Starting in the fourth and fifth centuries B.C, Greek philosophers tried to determine what the world was made of. Chief amongst them was Aristotle, who lived around 340 B.C. Aristotle was a student of the philosopher Plato and tutored Alexander the Great, conqueror of much of the known world. Aristotle founded a school of philosophy and wrote many books, some on science. Aristotle  and his followers made some observations of everyday occurrences, and then tried to draw all possible conclusions solely by logical arguments. unfortunately, they were not very interested in knowing exactly what happens or how it happens, or even if it happens, given different conditions. Their interest were mainly theorizing why specific events that they observed occurred.
Aristotle believed that all within reach was made up of four elements: Earth, Water, Air, and Fire. Each element had a "natural place." The highest  place belonged to Fire, then Air, then Water, and then at the bottom was earth. Motion occurred  because an element wanted to reached it's own natural place. Thus Water bubbled up through springs on Earth. Adding Fire to Water produced steam, a form of Air, that rose. A stone was tossed up, it was given "violent motion."  When this motion ceased, natural motion took over and the stone fell.

The writing of the early Greeks first came to Europe through Arabic translations in the twelfth century. until the sixteenth century, Europeans accepted the Greek teachings as truth, with no need for verification. One of the first European scientist to claim publicly that knowledge must be based on observations and experiments rather than ancient books was Galileo Galileo (1564-1642). He questioned the belief that Earth is the center of the universe. he doubted Aristotle views on physics, especially the idea that objects of large mass fall faster than objects of small mass. To prove Aristotle wrong , Galileo developed a systematic method of observation, experimentation, and analysis of results. from these analysis, conclusions are drawn.  These conclusions are then subjected to additional tests to find out if they are valid. Since Galileo's time, scientist all over the world have used these techniques and methods to gain a better understanding of the universe. Knowledge, skill, luck, imagination, trial and error, educated guesses, and great patience - all play a part. For example, the two Swiss scientists who discovered the new superconductors said they "felt free to try something crazy." The leader of the university of Houston superconductor research group, Paul Chu said " We feel we have an advantage over some other groups because we are not confined to conventional thinking, We think wildly."