Earth Science Guy: Radiometric Dating: A Christian Perspective
Radiometric Dating - A Christian Perspective, by Dr. Roger Wiens. RATE Index - A separate index of articles addressing the claims of the RATE project. Here is an interesting article, written by a Christian who also happens to be a scientist that works with radiometric dating. CLICK HERE to read. Radiometric Dating: A Christian Perspective. Dr. Roger C. Wiens Estates Drive, Los Alamos, NM [email protected]
Not trying to offend. Of course God is outside of creation and he can intervene in any way he sees fit. Do you mean by materialistic that all of the universe must be self caused? In my opinion, the big bang theory has forced scientists to grapple with the idea of a beginning, and thus a Beginner, and this has been a good thing. However, this is a spiritual and heart issue, not a scientific one.
This does not mean that nobody in the scientific community cannot recognize the truth.
Radiometric Dating and Creation Science
We should expect scientists to see God through their scientific work. Especially when the Bible tells us that all of creation testifies about God. The three statements you quoted from Binney, Silk, and Abraham Loeb were interesting as well. Much has changed in the scientific community knowledge-wise since I was unable to view the quotes in their original contexts but I searched Abraham Loeb and found his Harvard page.
Here is a link to the book. Igneous rocks are good candidates for dating. Recall that for igneous rocks the event being dated is when the rock was formed from magma or lava. When the molten material cools and hardens, the atoms are no longer free to move about.
Daughter atoms that result from radioactive decays occurring after the rock cools are frozen in the place where they were made within the rock. These atoms are like the sand grains accumulating in the bottom of the hourglass.
Radiometric Dating and Creation Science
Determining the age of a rock is a two-step process. First one needs to measure the number of daughter atoms and the number of remaining parent atoms and calculate the ratio between them. Then the half-life is used to calculate the time it took to produce that ratio of parent atoms to daughter atoms. However, there is one complication. One cannot always assume that there were no daughter atoms to begin with.
It turns out that there are some cases where one can make that assumption quite reliably. But in most cases the initial amount of the daughter product must be accurately determined. Most of the time one can use the different amounts of parent and daughter present in different minerals within the rock to tell how much daughter was originally present.
Each dating mechanism deals with this problem in its own way. Some types of dating work better in some rocks; others are better in other rocks, depending on the rock composition and its age. Let's examine some of the different dating mechanisms now. Potassium is an abundant element in the Earth's crust.
One isotope, potassium, is radioactive and decays to two different daughter products, calcium and argon, by two different decay methods. This is not a problem because the production ratio of these two daughter products is precisely known, and is always constant: It is possible to date some rocks by the potassium-calcium method, but this is not often done because it is hard to determine how much calcium was initially present.
Argon, on the other hand, is a gas. Whenever rock is melted to become magma or lava, the argon tends to escape. Once the molten material hardens, it begins to trap the new argon produced since the hardening took place. In this way the potassium-argon clock is clearly reset when an igneous rock is formed. In its simplest form, the geologist simply needs to measure the relative amounts of potassium and argon to date the rock. The age is given by a relatively simple equation: This is usually trapped in the form of very tiny air bubbles in the rock.
One percent of the air we breathe is argon. Any extra argon from air bubbles may need to be taken into account if it is significant relative to the amount of radiogenic argon that is, argon produced by radioactive decays. This would most likely be the case in either young rocks that have not had time to produce much radiogenic argon, or in rocks that are low in the parent potassium. One must have a way to determine how much air-argon is in the rock. This is rather easily done because air-argon has a couple of other isotopes, the most abundant of which is argon The ratio of argon to argon in air is well known, at Thus, if one measures argon as well as argon, one can calculate and subtract off the air-argon to get an accurate age.
One of the best ways of showing that an age-date is correct is to confirm it with one or more different dating Some young-Earth proponents recently reported that rocks were dated by the potassium-argon method to be a several million years old when they are really only a few years old.
