Hello Earth - Origins of Our Planet - Part III
Let's suppose that you have never seen frogs before. You are assigned by your teacher to write a report about the life of these small green animals. How they are born, how they grow, and how long they live. Let's suppose that you are the first person ever to study frogs. Because no one has studied frogs before you, there are no books available to teach you about their life cycle. This means that the only resource you have to help you is your own two eyes.
Now suppose that your report is due tomorrow. If you had more time, you could watch baby frogs as they grew and developed. You could take them into your room, place them in a glass container and study them, writing about each stage as they developed.
One solution might be to draw pictures of the many different frogs that you see in your local pond. You could then lay these drawings out on a table in order from smallest to largest. What do the drawings show? First, a picture of a small tadpole, followed by pictures of larger and larger tadpoles, until finally you have a picture of an adult frog.
The frog growth chart you created was completed without you having to wait and watch as one frog grew and developed. You have successfully created a theory of frog growth. How can you prove your theory? The only way to prove that your theory on frog growth is accurate would be to actually watch a single specimen pass through each step of the process. Is this necessary? That depends, but chances are pretty high that your theory is going to be proven accurate.
Now what do frogs have to do with understanding the development of the Earth? Remember that we discussed the many trillions of stars in our Universe? Like a giant backyard pond, we can look at hundreds of developing planetary systems throughout the Universe.