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Radioactive Dating Is Reliable

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Voting Style: Open Point System: 7 Point
Started: 5/21/2013 Category: Science
Updated: 4 years ago Status: Post Voting Period
Viewed: 1,975 times Debate No: 33867
Debate Rounds (4)
Comments (7)
Votes (3)




Since no one else wants to debate this, I will honor jh1234l's request to play devil's advocate.

Full Resolution

Radioactive dating is reliable.

BoP is on pro.


Radioactive Dating: "The technique of comparing the abundance ratio of a radioactive isotope to a reference isotope to determine the age of a material."[1]

Reliable: "Capable of being relied on; dependable;yielding the same or compatible results in different clinical experiments or statistical trials."[2]


1. The first round is for acceptance.
2. A forfeit or concession is not allowed.
3. No semantics, trolling, or lawyering.
4. All arguments must be visible inside this debate. Sources may be posted in an outside link.
5. Debate resolution, definitions, rules, and structure cannot be changed without asking in the comments before you post your round 1 argument. Debate resolution, definitions, rules, and structure cannot be changed in the middle of the debate.

Voters, in the case of the breaking of any of these rules by either debater, all seven points in voting should be given to the other person.

Debate Structure

Round 1: Acceptance
Round 2: Presenting all arguments (no rebuttals by pro)
Round 3: Refutation of opponent's arguments (no new arguments)
Round 4: Defending your original arguments and conclusion (no new arguments)




I accept. I will be Devil's Advocating. Please state your case.
Debate Round No. 1


I would like to thank jh1234l for presenting his arguments.

I. What Is Radioactive Dating?

Radioactive dating uses radioactive isotopes to determine the age of the Earth. In the nucleus of an atom, there are a set number of protons and neutrons. Atoms that deviate from the set number of neutrons are called isotopes, and each individual isotope is called a nuclide. Some nuclides are unstable, meaning that that nuclide will change into another nuclide at some point in time, depending on the nuclide's half-life. This transformation can be done in several different ways, but this debate focuses on radioactive decay, either through alpha-decay of beta-decay.

Getting back to the principle of half-life, a half-life of a nuclide is the amount of time it takes for half of the atoms in the sample to have decayed into its decay product. For certain nuclides, the "daughter nuclides", the result of the decay product, decay themselves until they produce stable daughter nuclides.

In isolated systems, it is easy to tell how old a sample is by determining where along the path of decay that particular sample is by determing the amount of daughter nuclides to the parent (original) nuclides. There is no reason to believe that mass-contamination affected every single sample. Quantum mechanics says otherwise.[1]

II. Dating Against the Historical Record

There have been many instances where radioactive dating has been matched up with the historical record.

II.A. Mount Vesuvius

Mount Vesuvius erupted on August 24th, 79 ACE. In 1997, a study was done to date the volcanic material. The time between 1997 and 79 was 1918 years. Incremental heating experiments on 12 samples of sanidine yielded 46 data points that resulted in an isochron age of 1925 years, only a 7 year deviation from the real event.[2][3]

II.B. Egyptian Tombs

Pharaoh Djoser was pharaoh around 2670 BCE until he died in around 2650 BCE. Radiocarbon dating of his tomb reveals an approximate age of 4,650 years old, which matches up with 2650 BCE, the time of his death. In another case, a tomb from around the time of Ptomley (i.e. 300-30 BCE) was dated. However, radioactive testing showed the age to be almost 0. It was later proved that the tomb was a fake, and brand new. In another case, samples taken from a pyramid in Dashur, Egypt were historically dated to be around 2050 years old. This date agrees with the age of the radioactive sample. Many other historical artificats have turned up, and when the radioactive dating's age is matched up with the historian's guess of its age, the two are almost always correct.[4][5][6]

