Radiometric or Absolute Rock Dating
DETERMINING AGE OF ROCKS AND FOSSILS
Study the chart that shows the half lives of various elements. Most of these elements can be found in rocks all over the Earth. Why would scientists want to use more than one type of element to determine the age of a rock? Why aren't they satisfied with just using one element? 5. Based on radiometric dating, the oldest rocks. Half-Life: Paper, M&M's, Pennies, or Puzzle Pieces. Students use M&M's (or pennies and puzzle pieces) to demonstrate the idea of radioactive decay. Seeing this connection will help students to understand how scientists can determine the age of a sample by looking at the amount of radioactive material in the sample. Scientists look at half-life decay rates of radioactive isotopes to estimate when a particular atom might decay. A useful application of half-lives is radioactive dating . This has to do with figuring out the age of ancient things. If you could watch a single atom of a radioactive isotope, U, for example, you wouldn't be able to .
Carbon dating is used to determine the age of biological artifacts up to 50, years old. This technique is widely used on recent artifacts, but educators and students alike should note that this technique will not work on older fossils like those of the dinosaurs alleged to be millions of years old.
Half-Life and Radioactive Decay
This technique is not restricted to bones; it can also be used on cloth, wood and plant fibers. Carbon dating has been used successfully on the Dead Sea Scrolls, Minoan ruins and tombs of the pharaohs among other things. Carbon is a radioactive isotope of carbon. The half-life of carbon is approximately 5, years.
The short half-life of carbon means it cannot be used to date fossils that are allegedly extremely old, e. The question should be whether or not carbon can be used to date any artifacts at all?
The answer is not simple. There are a few categories of artifacts that can be dated using carbon; however, they cannot be more 50, years old. Carbon cannot be used to date biological artifacts of organisms that did not get their carbon dioxide from How Do Scientists Use Half Life In Radiometric Hookup air.
This rules out carbon dating for most aquatic organisms, because they often obtain at least some of their carbon from dissolved carbonate rock. The age of the carbon in the rock is different from that of the carbon in the air and makes carbon dating data for those organisms inaccurate under the assumptions normally used for carbon dating.
This restriction extends to animals that consume seafood in their diet. As stated previously, carbon dating cannot be used on artifacts over about 50, years old. These artifacts have gone through many carbon half-lives, and the amount of carbon remaining in them is miniscule and very difficult to detect.
Carbon dating cannot be used on most fossils, not only because they are almost always allegedly too old, but also because they rarely contain the original carbon of the organism that has been fossilized.
Also, many fossils are contaminated with carbon from the environment during collection or preservation procedures. Scientists attempt to check the accuracy of carbon dating by comparing carbon dating data to data from other dating methods.
Other methods scientists use include counting rock layers and tree rings. When scientists first began to compare carbon dating data to data from tree rings, they found carbon dating provided "too-young" estimates of artifact age. Scientists now realize that production of carbon has not been constant over the years, but has changed as the radiation from the sun has fluctuated. Nuclear tests, nuclear reactors and the use of nuclear weapons have also changed the composition of radioisotopes in the air over the last few decades.
This human nuclear activity learn more here make precise dating of fossils from our lifetime very difficult due to contamination of the normal radioisotope composition of the earth with addition artificially produced radioactive atoms.
The various confounding factors that can adversely affect the accuracy of carbon dating methods are evident in many of the other radioisotope dating methods. Although the half-life of some of them are more consistent with the evolutionary worldview of millions to billions of years, the assumptions used in radiometric dating put the results of all radiometric dating methods in doubt.
The following is an article on this subject. Although the half-life of carbon makes it unreliable for dating fossils over about 50, years old, there are other isotopes scientists use to date older artifacts. These isotopes have longer half-lives and so are found in greater abundance in older fossils.
All of these methods are accurate only back to the last global catastrophe i. The assumptions are similar to the assumptions used in carbon dating. The mathematical premise undergirding the use of these elements in radiometric dating contains the similar confounding factors that we find in carbon dating method.
Most scientists today believe that life has existed on the earth for billions of years. This belief in long ages for the earth and the evolution of all life is based entirely on the hypothetical and non-empirical Theory of Evolution. All dating methods that support this theory are embraced, while any evidence to the contrary, e.
Prior to radiometric dating, evolution scientists used index fossils a. A paleontologist would take the discovered fossil to a geologist who would ask the paleontologist what other fossils searching for an index fossil were found near their discovery.
If it sounds like circular reasoning, it is because this process in reality is based upon circular reasoning. The process of using index fossils is describes by the late Creationist author and Ph. Henry Morris as follows:. All radiometric dating methods use this basic principle to extrapolate the age of artifacts being tested.
These long time periods are computed by How Do Scientists Use Half Life In Radiometric Hookup the ratio of daughter to parent substance in a rock, and inferring an age based on this ratio. This age is computed under the assumption that the parent substance say, uranium gradually decays to the daughter substance say, leadso the higher the ratio of lead to uranium, the older the rock must be. While there are many problems with such dating methods, such as parent or daughter substances entering or leaving the rock, e.
