Lectures will focus on absolute dating techniques. However, small quantities of radioactive C are produced in the Earth's upper atmosphere by interaction. Debunking the creationist radioactive dating argument. in a mineral, it would be a simple matter to calculate its age by the formula Carbon dating. To find the percent of Carbon 14 remaining after a given number of years, type in the of dating lies in trying to determine how much carbon 14 (the radioactive.
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Carbon has a relatively short half-life of 5, years, meaning that the fraction of carbon in a sample is halved over the course of 5, years due to radioactive decay to nitrogen The carbon isotope would vanish from Earth's atmosphere in less than a million years were it not for the constant influx of cosmic rays interacting with molecules of nitrogen N2 and single nitrogen atoms N in the stratosphere. Both processes of formation and decay of carbon are shown in Figure 1.
Diagram of the formation of carbon forward , the decay of carbon reverse. Carbon is constantly be generated in the atmosphere and cycled through the carbon and nitrogen cycles. Once an organism is decoupled from these cycles i. When plants fix atmospheric carbon dioxide CO2 into organic compounds during photosynthesis, the resulting fraction of the isotope 14C in the plant tissue will match the fraction of the isotope in the atmosphere and biosphere since they are coupled.
After a plants die, the incorporation of all carbon isotopes, including 14C, stops and the concentration of 14C declines due to the radioactive decay of 14C following. The currently accepted value for the half-life of 14C is 5, years. This means that after 5, years, only half of the initial 14C will remain; a quarter will remain after 11, years; an eighth after 17, years; and so on.
Carbon dating has shown that the cloth was made between and AD. Thus, the Turin Shroud was made over a thousand years after the death of Jesus. Describes radioactive half life and how to do some simple calculations using half life. History The technique of radiocarbon dating was developed by Willard Libby and his colleagues at the University of Chicago in The amount of strontium in a given mineral sample will not change. Therefore the relative amounts of rubidium and strontium can be determined by expressing their ratios to strontium These curves are illustrated in Fig It turns out to be a straight line with a slope of The corresponding half lives for each plotted point are marked on the line and identified.
It can be readily seen from the plots that when this procedure is followed with different amounts of Rb87 in different minerals, if the plotted half life points are connected, a straight line going through the origin is produced. These lines are called "isochrons". The steeper the slope of the isochron, the more half lives it represents. When the fraction of rubidium is plotted against the fraction of strontium for a number of different minerals from the same magma an isochron is obtained.
If the points lie on a straight line, this indicates that the data is consistent and probably accurate. An example of this can be found in Strahler, Fig If the strontium isotope was not present in the mineral at the time it was formed from the molten magma, then the geometry of the plotted isochron lines requires that they all intersect the origin, as shown in figure However, if strontium 87 was present in the mineral when it was first formed from molten magma, that amount will be shown by an intercept of the isochron lines on the y-axis, as shown in Fig Thus it is possible to correct for strontium initially present.
The age of the sample can be obtained by choosing the origin at the y intercept. Note that the amounts of rubidium 87 and strontium 87 are given as ratios to an inert isotope, strontium However, in calculating the ratio of Rb87 to Sr87, we can use a simple analytical geometry solution to the plotted data. Again referring to Fig. Since the half-life of Rb87 is When properly carried out, radioactive dating test procedures have shown consistent and close agreement among the various methods.
If the same result is obtained sample after sample, using different test procedures based on different decay sequences, and carried out by different laboratories, that is a pretty good indication that the age determinations are accurate. Of course, test procedures, like anything else, can be screwed up.
Mistakes can be made at the time a procedure is first being developed. Creationists seize upon any isolated reports of improperly run tests and try to categorize them as representing general shortcomings of the test procedure.
This like saying if my watch isn't running, then all watches are useless for keeping time. Creationists also attack radioactive dating with the argument that half-lives were different in the past than they are at present.
There is no more reason to believe that than to believe that at some time in the past iron did not rust and wood did not burn. Furthermore, astronomical data show that radioactive half-lives in elements in stars billions of light years away is the same as presently measured. On pages and of The Genesis Flood, creationist authors Whitcomb and Morris present an argument to try to convince the reader that ages of mineral specimens determined by radioactivity measurements are much greater than the "true" i.
The mathematical procedures employed are totally inconsistent with reality. Henry Morris has a PhD in Hydraulic Engineering, so it would seem that he would know better than to author such nonsense. Nucleosynthesis in type II supernovae. Discovery of a supernova explosion at half the age of the universe and its cosmological implications. Calibration against Pliny the Younger. Direct test of the constancy of fundamental nuclear constants. Oklo interactions have also been used to validate a young earth view after analysis of the restraints imposed on the alpha-decay half-lives.
The researchers chose a fluence monitor that is only 1. What is your field of study? What do you do Kevin?? Are you a disgruntled Science Teacher at a secondary school in Texas raised amidst bible-thumping nitwits who hate gay people and struggle to formulate sentences?? Explain in English how it works in the face of contamination and untrustworthy decay-rates. Let me go through it real slow and maybe the penny will drop. Let me demonstrate your faulty logic with an anology: We use a stopwatch to calculate the laptime of runners around a race track.
The stopwatch can only count long enough to accurately measure runners that run the track faster than 12mph. I tell you that my 92 year old Grandma would like to have her lap timed, she used to be a great runner when she was young, and would love to see how fast she it now. I ask you to do it anyway just to humour her. You cannot now claim that the stopwatch was the wrong way to measure her. The radioactive isotopes created in supernova explosions produce gamma rays with frequencies and fading rates that are predictable according to present decay rates.
Therefore, there is has been no measurable change in decay rates over , years and no factors that could affect decay rates have changed in over 1. Your paper by Overman is pretty funny. Nine references, one of which is a business statistics book and two of which are creationists. But I enjoy watching your confirmation bias. And there is no way to measure the one way speed of light. Try again, loser, with another creationist.
How about Kurt Wise? Or maybe Hugh Ross? Come on, Creepto, get cracking! See how I did that? I suppose the problem comes down to the origin of the granite samples and whether or not they are primordial granite or not. Tell you what though … the diamond Po halos stuff by Snelling is more compelling, as the location of the diamond is not important.
I gave the AiG link to Kevin too … I know you love those guys https: Do you only like to argue when your mates are with you? Again, boo fucking hoo. Right, all of chemistry is based on assumptions pulled out of the air because that explains why chemistry works so well. Oh, and nuclear chemistry is a total mystery; nobody knows why decay happens and analytical chemistry is just lucky I guess.
Tell you what, Creepto, you go ahead and believe that. Sucks to be you, Creepto. So unless you can manage to pull an interesting fact for grown-up debate out of your arse you should probably avoid the device with letters on it in front of you that has enabled your communicative diarrhoea.
I have not failed anything. I have been approached several times by the department to go back and finish what I started, as I had discovered some new useful things in the field that they would like to get published. That is all completely beside the point … and a cunning diversion from your inability to answer any actual scientific questions. Or does it happen all the time irrespective of how badly your side of the argument is going? Arrogance is in the eye of the beholder. And the need to explain everything from first principles every post, because the basic arguments get distorted and misrepresented at every turn.
Doc Bill You are too funny, Creepto! No one misrepresented your arguments, and do point out who did that, rather they pointed out your arguments were crapola. The process of nuclear decay is settled science, not a mystery, you buffoon. Geeze, louise, you are one thick brick.
Carbon 14 dating 1