D.Brewer+TimeLine+Project

__**Democritus (~ 470 to 380 B.C.)- Birth Place-**__ Abdera, Greece http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Democritus.html
 * __Scientific Contribution-__** He developed an atomic theory that was similar to the principles of matter and energy we use today. He wrote many books in a wide range of subjects including anything from chemistry to astronomy. He expanded on the core theory that the universe is composed of atoms. Democritus believed that because the universe was made up of atoms that everything else was and began working on a model of an atom. Although off on his thinking about what an atom looked like and consisted of Democritus gave the world a huge buliding block to our modern thinking.
 * [[image:Democritus_1.JPG width="200" height="154" caption="Democritus_1.JPG"]] ||
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 * [[image:Democritus_and_the_Void.JPG width="340" height="191" caption="Democritus_and_the_Void.JPG"]] ||
 * __Democritus_and_the_Void.JPG__ ||
 * [[image:Democritus_Theory_of_Solid_Objects.JPG width="345" height="215" caption="Democritus_Theory_of_Solid_Objects.JPG"]] ||
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__**Aristotle (384 B.C. to 322 B.C.)**- http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Aristotle.html __
 * Birth Place-**__ Stagira in northern Greece.
 * __Occupation and Scientific Contribution-__** Aristotle was a greek philosopher. He was a student of Platos and a teaher of Alexander the great. Both were geniuses of their time. Aristotle wrote about subjects such as physics, biology, logic, philosophy and many more. He wanted to develop and teach a universal model, the idea of countless diffent bodies in space such as stars, planets galaxies and solar systems. Aristotle came from a very early and almost primitive time so the amount of intellect that went into these ideas was huge. He began the thoughts of heliocentric theories even though they would not be proved true until much later by another scientist named Galileo. The idea of a heliocentric theory is that everything the universe consists of is directly revolving around the sun.


 * Major Events:**__

__**Birth Place-**__ Joseph Black was born in Bordeaux on April 16.
===**__Occupation and Scientific-__** Contribution Black's work in chemistry started out by using a basic magnesium carbonate. This led to his discovery of carbon dioxide. At the time, he called it, "fixed air." He didn't limit himself to just chemistry, as he worked in medicine as well. When he discovered carbon dioxide he submitted it to medical research. This enabled cures for diffent types of diseases by using carbon dioxide to bulid up immunities in the human body so sickness wouldn't return. These thoughts did backfire in some cases though because the carbon dioxide had a strong effect on some people, killing them before they could build up immunities._ http://www.chem.gla.ac.uk/dept/black.htm===

John Dalton (1766-1844) Birth Place- Eaglesfield, Cumbria
===__**Scientific Contributions-**__ English meteorologist who switched to chemistry when he saw the applications for chemistry of his ideas about the atmosphere. He proposed the //Atomic Theory// in 1803 which stated that all matter was composed of small indivisible particles termed atoms, atoms of a given element possess unique characteristics and weight, and three types of atoms exist: simple (elements), compound (simple molecules), and complex (complex molecules). Dalton's theory was presented in //New System of Chemical Philosophy// (1808-1827). This work identified chemical elements as a specific type of atom, therefore rejecting Newton's theory of chemical affinities. Instead, Dalton inferred proportions of elements in compounds by taking ratios of the weights of reactants, setting the atomic weight of hydrogen to be identically one. Following Richter, he proposed that chemical elements combine in integral ratios. Despite the importance of the work as the first view of atoms as physically real entities and introduction of a system of chemical symbols, //New System of Chemical Philosophy// devoted almost as much space to the caloric theory as to atomism. http://scienceworld.wolfram.com/biography/Dalton.html===

__1700-1800__
__- King Louis XIV died - 1715 - Richmond, Virginia is founded - 1737 - French and Indian war starts - 1754__

__**Birth Place-**__ Lenep in the Lower Rhine Province of Germany
===**__Scientific Contribution-__** Rontgen found that if the discharge tube is enclosed in a sealed, thick black carton to exclude all light, and if he worked in a dark room, a paper plate covered on one side with barium platinocyanide placed in the path of the rays became fluorescent even when it was as far as two metres from the discharge tube. During subsequent experiments he found that objects of different thicknesses interposed in the path of the rays showed variable transparency to them when recorded on a photographic plate. When he immobilised for some moments the hand of his wife in the path of the rays over a photographic plate, he observed after development of the plate an image of his wife's hand which showed the shadows thrown by the bones of her hand and that of a ring she was wearing, surrounded by the penumbra of the flesh, which was more permeable to the rays and therefore threw a fainter shadow. This was the first "röntgenogram" ever taken. In further experiments, Röntgen showed that the new rays are produced by the impact of cathode rays on a material object. Because their nature was then unknown, he gave them the name X-rays. [|http://nobelprize.org/nobel_prizes/physics/laureates/rontgen-bio.html]=== === || || Roentgen_Art.JPG ||===

