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However, radioisotope dating may not work so well in the future. The use of various radioisotopes allows the dating of biological and geological samples with a high degree of accuracy. Other useful radioisotopes for radioactive dating include uranium-235 (half-life = 704 million years), uranium-238 (half-life = 4.5 billion years), thorium-232 (half-life = 14 billion years) and rubidium-87 (half-life = 49 billion years). Potassium-40 is another radioactive element naturally found in your body and has a half-life of 1.3 billion years. However, the principle of carbon-14 dating applies to other isotopes as well. T = x 5,700 yearsīecause the half-life of carbon-14 is 5,700 years, it is only reliable for dating organic matter up to about 60,000 years old. So, if you had a fossil that had 10 percent carbon-14 compared to a living sample, then that fossil would be: t1/2 is the Libby half-life of carbon-14 (5,700 years).Nf/No is the percent of carbon-14 in the sample compared to the amount in living tissue.It is used in dating things such as bone, cloth, wood and plant fibers that human activities created in the relatively recent past. Radiocarbon dating, or carbon dating for short, is a way of determining the age of certain archeological artifacts of a biological origin up to about 50,000 years old. How do scientists know how old an object or human remains are? What methods do they use and how do these methods work? Extensive literature is available to which the reader can refer (Evin & Oberlin, 1998 Evinet al., 1999 Evin, 2002 Fontugne, 2002, 2004). An archaeologist finds a child mummy high in the Andes and says the child lived more than 2,000 years ago. 2 - USEFULNESS AND LIMITATIONS OF RADIOCARBON DATING We do not present the method of radiocarbon dating here. At an ar­chaeological dig, someone unearths a piece of wooden tool and finds it to be 5,000 years old. You probably have seen or read news stories about fascinating ancient artifacts. Thomas was excavated in Montana between 20. This T-Rex specimen is estimated to be 70 percent complete and one of 30 partially complete T-Rex fossils worldwide. Paleontologists of the Natural History Museum of Los Angeles prepare and assemble the fossils of a 66-million-year-old Tyrannosaurus rex nicknamed Thomas, in Los Angeles on March 27, 2008.