Radiometric dating clocks
However this web site ( convinced me that they could be useful as a reference tool, especially for those who attend the lectures, and I agreed.
I commented at the time that some of the quotes would not make sense without the lecture.
The wonder is, surely, that the remaining half come out to be accepted. Conference (145 International Scientists), Science, Vol. If we combine his results with the latest estimates of time based on radioactive minerals, we get the figures in Table 5, in which the last column indicates the estimated average rate of deposition.
There are gross discrepancies, the chronology is uneven and relative, and the accepted dates are actually selected dates." Anthropological Journal of Canada, Vol. Internal evidence in the strata, however, belies these estimates.
This finding was the snowball that started the whole avalanche.", Nature Of The Darwinian Revolution, p.3. George Wald, Nobel Laureate, Harvard, "One has only to contemplate the magnitude of this task to concede that the spontaneous generation of a living organism is impossible. One has only to wait: time itself performs the miracles," The Physics And Chemistry Of Life, p.12. These assumptions furnish the most serious limitations on the accumulation clock. The discrepancies between the rejected and the accepted are arbitrarily attributed to excess or loss of argon." Canadian Journal Of Earth Science, 4. ...ground-water percolation can leach away a proportion of the uranium present in the rock crystals.
Yet, here we are - as a result, I believe, of spontaneous generation." Scientific American, Vol. 2, p.46 "However improbable we regard this event, or any of the steps which it involves, given enough time it will almost certainly happen at least once. Rigorously closed systems probably do not exist in nature, but surprisingly, many minerals and rocks satisfy the requirement well enough to be useful for nuclear age determination. These types of errors, which can beset even the most meticulous radiometric analysis, often add up to sizable total errors..." Earth And Life Through Time, 1986, p.122. The mobility of the uranium is such that as one part of a rock formation is being improvised another part can become abnormally enriched..relatively low temperatures." Scientific American, Vol.235 (6):118 "DATING MOON SAMPLES: Pitfalls And Paradoxes", Everly Driscoll, "What complicates things for the uranium-lead method is that non-radiogenic lead 204, 206, 207 and 208 also exist naturally, and scientists are not sure what the ratios of non-radiogenic to radiogenic lead were early in the moon's history...
It should be no surprise, then, that fully half of the dates are rejected. The connection between activity and age is made through a set of assumptions. Thus Schuchert...found that if a geologic column were built up by superposing the thickest known part of each of the geologic systems in North America, from Cambrian to the present, the composite record would be about 259,000 feet thick.Research & Development, p.21, 6/1982 DISSENTERS EJECTED, R. Mauger, East Carolina Univ., "In general, dates in the 'correct ball park' are assumed to be correct and are published, but those in disagreement with other data are seldom published nor or the discrepancies fully explained.", Contributions To Geology, Vol.15 (1): 17. of Washington, "If the laboratory results contradict the field evidence, the geologist assumes that there is something wrong with the machine date. Ages calculated from these measurements increase with sample depth up to 22 million years for lavas deduced to be recent. It is obvious that radiometric technique may not be the absolute dating methods that they are claimed to be.To put it another way, 'good' dates are those that agree with the field data. ...these lavas are very young, probably less than 200 years old. Age estimates on a given geological stratum by different radiometric methods are often quite different (sometimes by hundreds of millions of years).The problem is one of judicious geologic selection.", Ages Of Rocks, Planets & Stars, Stanley, Johns Hopkins, "In accepting a date, even with a plus-or-minus figure, we are assuming that a dated rock has remained a closed system - i.e., that it has neither lost nor received parent or daughter atoms from some other source. The problem of how much lead was around to begin with still remains...If all of the age-dating methods (rubidium-strontium, uranium-lead and potassium-argon) had yielded the same ages, the picture would be neat. The lead ages, for example, have been consistently older... U., "If we assume that (1) a rock contained no Pb206 when it was formed, (2) all Pb206 now in the rock was produced by radioactive decay of U238, (3) the rate of decay has been constant, (4) there has been no differential leaching by water of either element, and (5) no U238 has been transported into the rock from another source, then we might expect our estimate of age to be fairly accurate.
A few (two) have charged that a small number of these quotes misrepresent the intent of the context.