5.4. The Geologic Calendar
5.4. The Geologic Calendar
As we've seen, compressing the entirety of the cosmological time scale into just a 365 days causes calendar time to speed up A LOT. But what if we compressed the entirety of Earth's 4.54 billion year history in a single year? Since we're compressing the history of everything you've ever known, loved or hated, and everything that has ever existed here into just a single year, things may get a tiny bit easier to understand, but time will still speed up a lot! So we'll just get to it now.
In this visualization, Earth formed at the start of New Year's Day / January 1 at midnight, and the present time maps onto the end of New Year's Eve / December 31 at midnight. Both Earth's formation and the present are represented by midnight at either end of the year. At this scale:
1 second ~ 144 years
1 minute ~ 8,640 years
1 hour ~ 518,265 years
1 day ~ 12.44 million years
Hadean = Jan. 1 - Feb. 13 (4.54 - 4 bya)
Archean = Feb. 13 - June 2 (4 bya - 2.5 bya)
Proterozoic = June 2 - Nov. 19 (2.5 bya - 540 mya)
Phanerozoic = Nov. 19 - present (540 mya - present)
Paleozoic = Nov.19 - Dec. 12 (540 mya - 252 mya)
Mesozoic = Dec. 12 - Dec. 25 (252 mya - 65 mya)
Cenozoic = Dec. 25 - present (65 mya - present)