Cosmic Calendar
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The Cosmic Calendar is a method to visualize the chronology of the universe, scaling its currently understood age of 13.787 billion years to a single year in order to help intuit it for pedagogical purposes in science education or popular science. A similar analogy used to visualize the geologic time scale and the history of life on Earth is the Geologic Calendar.
In this visualization, the Big Bang took place at the beginning of January 1 at midnight, and the current moment maps onto the end of December 31 just before midnight.[1] At this scale, there are 438 years per cosmic second, 1.58 million years per cosmic hour, and 37.8 million years per cosmic day.
The Solar System materialized in Cosmic September. The Phanerozoic corresponds only to the latter half of December, with the Cenozoic only happening on the penultimate day on the Calendar. The Quaternary only applies to the last four hours on the final Cosmic Day, with the Holocene only applying to the final 23 Cosmic Seconds. On the other hand, relic radiation is dated at the first fifteen minutes of the very first Cosmic Day; even if we stretch the Cosmic Calendar to 100 years, the relic radiation would still happen just after the start of the second Cosmic Day.
The concept was popularized by Carl Sagan in his 1977 book The Dragons of Eden and on his 1980 television series Cosmos.[2] Sagan goes on to extend the comparison in terms of surface area, explaining that if the Cosmic Calendar were scaled to the size of a football field, then "all of human history would occupy an area the size of [his] hand".[3] The Cosmic Calendar was reused in the 2014 series, Cosmos: A Spacetime Odyssey.[4]
Cosmology
[edit]Date | Gya (billion years ago) | Event |
---|---|---|
1 January, 0:00 | 13.787 | The Big Bang[7] |
1 January, 0:14 | 13.787 | The cosmic background radiation. Would have been last emitted 14 minutes after midnight |
1 January, 0:30 | 13.787 | First atoms |
19 January | 13 | GRB 090423, Oldest known Gamma Ray Burst |
26 January | 12.85 | First galaxies form[8] |
1 March | 11 | Milky Way Galaxy formed |
13 May | 8.8 | Milky Way Galaxy disk formed |
9 September | 4.57 | Formation of the Solar System |
14 September | 4.5 | Formation of the Earth and The Moon |
Date in year calculated from formula
T(days) = 365 days * ( 1- T_Gya/13.787)
Evolution of life on Earth
[edit]
Date | Gya (billion years ago) | Event |
---|---|---|
14 September | 4.1 | First known remains of biotic life (discovered in 4.1 billion-year-old rocks in Western Australia).[9][10] |
21 September | 3.8 | First Life (Prokaryotes)[11][12][13] |
30 September | 3.4 | Photosynthesis |
29 October | 2.4 | Oxygenation of atmosphere |
9 November | 2 | Complex cells (Eukaryotes) |
5 December | 0.8 | First multicellular life[14] |
7 December | 0.67 | Simple animals |
14 December | 0.55 | Arthropods (ancestors of insects, arachnids) |
17 December | 0.53 | Fish and Proto-amphibians |
18 December | 0.518 | Vertebrates |
19 December | 0.45 | Land plants; Ordovician–Silurian extinction events |
20 December | 0.4 | Jawed fish |
21 December | 0.35 | Insects and seeds |
22 December | 0.33 | Amphibians; Late Devonian extinction |
23 December | 0.3 | Reptiles |
24 December | 0.25 | Permian–Triassic extinction event; 57% of all biological families and 83% of all genera die |
25 December | 0.23 | Dinosaurs |
26 December | 0.201 | Mammals; Triassic–Jurassic extinction event |
27 December | 0.072 | Birds (avian dinosaurs) |
28 December | 0.13 | Flowers |
30 December, 6:24 | 0.066 | Cretaceous–Paleogene extinction event, non-avian dinosaurs go extinct;[15] Primates |
Human evolution
[edit]
Date / time | Mya (million years ago) | Event |
---|---|---|
31 December, 6:05 | 28 | Apes |
31 December, 14:24 | 12.3 | Hominids |
31 December, 20:00 | 7 | Chimpanzees and Humans split |
31 December, 22:24 | 2.8 | Homos and stone tools |
31 December, 23:44 | 0.4 | Domestication of fire |
31 December, 23:52 | 0.2 | Humans |
31 December, 23:55 | 0.115 | Beginning of most recent Glacial Period |
31 December, 23:58 | 0.035 | Sculpture and painting |
31 December, 23:59:32 | 0.012 | Agriculture |
History begins
[edit]
References
[edit]- ^ Blanchard, Therese Puyau (1995). "The Universe At Your Fingertips Activity: Cosmic Calendar". Astronomical Society of the Pacific. Archived from the original on 2007-12-16. Retrieved 2007-12-15.
