The history of Matter and Antimatter (AS2021067)

Democritus's Atomos

400 BCE

Democritus (c. 460–370 BCE)
Democritus, an ancient Greek philosopher, proposed the concept of atomism, suggesting that matter consists of indivisible particles called atoms. While his ideas were speculative, they laid the groundwork for later atomic theories.

John Dolton's atomic theory

1803

John Dalton (1766–1844)
In the early 19th century, Dalton developed the atomic theory, which proposed that elements are composed of indivisible atoms. This marked a more systematic approach to understanding the nature of matter.

Thomson's Discovery of electron

1897

J.J. Thomson (1856–1940)
Thomson discovered the electron in 1897 through cathode ray experiments. His model of the atom resembled a "plum pudding," with electrons embedded in a positively charged matrix.

Theory of special relativity

1905

Albert Einstein
Relativity also showed us that matter and energy are just two different forms of the same thing—a fact that Einstein expressed as E=mc2, the most widely recognized equation in history.

Rutherford's discovery of Nucleus and Proton

1908

Ernest Rutherford (1871–1937)
Rutherford conducted the gold foil experiment in 1909, leading to the discovery that atoms have a small, dense nucleus. This challenged Thomson's model and introduced the idea of a central, positively charged core.

Niles Bohr's Planetary Model

1913

Niels Bohr (1885–1962)
Bohr's model of the atom (1913) incorporated quantized electron orbits, explaining spectral lines. This model played a crucial role in understanding atomic structure.

Louise de Broglie wave particle duality

1924

In 1924 Louis de Broglie introduced the idea that particles, such as electrons, could be described not only as particles but also as waves. This was substantiated by the way streams of electrons were reflected against crystals and spread through thin metal foils.

Dirac postulates the existence of antiparticals

1928

Paul Dirac (1902–1984)
In 1928, Dirac developed the Dirac equation, unifying quantum mechanics and special relativity. This equation predicted the existence of antimatter as a natural consequence.

Discovery of 1st particle of antimatter by Carl Anderson

1932

Carl D. Anderson (1905–1991)
Anderson discovered the positron, the first antimatter particle, in 1932 while studying cosmic rays. This observation confirmed Dirac's theoretical predictions.

James Chadwick discovery of Neutron

1932

James Chadwick
Chadwick is best known for his discovery of the neutron in 1932. A neutron is a particle with no electric charge that, along with positively charged protons, makes up an atom's nucleus. Bombarding elements with neutrons can succeed in penetrating and splitting nuclei, generating an enormous amount of energy.

Antiproton

1955

Emilio Segre
Emilio Gino Segrè (Italian)1 February 1905 – 22 April 1989) was an Italian and naturalized-American physicist and Nobel laureate, who discovered the elements technetium and astatine, and the antiproton, a subatomic antiparticle, for which he was awarded the Nobel Prize in Physics in 1959'

The Bevatron discovers the antineutron

1956

The antineutron was discovered in proton–antiproton collisions at the Bevatron (Lawrence Berkeley National Laboratory) by the team of Bruce Cork, Glen Lambertson, Oreste Piccioni, and William Wenzel in 1956, one year after the antiproton was discovered.

Concepts of quarks

1964

The quark model was independently proposed by physicists Murray Gell-Mann and George Zweig in 1964. Quarks were introduced as parts of an ordering scheme for hadrons, and there was little evidence for their physical existence until deep inelastic scattering experiments at the Stanford Linear Accelerator Center in 1968.

Antinuclei

1965

The answer to the antinuclei question was found in 1965 with the observation of the antideuteron, a nucleus of antimatter made out of an antiproton plus an antineutron (while a deuteron – the nucleus of the deuterium atom – is made of a proton plus a neutron).

First proton-antiproton collisions

1981

The Intersecting Storage Rings produced the world's first proton-antiproton collisions on 4 April 1981, paving the way for proton-antiproton collisions in the Super Proton Synchrotron (SPS), and the Nobel prize for Simon van der Meer and Carlo Rubbia.

First production of Antihydrogen at CERN

1995

In 1995, physicists at CERN announced that they had successfully created the first atoms of antihydrogen at the Low Energy Antiproton Ring (LEAR). The researchers allowed antiprotons circulating inside LEAR to collide with atoms of a heavy element.

Quantum supermacy

2020

October 23, 2019: Google Al Quantum and collaborators announce that their quantum computer, Sycamore, performed a specific task in 200 seconds that would take the world's most powerful supercomputer 10,000 years to complete, -enchmark for quantum supremacy. This represents ↓ a significant step forward in quantum computing.