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Dating Techniques Dendrochronology and Carbon Dating - #FOTD272

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Dating techniques dendrochronology and carbon dating When you watch these programmes and they say that things are so many thousand  years old, how can they tell? Dendrochronology is also called the dating of tree rings. It is a method of dating that allows you to determine the exact year then the specific rings were formed and also gives information about the atmospheric conditions at that time. It also works on wood in works or art and architecture, like wooden frames around paintings and furniture As trees grow the new growth is in layers of cells near the bark and the growth rate depends on the climate that season. There is more growth in summer than winter so the tree ring will be thicker in the summer. If there is better weather one year then the rings will be thicker and worse weather thinner. The oldest tree ring measurements found so far range from 12,580 - 13,900 years old. Radiocarbon dating It is based around radiocarbon also called carbon 14. It is an isotope of carbon An isotope has the same number of protons but a different number of neutrons It is taken up by plants in photosynthesis and incorporated into plant tissue the plants are eaten by animals and it is incorporated into animal tissues. When the organism dies there is no more take up or release of carbon with the environment for that organism. So what you can do is measure how much carbon 14 is in the plant or animal and then calculate how long ago it died. This is because the carbon 14 undergoes radioactive decay. It has a half life - the amount of time that half of the substance decays and for carbon 14 it is about 5,730 years So if half the carbon in a dead organisms or coal or a wood is carbon 14 then that organism was alive about 5,730 If a quarter of it is carbon 14 then that is  a half and another half so 11,460 years old The oldest dates that can reliably be measured by this process are from about 50,000 years ago. What if we want to measure the age above this, look out for dating techniques part two. A new Science fact every day on Facebook live and YouTube every day, 365 days of the year. Subscribe to my channel here https://www.youtube.com/c/MarkLotsu?sub_confirmation=1 Like this video? Share it here: https://youtu.be/MXTGiBXn0Eo For daily FB live FOTD follow https://www.facebook.com/marklotsulife/ Instagram https://www.instagram.com/marklotsu/ Twitter https://twitter.com/marklotsulife
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