Aristotle

Chance and spontaneity
Further information: Accident (philosophy)
According to Aristotle, spontaneity and chance are causes of some things, distinguishable from other types of cause such as simple necessity. Chance as an incidental cause lies in the realm of accidental things, "from what is spontaneous". There is also more a specific kind of chance, which Aristotle names "luck", that only applies to people's moral choices.^[52][53]
Astronomy
Further information: History of astronomy
In astronomy, Aristotle refuted Democritus's claim that the Milky Way was made up of "those stars which are shaded by the earth from the sun's rays," pointing out partly correctly that if "the size of the sun is greater than that of the earth and the distance of the stars from the earth many times greater than that of the sun, then... the sun shines on all the stars and the earth screens none of them."^[54] He also wrote descriptions of comets, including the Great Comet of 371 BC.^[55]
Geology and natural sciences
Further information: History of geology
Aristotle noted that the ground level of the Aeolian islands changed before a volcanic eruption.
Aristotle was one of the first people to record any geological observations. He stated that geological change was too slow to be observed in one person's lifetime.^[56][57] The geologist Charles Lyell noted that Aristotle described such change, including "lakes that had dried up" and "deserts that had become watered by rivers", giving as examples the growth of the Nile delta since the time of Homer, and "the upheaving of one of the Aeolian islands, previous to a volcanic eruption."'^[58] Aristotle also made many observations about the hydrologic cycle and meteorology (including his major writings "Meteorologica"). For example, he made some of the earliest observations about desalination: he observed early – and correctly – that when seawater is heated, freshwater evaporates and that the oceans are then replenished by the cycle of rainfall and river runoff ("I have proved by experiment that salt water evaporated forms fresh and the vapor does not when it condenses condense into sea water again.")^[59]