Age of the Earth: Difference between revisions
imported>Anthony.Sebastian (tweak intro; add ref) |
imported>Anthony.Sebastian m (rearrange refs) |
||
| Line 1: | Line 1: | ||
{{subpages}} | {{subpages}} | ||
The '''age of the [[Earth]]''' is generally agreed by scientists to be 4.54 billion years (4.54*10<sup>2</sup>), plus or minus about 1%. | The '''age of the [[Earth]]''' is generally agreed by scientists to be 4.54 billion years (4.54*10<sup>2</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=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>[http://www.talkorigins.org/faqs/faq-age-of-earth.html Age of the Earth]. Talkorigins.org</ref> | ||
In his 1991 book, ''The Age of the Earth'', G. Brent Dalrymple gives two examples for visualizing a time period of 4.54 Ga (billion years):<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> | In his 1991 book, ''The Age of the Earth'', G. Brent Dalrymple gives two examples for visualizing a time period of 4.54 Ga (billion years):<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> | ||
Revision as of 20:50, 2 December 2011
The age of the Earth is generally agreed by scientists to be 4.54 billion years (4.54*102), plus or minus about 1%. That estimate has been made mainly through radiometric dating of Earth rocks and meteorites.[1] [2] [3]
In his 1991 book, The Age of the Earth, G. Brent Dalrymple gives two examples for visualizing a time period of 4.54 Ga (billion years):[2]
|
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!
|
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.
- ↑ 2.0 2.1 2.2 Dalrymple GB. (1991) The Age of the Earth. Stanford University Press. ISBN 9780804715690. | Google Books preview.
- ↑ Age of the Earth. Talkorigins.org