- ^ Witt, Steven (December 2024). "Libraries at the intersection of history and the present". IFLA Journal. 50 (4): 691–695. doi:10.1177/03400352241299307. ISSN 0340-0352.
- ^ "The Shores of the Cosmic Ocean". Cosmos: A Personal Voyage. Episode 1. 1980-10-01. Event occurs at 51:10. Public Broadcasting Service.
- ^ Zakariya, Nasser (July 2015). "Exhibiting Cosmos". Technology and Culture. 56 (3): 738–744. doi:10.1353/tech.2015.0086. ISSN 1097-3729.
- ^ "Cosmic Calendar". visav.phys.uvic.ca. Retrieved 2025-02-18.
- ^ "The Cosmic Calendar". www.yorku.ca. Retrieved 2025-02-18.
- ^ "Planck reveals an almost perfect universe". Max-Planck-Gesellschaft. March 21, 2013. Retrieved 2020-11-17.
- ^ "First Galaxies Born Sooner After Big Bang Than Thought". Space.com. 14 April 2011. Retrieved 2015-11-07.
- ^ Borenstein, Seth (19 October 2015). "Hints of life on what was thought to be desolate early Earth". Excite. Yonkers, New York: Mindspark Interactive Network. Associated Press. Retrieved 2015-10-20.
- ^ Bell, Elizabeth A.; Boehnike, Patrick; Harrison, T. Mark; et al. (19 October 2015). "Potentially biogenic carbon preserved in a 4.1 billion-year-old zircon" (PDF). Proc. Natl. Acad. Sci. U.S.A. 112 (47): 14518–21. Bibcode:2015PNAS..11214518B. doi:10.1073/pnas.1517557112. ISSN 1091-6490. PMC 4664351. PMID 26483481. Retrieved 2015-10-20. Early edition, published online before print.
- ^ Ohtomo, Yoko; Kakegawa, Takeshi; Ishida, Akizumi; Nagase, Toshiro; Rosing, Minik T. (8 December 2013). "Evidence for biogenic graphite in early Archaean Isua metasedimentary rocks". Nature Geoscience. 7 (1): 25–28. Bibcode:2014NatGe...7...25O. doi:10.1038/ngeo2025.
- ^ Borenstein, Seth (13 November 2013). "Oldest fossil found: Meet your microbial mom". AP News. Retrieved 15 November 2013.
- ^ Noffke, Nora; Christian, Daniel; Wacey, David; Hazen, Robert M. (8 November 2013). "Microbially Induced Sedimentary Structures Recording an Ancient Ecosystem in the ca. 3.48 Billion-Year-Old Dresser Formation, Pilbara, Western Australia". Astrobiology. 13 (12): 1103–24. Bibcode:2013AsBio..13.1103N. doi:10.1089/ast.2013.1030. PMC 3870916. PMID 24205812.
- ^ Erwin, Douglas H. (9 November 2015). "Early metazoan life: divergence, environment and ecology". Phil. Trans. R. Soc. B. 370 (20150036): 20150036. doi:10.1098/rstb.2015.0036. PMC 4650120. PMID 26554036.
- ^ "Cosmos: A Spacetime Odyssey (@35min)". Archived from the original on 2014-03-11. Retrieved 2014-03-11.