III. Reliability of Different Methods

In almost all cases, using different isotopes to measure the dates in rocks produces around the same age, indicating the reliability of all of them. "The utility of using multiple techniques was shown dramatically in work by H. Baadsgaard, a professor at the University of Alberta, Canada, and his colleagues in 1993. These researchers used all three methods... to date samples from a volcanic ash layer in sedimentary rocks from western Canada. By separating different minerals from the ash layer, Baadsgaard was able to find material suitable for each of the dating techniques—zircon crystals for uranium-lead dating, potassium-rich mica for potassium-argon dating, and feldspar crystals for the rubidium-strontium method. When the researchers compared their results, they found no discernible difference among the dates. Three completely independent techniques gave ages of 72.5, 72.5, and 72.4 million years, in each case with a measurement uncertainty of just a few tenths of a million years."[7]

There are more cases of this. During the triassic period, there was a multiple-impact event that featured several asteroids colliding with the Earth in different locations. Here were the results of five studies from across the globe (stratigraphic dating means that the crater itself has not been dated. Instead, the rock strata above and below the crater was dated):

Crater Country Diameter Million Years Ago Dating Method
Manicouagan Canada 100 km 214 ± 1 U-Pb on zircons
Saint Martin Canada 40 km 219 ± 32 Rb/Sr
Rochechouart France 25 km 214 ± 8 Ar/Ar laser spot fusion
Obolon Ukraine 15 km 215 ± 25 stratigraphic
Red Wing USA 9 km 200 ± 25 stratigraphic


Not only are different radioactive methods consistent with each other, they are also consistent with other forms of dating, like luminescence dating (a technique that takes advantage of electrons trapped in crystal lattice). Take, for example, a group of human skeletons in Australia (note that the different skeletons have been calculated to be 57,000-71,000 years old, meaning that sample should be within those numerals):
  • Mass spectrometer U-series (Th/U) on 4 bone shavings: 69.8 ± 2.1
  • Gamma spectrometer U-series (Th/U and Pa/U) on the skull cap: 64.1 ± 3.7 (Th/U) 60 ± 5 (Pa/U)
  • Electron Spin Resonance (ESR) on tooth enamel: 63 ± 6 (EU) [closed system, early U uptake]
  • Optically Stimulated Luminescence (OSL) on sediment recovered directly under the soil horizon: 61 ± 2 [weighted mean of previous 2 ages]

This indicates that a lot of methods, including radioactive methods, produce the same result, indicating its reliability.


[3]: Renne PR, Sharp WD, Deino AL, Orsi G, Civetta L. 40Ar/39Ar dating into the historical realm: Calibration against Pliny the Younger. Science, 1997; 277: pp. 1279–80.
[4]: Macdougall, Doug (2008-05-31). Nature’s Clocks: How Scientists Measure the Age of Almost Everything, University of California Press. pp. 1016-1017



Thanks to Sabutai for his well thought out response. This round is reserved for making arguments, not rebuttals, so here are mine:

1. Contamination and assumptions

Potassium-argon dating assumes that the sample being measured has remained in a closed system since the event being dated. [1] This has a problem: perfectly closed systems do not exist even in laboratory conditions. [2] If contamination is inevitable, and K-Ar requires it to be in a closed system and therefore not be contaminated, then it cannot work.

2. Inconsistencies

Different radiometric dating methods frequently produce results that do not agree. Out of the following results from the same rock sample from the Allende meteorite, 0.14 billion years (or 140000000 years) were different between the ages 4.48 b.y. (billion years) and 4.56 b.y. produced by different dating methods. This means that skewed results can be produced.

4.52 +/- 0.02
4.53 +/- 0.02
4.48 +/- 0.02
4.55 +/- 0.03
4.55 +/- 0.03
4.57 +/- 0.03
4.50 +/- 0.02
4.56 +/- 0.05

Many other disagreeing results have been found, such as 2 samples of rock taken from locations that were really near eachother yielding to differences in dated age of 1350 million years, which is not something that sounds good for radiometric dating proponents. [4]

This indicates that there are many flaws in radiometric dating, and therefore it is not reliable.

