Visualizing the Vastness of Time
Click calendar to enlarge.
Recorded human history is the tiny bright spot at the lower right of the Cosmic Calendar. You'll probably have to click on the calendar to see that spot.
On This Scale
[ Cosmic Calendar interval = real years ]
1 year on Cosmic Calendar = 13.8 billion years, or 13,800,000,000 years
1 month = about 1 billion years (precisely 1.15 by)
1 day = nearly 40 million years (37.78 my)
1 hour = just over 1.5 million years (1.574 my)
1 minute = about 26,000 y (26,237 y)
1 second = about 450 y (437.30 y)
[ One second equals 4.5 centuries! ]
Important Dates on the Cosmic Calendar
January 1
Big Bang
January 10
First stars burst into light.
January 13
First small galaxies coalesce.
March 15, about 11 billion years ago
Milky Way, our galaxy, forms.
But our Sun is still in the far future. Meanwhile, first-generation stars are living out their lives , and then fertilizing space with heavier elements like carbon, nitrogen, oxygen, sulfur, phosphorus, iron, ... , elements that were present in the gas cloud that formed our Solar System.
August 31
The Sun is born, 4.5 billion years ago -- about 6.5 billion years into the life of the Milky Way.
September 21, 3.5 billion years ago
Earliest evidence of life.
December 17
Animals venture onto land.
December 28
First flowering plants appear.
December 30
Impact of asteroid* (Chicxulub, 66 million years ago) that ends the reign of dinosaurs.
(* or asteroid or some kind of celestial body)
December 31, sometime after 11 PM
First humans appear.
December 31, 11:59
First cave pictures, about 30,000 years ago; then agriculture, about 10,000 years ago.
December 31, 11:59:46
Writing invented; recorded history begins in the last 14 seconds on the Cosmic Calendar.
December 31, last few seconds on the Cosmic Calendar, some birthdays:
Moses, 7 seconds ago; Buddha, 6 seconds ago; Jesus, 5 seconds ago; Mohammed, 3 seconds ago; less than 2 seconds ago, East and West discover each other.
December 31, 11:59:59
Roughly one second ago, we began to use science to understand our world and our universe.
December 31, midnight
Now -- the present moment.
Carl Sagan: "We are a way for the Cosmos to know itself."
•••••••
Exercises
(Disclaimer: the "calculations" below done hastily and roughly; corrections might appear quietly in the dead of night.)
Finding dates on the Cosmic Calendar
On the first of two tables below, find the dates in "million years ago" (mya) of any geological period of interest. Then try to figure out the corresponding calendar date on Carl Sagan's Cosmic Calendar at the top of this page. Use the numbers in On This Scale below the calendar to make your conversions.
Here's is example; try to confirm it.
The Hadean Period was around 4,600 mya, or 4.6 billion years ago. The corresponding date on the Cosmic Calendar is around the middle of August.
Another: The Quarternary Period, which began 2.58 mya, falls on December 31 at about 10:45 PM, or about 1 hour and 15 minutes before the end of the Cosmic Calendar.
Try it for a period of interest to you.
Here's a continuation of the chart above:
Two figures above from https://www.researchgate.net/figure/Viewing-Anthropocenic-Ages-through-astronomical-and-geochronological-time-scales-Big_fig3_335715898
This page has some great illustrations summarizing various aspects of Earth's history. The writing needs editing, but the explanations and illustrations are very clear. You might find it interesting to read.
