How old
13.8 billion years, compressed into one calendar year.
Carl Sagan's Cosmic Calendar: Big Bang on January 1 at midnight, today on December 31 at midnight. Let the universe play out in thirty seconds — and watch all of human history happen in the last eight seconds.
Position in cosmic yearJanuary 1 · 00:00
Big Bang
Milky Way
Cosmic Noon
Sun
Oxygen
Cambrian
Today
Scale
In the cosmic calendar, 1 second = 437 years. A human lifetime is one-eighth of a second. All recorded history (since the first writing) spans 12 seconds. The Industrial Revolution is 0.6 seconds before midnight.
Sources
Universe age 13.787 Gyr (Planck mission 2018, ΛCDM). Earth 4.54 Gyr (Hadean zircons). First life signs 3.8 Gyr (Greenland). Cambrian Explosion 538.8 Mya. K-Pg extinction 66.04 Mya. Homo sapiens 315'000 yr (Jebel Irhoud, Morocco). Inspired by Carl Sagan's Cosmos.