Barrow and he has an interesting discussion on the speed of light in our geological past.On pages 186 and 187 he describes the discovery at Oklo in the West African Republic of Gabon, of the remnants of an ancient site where an accident of geology produced, for a while, the conditions suitable for a sustained chain reaction to take place - a sort of natural nuclear reactor.The secret to this impeccable precision is the correct measurement of the second as the base unit of modern time-keeping.The International System of Units (SI) defines one second as the time it takes a Cesium-133 atom at the ground state to oscillate exactly 9,192,631,770 times.Isn’t dendrochronology accurate for checking radiocarbon dating?-- some quotes on radiocarbon dating Change in Decay Rates Atomic Ages Cesium 133 Oldest Living Tree?Atomic clocks are designed to detect this frequency, most of them today using ; a cloud of atoms that is tossed upwards by lasers in the Earth's gravitational field.If one could see an atomic fountain, it would resemble a water fountain. To achieve the highest possible level of accuracy, the International Bureau of Weights and Measures combines the output of about 400 atomic clocks in 69 national laboratories worldwide to determine TAI.
My thought is, can the relative natural abundances of these chains' terminal products (Pb208,207, and 206) be used to calculate an initial abundance and time frame for the original atomic abundances of the parent isotopes which could be compared to the predictions of Willie Fowler regarding stellar nucleogenesis processes. Thanks again for all your interesting and informative web postings and work.
International Atomic Time (TAI) is one of the main components of Coordinated Universal Time (UTC), the time scale used to determine local times around the world. International Atomic Time is an extraordinarily precise means of time-keeping.
Atomic clocks deviate only 1 second in up to 100 million years.
Furthermore, there is evidence that the main radioactive elements were concentrated in a layer low in the mantle and came to the surface progressively after that.
I emailed you about this topic a year or two ago, and I've since taken a class in radioisotope chemistry at UCI.The process is also assisted by the presence of point defects/color centers in cesium halide films.