HSCI 3013 Discussion Exercise 2:



As well educated Greeks, living in the time of Aristotle, we all know that there are four elements: air, water, earth and fire. How they move is more controversial. Assume that an element will display its natural motion when a small sample of one element is allowed to move freely in a large sample of another element. moved freely. For example, a small sample of water moving in air ( = rain ) shows that water descends in air.



1.) Construct a list of natural motions for all pairs of elements.

2.) Imagine that the universe is a cubical box. If the universe initially contains equal amounts of all four elements, at all points, and the elements are then allowed to perform natural motions according to principles you discovered in (1) above, what will the final structure of the universe be?

3) Imagine that the universe is a finite sphere, in which 'down' is defined as any direction along a radius towards the center and 'up' is defined as any direction radially away from the center. If the universe initially contains equal amounts of all four elements, at all points, and the elements are then allowed to perform natural motions according to principles you discovered in (1) above, what will the final structure of the universe be?