Some may have mistaken this to mean that the sample had been dated to 20,000 radiocarbon years.The second characteristic of the measurement of radiocarbon is that it is easy to contaminate a sample which contains very little radiocarbon with enough radiocarbon from the research environment to give it an apparent radiocarbon age which is much less than its actual radiocarbon age..action_button.action_button:active.action_button:hover.action_button:focus.action_button:hover.action_button:focus .count.action_button:hover .count.action_button:focus .count:before.action_button:hover .count:before.u-margin-top--lg.u-margin-left--sm.u-flex.u-flex-auto.u-flex-none.bullet. Content Wrapper:after.hidden.normal.grid_page.grid_page:before,.grid_page:after.grid_page:after.grid_page h3.grid_page h3 a.grid_page h3 a:hover.grid_page h3 a.action_button.grid_page h3 a.action_button:active.grid_page h3 a.action_button:hover.grid_page h3 a.action_button:not(.fake_disabled):hover.grid_page h3 a.action_button:not(.fake_disabled):focus.grid_pagediv. The shells of live freshwater clams can, and often do, give anomalous radiocarbon results.
Thus, it is possible (and, given the Flood, probable) that materials which give radiocarbon dates of tens of thousands of radiocarbon years could have true ages of many fewer calendar years. The shells of live freshwater clams have been radiocarbon dated in excess of 1600 years old, clearly showing that the radiocarbon dating technique is not valid.In the early days of radiocarbon analysis this limit was often around 20,000 radiocarbon years.Thus, all the researcher was able to say about samples with low levels of radiocarbon was that their age was greater than or equal to 20,000 radiocarbon years (or whatever the sensitivity limit of his apparatus was).These two measures of time will only be the same if all of the assumptions which go into the conventional radiocarbon dating technique are valid.Comparison of ancient, historically dated artifacts (from Egypt, for example) with their radiocarbon dates has revealed that radiocarbon years and calendar years are not the same even for the last 5,000 calendar years.It is not difficult to see how such a claim could arise, however.