How can objects be sorted?

Sorting things into categories is the first step in understanding nature. To sort items, you need to carefully observe them. This often leads to new insights into nature.

How do we sort? First we identify common properties like color, size or weight. Based on these properties we create categories for the objects to be sorted. To be placed into a category, all items will have the same criteria, or characteristics. Finally, we group the items based upon these traits into the categories.

For example, Ted and Barkley sorted the apples for the purpose of selling them. They first picked the property of size and separated the apples based upon which were small and large. This was a simple choice, but perhaps not the best when considering eating the apples. Next Barkley and Ted decided to sort the apples by color. Through experience, Ted knew that he didn't want to eat brown apples. Sorting the apples into red and brown piles helped them see how many apples might be tasty or not. This is an example of how scientists refine their sorting to produce better results. This leads to a better understanding of nature.

A good example of sorting in the physical world is sorting matter. You can identify if something is a solid, liquid, or gas. On Earth, some materials can be found in more than one state of matter. To understand our Universe, astronomers sort stars into various types and study the life of stars. Biologists understand animals and plants better by observing, sorting and classifying them. Classifying the common traits of animals has led to an understanding of how animals may have changed over time.