Document Type
Article
Publication Date
1981
Department 1
Physics
Abstract
Teachers who watched the first episode of Carl Sagan's Cosmos show on the Public Broadcasting System may have been impressed by his use of the "Cosmic Calendar" to dramatically introduce the evolutionary time scale of the universe. In this calendar, which Sagan first represented in The Dragons of Eden, the 15 billion year history of the universe is compressed into a single year. Each month represents 1.25 billion years, each day 40 billion years, and each second 500 years. At this scale the entire recorded history of mankind flashes by during the final 10 seconds of the cosmic year. [excerpt]
Copyright Note
This is the publisher's version of the work. This publication appears in Gettysburg College's institutional repository by permission of the copyright owner for personal use, not for redistribution.
DOI
10.1119/1.2340742
Recommended Citation
Marschall, Laurence. (1981) A Cosmic Clock in the Classroom. The Physics Teacher 19: 185. DOI: 10.1119/1.2340742
Required Publisher's Statement
The original version is available from the publisher at: http://tpt.aapt.org/