Age of the Earth: Difference between revisions
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The '''age of the [[Earth]]''' is generally agreed by scientists to be 4.54 billion years (4.54*10<sup> | {{dambigbox|Age of the Earth|Earth}} | ||
The '''age of the [[Earth]]''' is generally agreed by scientists to be 4.54 billion years (4.54*10<sup>9</sup>), plus or minus about 1%. That estimate has been made mainly through radiometric dating of Earth rocks and meteorites.<ref name=usgsage>[http://pubs.usgs.gov/gip/geotime/age.html Age of the Earth]. U.S. Geological Survey.</ref> <ref name=dalrymple2004>Dalrymple GB. (2004) ''Ancient Earth, Ancient Skies: the Age of Earth and its Cosmic Surroundings''. Stanford University Press. ISBN 9780804749336. | [http://books.google.com/books?id=TNxo_TDGpH0C&source=gbs_navlinks_s Google Books preview].</ref> <ref name=dalrymple1991>Dalrymple GB. (1991) ''The Age of the Earth''. Stanford University Press. ISBN 9780804715690. | [http://books.google.com/books?id=a7S3zaLBrkgC&dq=dalrymple+earth&source=gbs_navlinks_s Google Books preview].</ref> <ref>Chris Stassen. [http://www.talkorigins.org/faqs/faq-age-of-earth.html Age of the Earth]. The TalkOrigins Archive</ref> | |||
In his 1991 book, ''The Age of the Earth'', geologist/geophysicist [http://www.coas.oregonstate.edu/index.cfm?fuseaction=content.search&searchtype=people&detail=1&id=460 G. Brent Dalrymple] gives two examples for visualizing a time period of 4.54 Ga (billion years):<ref name=dalrymple1991 /> | |||
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<font face="Gill Sans MT">If a piece of string 2.5 cm long (about an inch) represents one year, for example, then a 183-cm length (about 6 feet) is equivalent to the average lifetime of a person living in the United States. A string representing all of recorded human history would be fully a kilometer long, but a piece representing 4.5 billion years would be 114,280 km [71,010 miles] long! | |||
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Four and one-half billion quarters would form a stack nearly 8,000 km [4,971 miles] high. | |||
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Can anyone fully visualize a string that would wrap around the Earth nearly three times, or a stack of quarters that would reach from here through the center of the Earth and halfway to the other side?</font><ref name=dalrymple1991/> | |||
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==Geological evidence== | ==Geological evidence== |
Latest revision as of 09:47, 10 May 2024
The age of the Earth is generally agreed by scientists to be 4.54 billion years (4.54*109), plus or minus about 1%. That estimate has been made mainly through radiometric dating of Earth rocks and meteorites.[1] [2] [3] [4]
In his 1991 book, The Age of the Earth, geologist/geophysicist G. Brent Dalrymple gives two examples for visualizing a time period of 4.54 Ga (billion years):[3]
If a piece of string 2.5 cm long (about an inch) represents one year, for example, then a 183-cm length (about 6 feet) is equivalent to the average lifetime of a person living in the United States. A string representing all of recorded human history would be fully a kilometer long, but a piece representing 4.5 billion years would be 114,280 km [71,010 miles] long!
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Geological evidence
The main geological evidence is found from lead, as there is assumed to be none of the original crust left due to erosion.
References
- ↑ Age of the Earth. U.S. Geological Survey.
- ↑ Dalrymple GB. (2004) Ancient Earth, Ancient Skies: the Age of Earth and its Cosmic Surroundings. Stanford University Press. ISBN 9780804749336. | Google Books preview.
- ↑ 3.0 3.1 3.2 Dalrymple GB. (1991) The Age of the Earth. Stanford University Press. ISBN 9780804715690. | Google Books preview.
- ↑ Chris Stassen. Age of the Earth. The TalkOrigins Archive