Debate Round No. 2


I would like to thank jh1234l for presenting his arguments.

I. Contamination and Assumptions

The large majority of isochron dating results are in accordance with the mainstream age and history of the Earth. If the results were essentially random numbers, that would not be the expected distribution of results. "Counter-intuitive" ages -- for example results which indicate an event earlier than the time of crystallization of the sampled object - are usually produced by inappropriate selection of samples, and can be avoided in most cases. The processes which could produce incorrect isochron ages require special circumstances, and are not universally applicable across the wide range of rock and mineral types on which isochron dating (by several different radioactive isotopes) has been successfully performed. Basically, most isochron dating has a built-in check for contamination, and pleas to contamination do not address the fact that radiometric results are nearly always in agreement with old-Earth expectations. If the methods were producing completely "haywire" results essentially at random, such a pattern of concordant results would not be expected.[1][2]

Overall, only data that falls into a "straight line" is considered to be admissible. Incoherent results are not used. So in conclusion, while contamination is possible, in all published cases, there is a coherent line that is uncontaminated.

II. Inconsistencies

The chart which my opponent provides showing the various dating attempts of the Allende meteorite is actually evidence of radioactive dating's reliability. While there is a difference of about 100 million years between the two extremes, on the scale of 4.5 billion years, that's a total error of only 2%, which is pretty good for the dating of such old objects.

Consider the Mundrabrilla meteorite. There were four successive dating attempts:
  • 4.50 +/- 0.06 by
  • 4.57 +/- 0.06 by
  • 4.54 +/- 0.04 by
  • 4.50 +/- 0.04 by[2]

Using the margins of error, one can reasonably assume that this meteorite is 4.51-4.52 billion years old, which all four data points agree with.

Or take the meteorite Y-75011:

  • 4.50 +/- 0.05 by
  • 4.52 +/- 0.16 by
  • 4.46 +/- 0.06 by
  • 4.52 +/- 0.33 by[2]

Again using the margins of error, one can reasonably assume that this meteorite is 4.50-4.52 billion years old, which all four data points agree with.

Finally, here is a visual representation of several dating methods on one sample:


The ages of the Fen Complex (A,B) are on two separate dikes within the Fen Complex. Not only are their ages similar, but the direction of magnetization in the rocks is also identical and indicates that Oslo, Norway was located at about 30 degrees south at the time. This is an important consideration. In order to refute the ages, ye-creationists must not only explain how three different isotopic systems (with different decay constants and chemical behavior) all gave the same age and the same magnetic direction. It is also not trivial that the magnetic direction in these rocks indicates that Norway has moved northward following the emplacement
of these rocks.[5][6]

In the first point, I mentioned that "straight line" plots prove consistencies in dating. This is a graph showing the age of rocks as distance from a specific volcano increases (the closer to a volcano a rock is, the younger it is because it was thrown out in a recent eruption) using the dating of the formation of the Hawaiian Islands based upon radiometric dating of lava flows:


It shows a clear linear slope, a strong, direct correlation between the tectonic motion of the Pacific Plate over the Hawaiian hotspot, and the age of the Hawaiian Island chain. It was shown that as samples get further away from a volcano, they get older, and that the line is relatively straight (although some timeframes may have erupted more or less material, showing the small errors).[4]

Overall, radioactive dating has produced very reliable, consistent results. However, my opponent does cite one sample which a large discrepancy. However, that study has a potential problem. While most layers of the ground are sorted by age, there is a possibility for overturning. There could have been overturning by faulting or folding, or lava intrusions. There are many examples of this too.[7]

In addition, and more importantly, an instance where a method fails to work does not imply that it does not ever work. The question is not whether there are "undatable" objects, but rather whether or not all objects cannot be dated by a given method. The fact that one wristwatch has failed to keep time properly cannot be used as a justification for discarding all watches. These arguments also fail to address the fact that radiometric dating produces results in line with "evolutionary" expectations about 95% of the time (Dalrymple 1992, personal correspondence). The claim that the methods produce bad results essentially at random does not explain why these "bad results" are so consistently in line with mainstream science. Why is it that five radiometric dating methods agree on the age of one of the Earth's oldest rock formations?[2][8]

Overall, one or two problems in dating should not discredit the whole process.


