Most amino acids exist in two forms, commonly called "left" and "right." Living organisms use only "left" amino acids, but after death, the "left" amino acids begin changing to "right" forms, until there is an equal number of both. This suggests the possibility of using the amount of change as a measure of time, leading to the development of amino-acid dating. This dating of method does not confirm the results of other methods of dating. Published in Origins v. 12, n. 1.
Radioisotope ages are calculated from ratios of certain atoms. The isotopic ratios can be precisely measured, but the calculation of age from that ratio involves assumptions that may vary depending on the philosophical orientation of the investigator. Published in Origins v. 10, n. 2.
A review of the book, Christianity and the Age of the Earth. The book presents a biased viewpoint against recent creation, but does point out some serious challenges that confront recent creationists. Published in Origins v 10, n. 1.
The picture that emerges from all the data that relate to cosmic chronology appears to be one of dynamic physical processes operating over extended periods of time, during the last 4.5 billion years of which discrete entities of the Solar System have been in existence. This suggests the word "earth" in Genesis 1 may refer to the land surface of the planet, and not to the planet itself. Published in Origins v. 8, n. 1.
Dates based on amino-acid racemization and uranium radioactive decay were quite different, with preference given to the radiometric dates. Published in Origins v. 8, n. 1.
A number of factors could affect the relation of C-14 concentration to real time. The author discusses the effects on C-14 dates of cosmic ray intensity, geomagnetic field strength, water vapor concentration, and dilution by the biosphere carbon. Published in Origins v. 6, n. 1.
A review of the book, Principles of Isotope Geology. This is an authoritative textbook on radioisotope dating that provides useful background information, regardless of philosophical persuasion. Published in Origins v. 6, n. 1.
Radiometric dates are subject to uncertainties due to the assumptions inherent in the method and to the effects of non-natural changes in the earth's crust on the third day of creation and during the biblical Flood. Published in Origins v. 4, n. 2.
Tektites are formed from molten target rocks by an extraterrestrial impact. Australian tektites dated at about 700,000 years are found resting on soil dating less than 10,000 years old. This discrepancy is unresolved at present, and provides an opportunity for further research that could be very significant for the question of radiometric dating. Published in Origins v. 4, n. 2.
Major tektite falls in Australia in strata as young as 5700 years old according to radiocarbon dating have called in question both the fission-track and the K-Ar methods of dating which assign these identical tektites an age of about 700,000 years. Published in Origins v. 3, n. 2.
Claimed correlation of C-14 ages with depth is not a sound argument for the accuracy of C-14 dates because in the great majority of cases, a linear relationship between depth and C-14 concentration does not exist. Published in Origins v. 2, n. 1.
A review of the article, Non-Poisson Distributions Observed During Counting of Certain Carbon-14-Labelled Organic (Sub)Mono-Layers.Small anomalies in counting C-14 disintegrations are probably explained by the experimental conditions and do not offer help for reducing the chronology based on C-14. Published in Origins v. 1, n. 2.
