Atomic Timeline

By joser915
  • 460 BCE

    Democritus

    Democritus was a central figure in the development of the atomic theory of the universe. He theorized that all material bodies are made up of indivisibly small “atoms.” Aristotle famously rejected atomism in On Generation and Corruption. Aristotle refused to believe that the whole of reality is reducible to a system of atoms, as Democritus said. As it turned out, though, Democritus was right. https://www.britannica.com/biography/Democritus
  • 384 BCE

    Aristotle

    Aristotle disagreed with Democritus' theory. He was also a philosopher, not a scientist. He believed you could understand and figure out things by simply thinking about them. He also believed that everything was a combination of the four elements: earth, fire, water, air. His theory was that a mass of incomprehensible size was everywhere; he called this 'hyle'. There was no separate 'particles' for each material, it was all one. https://historyoftheatomictheory.weebly.com/aristotle.html
  • 727

    Sir Isaac Newton

    Like Boyle, Newton studied gases, and the possibility of atoms existing, and like Boyle, his work was impeded by the church. He proposed a mechanical universe where small solid masses were in motion. In short, he believed that there were little tiny pieces of mass that were 'swimming' everywhere. https://historyoftheatomictheory.weebly.com/isaac-newton.html

  • John Dalton

    Dalton's atomic theory proposed that all matter was composed of atoms, indivisible and indestructible building blocks. While all atoms of an element were identical, different elements had atoms of differing size and mass. http://www.iun.edu/~cpanhd/C101webnotes/composition/dalton.html

  • J.J. Thomson

    In 1897, J.J. Thomson discovered the electron by experimenting with a Crookes, or cathode ray, tube. He demonstrated that cathode rays were negatively charged. ... Thomson realized that the accepted model of an atom did not account for negatively or positively charged particles http://www.abcte.org/files/previews/chemistry/s1_p5.html

  • Eugen Goldstein

    He is credited with the discovery of protons. Goldstein contributed greatly to the study of cathode rays. He discovered protons with the experiments he did with cathode rays which would knock electrons of atoms and attract them to a positively charged electrode http://chemed.chem.purdue.edu/genchem/history/goldstein.html

  • Ernest Rutherford

    Rutherford overturned Thomson's model in 1911 with his well-known gold foil experiment in which he demonstrated that the atom has a tiny and heavy nucleus. Rutherford designed an experiment to use the alpha particles emitted by a radioactive element as probes to the unseen world of atomic structure. https://www.physicsoftheuniverse.com/scientists_rutherford.html

  • Max Planck

    Max Planck, a German physicist, is best known as the originator of the quantum theory of energy for which he was awarded the Nobel Prize in 1918. His work contributed significantly to the understanding of atomic and subatomic processes. Planck was born in Kiel, Germany in 1858. https://micro.magnet.fsu.edu/optics/timeline/people/planck.html

  • Hantaro Nagaoka

    Image result for Hantaro Nagaoka in contribution to atomic theory
    In 1904, Nagaoka proposed an alternative planetary model of the atom in which a positively charged center is surrounded by a number of revolving electrons, in the manner of Saturn and its rings. Nagaoka's model made two predictions: a very massive atomic center (in analogy to a very massive planet) https://link.springer.com/chapter/10.1007/978-3-540-70626-7_10

  • Robert Andrews Millikan

    Atomic Theory & Oil Drop Experiment. Learn about the life and achievements of American physicist Robert Millikan. His oil drop experiment helped to quantify the charge of an electron, which contributed greatly to our understanding of the structure of the atom and atomic theory. https://www.britannica.com/biography/Robert-Millikan

  • Enrico Fermi

    In 1938, Fermi was awarded the Nobel Prize in Physics "for his demonstrations of the existence of new radioactive elements produced by neutron irradiation, and for his related discovery of nuclear reactions brought about by slow neutrons." https://www.atomicheritage.org/profile/enrico-fermi

  • Albert Einstein

    The Atomic theory is a scientific theory that states that all mater is composed of tiny particles, called atoms. Albert Einstein is perhaps most famous for his Theory of Relativity. Albert Einstein played a very important role in the development of the Quantum Theory http://ansnuclearcafe.org/2012/03/20/albert-einstein-and-the-most-elemental-atomic-theory/#sthash.5B3g795t.dpbs

  • Erwin Schrödinger

    In 1926 Erwin Schrödinger, an Austrian physicist, took the Bohr atom model one step further. Schrödinger used mathematical equations to describe the likelihood of finding an electron in a certain position. This atomic model is known as the quantum mechanical model of the atom http://www.abcte.org/files/previews/chemistry/s1_p6.html

  • Neils Bohr

    In 1913, Niels Bohr proposed a theory for the hydrogen atom based on quantum theory that energy is transferred only in certain well defined quantities. Electrons should move around the nucleus but only in prescribed orbits. When jumping from one orbit to another with lower energy, a light quantum is emitted. https://www.nobelprize.org/prizes/physics/1922/bohr/facts/

  • James Chadwick

    James Chadwick played a vital role in the atomic theory, as he discovered the Neutron in atoms. Neutrons are located in the center of an atom, in the nucleus along with the protons. They have neither a positive nor negative charge, but contribute the the atomic weight with the same effect as a proton http://www.abcte.org/files/previews/chemistry/s1_p6.html

  • Satyendra Nath Bose

    Physicist Satyendra Nath Bose, born on January 1, 1894, in Calcutta, India, discovered what became known as bosons and went on to work with Albert Einstein to define one of two basic classes of subatomic particles. Much of the credit for discovering the boson, or "God particle," was given to British physicist Peter Higgs, much to the chagrin of the Indian government and people. https://www.biography.com/people/satyendra-nath-bose-20965455

  • Peter Higgs

    he Higgs field occupies everything in the universe. It is visualized as molasses that drags particles that move through it. Particles that interact with the Higgs, receive mass. So electrons that hardly interact with the field have very little mass, and protons and neutrons that interact with it regularly have more mass. https://www.nobelprize.org/prizes/physics/2013/higgs/facts/

  • MIT - Discovery Of Photonic Molecule

    Scientists at MIT, Harvard University, and elsewhere have now demonstrated that photons can be made to interact — an accomplishment that could open a path toward using photons in quantum computing, if not in light saber http://news.mit.edu/2018/physicists-create-new-form-light-0215

  • Alan Guth

    Alan Guth is a theoretical physicist and cosmologist, known mainly for his work on elementary particle theory and how particle theory is applicable to the early universe, and particularly for the idea, which he developed around 1980, of cosmic inflation and the inflationary universe, the idea that the nascent universe passed through a phase of exponential expansion soon after the Big Bang, driven by a positive vacuum energy density https://www.physicsoftheuniverse.com/scientists_guth.html