[6]: McDougall, I. and Harrison, T.M., 1999, Geogchronology and thermochronology by the 40Ar/39Ar method, Oxford University Press, Oxford, pp. 269
[8]: Dalrymple, G. Brent, 1986. Radiometric Dating, Geologic Time, and the Age of the Earth: A Reply to "Scientific" Creationism. U.S. Geological Survey Open-File Report 86-110. pp. 76



Thanks for the response!
This round was reserved for refuting my opponent's (Subutai's) arguments.

What is radioactive dating?

I concede this argument. This is just a extended definition. However, thanks for giving the voters context and basic knowledge about the thing in question. I appreciate it.

Dating against historical record ([1])

However, there are some instances that radiometric dating did not work well against the historic record. Lava known to be 168 years old have yielded a potassium-argon age of 2.96 billion years old. Some volcanic rocks known to be modern (e.g. was not stuck in the ground for a long time before the volcano erupt) have lead-uranium ages of billions of years.

Agreement of different methods

Note that the ages of different samples measured by different methods were used, not the age of the same sample measured by different methods, which is not how the scientific method works, therefore this argument was not valid.

[1]"Evolution: Its Collapse In View?" by Henry Hiebert

Debate Round No. 3


I would like to thank jh1234l for this debate.

I. Dating Against the Historical Record

Again, my opponent is using a couple of isochron inconsistencies as the main force behind his argument, which I already showed in Round 3 was fallacious. Again, radiometric dating produces results in line with "evolutionary" expectations about 95% of the time. Trying to show that the other 5% disproves that radioactive dating is reliable is incorrect.[1][2]

Even so, there is an explanation for the problem my opponent cites. As this article mentions: The scientists did date something as being million of years old, but it wasn't lava. Notice the title of the actual scientific report: Radiogenic Helium and Argon in Ultramafic Inclusions from Hawaii, J.G. Funkhouser and J.J. Naughton, Journal of Geophysical Research 73:14 pp. 4601-4607 (15 July 1968). The important word here is "Inclusions". The scientists were not out to date the lava: they were dating some chunks of olivine that were stuck in the lava like raisins. This lava was not hot enough to melt olivine, so the chunks were carried along when the eruption brought lava up from the depths. Of course the olivine inclusions dated as being old. They are old."[3]

In addition, they weren't even really dating the olivine inclusion, or xenoliths. The paper was able whether or not Potassium/Argon dating should be used on such objects, which they concluded that it shouldn't. K/Ar dating should not be used on xenoliths. But, the article clearly states that the surrounding lava was dated correctly. This article casts no doubts whatsoever on the dating of lava.[3][4]

As for my opponent's volcanic rocks problem, he doesn't cite a study, but rather a book that may or may not have cited a study. The author of the book most likely misinterpreted the results, like I mentioned above. In addition, the key word is some, which does not disprove the reliability of radioactive dating.

II. Reliability of Diferent Methods

It was the same sample, in a way. It was from the same Triassic-era event. The 5 meteorites hit the Earth at different locations, but all around the same time (within a few hours). Another way to look at this is by drawing a map. Today, the continents are moving about one inch a year. This is a simple fact which can be measured by anyone with good GPS equipment. So, in 214 million years, the continents could have moved three thousand miles. To get a map of that past world, geologists did K/Ar datings of ancient lava flows. The three main craters form a dead straight line on that map, indicating that they are from the same event.[5][6]

My opponent also fails to counter any of my other arguments, such as the comparison of radioactive dating and luminescence dating on the same sample.

