Old Dudes Time line Project

440BC-Democritus

440

the idea of the atom, an indivisible particle that all matter is made of.They are physically indivisible, empty space lies between atoms, and that atoms are and always will be in motion. He also believed there are an infinite amount of different atoms that differ in size and shape. This idea is largely rejected by natural philosophers in favor of the Aristotlean view.

Medieval Alchmey

Period: Feb 28, 1000 to Feb 28, 1650

The alchemists sought a universal solvent, attempted to change lead and other metals into gold, and tried to discover an elixir which would prolong life. The alchemists learned how to use metallic compounds and plant-derived materials to treat diseases.
•To discover the relationship of man to the cosmos and take advantage of that relationship to the betterment of mankind.
•To find the "philosopher's stone," turns object to gold
http://historymedren.about.com/od/alchemy/p/alchemy.htm

John Dalton

Mar 1, 1897

He claimed the reason elements combined was because all elements are made up of atoms. He also created a 4 part atomic theory. First, all particles are made of atoms, they cant be divided or destroyed. Second, atoms of the same elements are identical and diferent element http://www.studentsoftheworld.info/sites/science/16455.php
element, such as hydrogen, oxygen, nitrogen, etc., differed from the next only by its weight.

J.J. Thomson

Mar 1, 1897

Thompson discovered that all atoms contain particles, now known as electrons. Thomson made this discovery with his research with cathode rays. He found that the rays could be deflected by an electric field. He compared the deflection of the beams to the electric and magnetic fields to discover the rays mass, which proved the rays were matter.
http://www.studentsoftheworld.info/sites/science/16455.php

Marie and Pierre Currie

Mar 1, 1898

Marie Curie, with the help of her husband Pierre, created the element Polonium. Marie named it after her homeland, Poland.A couple months after creating Polonium, the couple discovered the element radium.Marie Curie was the first woman to be awarded with the Nobel Prize.Only a few months later, she passed away because of aplastic anemia, a bone marrow circulation problem/disease. This disease is very often linked with over exposure to radioactive substances.
http://nobelprize.org/nobel_prizes/

Henri Becquerel

Mar 1, 1903

Henri Becquerel won the Nobel Prize for the discovery of radioactivity. Radioactivity relates to the spontaneous discharge of atomic particles by an element.Becquerel's earliest work was concerned with the plane polarization of light, with the phenomenon of phosphorescence and with the absorption of light by crystals.
http://nobelprize.org/nobel_prizes/physics/laureates/1903/becquerel-bio.html

Ernest Ruthford

Mar 1, 1909

Rutherford contributed to the history of chemistry with an experiment where he shot a beam of positively charged particles at a sheet of gold foil. He had thought that the atoms would be soft,and expected them to pass through the sheet. Most of the particles did, but some were reflected back. This led Rutherford to create his own model, where there was a small positively charged nucleus with negative electrons orbiting around it.
http://www.physics.carleton.ca/research/ilc/tpc2.html

Niels Bohr

Mar 1, 1913

Bohr suggested that electrons travel around the nucleus in defined paths that were certain levels away from the nucleus. He also said that the electrons must be on one of the paths, but can jump between the paths.In 1913 Bohr explained the structure of the hydrogen atom and the circumstances relating to the emission and absorption of light. Further studies led to an explanation of the periodic system of elements.
http://nobelprize.org/nobel_prizes/physics/laureates/1922/bohr-bio.html

James Chadwick

Mar 1, 1932

James Chadwick discovers the electrically neutral part of an atomic nucleus, the neutron. Neutrons are able to split an atom without being repelled by electrical forces in a nuclei.Chadwick in a way helpped find out the fission of the of uranium 235 and wich helped create the atomiv bomb.
http://nobelprize.org/nobel_prizes/physics/laureates/1935/chadwick.html