624-547 B.C. | Thales of Miletus postulates that water is the basic substance of the Earth. He also was acquainted with the attractive power of magnets and rubbed amber. |
580-500 B.C. | Pythagoras held that the Earth was spherical. He sought a mathematical understanding of the universe. |
500-428 B.C., 484-424 B.C. | Anaxagoras and Empedocles. Anaxagoras challenged the previous Greek contention about the creation and destruction of matter by teaching that changes in matter are due to different orderings of indivisible particles (thus his teachings were a precursor to the law of the conservation of matter). Empedocles reduced these indivisible partices into four elements: earth, air, fire, and water. |
460 - 370 B.C. | Democritus developed the theory that the universe consists of empty space and an (almost) infinite number of invisible particles which differ from each other in form, position, and arrangement. All matter is made of indivisible particles called atoms. |
384-322 B.C. | Aristotle formalized the gathering of scientific knowledge. While it is difficult to point to one particular theory, the total result of his compilation of knowledge was to provide the fundamental basis of science for a thousand years. |
310-230 B.C. | Aristarchus describes a cosmology identical to that proposed by Copernicus 2,000 years later. However, given the great prestige of Aristotle, Aristarchus' heliocentric model was rejected in favor of the geocentric model. |
287-212 B.C. | Archimedes was a great pioneer in theoretical physics. He provided the foundations of hydrostatics. |
70-147 AD | Ptolemy of Alexandria collected the optical knowledge of the time. He also invented a complex theory of planetary motion. |
~1000 AD | Alhazen, an Arab, produced 7 books on optics. |
1214 - 1294 AD | Roger Bacon taught that in order to learn the secrets of nature we must first observe. He thus provided the method by which people can develop deductive theories using evidence from the natural world. |
1473 - 1543 AD | Nicholaus Copernicus set forth the theory that the earth revolves around the sun. This heliocentric model was revolutionary in that it challenged the previous dogma of scientific authority of Aristotle, and caused a complete scientific and philosophical upheaval. |