma genitalium) in software
2012: Jennifer Doudna's group invents the CRISPR-cas9 system for gene editing
2012: Kiyotaka Miura at Kyoto University invents quartz glass memories that can hold data for millions of years
2012: PAL-V builds a flying car
2014: Floyd Romesberg chemically synthesizes two artificial nucleotides and inserts them into a bacteria thus creating a new genetic alphabet
2014: Robert Lanza generates human stem cells from adults
2015: Junjiu Huang genetically modifies human embryos
2016: Gravitational waves are observed for the first time, 100 years after they were discovered by Einstein
See also A Timeline of Neuroscience

A note on the past, the present and the future

In my opinion, scientific and technological progress accelerated dramatically between the 1880s and the 1920s and then has steadily declined. To populate the more recent decades i had to pick events that are probably not in the same class as the events of earlier decades.

When "futurists" talk about "accelerating progress", they are usually not talking about new ideas and inventions, but about the refinement of old ideas and inventions, particularly in electronics, a fact that is due mainly to progress in manufacturing (miniaturization, customization, integration, etc). They mainly count a new product in an existing category as progress, and even the new releases of a product as progress.

They don't count (and discount) the many examples of fields in which progress has fallen short: travel speed has actually decreased with the decommissioning of the Concorde in 2003; energy is still mostly provided by oil, followed by nuclear; the agricultural revolution (which increased grain yields by 126% between 1950 and 1980) has stalled; life expectancy in most developed countries is no longer increasing; incomes have been stagnating for decades in the West and are actually falling in parts of Europe; health care is more likely to deteriorate than improve; the Great Recession of 2008 was the biggest in 80 years; the space program of the 1960s (that took us to the Moon in 1969 but nowhere else) has been largely abandoned and the Space Shuttle retired; the flying car debuted in 1956 but we still drive regular cars; smartphone batteries last about one day whereas traditional phones were working 24/7 and voice quality has deteriorated dramatically with smartphones; not to mention customer support that is rapidly dwindling towards a simple "good luck, buyer"; on october 21 of 2011 Google's news aggreator displayed "Internal Server Error" as the main news of the day; etc. Even population, that was supposed to increase exponentially forever, has begun to decline in some countries. And of course the attention span of people, especially the abovesaid futurists (whom i find stunningly ignorant about history, economics and even technology and science), has been declining exponentially, something that qualifies as "progress" only in the universe of insects.

The unquestionable progress has been in manufacturing techniques. In particular, the rate of miniaturization has been truly stunning in the last century. The recent "miracles" of technology were not due to conceptual breathroughts (a smartphone was simply a bad camera plus a bad phone plus a bad computer plus a bad camcorder) but were due to progress in manufacturing techniques, a progress that started when transistors were invented. This progress accounts for the ability to integrate more functions in smaller devices. Whether this constitutes "invention/discovery" is debatable. In my opinion it belongs to a different timeline.

See also my essay on Regress and the debate on the stagnation of innovation:

(If you didn't even know that there is a debate about the stagnation of innovation, you just proved my point).