AlChemists-500BC-1720--- develop the theory—that all metals are composed of mercury and sulfur and that it is possible to change base metals into gold.
Democritus-442 BC---Greek philosopher, who developed the atomic theory of the universe,His atomic theory anticipated the modern principles of the conservation of energy and the irreducibility of matter.
Aristotle-384-322 BC---Aristotle provided us with knowledge of natural science including Physics, which gives a vast amount of information on astronomy, meteorology, plants, and animals.
Lavoisier-1777---French chemist, who is considered the founder of modern chemistry. Lavoisier clarified the concept of an element as a simple substance that could not be broken down by any known method of chemical analysis, and he devised a theory of the formation of chemical compounds from elements.
Coulomb-1780's---He explianed that like fluids repelled and unlike attracted,this was important in the development of the theory of absolute measurement, and had a great impact on electrical potential.
John Dalton-1803---British chemist and physicist, who developed the atomic theory upon which modern physical science is founded.Dalton's most important contribution to science was his theory that matter is composed of atoms of differing weights and combine in simple ratios by weight.
Crookes-1870's---Sir William Crookes constructed this forerunner of the modern television picture tube in the 1870s to investigate the properties of cathode rays.
Becquerel-1896---Wilhelm Röntgen discovered X rays by observing the fluorescence they produced.
The Curies-1898---Pierre Curie and his wife Marie Curie stated that radioactive materials cause atoms to break down spontaneously, releasing radiation in the form of energy and subatomic particles.
J.J. Thomson-1898---J.J Thomson was the first to discover the electron.
Max Planck-1900---In 1900 Planck stated that energy is radiated in small, discrete units, which he called quanta.
Albert Einstein-1905---Einstein was known as the creator of the special and general theories of relativity and for his intelligent hypothesis concerning the particle nature of light.
Robert Millikan-1908-1917---American physicist, best known for his work in atomic physics and major science, dealing with the fundamental constituents of the universe, the forces they exert on one another, and the results produced by these forces.
Ernest Rutherford-1909-1911---British physicist, who became a Nobel laureate for his pioneering work in nuclear physics and for his theory of the structure of the atom.
Neils Bohr-1913---Bohr made numerous contributions to our understanding of atomic structure and quantum mechanics.
Geiger-1925---Geiger was the first scientist to explain DNA.
Erwin Schroedinger-1926---Schroedinger explained movement of an electron in an atom as a wave.
Chadwick-1931---British physicist James Chadwick measured the energy of the protons emerging from the hydrogen atoms.
Otto Hahn-1938---German physical chemist and Nobel laureate, best known for his contributions in the field of radioactivity.
Lise Meitner-1938---Austrian-Swedish physicist, who first identified nuclear fission.
> Murry Gell-1964---United States physicist, noted for his classification of subatomic particles and his proposal of the existence of quarks.