| 1564 - 1642 | Galileo Galilei is considered by 
many to be the father of modern physics because of his 
willingness to replace old assumptions in favor of new
scientifically deduced theories. He is famous for his celestial theories,
and his works on mechanics paved the way for Newton. | 
| 1546 - 1601, 1571 - 1630 | Tycho Brahe and Johannes Kepler. Brahe's accurate 
celestial data allow Kepler to develop his theory of elliptical 
planetary motion and provide evidence for the Copernican system. 
In addition, Kepler writes a qualitative description of gravitation. | 
| 1642 - 1727 | Sir Isaac Newton develops the laws of mechanics 
(now called classical mechanics)
 which explains object motion in a mathematical fashion. |  | 
| 1773 - 1829 | Thomas Young develops the wave theory of light
and describes light interference. | 
| 1791 - 1867 | Michael Faraday creates the electric motor,
and develops an understanding of electromagnetic induction,
which provides evidence that electricity and magnetism are related.
In addition, he discovers electrolysis and describes the 
conservation of energy law. | 
| 1799 - 1878 | Joesph Henry's research on electromagnetic
induction is performed at the same time as Faraday's.
He constructs the first motor; his work with electromagnets
leads directly to the development of the telegraph. | 
| 1873 | James Clerk Maxwell performs important research in three areas:
 color vision, molecular theory, and electromagnetic theory.
The ideas underlying Maxwell's theories of electromagnetism
describes the propagation of light waves in a vacuum. | 
| 1874 | George Stoney develops a theory 
of the electron and estimates its mass. | 
| 1895 | Wilhelm Röntgen discovers x rays. | 
| 1898 | Marie and Pierre Curie separate radioactive elements. | 
| 1898 | Joseph Thompson measures the electron, and puts forth his 
"plum-pudding" model of the atom -- that the atom is
 a slightly positive sphere with small, 
raisin-like negative electrons inside. |