Particle physics: A timeline

17 февраля 2012, 13:38

Following is a timeline of particle physics following the announcement Tuesday that scientists believe they are nearer to finding the elusive Higgs Boson, predicted to be the particle that confers mass.



5th century BC: Greek philosopher Democritus suggests the Universe consists of empty space and of invisible and indivisible particles called atoms.


John Dalton.


1802: John Dalton, a Quaker-educated English physicist and chemist, lays groundwork of modern theory of the elements and the atom.


John Dalton


1897: Electron discovered by Britain's Joseph Thomson, who later proposes a "plum pudding" model of the atom. He suggests the atom is a slightly positive sphere with raisin-like electrons inside that have a negative charge.

Joseph Thomson.

Joseph Thomson


1899-1919: New Zealand physicist Ernest Rutherford identifies atomic nucleus, the proton and alpha and beta particles.

Ernest Rutherford.

Ernest Rutherford


1920s: Advances in quantum theory, about the behaviour of matter at the atomic level.

1932: Neutron, similar to the proton but with no electrical charge, is discovered by James Chadwick of Britain. The first antiparticle, the positron (the mirror particle to the electron), is discovered by American Carl Anderson.

James Chadwick.

                   Carl Anderson

James Chadwick                                      Carl Anderson


1934: Italy's Enrico Fermi postulates the existence of the neutrino (Italian for "little neutral one"), a neutral-charge partner to the electron. Theory is confirmed in 1959.

Enrico Fermi.

Enrico Fermi 


1950s: Invention of particle accelerator leads to surge in discoveries of sub-atomic particles.


- British physicist Peter Higgs postulates existence of a particle, later known as the Higgs Boson, that provides mass to otherwise massless particles.

Peter Higgs.

Peter Higgs


- Murray Gell-Mann and George Zweig of the United States propose that protons and neutrons are comprised of quarks.

George Zweig.                 Enrico Fermi.

Murray Gell-Mann                              George Zweig


1974: Development of the "Standard Model," a theory that everything in the Universe comprises 12 building blocks divided into two families, leptons and quarks, and these are governed by four fundamental forces.

1977-2000: Flurry of discoveries that strengthens Standard Model hypothesis, including the existence of bottom and top quarks, tau lepton, gluon, tau neutrino and the W and Z bosons which help carry the "weak" force.

Source: AFP    

Нравится Поделиться
Хотите больше статей? Смотреть все
Добавить комментарий
Most Read
Most Discussed