The Scale of Things - Nanometers and More. (Source: Office of Science, U.S. Department of Energy) (click on image to enlarge)
Secret Worlds: The Universe Within
View the Milky Way at 10 million light years from the Earth. Then move through space towards the Earth in successive orders of magnitude until you reach a tall oak tree. After that, begin to move from the actual size of a leaf into a microscopic world that reveals leaf cell walls, the cell nucleus, chromatin, DNA and finally, into the subatomic universe of electrons and protons.
Once the tutorial has completely downloaded, a set of the arrows will appear that allow the user to increase or decrease the view magnitude in Manual mode. Click on the Auto button to return to the Automatic mode.
Notice how each picture is actually an image of something that is 10 times bigger or smaller than the one preceding or following it. The number that appears on the lower right just below each image is the size of the object in the picture. On the lower left is the same number written in powers of ten, or exponential notation. Exponential notation is a convenient way for scientists to write very large or very small numbers.