SmithLifeScience

Geologic Time Comparisons

Geologic Time in One Year

January 1 is 4.6 bya
March: oldest known rocks are formed
Late March: first forms of life (bacteria and algae) are preserved as fossils
September 3: first multi-celled creatures (seaweed) appear
November 11: Phanerozoic Eon (most recent eon) begins
December 5: Reptiles appear
December 14: first mammals appear
December 26: Dinosaurs go extinct
5 PM on December 31: first hominids (human-like ancestors) appear
11:48 PM on December 31: first modern humans (Homo sapiens) appear
11:58:45 p.m. on December 31: The last glacier receded
11:59:30 on December 31: Written history begins
3 seconds before midnight: Columbus lands in the Americas
You were born 1/10th of a second before midnight

Geologic time as the distance from Los Angeles to New York City:
The distance from LA to NYC is approximately 4500 kilometers (km). Therefore, each kilometer represents one million years of Earth history. Look at a map of the United States. Start the geologic time journey in LA.

Precambrian would last until Pittsburgh
Paleozoic would be entirely in Pennsylvania
Mesozoic would get us to New Jersey, only 66 km from NYC.
The most recent Ice Age ended about 10,000 years ago. 10,000 years
The past 2000 years of history would be represented by a sidewalk (2 meters)
A human lifespan would be half of the width of a curb (100 millimeters)