To conclude, here is a chart showing the various dating methods on a meteorite found in western Greenland:

Description Technique Age (in billions of years)
Amitsoq gneisses (western Greenland) Rb-Sr isochron 3.70 +/- 0.12
Amitsoq gneisses (western Greenland) 207Pb-206Pb isochron 3.80 +/- 0.12
Amitsoq gneisses (western Greenland) (zircons) U-Pb discordia 3.65 +/- 0.05
Amitsoq gneisses (western Greenland) (zircons) Th-Pb discordia 3.65 +/- 0.08
Amitsoq gneisses (western Greenland) (zircons) Lu-Hf isochron 3.55 +/- 0.22


And the same rock taken back from the Moon on Apollo 11:

Description Sample # Technique Age (in billions of years)
Apollo 11 - High-K basalt 10072 40Ar/39Ar whole rock 3.49 +/- 0.05
Apollo 11 - High-K basalt 10072 40Ar/39Ar whole rock 3.52 +/- 0.04
Apollo 11 - High-K basalt 10072 40Ar/39Ar plagioclase 3.57 +/- 0.05
Apollo 11 - High-K basalt 10072 40Ar/39Ar plagioclase 3.56 +/- 0.06
Apollo 11 - High-K basalt 10072 40Ar/39Ar ilmenite 3.58 +/- 0.05
Apollo 11 - High-K basalt 10072 40Ar/39Ar pyroxene 3.55 +/- 0.05
Apollo 11 - High-K basalt 10072 Rb-Sr isochron 3.57 +/- 0.05
Apollo 11 - High-K basalt 10072 Sm-Nd isochron 3.57 +/- 0.03


Overall, the different methods do agree with each other.


[2]: Dalrymple, G. Brent, 1986. Radiometic Dating, Geologic Time and the Age of the Earth: A Reply to "Scientific" Creationism, U.S. Geological Survey Open-File Report 86-110. pp.76.
[4]: Funkhouser, J.G. and J.J. NaughtonRadiogenic Helium and Argon in Ultramafic Inclusions from Hawaii, Journal of Geophysical Research 73:14 pp. 4603 (15 July 1968)
[6]: Spray, J., S. Kelley, and D. Rowley. Evidence for a late Triassic Multiple Impact Event on Earth. Nature 392, pp. 171-173 (12 March 1998)


jh1234l forfeited this round.
Debate Round No. 4
7 comments have been posted on this debate. Showing 1 through 7 records.
Posted by jh1234l 4 years ago
I can play devil's advocate for this debate.
Posted by Subutai 4 years ago
VVV. And that is why you always provide definitions if you want to have a serious debate.
Posted by Happyreclusive 4 years ago
I strongly recommend that you date no one who is radioactive no matter how reliable she is.
Posted by RoyLatham 4 years ago
Oh, sorry. You are *defending* the reliability of radiometric dating. Nevermind.
Posted by RoyLatham 4 years ago
I will accept this debate. I'm knowledgeable in the subject matter. "Reliable" implies a statistical measure, so you should be prepared to present and defend statistical arguments.
Posted by Smithereens 4 years ago
hmm, considering asking to debate. Don't know anything on this subject though.
Posted by TheNoobWhoNeverBecameAPro 4 years ago
Har har eet eez soh unreelayabell eet eez layk da weharr 4cahst!
3 votes have been placed for this debate. Showing 1 through 3 records.
Vote Placed by JonMilne 4 years ago
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Total points awarded:60 
Reasons for voting decision: Con forfeited his last round, and also conceded quite a few points to Pro. In addition, Con's responses were way too brief and did not address the vast bulk of Pro's arguments, who incidentally managed to go into great detail and explain the radiometric dating process very well. Finally, Con also loses sources for citing Creationwiki, as well as an extremely dubious anti-evolution paper, which Pro tore apart.
Vote Placed by 1Devilsadvocate 4 years ago
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Reasons for voting decision: F.F. (& pro dominated anyway)
Vote Placed by Bullish 4 years ago
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Total points awarded:40 
Reasons for voting decision: Forfeit.