Wikipedia:Today's featured article/July 6, 2023: Difference between revisions
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{{Main page image/TFA|image=1 MV accelerator mass spectrometer.jpg|caption= An accelerator mass spectrometer used for carbon-14 dating}} |
{{Main page image/TFA|image=1 MV accelerator mass spectrometer.jpg|caption= An accelerator mass spectrometer used for carbon-14 dating}} |
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'''[[Radiocarbon dating]]''' is used to determine the age of carbon-bearing material by measuring its [[Carbon-14|radiocarbon]], the radioactive [[isotope]] carbon-14. Invented by [[Willard Libby]] in the late 1940s, it soon became a standard tool for archaeologists. Radiocarbon is constantly created in the atmosphere, when [[cosmic ray]]s create free [[neutron]]s that hit [[nitrogen]]. Plants take in carbon, including radiocarbon, through [[photosynthesis]], and after an animal or plant dies, it stops exchanging carbon with its environment. [[half-life|Half of the radiocarbon decays]] every 5,730 years; the oldest dates that can be reliably measured are around 50,000 years ago. The amount of radiocarbon in the atmosphere was reduced starting from the late 19th century by fossil fuels, which contain little radiocarbon, but nuclear weapons testing almost doubled levels by |
'''[[Radiocarbon dating]]''' is used to determine the age of carbon-bearing material by measuring its levels of<!-- added "levels of" to make more clear what quantity is being measured --> [[Carbon-14|radiocarbon]], the radioactive [[isotope]] carbon-14. Invented by [[Willard Libby]] in the late 1940s, it soon became a standard tool for [[archaeology|archaeologists]]<!-- linked to conform with article lead -->. Radiocarbon is constantly created in the [[Atmosphere of Earth|atmosphere]]<!-- linked to conform with article lead -->, when [[cosmic ray]]s create free [[neutron]]s that hit [[nitrogen]]. Plants take in carbon, including radiocarbon, through [[photosynthesis]], and after an animal or plant dies, it stops exchanging carbon with its environment. [[half-life|Half of the radiocarbon decays]] every 5,730 years; the oldest dates that can be reliably estimated<!-- reworded as the dates are not measured, the levels of radiocarbon are --> are around 50,000 years ago. The amount of radiocarbon in the atmosphere was reduced starting from the late 19th century by fossil fuels, which contain little radiocarbon, but [[nuclear weapons testing]]<!-- linked to conform with article lead --> almost doubled levels by around 1965<!-- conform with article lead -->. [[Accelerator mass spectrometry]] ''(apparatus pictured)'' is the standard method used, which allows<!-- reworded to conform with character limit --> minute samples. Libby received the [[List of Nobel laureates in Chemistry|Nobel Prize in Chemistry<!-- changed link text to better conform with mos:egg -->]]<!-- removed "for his work" to conform with character limit, as nobel prizes are generally awarded for one's work --> in 1960. {{TFAFULL|Radiocarbon dating}} |
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Revision as of 21:30, 29 June 2023
Radiocarbon dating is used to determine the age of carbon-bearing material by measuring its levels of radiocarbon, the radioactive isotope carbon-14. Invented by Willard Libby in the late 1940s, it soon became a standard tool for archaeologists. Radiocarbon is constantly created in the atmosphere, when cosmic rays create free neutrons that hit nitrogen. Plants take in carbon, including radiocarbon, through photosynthesis, and after an animal or plant dies, it stops exchanging carbon with its environment. Half of the radiocarbon decays every 5,730 years; the oldest dates that can be reliably estimated are around 50,000 years ago. The amount of radiocarbon in the atmosphere was reduced starting from the late 19th century by fossil fuels, which contain little radiocarbon, but nuclear weapons testing almost doubled levels by around 1965. Accelerator mass spectrometry (apparatus pictured) is the standard method used, which allows minute samples. Libby received the Nobel Prize in Chemistry in 1960. (Full article...)