SCIENTISTS THAT HAVE CONTRIBUTED TO THE UNDERSTANDING OF MATTER OR ATOMIC STRUCTURE

Timeline created by madyguinn
  • 384

    The Greeks: Aristotle

    The Greeks: Aristotle
    Asitotle lived between 384- 422 B.C. Aristotle looked deeper when people began questioning objects and how they were made. He found that there were four causes; the first cause is the Material Cause in which said what stuff is made from. Second cause: The efficent marker of things. Third Cause: Formal which is the pattern. Forth Cause: The prupose that something is made.
    He thought that everything had a goal.
  • 429

    The Greeks: Pluto

    The Greeks: Pluto
    Most modern scholors believe Pluto was born between 429- 423 BC. Pluto used Empedocles element theory, and identified each element with a regular solid: fire= tetrahedron, air= octahedron, water= icosahedron, and earth= cube.
  • 430

    The Greeks: Empedocles

    The Greeks: Empedocles
    Empedocles was born around the 5th Century BCE and died around 430 BC. He had two important views that said the world is due to the mixing and seperation of four parts: earth, air, fire, and water; he called these the "roots." The second part was the blending and seperation of elements he liked to call it Love and Strife. Love was the blending of elements to create the world. Strife was the force pulling elements away.
  • 460

    The Greeks: Democritus

    The Greeks: Democritus
    Democritus lived between 460- 457 BC. Leucippus was succeeded by Democritus. Together they found the ancient atomic theory (basic). Leucippus and Democritus did not accept the Eleatic hypothesis that said "everything is one," so they dug deeper, and discovered that the world essentially consists of myraids of timny indicisible particles, which they called atoms.
  • 480

    The Greeks: Leucippus

    The Greeks: Leucippus
    Predicted that he libed between 480- 420 BC. Leucippus's dates were unknown, yet it is believed that he lived during the 5th Century B.C.E. Leucippus was succeeded by Democritus. Together they found the ancient atomic theory (basic). Leucippus and Democritus did not accept the Eleatic hypothesis that said "everything is one," so they dug deeper, and discovered that the world essentially consists of myraids of timny indicisible particles, which they called atoms.
  • Household Clocks Invented

    Household Clocks Invented
    The clock was invented by the Sun! Not a specific person invented the clock but rather a group of people who studied the sun's behaviors and the hours in a day. The household clock was introduced in 1620.
  • John Dalton

    John Dalton
    John Dalton studied weather and these studies of gases lead him to begin forming his atomic theory, but in fact, a lot of his theory was discovered using deductive reasoning and later proved correct.
    In 1803, John Dalton discovered the law of multiple proportions. The law states that whenever two elements form more than one compound, the different masses of one element that combine with the same mass of the element are in the ration of small, whole numbers.
  • Joseph John Thompson (J.J. Thompson)

    Joseph John Thompson (J.J. Thompson)
    Shortley after 1897 Thompson brainstomed one of the most brilliant ideas, the discovery of the electron. For many years Thompson and other scientists knew that if an electric current was passed through a vacuum tube, small glowing particles could be seen.
    Thompson's theory of the atomic model became known as the Raisin Bread Theory, which stated that atoms looked like pieces of raisin bread. (Plum Pudding) in 1904.
    Rutherford then further proved that electrons are not inside the nucleus.
  • Max Planck

    Max Planck
    Planck discovered the quantum theory. He discovered that energy emitted from a resonator could only be small values of quanta. He realized that the energy resonator of frequency is used by the equation E=hv. Where E= universal constant that is known as Planck's constant= 6.626X10^-34 J*sec. The equation was about the absorbtion and emission or energy and not the actual waves themselves. DIscovery made in 1900.
  • Hershey Bar

    Hershey Bar
    Milton Hershey invented the first Milk Chocolate Hershey bar in 1900.
  • Hantaro Nagaoka

