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| Carbon Dating |
 Title text: This dating is corroborated by the presence of stone tools at the site, rather than earlier and less effective helium ones. |
Explanation
Carbon dating is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. This method is commonly used by archeologists and is invaluable in terms of predicting the time an piece of organic matter came from, like fossils. The punchline of this comic stems from the fact that carbon in the universe was created in the first round of stars fusing elements, and thus a cosmologist's only conclusion from the presence of carbon in a skeleton is "this skeleton is less than 13.6 billion years old", which is not useful information for judging artifacts found on Earth (a planet which is less than 5 billion years old).
The title text talks about how stone tools were found at the site of the excavation, most likely dating from the Stone Age. Tools made out of stone are often solid and durable, making them great choices for heavy duty tasks. Helium, however is a gas and is difficult to shape into a solid mass[citation needed]. However, it was produced in great quantities after the Big Bang, accounting for about ~25% of the elements produced by the Early Universe.
Carbon dating or radio carbon dating is is method used by archeologists to determine the age of an organic object. The method uses the fact that carbon consumed by living organisms contains a fixed ratio of the carbon isotopes C12, C13, and C14. Since C14 is radioactive, it decays over time. By checking how much C14 is left in the leftover of an organism, archeologists can determine how long ago the organism consumed carbon and thus how long ago it lived.
First carbon was created roughly 13.6 billion years ago in supernova explosions of the very first stars. Thus, astronomers can determine that any specimen they find that contains carbon must be younger than 13.6 billion years. Compared to the accuracy of radio carbon dating, can determine the age of an organic object younger than 50000 years within centuries of accuracy, this is highly unspecific.
In the very beginning of the universe, as part of the primordial nucleosynthesis, only hydrogen, helium, and a very small amount of lithium was created. All other elements firts occurred in stars and thus are also less than 13.6 billion years old.
Transcript
- [Ponytail, standing, is pointing at a blackboard containing a drawing of a skull and some bones/bone fragments, as well as a graph and some lines of text. She is speaking to Cueball and Megan, who are standing beside her.]
- Ponytail: The high carbon content of the skeleton indicates that the individual lived less than 13.6 billion years ago, after the first round of stellar nucleosynthesis.
- [Caption below the panel:]
- Cosmologist carbon dating
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