1700AD-1800AD

=James Bradley 1728= James Bradley was born in England in 1693. James Bradley determined speed of light within 5% accuracy by "aberration of starlight". He was trying to detect stellar parallax. Bradley found did not find the stellar parallax, but found a cyclical motion. He found this to be the aberration of light in an annual pattern. He calculated to find that the star should have been most south in December, and should be most north in June. Actually it was in the most northern point in september and its most southern point in march. With this he could calculate the speed of light within 5% accuracy. James Bradley died in 1762.

=Joseph Priestley 1774= Joseph Priestley was born in England in 1733. Priestley was not only a chemist, but was also a minister of the unitarian church. Priestley was a close friend of Benjamin Franklin. Joseph Priestley discovered oxygen, carbon monoxide, and nitrous oxide. Before Joseph Priestley, chemists thought that the air we breath was an element. Priestley made it clear that air is not an element. He heated mercuric oxide and observed its necessity in combustion. He was also the father of the electrical inverse-square law. Preistley died in 1804.

=Antoine Lavosier 1778= == Antoine Lavosier was born in France in 1743. He is considered the father of modern chemistry. He stated the first version of the conservation of mass. He helped discover and name oxygen. He discovered hydrogen in 1783. He helped build the metric system. He wrote the first list of all known elements. He reformed chemical nomenclature. He discovered that matter always has the same mass, even though the matter can change shape, size, or form. He noticed that water turned into steam and used this for his first law of conservation of mass. He was a business man and used the money he made to fund his experiments. Lavosier died in 1789.