Fall.2008.MMA.Boyle.Timeline

//Boyle & Barron Wiki Time Line//
=DEMOCRITUS=



Born: 460BC Died: 370BC

Democritus is known through the criticism of Aristotle and Theophrastus. Democritus believed that there was something so small that we couldn't see that makes up everything and when they are arranged together in different ways they make up different things. He had the basic idea that when you break something in half and in half again and so on, then eventually it would come down to something that couldn't be broken down anymore, the atom. The word atom comes from "atomos" which means invisible.



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=ARISTOTLE=



Born: 384BC Died: 322BC

Aristotle is one of the most famous philosophers there is. He was a student of Plato. Aristotle came up with the elements fire, earth, air, and water. He was the first person who even comprehended the fact that there were elements. This lead to the foundation of modern chemistry and the basis for science.



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=JOHN DALTON=



Born: 1766 Died: 1844

John Dalton proposed an atomic theory stating that: - All matter consists of tiny particles. - Atoms are indestructible and unchangeable - Elements are characterized by the mass of there atoms - When elements react, their atoms combine in simple, whole number ratios John Dalton was the first person to compose a table of atomic weights. this idea has transformed to what we now know as the periodic table. He believed that atoms of different elements had different masses.

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=WILHELM C ROENTGEN=



Born: 1845 Died: 1923

He was born in germany to the a merchant and cloth maker. Roentgen was studying the effects of different types of vacuum tubes when he discovered the X-Ray. His discovery was accidental when he was using cardboard to prevent cathode rays from escaping from the vacuum. He won the nobel prize in physics for his discovery. By discovering this x-ray he was awarded numerous other awards and had many streets named after him.



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=HENRI BECQUEREL=



Born: 1852 Died: 1908

Becquerel was fascinated by Roentgen's discovery of X-Rays. He started to work with uranium and discovered radiation. "He placed phosphorescent crystals upon a photographic plate that had been wrapped in opaque paper so that only a penetrating radiation could reach the emulsion. He exposed his experimental arrangement to sunlight for several hours, thereby exciting the crystals in the customary manner.He thus confirmed his view that something very similar to X rays was emitted by this luminescent substance at the same time it threw off visible radiation. But the following week Becquerel learned that his uranium salts continued to eject penetrating radiation even when they were not made to phosphoresce by the ultraviolet in sunlight."



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=**JJ THOMPSON**=



Born: 1856 Died: 1940

JJ Thompson made a enormous step forward in science when he discovered the electron. He used a cathode ray tube in his experiments to come to an understanding why an electric current could be seen within it. When he introduced an electrical charge the glow would bend towards the positive side. Thus concluding that inside atoms were negative charges. He came up with the Plum Pudding model.



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=**MARIE CURIE**=



Born: 1867 Died: 1934

Maire Curie came up with the theory of creation of radioactivity. Also she came up with how to isolate radioactive isotopes. Also she discovered two new elements Radium and Polonium, this lead her to get the Noble prize in both chemistry and physics. This was an unheard of feat for a woman in her time.



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=**ERNEST RUTHERFORD**=



Born: 1871 Died: 1937

Rutherford discovered that there were different types of rays; Alpha, Beta, and Gamma. He also discovered that radioactive elements have half-life which can be used to find the age of an element.



Rutherford-Bohr model

Planetary model

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=**ROBERT MILLIKAN**=



Born: 1868 Died: 1953

Robert Millikan is most famous for the oil drop experiment in which he measured the charge of an electron. He let and oil drop fall from the top of a barrel that was in a vacuum. Then he let the drops of oil fall and as they fell he would charge plates at bottom of the barrel. Then he would observe that sometimes the electrons would float above the bottom. This was due the fact that they had opposite charges and equal charges,using this theory he accurately came up with the measurement of 1.602 x 10^-19 coulomb.



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=**HANS GEIGER**=



Born: 1882 Died: 1945

Geiger invented a machine that released alpha particles onto gold foil. They appeared as flashes of light. This machine was called the Geiger Counter. Geiger also participated in the making of the atomic bomb for Germany with a group of scientist in the "Uranium Club".



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=NIELS BOHR=



Born:1885 Died:1962

He came up with the model of a quantum atom. He was the first person to come up with this model and make it work. Also he founded his own instuite for theoretical physicist, all the best physicist of the time spent time at his institute. He was a major player in the manhatten project and helped move physics into the 21st century.



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=ERWIN SCHRODINGER=



Born: 1887 Died: 1961

Schrodinger developed the equation for wave lengths for quantum mechanics. "Erwin Schrödinger was a brilliant theoretical and experimental physicist who worked in Vienna, Zürich and Berlin in the first half of the 20th century. He was a significant contributor to the wave theory of matter, a form of quantum physics, and he devised the mathematical equation of wave mechanics that bears his name."



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=**JAMES CHADWICK**=



Born: 1891 Died: 1974

Chadwick worked with Rutherford in Germany. While he worked there he discovered the neutron. He discovered that the neutron was about 0.1 greater than a protons. He believed there was something else in the atom that made up the mass considering that the electrons made up very little of it. He won the Nobel prize in physics in 1935.



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=WERNER HEISENBERG=



Born: 1901 Died: 1976

Heisenberg was one of the leading scientist for the Germany nuclear energy project known as the "Uranium Club". He was one of the 10 scientist arrested by American soldiers towards the end of WWII. He also won the Noble prize in physics in 1932.



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