Ages of many millions of years for rocks and fossils are glibly presented as fact in many textbooks, the popular media, and museums. One has only to wait: time itself performs the miracles.”1 Yet few people seem to know how these radiometric dating methods work.For decades, the biologists have boldly proclaimed that, whereas we cannot observe today one type of creature evolving into a totally different type of creature, “Time is the hero of the plot. No one even bothers to ask what assumptions drive the conclusions.Some isotopes of some elements are radioactive; that is, they are unstable because their nuclei are too large.To achieve stability, these atoms must make adjustments, particularly in their nuclei.Thus, geologists refer to uranium-lead (two versions), potassium-argon, rubidium-strontium, or samarium-neodymium dates for rocks.Note that the carbon-14 (or radiocarbon) method is not used to date rocks, because most rocks do not contain carbon.I can do this by working from the definition of "half-life": in the given amount of time (in this case, hours.
It is the number of neutrons in their nuclei that varies, but too many neutrons make the nuclei unstable, as in carbon-14.(Whatever you're being treated for is the greater danger.) The half-life is just long enough for the doctors to have time to take their pictures.The dose I was given is -younger copy of an earlier document (in which case it is odd that there are no references to it in other documents, since only famous works tended to be copied), or, which is more likely, this is a recent forgery written on a not-quite-old-enough ancient parchment.Each atom is understood to be made up of three basic parts.The nucleus contains protons (tiny particles each with a single positive electric charge) and neutrons (particles without any electric charge).