Radiometric dating, or radioactive dating as it is sometimes called, is a method used to date rocks and other objects based on the known decay rate of radioactive isotopes.Different methods of radiometric dating can be used to estimate the age of a variety of natural and even man-made materials. Wiens has a Ph D in Physics, with a minor in Geology.His Ph D thesis was on isotope ratios in meteorites, including surface exposure dating.Strata Thickness- In the late 1800s, a British geologist estimated that 75 million years has lapsed since the beginning of the Cambrian.This estimate was based upon the maximum known thickness of strata (from Cambrian to present) divided by the average rate of sedimentation in modern environments. Joly used the salinity of ocean water to determine the age of the earth.
If you want to revive discussion, please use the talk page or initiate a thread at the village pump.He calculated the modern rate of salt delivery to the oceans, and suggested that the present salinity of ocean water would take at least 100 million years to develop.In the 1860's, English physicist Lord Kelvin disagreed with Charles Lyells proposition that the earth behaves in a uniform, unchanging manner.-- Alarics (talk) , 29 September 2009 (UTC) As examples of Wikipedia editors confused by the ambiguity of the YYYY-MM-DD style, who have input what appear to be dates in the YYYY-DD-MM style (I am assuming of course that they were not dyslexic), we have , , , , , and . B.: Since I pointed out these errors, users have deleted or corrected the errors, so you will have to look back in the history to see my point.Note: these are examples where our fix-it bots have not yet gotten around to "fixing" the entry.I note with great interest btw that in the short time since I pointed to the above example User: Rjwilmsi has already made a fix to the first date, a sign at how efficient our fixer-uppers are, and how even searcing out all such instances that exist today don't reflect the true level of confusion of the inputting editors, as fixer bots have already "fixed" unknown numbers of such errors.Similarly, in my second example above, User Eubulides' solution where the date made no sense has been to delete the entire citation (and he has done us the service of putting the other dates into YYYY-MM-DD format).--Epeefleche (talk) , 3 October 2009 (UTC)Goodness me, what a lot of head-in-the-sand nonsense has been written here.Mountains, erosion, and variations in climate were considered to be punishment for the sins committed by humanity.Buffon's Iron Sphere Experiments- On the basis of iron sphere cooling experiments, Frenchman Georges de Buffon estimated that the Earth would have needed 75,000 years to cool to its present temperature.Radiometric dating is used to estimate the age of rocks and other objects based on the fixed decay rate of radioactive isotopes.Learn about half-life and how it is used in different dating methods, such as uranium-lead dating and radiocarbon dating, in this video lesson. As we age, our hair turns gray, our skin wrinkles and our gait slows.