**__Birth Place-__** Paris, France
===__**Scientific Contribution-**__ 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 (his doctorate thesis). He also worked on the subject of terrestrial magnetism. In 1896, his previous work was overshadowed by his discovery of the phenomenon of natural radioactivity. Following a discussion with Henri Poincaré on the radiation which had recently been discovered by Röntgen (X-rays) and which was accompanied by a type of phosphorescence in the vacuum tube, Becquerel decided to investigate whether there was any connection between X-rays and naturally occurring phosphorescence. He had inherited from his father a supply of uranium salts, which phosphoresce on exposure to light. When the salts were placed near to a photographic plate covered with opaque paper, the plate was discovered to be fogged. The phenomenon was found to be common to all the uranium salts studied and was concluded to be a property of the uranium atom. Later, Becquerel showed that the rays emitted by uranium, which for a long time were named after their discoverer, caused gases to ionize and that they differed from X-rays in that they could be deflected by electric or magnetic fields. For his discovery of spontaneous radioactivity Becquerel was awarded half of the Nobel Prize for Physics in 1903, the other half being given to Pierre and Marie Curie for their study of the Becquerel radiation. [|http://nobelprize.org/nobel_prizes/physics/laureates/becquerel-bio.html]=== ===|| || || Henry_Bequerel.JPG ||===

__**Birth Place-**__ Cheetham Hill in Manchester
===__**Scientific Contribution-**__ Thomson's early interest in atomic structure was reflected in his //Treatise on the Motion of Vortex Rings// which won him the Adams Prize in 1884. His //Application of Dynamics to Physics and Chemistry// appeared in 1886, and in 1892 he had his //Notes on Recent Researches in Electricity and Magnetism// published. This latter work covered results obtained subsequent to the appearance of James Clerk Maxwell's famous "Treatise" and it is often referred to as "the third volume of Maxwell". Thomson co-operated with Professor J. H. Poynting in a four-volume textbook of physics, //Properties of Matter// and in 1895 he produced //Elements of the Mathematical Theory of Electricity and Magnetism,// the 5th edition of which appeared in 1921. [|http://nobelprize.org/nobel_prizes/physics/laureates/thomson-bio.html]===

__**Birth Place-**__ Warsaw, Poland
===__**Scientific Contribution-**__ Curie's early researches, together with her husband, were often performed under difficult conditions, laboratory arrangements were poor and both had to undertake much teaching to earn a livelihood. The discovery of radioactivity by Henri Becquerel in 1896 inspired the Curies in their brilliant researches and analyses which led to the isolation of polonium, named after the country of Marie's birth, and radium. Mme. Curie developed methods for the separation of radium from radioactive residues in sufficient quantities to allow for its characterization and the careful study of its properties, therapeutic properties in particular. Madam Curie throughout her life actively promoted the use of radium to alleviate suffering and during World War I, assisted by her daughter, Irene, she personally devoted herself to this remedial work. She retained her enthusiasm for science throughout her life and did much to establish a radioactivity laboratory in her native city - in 1929 President Hoover of the United States presented her with a gift of $ 50,000, donated by American friends of science, to purchase radium for use in the laboratory in Warsaw. http://nobelprize.org/nobel_prizes/physics/laureates/marie-curie-bio.html=== ===|| || || Marie_Curie.JPG ||===

__**Birth Place-**__ Morrison, Illinois
===__**Scientific Contribution-**__ As a scientist, Millikan made numeroa lot of huge discoveries, chiefly in the fields of electricity, optics, and molecular physics. His earliest major success was the accurate determination of the charge carried by an electron, using the elegant "falling-drop method"; he also proved that this quantity was a constant for all electrons demonstrating the atomic structure of electricity. Next, he verified experimentally Einstein's all-important photoelectric equation, and made the first direct photoelectric determination of Planck's constant h. In addition his studies of the Brownian movements in gases put an end to all opposition to the atomic and kinetic theories of matter. During 1920-1923, Millikan occupied himself with work concerning the hot-spark spectroscopy of the elements (which explored the region of the spectrum between the ultraviolet and X-radiation), thereby extending the ultraviolet spectrum downwards far beyond the then known limit. The discovery of his law of motion of a particle falling towards the earth after entering the earth's atmosphere, together with his other investigations on electrical phenomena, ultimately led him to his significant studies of cosmic radiation (particularly with ionization chambers). [|http://nobelprize.org/nobel_prizes/physics/laureates/millikan-bio.html]=== ===|| || || Robert_Millikan.JPG ||===

__**Birth Place-**__ Nelson, New Zealand
===__**Scientific Contribution-**__ Rutherford's first researches, in New Zealand, were concerned with the magnetic properties of iron exposed to high-frequency oscillations, and his thesis was entitled //Magnetization of Iron by High-Frequency Discharges//. He was one of the first to design highly original experiments with high-frequency, alternating currents. His second paper, //Magnetic Viscosity//, was published in the //Transactions of the New Zealand Institute// and contains a description of a time-apparatus capable of measuring time intervals of a hundred-thousandth of a second. http://nobelprize.org/nobel_prizes/chemistry/laureates/rutherford-bio.html=== ===|| || || Ernest_Rutherford.JPG ||===

