I like to use a meter stick and be very intentional with my spacing to model time as a scale. I also avoid using the far right ... of the Earth that is characteristic of a particular span of geologic ...

Prehistoric time line, geologic time scale, photos, facts, maps, and more from National Geographic. Humans have walked the Earth for 190,000 years, a mere blip in Earth's 4.5-billion-year history.

According to the International Union of Geological Sciences (IUGS), the professional organization in charge of defining Earth’s time scale ... you start naming geologic-time terms, you need ...

We will provide a list of web sites with relevant information. The geologic time scale is divided into eons, eras, periods, epochs, and ages. Our activities, and the time scale for download above, ...