• 460


    In 460 BC, the first philosopher named Democritus developed an idea of atoms. He asked the question “if you broke a piece of matter in half, and then you broke it again in half, how many breaks would it take before you can break it no further. Democritus thought it ended at some point, a smallest bit of matter. He called these basic matter particles, atoms.
  • John Dalton's Experiments

    John Dalton's Experiments
    This year John Dalton performed experiments with various chemicals showing that matter seem to consist of elementary lumpy particles (also known as atoms.) He didn't know about this structure but he understood the evidence pointed to something that is fundamental.
  • Max Planc's discovery on vibrating atoms

    Max Planc's discovery on vibrating atoms
    Discovered that when you vibrate atoms strong enough, you will be able to measure to the energy only in discreet units. He called his discovery energy packets, quanta.
  • J J Thomson's Discovery

    J J Thomson's Discovery
    J J Thomas discovered that Atoms consist of a large spehere of uniform possive charge which is embedded with smalled negatively charged particles (also known as corpuscles).
  • Rutherfords new model of the atom

    Rutherfords new model of the atom
    This year, Rutherford made a new model of the atom in which all the atoms are crammed inside a tiny nucelus about ten thousand times smaller than the atom as a whole.
  • Niels Bhor

    Niels Bhor
    He came up with a theory that said electrons do not spiral into the nucleus and come out with instructions for what does happen. Bhor said that he had rules that seemed impossible, but they described the way atoms operate. One of his rules were that electrons can orbit only at certain allowed distances from the nucleus.
  • Wolfgang Pauli discovery

     Wolfgang Pauli discovery
    Au Austrian physicist named Wolfgang Pauli predicited that an electron would spin while it orbits around the nucleus. He also predicted that the electron can spin in two directions.
  • Louis de Broglie

    Louis de Broglie
    He thought about particles of matter. He thought that if light can exist as both particles and waves, why couldn’t atom particles also be like waves. He showed from Einstein’s most notable equation E=mc2, that matter waves can be like that if they existed at all.
  • Max Born

    Max Born
    Came up with the idea about “psi.” He thought that they resembles waves of chance. These ripples moves along waves of chance, made up of places where particles may occur and places where no particles occurred.
  • James Chadwick

    James Chadwick
    He discovered that the nuceleus of an atom contains neutrons, electrically neutral particles with a mass similar to that of a proton.
  • Werner Heisenberg

    Werner Heisenberg
    Said that charged particles bounce photons of light back and forth between them. This exchange of photons provided a way for the electromagnetic force to act between the particles. Heisenberg’s theory stated that a proton shoots a photon at the electron and vice versa.
  • Hideki Yukawa

    Hideki Yukawa
    Suggested that exchange forces might also describe the strong force between nucleons. Virtual photons however don’t have enough strength for this force, so he concluded that there must exist a new king of virtual particle. He used Heisenberg’s principle to explain that a virtual particle can exist for a small fraction of a second.
  • Murray Gell Man and Yuval Ne’Man

    Murray Gell Man and Yuval Ne’Man
    They classified all the particles then were known. There method became known as the eightfold way. It was like the periodic tale. That table was for elements but the eightfold was for particles.

    Thanks to the website which gave me all the information for this timeline