The Cosmic Calendar is a method to visualize the
chronology of the universe
The chronology of the universe describes the history and future of the universe according to Big Bang cosmology.
Research published in 2015 estimates the earliest stages of the universe's existence as taking place 13.8 billion years ago, wit ...
, scaling its
currently understood age of 13.8 billion years to a single
year
A year or annus is the orbital period of a planetary body, for example, the Earth, moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the hou ...
in order to help intuit it for pedagogical purposes in
science education
Science education is the teaching and learning of science to school children, college students, or adults within the general public. The field of science education includes work in science content, science process (the scientific method), some ...
or
popular science
''Popular Science'' (also known as ''PopSci'') is an American digital magazine carrying popular science content, which refers to articles for the general reader on science and technology subjects. ''Popular Science'' has won over 58 awards, incl ...
.
In this visualization, the
Big Bang
The Big Bang event is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models of the Big Bang explain the evolution of the observable universe from the ...
took place at the beginning of January 1 at midnight, and the current moment maps onto the end of December 31 just before midnight.
At this scale, there are 437.5 years per cosmic second, 1.575 million years per cosmic hour, and 37.8 million years per cosmic day.
The concept was popularized by
Carl Sagan
Carl Edward Sagan (; ; November 9, 1934December 20, 1996) was an American astronomer, planetary scientist, cosmologist, astrophysicist, astrobiologist, author, and science communicator. His best known scientific contribution is research on ext ...
in his 1977 book ''
The Dragons of Eden
''The Dragons of Eden: Speculations on the Evolution of Human Intelligence'' is a 1977 book by Carl Sagan, in which the author combines the fields of anthropology, evolutionary biology, psychology, and computer science to give a perspective on ho ...
'' and on his 1980 television series ''
Cosmos
The cosmos (, ) is another name for the Universe. Using the word ''cosmos'' implies viewing the universe as a complex and orderly system or entity.
The cosmos, and understandings of the reasons for its existence and significance, are studied in ...
''. Sagan goes on to extend the comparison in terms of surface area, explaining that if the Cosmic Calendar is scaled to the size of a football field, then "all of human history would occupy an area the size of
ishand".
Episode 1: The Shores of the Cosmic Ocean (''Cosmos: A Personal Voyage'', Carl Sagan)
/ref>
A similar analogy used to visualize the geologic time scale
The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochrono ...
and the history of life on Earth is the Geologic Calendar
Cosmology
Date in year calculated from formula
T(days) = 365 days * ( 1- T_Gya/13.797 )
Evolution of life on Earth
Human evolution
History begins
See also
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* List of timelines
This is a list of timelines currently on Wikipedia.
Overview
There are several types of timeline articles.
*''Historical timelines'' show the significant historical events and developments for a specific topic, over the course of centuries or ...
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References
External links
More information on the image used for this article.
The Cosmic Calendar in a Google Calendar format
The Cosmic Calendar relayed in real time.
{{Portal bar, History, Astronomy, Stars, Spaceflight, Outer space, Solar System, Science
Units of time
Calendar
A calendar is a system of organizing days. This is done by giving names to periods of time, typically days, weeks, months and years. A date is the designation of a single and specific day within such a system. A calendar is also a physi ...
Time in astronomy