Geologists assert that generally speaking, older dates are found deeper down in the geologic column, which they take as evidence that radiometric dating is giving true ages, since it is apparent that rocks that are deeper must be older. But even if it is true that older radiometric dates are found lower down in the geologic column which is open to questionthis can potentially be explained by processes occurring in magma chambers which cause the lava erupting earlier to appear older than the lava erupting later.
Lava erupting earlier would come from the top of the magma chamber, and lava erupting later would come from lower down. A number of processes could cause the parent substance to be depleted at the top of the magma chamber, or the daughter product to be enriched, both of which would cause the lava erupting earlier to appear very old according to radiometric dating, and lava erupting later to appear younger.
Other possible confounding variables are the mechanisms that can alter daughter-to-parent ratios. We can see that many varieties of minerals are produced from the same magma by the different processes of crystallization, and these different minerals may have very different compositions.
Context for Use
It is possible that the ratio of daughter to parent substances for radiometric dating could differ in the different minerals. Clearly, it is important to have a good understanding of these processes in order to evaluate the reliability of radiometric dating. Other confounding factors such as contamination and fractionation issues are frankly acknowledged by the geologic community, but are not taken into consideration when the accuracy and validity of these dating methods are examined.
The following quotation from Elaine G. Kennedy addresses this problem. Contamination and fractionation issues are frankly acknowledged by the geologic community.
For example, if a magma chamber does not have homogeneously mixed isotopes, lighter daughter products could accumulate in the upper portion of the chamber.
If this occurs, initial volcanic eruptions would have a preponderance of daughter products relative to the parent isotopes. Such a distribution would give the appearance of age.
Students' quiz scores and video views will be trackable in your "Teacher" tab. However, once rocks or fossils become much older than that, all of the "traps" in the crystal structures become full and no more electrons can accumulate, even if they are dislodged. So, radiocarbon dating is also useful for determining the age of relics, such the Dead Sea Scrolls and the Shroud of Turin. Students should be able to understand the principles and have that as a background so that age determinations by paleontologists and geologists don't seem like black magic.
As the magma chamber is depleted in daughter products, subsequent lava flows and ash beds would have younger dates. Such a scenario does not answer all of the questions or solve all of the problems that radiometric dating poses for those who believe the Genesis account of Creation and the Flood. It does suggest at least one aspect of the problem that could be researched more thoroughly. The problems inherent in radiometric dating often cause them to be so unreliable that they contradict one another rather than validating each other.
It would really be nice if geologists would just do a double blind study sometime to find out what the distributions of the ages are.
In practice, geologists carefully select what rocks they will date, and have many explanations for discordant dates, so it's not clear how such a study could be done, go here it might be a good project for creationists. There is also evidence that many anomalies are never reported. There are so many complicated phenomena to consider like this that it calls the whole radiometric dating scheme into question.
Only then can you gauge the accuracy and validity of that race. We need to observe when the race begins, how the race is run are there variations from learn more here course, is the runner staying within the course, are they taking performance enhancing drugs, etc. All bases must be covered if we are going to accurately time the race.
This is the major flaw in radiometric dating, e. Secondly, you must have an observable time span so we can be certain nothing has affected the amount of the radioactive element being measured, e. Finally, we need to be certain about the end or finish point. This is some finite point in the future.
Without an accurate starting time, an observable span in between, and an observable finish, our measurement cannot be deemed accurate. The wrath of God is being revealed from heaven against all the godlessness and wickedness of men who suppress the truth by their wickedness, since what may be known about God is plain to them, because God has made it plain to them.
For since the creation of the world God's invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that men are without excuse. For although they knew God, they neither glorified him as God nor gave thanks to him, but their thinking became futile and their foolish hearts were darkened. Although they claimed to be wise, they became fools and exchanged the glory of the immortal God for images made to look like mortal man and birds and animals and reptiles, Rom How Do Scientists Use Half Life In Radiometric Hookup Beware of people who subscribe to a theory based upon naturalism and materialism exclusively.
If you blindly accept the Theory of Evolution, you are in danger of believing a fairytale for grownups called the Theory of Evolution. They point to minor changes within an organism, e.
The Earth's magnetic field is generated by electrical currents that are produced by convection in the Earth's core. But if you have a large enough sample, a pattern begins to emerge. Become a Member Already a member? A region where lines of force move electrically charged particles, such as around a magnet, through a wire conducting an electric current, or the magnetic lines of force surrounding the earth magnetism:
In reality, microevolution is evidence of adaptation, not a move up the phylogenetic tree of an organism with increasing complexity changing fish into amphibians, reptiles into mammals and monkeys into men.
The fact remains that every living organism appears abruptly in the fossil record, fully formed without the transitional fossils that should be there if Darwinian evolution is true. Carbon, Radiometric Dating and Index Fossils. Some of these other isotopes include: Henry Morris as follows: