Physics
Physics is classified by Aristotle as the study of things in motion, and the nature of the motions of different things.
One classification Aristotle makes is the difference between natural motion and violent motion.
"Violent motion" is motion caused by an outside force,
"Natural motion" would be an animal moving of its own accord or an inanimate object going to its “proper place”.
To explain the falling of a stone to the ground, for instance, Aristotle wrote that an object always goes towards its proper place. A stone goes towards the earth, just like water, but a stone sinks through water because it is closer to the earth than water.
Wood comes from earth, but floats in water, so Aristotle considered it a mixture of the earth and air. Which is why it will burn and produce smoke which rises to the air and ash which stays on the earth. Likewise, air moves upward towards the sky, but fire cuts up through the air.
Aristotle’s laws of motion are:
1. "Heavier things fall faster, with the falling speed being proportional to the weight of the object."
2. "The speed of the object depends inversely on how dense the substance the object is falling through is. That is, the same object will fall twice as fast through a substance that is half as dense."
Although these laws seem somewhat correct, even obvious, it was from these conjectures, Aristotle concluded a vacuum is impossible, because then objects would fall at infinite speeds. It is now known that with out gravity nothing would actually fall.
One classification Aristotle makes is the difference between natural motion and violent motion.
"Violent motion" is motion caused by an outside force,
- Aristotle believed that the speed of an object in violent motion is proportional to the force applied.
"Natural motion" would be an animal moving of its own accord or an inanimate object going to its “proper place”.
- "Proper place," according to Aristotle, ment every object in the universe has a proper place determined by a combination of four elements: earth, water, air, and fire.
- any object not in its proper place will strive to get there
- For example:
- A stone falling to the earth
- or puffs of smoke rising
To explain the falling of a stone to the ground, for instance, Aristotle wrote that an object always goes towards its proper place. A stone goes towards the earth, just like water, but a stone sinks through water because it is closer to the earth than water.
Wood comes from earth, but floats in water, so Aristotle considered it a mixture of the earth and air. Which is why it will burn and produce smoke which rises to the air and ash which stays on the earth. Likewise, air moves upward towards the sky, but fire cuts up through the air.
Aristotle’s laws of motion are:
1. "Heavier things fall faster, with the falling speed being proportional to the weight of the object."
2. "The speed of the object depends inversely on how dense the substance the object is falling through is. That is, the same object will fall twice as fast through a substance that is half as dense."
Although these laws seem somewhat correct, even obvious, it was from these conjectures, Aristotle concluded a vacuum is impossible, because then objects would fall at infinite speeds. It is now known that with out gravity nothing would actually fall.
- The vacum that exists in space dosen't really cause people to move all that fast.