    Hantaro Nagaoka
    He was primarily responsible for promoting the advancement of physics in Japan. In 1904, Nagoaka had developed an early but incorrect plaetary model of the atom. He based his model of the atom around the rings of the Planet Saturn. He explained that the rings are held there due to its massive orbit.
    Even though the model was wrong, it still allowed for the discovery of the atoms rings. He started spectroscopic experiments to investigate the actaul arrangement of electrons in the atom in 1908.
  • Robert Millikan

    Robert Millikan
    Millikan's earliest success was discovering the negative charge carried by electrons using his oil-drop method in 1910. He preformed this by determining the charge of oil drops when held at equilibrium. He measured the density, mass, and radii of the oil drops and he calculated the gravitational and buoyant forces in order to find the charge. He concluded that the charge of an electron was 1.5924(17)X10^-19C.
    He also spent a chunck of his time from 1920-1923 working with spectroscopy.
  • Lord Ernest Rutherford

    Lord Ernest Rutherford
    Rutherford's most famous experiment was in 1911, "The Gold Foil Experiment" in which he tested J.J. Thompson's plum pudding model. He shot energetic alpha particles at foil, and measured the angle of the particles as they came out the other end. Since he already knew that electrons were negitively charged he guessed that the atoms also consisted of positive charges so that they would "cancel" eachother out. Rutherford explained this with a remodeled version of the atom, + mass in nucleus.
  • Niels Bohr

    Niels Bohr
    Bohr agreeed with Rutherford about an atom having a nucleus but he had a different opinion concerning the location and movement of the electrons. Bohr theorized that electrons were located on different energy levels that were fixed at different distances from the nucleus in 1913. He claimed that electrons that absorbed energy were on levels farther away from the nucleus. While electrons that radiated energy were on the levels closer to the nucleus.
  • Werner Heisenberg

    Werner Heisenberg
    When Heisenberg was only 23 in 1925 he published his theory of quantum mechanics, the mathematical description of the movement of subatomic particles.
    His most famous accomplishment is his Principle of Uncertainty in 1927. This principle deals with quantum mechanics, and states that it's impossible to know the position and momentum of a particle at the same time, because while you accurately measure the particle's position, the measurement of the momentum becomes less accurate, and vise versa.
  • Erwin Schrodinger

    Erwin Schrodinger
    In 1917, Schrodinger publsihed his first ideas on the quantum mechanic model. In 1920, Schrodinger began to study the thesis of Louis de Broglie's, and published his wave model equation, or the quantum mechanic model in 1927. The QMM is an equation that mathematically expalins the properties of electrons. It is based on quantum theory, which states that matter has properties associated with waves, much like light.
  • Louis de Broglie

    Louis de Broglie
    Sym= h/mv, sym= wavelength, h=planck's constant, mv= the mass of a particle v. His quantum theory was then later confirmed by the discovery of electron diffraction by crystals in 1927.
    Broglie found that when electrons pass through a screen or pass through slits of a screen, it produces a flash of light at just one place on the screen. The electrons create a pattern of dark and bright bands which are formed on the screen, which confirms that electrons behave like waves while they are traveling.
  • Sir James Chadwick

    Sir James Chadwick
    Chawick's most famous discovery was of the neutron in 1932. This led to the fissioning of Uranium-235, and therefore the atomic bomb. He observed that, if exposed to assault of alpha particles, beryllium released unknown readiation that ejected protons from nuclei of substances. The discovery also refuted previous ideas that the extra mass in the nucleus was protons paired with electrons (this would supposedly make it neutral).
  • Chapstick Introduction

    Chapstick Introduction
    Even though the idea of lip balm was discovered long before, the brand "Chapstick" was not released and patened until 1963, by John Morton. A man named Fleet was the original inventor of Chapstick, but since he was not selling enough he sold the idea to Morton.
  • Bottled Water Introduced

    Bottled Water Introduced
    The first PVC (polyvinyl chloride) water bottle was introduced. Was introduced by Perrier.
  • Cell Phone Released/ Introduced

    Cell Phone Released/ Introduced
    The first cell phone was introduced in Japan by Martin Cooper, he was working at Motorola.