The Fourth Dimension

Draw a straight line on a piece of paper. The line has only one dimension. Now draw a square. The square has two dimensions. A dimension is a property of space, or an extension in a given direction. Now, if you are able, draw a cube. A cube has three dimensions.

When you watch a movie in "3-D," or three dimensions, you are probably required to wear special glasses that trick your mind into seeing depth on a flat screen.

We will also work with a fourth dimension—time. The distance from the floor to the top of your head is your height. Stretching your arms out, the distance from one fingertip to the other is an example of width. Putting your hands in front of you provides you with the third dimension—depth. Think about the future. It is likely that your dimensions will change over time, so in this case, time can be considered the fourth dimension.

The sizes and shapes of nations and regions can also change over time. In 1776, the United States consisted of only thirteen states along or near the coast of the Atlantic Ocean. By 1912, 48 states stretched across the mainland of North America. The United States expanded even further west as Alaska and Hawaii joined the union in 1959.

Soon we will study the lands between the Tigris and Euphrates Rivers in a land that today is part of the nation of Iraq.

Resources:

Download this lesson as Microsoft Word file or as an Adobe Acrobat file.

Download a lesson plan that includes the Florida Next Generation Sunshine State Standards (2011) as a Microsoft Word file or as an Adobe Acrobat file.

Listen to Mr. Dowling read this lesson. (mp3)