But the potassium-argon method, with its long half-life, was never intended to date rocks only 25 years old. These people have only succeeded in correctly showing that one can fool a single radiometric dating method when one uses it improperly. The false radiometric ages of several million years are due to parentless argon, as described here, and first reported in the literature some fifty years ago.
Note that it would be extremely unlikely for another dating method to agree on these bogus ages. Getting agreement between more than one dating method is a recommended practice. Although potassium-argon is one of the simplest dating methods, there are still some cases where it does not agree with other methods. When this does happen, it is usually because the gas within bubbles in the rock is from deep underground rather than from the air.
This gas can have a higher concentration of argon escaping from the melting of older rocks. This is called parentless argon because its parent potassium is not in the rock being dated, and is also not from the air. In these slightly unusual cases, the date given by the normal potassium-argon method is too old.
Radiometric dating from a “Christian perspective” | Creation – Myth or Miracle?
However, scientists in the mids came up with a way around this problem, the argon-argon method, discussed in the next section. Even though it has been around for nearly half a century, the argon-argon method is seldom discussed by groups critical of dating methods.
This method uses exactly the same parent and daughter isotopes as the potassium-argon method. In effect, it is a different way of telling time from the same clock.
Instead of simply comparing the total potassium with the non-air argon in the rock, this method has a way of telling exactly what and how much argon is directly related to the potassium in the rock.
In the argon-argon method the rock is placed near the center of a nuclear reactor for a period of hours. A nuclear reactor emits a very large number of neutrons, which are capable of changing a small amount of the potassium into argon Argon is not found in nature because it has only a year half-life.
This half-life doesn't affect the argon-argon dating method as long as the measurements are made within about five years of the neutron dose. The rock is then heated in a furnace to release both the argon and the argon representing the potassium for analysis. Rather, the offset is equal to one half-life, or 5, years for carbon The initial portion of the calibration curve in Figure 9 has been widely available and well accepted for some time, so reported radiocarbon dates for ages up to 11, years generally give the calibrated ages unless otherwise stated.
The calibration curve over the portions extending to 40, years is relatively recent, but should become widely adopted as well. These methods may work on young samples, for example, if there is a relatively high concentration of the parent isotope in the sample.
In that case, sufficient daughter isotope amounts are produced in a relatively short time. As an example, an article in Science magazine vol. There are other ways to date some geologically young samples. Besides the cosmogenic radionuclides discussed above, there is one other class of short-lived radionuclides on Earth. These are ones produced by decay of the long-lived radionuclides given in the upper part of Table 1. As mentioned in the Uranium-Lead section, uranium does not decay immediately to a stable isotope, but decays through a number of shorter-lived radioisotopes until it ends up as lead.
While the uranium-lead system can measure intervals in the millions of years generally without problems from the intermediate isotopes, those intermediate isotopes with the longest half-lives span long enough time intervals for dating events less than several hundred thousand years ago.
Note that these intervals are well under a tenth of a percent of the half-lives of the long-lived parent uranium and thorium isotopes discussed earlier.
Two of the most frequently-used of these "uranium-series" systems are uranium and thorium These are listed as the last two entries in Table 1, and are illustrated in Figure A schematic representation of the uranium decay chain, showing the longest-lived nuclides. Half-lives are given in each box. Solid arrows represent direct decay, while dashed arrows indicate that there are one or more intermediate decays, with the longest intervening half-life given below the arrow.
Like carbon, the shorter-lived uranium-series isotopes are constantly being replenished, in this case, by decaying uranium supplied to the Earth during its original creation. Following the example of carbon, you may guess that one way to use these isotopes for dating is to remove them from their source of replenishment. This starts the dating clock. In carbon this happens when a living thing like a tree dies and no longer takes in carbonladen CO2. For the shorter-lived uranium-series radionuclides, there needs to be a physical removal from uranium.
