New findings cast doubt on scientists’ ability to be certain about their consensus views.
Paper spotlights key flaw in widely used radioisotope dating technique (North Carolina State University). Physicists just noticed a factor not included in common radiometric dating techniques: differential mass diffusion. This means that different isotopes of parent or daughter elements can diffuse out of rocks at different rates.
An oversight in a radioisotope dating technique used to date everything from meteorites to geologic samples means that scientists have likely overestimated the age of many samples, according to new research from North Carolina State University.
The problem does not apply to radiocarbon dating, but only to radioisotopes that give long ages in the millions of years, such as rubidium-strontium. The researchers also believe that corrections can be made to make published dates more accurate. But the press release reveals something suspect: scientists usually see scatter in the dates, so they tweak the data according to an arbitrary standard:
The data from radioisotope analysis tends to be somewhat scattered. So, researchers “normalize” the data by making a ratio with strontium-86, which is stable – meaning it doesn’t decay over time.
The wrinkle, however, is that ratios will change if the other isotopes are moving around. In fact, strontium-86 is more likely to diffuse out, because it’s smaller. This can lead to date inflation. Michael Irving at The New Atlas quotes one of the researchers: “If we don’t account for differential mass diffusion, we really have no idea how accurate a radioisotope date actually is.”
Continue reading at CREV