Science Over Time

By sschaibl90
  • 400 BCE

    Democritus

    Democritus
    Believed all atoms were hard and symmetrical. He believed they could not be destroyed and moved freely forever until something stopped them or made them change paths. Born: 460 B.C. Died: 370 B.C. Fun Fact: Very little is know about the beginning and end of Democritus life.

  • John Dalton FRS

    John Dalton FRS
    Had three parts to his theory. He believed matter is made up of atoms which cannot be separated. He believed that the atoms in an element had to have the same mass, and he believed that compounds were combined atoms. Born: September 6, 1766 Died: July 22, 1844 Fun Fact: He was a meteorologist as well

  • Joseph John Thompson

    Joseph John Thompson
    His experiments showed the first signs of electrons or small negatively charged particles. Born: December 18, 1856 Died: August 30, 1940 Fun Fact: His son became a professor at London University

  • Ernest, Baron Rutherford of Nelson

    Ernest, Baron Rutherford of Nelson
    Discovered that atoms are made up mostly of space and that the large sum of mass they contain is packed tightly in the small nucleus Born: August 30, 1871 Died: October 19, 1937 Fun Fact: Considered to be the greatest experimentalist since Michael Faraday

  • Robert Andrews Millikan

    Robert Andrews Millikan
    Expressed that electrons had could be measured charge with quantity. He measured the charges and masses of electrons. In doing so he was able to form the atomic structure of electricity. Born: March 22, 1868 Died: December 19, 1953 Fun Fact: Was the first person to get a Ph.D. from the physics department at Columbia University

  • Niels Henrik David Bohr

    Niels Henrik David Bohr
    Believed that electrons orbit the nucleus in set rings that each have a designated size and amount of energy. And the way the electrons orbit depends on the size of the orbit. Ex: The smallest orbit produces the least amount of energy. Born: October 7, 1885 Died: November 18, 1962 Fun Fact: Neils was known for setting off explosions in class when he was a student

  • Werner Karl Heisenberg

    Werner Karl Heisenberg
    Developed the first mathematical formula for quantum theory. Believed that only observable quantities should effect the theory and that whatever happened inside the atom was to be avoided. Born: December 5, 1901 Died: February 1, 1976 Fun Fact: He was a wonderful pianist

  • Sir James Chadwick

    Sir James Chadwick
    Proved that neutrons existed and was able to measure and record their mass. Born: October 20, 1891 Died: July 24, 1974 Fun Fact: Received the Nobel Prize for Physics in 1935 because of his discovery