The chemistry of uranium and thorium are such that they are in fact easily removed from each other. Uranium tends to stay dissolved in water, but thorium is insoluble in water. So a number of applications of the thorium method are based on this chemical partition between uranium and thorium.Carbon Dating: What it Means to the Christian Faith
Sediments at the bottom of the ocean have very little uranium relative to the thorium. Because of this, the uranium, and its contribution to the thorium abundance, can in many cases be ignored in sediments. Thorium then behaves similarly to the long-lived parent isotopes we discussed earlier.
It acts like a simple parent-daughter system, and it can be used to date sediments. On the other hand, calcium carbonates produced biologically such as in corals, shells, teeth, and bones take in small amounts of uranium, but essentially no thorium because of its much lower concentrations in the water.
This allows the dating of these materials by their lack of thorium. A brand-new coral reef will have essentially no thorium As it ages, some of its uranium decays to thorium While the thorium itself is radioactive, this can be corrected for. Comparison of uranium ages with ages obtained by counting annual growth bands of corals proves that the technique is page.
The method has also been used to date stalactites and stalagmites from caves, already mentioned in connection with long-term calibration of the radiocarbon method. In fact, tens of thousands of uranium-series dates have been performed on cave formations around the world.
Previously, dating of anthropology sites had to rely on dating of geologic layers above and below the artifacts. But with improvements in this method, it is becoming possible to date the human and animal remains themselves. Work to date shows that dating of tooth enamel can be quite reliable. However, dating of bones can be more problematic, as bones are more susceptible to contamination by the surrounding soils.
As with all dating, the agreement of two or more methods is highly recommended for confirmation of a measurement. If the samples are beyond the range of radiocarbon e. Non-Radiometric Dating Methods for the PastYears We will digress briefly from radiometric dating to talk about other dating techniques.
It is important to understand that a very large number of accurate dates covering the pastyears has been obtained from many other methods besides radiometric dating.
We have already mentioned dendrochronology tree ring dating above. Dendrochronology is only the tip of the iceberg in terms of non-radiometric dating methods. Here we will look briefly at some other non-radiometric dating techniques. One of the best ways to measure farther back in time than tree rings is by using the seasonal variations in polar ice from Greenland and Antarctica. There are a number of differences between snow layers made in winter and those made in spring, summer, and fall.
These seasonal layers can be counted just like tree rings. The seasonal differences consist of a visual differences caused by increased bubbles and larger crystal size from summer ice compared to winter ice, b dust layers deposited each summer, c nitric acid concentrations, measured by electrical conductivity of the ice, d chemistry of contaminants in the ice, and e seasonal variations in the relative amounts of heavy hydrogen deuterium and heavy oxygen oxygen in the ice. These isotope ratios are sensitive to the temperature at the time they fell as snow from the clouds.
The heavy isotope is lower in abundance during the colder winter snows than it is in snow falling in spring and summer. So the yearly layers of ice can be tracked by each of these five different indicators, similar to growth rings on trees. The different types of layers are summarized in Table III. Page 17 Ice cores are obtained by drilling very deep holes in the ice caps on Greenland and Antarctica with specialized drilling rigs.
As the rigs drill down, the drill bits cut around a portion of the ice, capturing a long undisturbed "core" in the process. These cores are carefully brought back to the surface in sections, where they are catalogued, and taken to research laboratories under refrigeration.
A very large amount of work has been done on several deep ice cores up to 9, feet in depth. Several hundred thousand measurements are sometimes made for a single technique on a single ice core.
Radiometric dating from a “Christian perspective”
A continuous count of layers exists back as far asyears. In addition to yearly layering, individual strong events such as large-scale volcanic eruptions can be observed and correlated between ice cores. A number of historical eruptions as far back as Vesuvius nearly 2, years ago serve as benchmarks with which to determine the accuracy of the yearly layers as far down as around meters. As one goes further down in the ice core, the ice becomes more compacted than near the surface, and individual yearly layers are slightly more difficult to observe.
For this reason, there is some uncertainty as one goes back towardsyears. Recently, absolute ages have been determined to 75, years for at least one location using cosmogenic radionuclides chlorine and beryllium G. These agree with the ice flow models and the yearly layer counts.