How Good Are Those Young-Earth Arguments?
Young Earthers point to an infamous dating error as datingg that the Earth is only as old as the Bible says. Filed under General ScienceNatural HistoryReligion. Skeptoid Podcast March 24, Podcast transcript Download Subscribe. Today we're going to point our skeptical eye at one of the key players in the debate between geologists and Young Earthers over the age of the Earth. In June ofDr. Steven Austin took a sample of dacite from the new lava dome inside Mount St. Helens, the volcano in Washington state.
The dacite sample was known to have been formed from a magma flow, and so its actual age was an established etha. Austin submitted the sample for radiometric dating to an independent laboratory in Cambridge, Massachusetts. The results mpunt back dating the rock toyears old, with certain compounds within it as old as 2. Austin's conclusion is that radiometric dating is uselessly unreliable. Critics found that Dr. Austin chose a dating technique that is inappropriate for the sample tested, and charged that he deliberately used the wrong experiment in order mount etna carbon dating promote the idea that science fails to show that the Earth is older than the Bible claims.
Yet the experiment remains as one of the cornerstones of the Young Earth movement. Mount etna carbon dating most people who have heard of datjng incident before, that's probably about the total depth of what they've heard. And there's pretty good reason for mount etna carbon dating Geology dating is pretty complicated, and if you look at Dr. Austin's paper or at any scholarly criticism of it, your eyes will quickly glaze over from the extraordinary detail and intricacy.
So I thought this would be a great place datong point Skeptoid's skeptical eye, and see how much of the chaff we can cut through mounh see what mount etna carbon dating bare facts of the case really are. Obviously both sides of this debate have agendas to promote, and that means that any summary you're likely moint read was probably motivated by one agenda or enta other. Let's begin with a basic understanding of the radiometric dating technique used, K-Ar, or potassium-argon.
This dating technique depends on the fact that the radioactive isotope of potassium, 40 K, naturally decays into other elements, as do all unstable radioactive elements. There are two ways moubt this happens to 40 K. About 89 percent of the time, carbn neutron inside the 40 K undergoes beta decay, in which the neutron decays into a proton and an electron. This gain of a proton turns the potassium into calcium. But about 11 percent of the time, an extra proton inside the 40 Moun captures one of its electrons and merges with it, turning the proton into a neutron and a neutrino, and converting the potassium into argon.
In both events, the atomic mass remains unchanged, but the number of protons changes, thus turning the element from one to another. This happens to 40 K everywhere in the universe that it exists, and at the same rate, which is a half-life of 1. This means carbonn if you have atoms of 40 K, 1. You'll also have 83 argon atoms, and calcium atoms. If I take a sample and measure an argon to potassium ratio of However, all of these numbers are probabilities, not absolutes.
You need to have a statistically meaningful amount of argon before your result would be considered significant. Below about 10, yearsetan results are not significant; there's not yet enough argon created. In addition, the initial amount of 40 K that you started with is never measured directly; instead, it is assumed to always crbon.
This has a standard deviation, so it also contributes to the margin of error. So when my result says the sample was 2. The bell curve of probable age starts at about 1. So whether you call it an exact ,ount or not moujt a matter of linguistics. Although the exact age can't be known, the probabilities can be exactly calculated. Austin's sample was known to have solidified inits argon content was clearly well below the threshhold where an amount of carbom sufficiently useful for dating could have been present.
And even that threshhold applies to only the most sensitive detection mount etna carbon dating. Potassium-argon dating is done by destructively crushing and heating the sample and spectrally analyzing the resulting gases. The equipment in use at the time at the lab employed by Dr. Austin, Geocron Laboratorieswas of a type sensitive enough to only detect higher concentrations of argon gas.
Geocron clearly stated that their equipment was only capable of accurate results when the sample contained a concentration of argon mounh enough to be consistent with 2, years or older. And so, by any standard, it was scientifically meaningless for Dr. Austin to apply Geocron's potassium-argon dating to his sample of dacite known to be only six years old.
But let's ask the obvious question. If there wasn't yet enough argon in the rock to be detectable, and the equipment that was used was not sensitive enough to detect any argon, how was enough argon found that such old results were returned? There are two possible reasons that the old dates were returned. The first has to do with the reason Geocron's equipment was considered useful only for high concentrations of argon. There would always be a certain amount of argon inside the mass spectrometer left over from cabron experiments.
If the sample being tested is old enough to have significant argon, this leftover contamination would be statistically insignificant; so this was OK for Geocron's mojnt purposes. But for a sample with little or no argon, it would produce a falsely old result. This was undoubtedly a factor in Dr. The second possibility is that so-called "excess argon" could have become trapped in the Mount St.
This is where we find the bulk of the confusing complexity in Austin's paper and in those of his critics. The papers all go into great detail describing the various ways that argon-containing compounds can be incorporated into magma. These include the occlusion etnw xenoliths and xenocrysts, which are basically contaminants from existing old rocks that get mixed in with the magma; and phenocrysts, which are crystals of all sorts of different minerals that form inside the rock in different ways depending on how quickly the magma cools.