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Lesson 7. C-14 Dating. Carbon -14 Dating. We know when you died !. The time it takes for half of the Carbon -14 atoms in a sample to decay is call the “Half – Life”. The “Half-Life” of C-14 is 5,730 years. In living things, about 12 in a trillion carbon atoms are C-14.
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Lesson 7 C-14 Dating
Carbon -14 Dating We know when you died !
The time it takes for half of the Carbon -14 atoms in a sample to decay is call the “Half – Life”
In living things, about 12 in a trillion carbon atoms are C-14. • This ratio remains constant as long as you stay alive. By eating and breathing , you gain as much C-14 as you lose.
When a living thing is alive, the amount of C-14 in its body remains constant After death the body begins losing C-14 at a constant rate
When something dies, it begins losing C-14 at the constant Half-Life rate. • By measuring how much C-14 is left , we can estimate how long ago that thing died After the tree dies and is buried, its Carbon-14 begins to decay at the half-life rate, which is 5,730 years 100% of C-14 50% of C-14 25% of C-14 12.5% of C-14 Died 11,460 years ago Died 17,190 years ago Died 0 years ago Died 5730 years ago
The Ice Man • A German tourist inthe Italian Alpsdiscovered theremains of the "Iceman" in the iceof a glacier in 1991.
Living things have 0.23 Bq of radiation per gram of Carbon. Iceman's carbon showed 0.121 Bq, or about half what it would be if the Iceman were alive. The Iceman
The Iceman • Since the half-life of carbon-14 is about 5700 years, the Iceman's remains are about 5700 years old.
Lindow Man • This body was found in peat moss, in a bog and was thought to be a recent Murder Victim. • When the suspect was told a body had been found, he confessed to the murder
Lindow man • When they did a C-14 test on the body, they found out it was really a sacrifice victim form 2000 years ago. • The murderer was still convicted anyway
Shroud of Turin • Probably the most controversial object dated to this point • Believed to be the burial shroud of Jesus, brought back from the Middle East during the Crusades, about 1370
Shroud of turin • In 1988, three laboratories were given four pieces of fabric
Shroud of Turin • Using C-14 dating, the labs all agreed that the shroud was 608-728 years old, which meansthat it came into existence sometime between1260 and 1380 AD
Shroud of Turin • Recent research indicates the C-14 Dating may not be accurate because during a fire (1532), that damaged it , smoke introduced new C-14 into the shroud. Scorch Marks
We may never know the truth, because the Catholic Church has said, no one can test it again