Sources
Help build the largest human-edited directory on the web.
Submit a site - Become an editor
Wikipedia. Licensed under the GNU Free Documentation License.
Are you an expert in this subject? Join the discussion and share your knowledge at Wikipedia.org.
Aristotelian physics
From Wikipedia, the free encyclopedia
The Greek philosopher Aristotle (384 BC – March 7, 322 BC) developed many theories on the nature of physics that somewhat differ from what are now understood as the laws of physics.
Contents |
Aristotle taught that the elements that composed the Earth were different than those that made up the heavens and Outer space.[1] He also taught that dynamics were mostly determined by the characteristics and nature of the substances that the object that was moving was composed of.[1]
Aristotle believed that there were four main elements or compounds that made up the Earth: earth, air, water and fire.[a][2] He also held that all the heavens, and every particle of matter in the universe, was formed out of another, fifth element he called 'aether' (also transliterated as "ether")[2], which was supposedly weightless and "incorruptible".[2] Aether was also known by the name 'quintessence' - literally, "fifth substance".[3]
Heavy substances such as iron and metals were considered to be primarily consisting of the "element" of earth, with a limited amount of matter from the other elements. Other, less heavy and/or dense objects were thought to be less earthy, and composed of a greater mixture of the other elements.[3] Humans were shaped with all of the substances, with the exception of ether, but the relative proportion of elements was unique to each person, and there was no standard amount of each within the human body.[3]
Aristotle held that each of the four worldly elements would each seek each other and cluster together, and that this seeking of other similar elements would have to be hindered to be stopped, as it was as natural as two magnets rejecting each other, or rain falling from the clouds. For instance, because smoke was mainly air, it would rise to meet the air in the sky. He also taught that objects and matter could only move so long as a form of energy was forcing it in a given direction.[4] Therefore, if all the applied forces on Earth were removed, such as the throwing of a rock, then nothing could move.[4] This idea had flaws that were visible even back in the time of the concept's beginnings. Many people questioned how an object such as an arrow could continue to move forward after it had left the power released by the string, and continue to sail forward. Aristotle proposed an idea that arrows, etc., created a type of vacuum behind them that forced them forward.[4]
The reign of Aristotelian notions of physics lasted for over two millennia, and provided the first explanation of physics. However, after the work of Galileo, Descartes, and many others, it became generally accepted that Aristotle's physics were not correct or viable.[5] Despite this, Aristotle's physics were able to live into the late seventeenth century, and perhaps longer, as they were still taught in universities at the time. Although modern physics differs greatly, the physics of Aristotle provided a basic structure for physics after Aristotle's death (and the death of his model of physics) to be built upon.
a ^ The term 'earth' refers to a pure element that Aristotle theorized, not the actual planet Earth, which is known to be composed of a large number of elements. The same applies to the other terminologies used. 'Air' refers to a pure element of air, opposed to the air we breathe, which is made up of many elements.
- ^ a b Physics of Aristotel vs. The Physics of Galileo. Retrieved on 26 March, 2007.
- ^ a b c www.hep.fsu.edu. Retrieved on 26 March, 2007.
- ^ a b c Aristotel's physics. Retrieved on 27 March, 2007.
- ^ a b c Physics of Aristotle vs. The Physics of Galileo. Retrieved on 28 March, 2007.
- ^ Aristotel's physics. Retrieved on 28 March, 2007.