How old are you? To you, your lifespan probably seems like a large amount of time. The span of just ten years seems like an eternity. As your grow older, time seems to pass more quickly. Consider your grandparents. How old are they? How long ago where your great-grandparents born? Looking way back into history, how long ago did the Egyptians build the pyramids?

To us, as humans, the Egyptian Empire existed in ancient history. To the Earth, however, it happened in just the blink of an eye ago.
The Earth as been evolving and changing for many hundreds of millions of years, even billions of years.

The changes that take place in the Earth’s landscape are usually very slow by human standards. It takes many generations of lifetimes before any noticeable changes have taken place in the landscapes of a particular location.

Yet, in geologic time, the Earth is constantly changing and evolving. What we see today will be very different in the future. The mountains, rivers, lakes, and land formations of today will not exist at some point in the distant future.