__Major Events: 1875-1900__
- 1899 "Boer War" - 1883 Krakatoa Erupts - Adolf Hitler is born on April 20, 1889

__Birth Place-__** Vienna, Italy __**Scientific Contributions-**__ Erwin's most notable acheivments were finding the hydrogen-like atom which is an atom just like hydrogen but instead of being nuetral is carries a positive charge. He had a very difficult time during his life because he was jewish and he had to find a country that had not adopted anti-semitism as a national policy everntually settled in Ireland where he started a school where he remained for 17 years and became a citizen of ireland. some of his accomplishmenst are a Nobel Pirize in Physics in 1933 and his work with the Schridinger equation which describes space and time dependence. http://nobelprize.org/nobel_prizes/physics/laureates/schrodinger-bio.html || || || Erwin_Schrodinger.JPG ||
 * Erwin Schrodinger (1877-1961)

__**Birth Place-**__ Copenhagen, Denmark
===__**Scientific Contributions-**__ Bohr studied under some of the most well known scientists of all time, Ernest Rutherford and J.J. Thompson. His biggest contribution to science is the Bohr Model of the atom which shows that electrons travel in orbits around the nucleas, not just random. His thoery also shows that electrons can also move between the different electron levels. for his contribution to the structure of the atom he was awarded the Nobel prize for Physics in 1922. Bohr was also part of the Manhattan project which developed the atom bombs that were dropped on japan during World War II in Nagasaki and Hiroshima. http://nobelprize.org/nobel_prizes/physics/laureates/bohr-bio.html===

**__Birth Place-__** March 14, 1875 at Ulm, Germany
===__**Scientific Contributions-**__ Before the "atom bomb" Einstein was most famous for his "Theory of Relativity". Einsteins "Theory of Relativity" is a combination of two types of relativity. Special and General Relativity. Special Relativity is "Special relativity is a theory of the structure of spacetime. General Relativity is "The development of general relativity began with the equivalence principle, under which the states of accelerated motion and being at rest in a gravitational field are physically identical." This theory won Einstein the Noble Prize in 1921. http://nobelprize.org/nobel_prizes/physics/laureates/einstein-bio.html ===

**__Birth Place-__** Chesire England
===__**Scientific Contributions-**__ During his career as a scientist he worked with Ernest Rutherford. Also during the first world war he was interned by Germany but was able to set up a labrotory and continue his work. Some of his most notable acheivments were finding a particle in the nucleas of an atom which had no charge which he called a neutron. for this discovery he was awarded the Nobel Prize for Physics but during the same time a German scientist had found the neutron and as a result Chadwick offered to share the prize with the german scientist. Chadwick later became a professor at Liverpool Univerity and worked on the Manhattan project in the United states which developed the atomic bombs that were dropped on japan during the second world war. For his work on this project he was knighted by the quenn of england. [|http://nobelprize.org/nobel_prizes/physics/laureates/chadwick-bio.html]=== ===|| || || James_Chadwick.JPG ||===

__**Birth Place-**__ Wurzburg, Germany
===__**Scientific Contribution-**__ His new theory was based only on what can be observed, that is to say, on the radiation emitted by the atom. We cannot, he said, always assign to an electron a position in space at a given time, nor follow it in its orbit, so that we cannot assume that the planetary orbits postulated by Niels Bohr actually exist. Mechanical quantities, such as position, velocity and others should be represented, not by ordinary numbers, but by abstract mathematical structures called "matrices" and he formulated his new theory in terms of matrix equations. Later Heisenberg stated his famous //principle of uncertainty//, which lays it down that the determination of the position and momentum of a mobile particle necessarily contains errors the product of which cannot be less than the quantum constant //h// and that, although these errors are negligible on the human scale, they cannot be ignored in studies of the atom. [|http://nobelprize.org/nobel_prizes/physics/laureates/heisenberg-bio.html] || || || Heisenberg_Art.JPG ||===

__1900-1915__
- The first world war begins in 1911 - San Francisco Earthquake in 1906 - The Titanic sinks in 1912

- In 1918 WWI ends after seven years - The second World war begins and ends by 1945 with the explosion of the atom bomb in Japan - The "Great Depression" takes place in 1929

[[image:dalton1.JPG width="135" height="111" caption="dalton1.JPG"]]
Dalton's atomic model was basically a plain sphere. Dalton belived that an atom was just a sphere with no charge at all. Later the charges of electrons and protons would be added. This model was invented in the early 1800's.

The plum-pudding model shows a more complex version of Dalton's atomic model. At this point there was both negative and positive charges displayed by the positive and negative signs in the sphere. This was developed in the late 1800's.

=|| = The electron cloud model shows a large area outside the nucleus that is all electrons. This means that the inside of the model is positive and the outside ins negative. This model was developed in the early 1900's.

=|| = Like the electron cloud, the planetary model has a nucleus or center that is positive with a lot of negative electrons orbiting the center. This was developed in the mid 1900's.== =|| = The Rutherford model displays a positive charge of an atom that is contained in the boudaries of a tiny nucleus, while the negative charges of the electrons travel around the nucleus.a modern day comparison to this model would be the nucleus being pea and surrounding the pea is a large football stadium. This was developed in the early 1900's.