Changes

''See also [[Counterexamples to an Old Earth]]''.

''See also [[Counterexamples to an Old Earth]]''.

'''Radiometric dating''' is a method of determining the approximate age of an artifact by measuring the amount of radioactive decay that has occurred.<ref>[http://pubs.usgs.gov/gip/geotime/radiometric.html Radiometric Time Scale] USGS</ref> Radiometric dating is mostly used to determine the age of rocks, though a particular form of radiometric dating&mdash;called [[Radiocarbon dating]]&mdash;can date wood, cloth, skeletons, and other organic material. Radiometric dating requires careful analysis and control over the isotopic mix of atoms in the original sample, as well as careful analysis and control of factors (e.g. chemical changes) that might have changed the amounts of the various elements in the sample during the decay interval.  These difficulties are considerable, and are discussed below. It also requires knowledge of the rates at which various isotopes decay. These rates are known to great accuracy.

'''Radiometric dating''' is a method of determining the age of an artifact by assuming that on average decay rates have been constant (see below for the flaws in that assumption) and measuring the amount of radioactive decay that has occurred.<ref>[http://pubs.usgs.gov/gip/geotime/radiometric.html Radiometric Time Scale] USGS</ref> Radiometric dating is mostly used to determine the age of rocks, though a particular form of radiometric dating&mdash;called [[Radiocarbon dating]]&mdash;can date wood, cloth, skeletons, and other organic material.

Because analysis of the various control variables that could affect the chemical composition of the sample during the decay period often depends on shrewd guesswork, radiometric dating as a whole could be said to fail the standards of testability and [[falsifiability]], and so claims based on radiometric dating may fail to qualify under the ''[[Daubert]]'' standard for court-admissible scientific evidence.  The underlying decay rates, on the other hand, are completely testable and falsifiable.

Because radiometric dating fails to satisfy standards of testability and [[falsifiability]], claims based on radiometric dating may fail to qualify under the ''[[Daubert]]'' standard for court-admissible scientific evidence.  It is more accurate for shorter time periods (e.g., hundreds of years) during which control variables are less likely to change.  

 

Radiometric dating is more accurate for shorter time periods (e.g., hundreds of years), during which control variables are less likely to change.

 

Due to so many different kinds or radiometric dating in use (i.e [[Radiocarbon dating]], also called carbon dating, [[Potassium-argon dating]], [[Uranium-lead dating]], [[Uranium-thorium]] and [[Rubidium-strontium dating]]), all of which concur with each other when dating objects, it is extremely unlikely that all of them are wrong in the exact same way. Therefore, support for radiometric dating is virtually universal in the scientific community.

== Key implausible assumptions ==

== Key implausible assumptions ==

=== Rate of decay ===

=== Rate of decay ===

Another assumption is that the rate of decay is constant over long periods of time.  Radiometric dating requires that the decay rates of the isotopes involved be accurately known, and that there is confidence that these decay rates are constant.  Fortunately, this is the case.  The physical constants (nucleon masses, fine structure constant) involved in radioactive decay are well characterized, and the processes are well understood.  Careful astronomical observations show that the constants have not changed significantly in billions of years&mdash;spectral lines from distant galaxies would have shifted perceptibly if these constants had changed.  In some cases radioactive decay itself can be observed and measured in distant galaxies when a supernova explodes and ejects unstable nuclei.

Another assumption is that the rate of decay is constant over long periods of time, particularly as energy levels changed enormously.

 

There is no reason to expect that the rate of decay of a radioactive material is largely constant,<ref>At least one example of a change in the rate has been observed in laboratory experiments.  See Walker, 2000.</ref> and it was almost certainly not constant near the creation or beginning of the universe.<ref>Multiple references:

There are a few effects that can alter radioactive half-lives, but they are mostly well understood, and in any case would not materially affect the radiometric dating results.  That is, the analysis of the isotopic and chemical composition of the sample has far greater uncertainty than any uncertainty in the decay rate itself.

 

The major reason that decay rates can change is that the electric field, from the atom's electron cloud, can change due to chemical changes.  That is, electrons can move closer to or farther away from the nucleus depending on the chemical bonds.  This affects the coulomb barrier involved in [[Alpha decay]], and therefore changes the height and width of the barrier through which the alpha particle must [[Quantum tunnelling|tunnel]].  The effect of this on alpha decay, which is the most common decay mode in radiometric dating, is utterly insignificant.

 

There is another effect that takes place in the "electron capture" type of [[Beta decay]].  This is an example of the [[Weak force]], and is fairly rare.  Electron capture requires that there be an electron in the vicinity of the nucleus, so its activity depends strongly on the configuration of the electron cloud, which depends on the chemical state.  In fact, it is possible to shut down electron capture completely&mdash;simply ionize the substance so that there are no electrons nearby.

 

There is a fairly well-known example of chemical state affecting electron capture activity.  The ⁷Be nucleus (Beryllium-7) is an electron capturer with a half-life of about 53 days, turning into Lithium-7.  The variation is about 1.5%.  While this half-life is way too short to be useful for radiometric dating, the effect of the chemical state is noticeable.  The reason is that, because the atomic number is only four, the 2s valence electrons are very close to the 1s electrons involved in capture.<ref>Huh, C.-A., Dependence of the decay rate of ⁷Be on chemical forms, Earth and Planetary Science Letters 171:325–328, 1999.</ref>

 

There is another effect, that is not understood.  It appears that some radioactive decays are affected the Sun, and fluctuate over a period of about 33 days as the Sun rotates.  The variation is about one tenth of a percent.  It has been observed in silicon-32 and chlorine-36.  While it is not understood why this happens, it would average out over long time periods and therefore not affect the final result.

 

Creationists cast doubt on this analysis, and some apparently believe that decay rates could be so far off (by a factor of millions or more) that it could explain observations pointing to an old-Earth time-frame while young-Earth cosmology was actually taking place.  They cite large numbers of articles on Creationist web sites.<ref>Multiple references:

*Sibley, Andrew (August 2013). [https://creation.com/radioactive-decay-rates-and-solar-activity Variable radioactive decay rates and the changes in solar activity]. ''Creation Ministries International'' (from the ''Journal of Creation 27(2):3–4''). Retrieved January 4, 2018.

*Sibley, Andrew (August 2013). [https://creation.com/radioactive-decay-rates-and-solar-activity Variable radioactive decay rates and the changes in solar activity]. ''Creation Ministries International'' (from the ''Journal of Creation 27(2):3–4''). Retrieved January 4, 2018.

*Wieland, Carl. [https://creation.com/rate-group-reveals-exciting-breakthroughs RATE group reveals exciting breakthroughs!]. ''''Creation Ministries International''. Retrieved January 4, 2018.

*Wieland, Carl. [https://creation.com/rate-group-reveals-exciting-breakthroughs RATE group reveals exciting breakthroughs!]. ''''Creation Ministries International''. Retrieved January 4, 2018.

*Thomas, Brian (August 5, 2009). [http://www.icr.org/article/4816 Radioactive Decay Rates Not Stable]. ''Institute for Creation Research''. Retrieved January 4, 2018.

*Thomas, Brian (August 5, 2009). [http://www.icr.org/article/4816 Radioactive Decay Rates Not Stable]. ''Institute for Creation Research''. Retrieved January 4, 2018.

*Snelling, Andrew A. (October 1, 2009). [https://answersingenesis.org/geology/radiometric-dating/radiometric-dating-problems-with-the-assumptions/ Radiometric Dating: Problems with the Assumptions]. ''Answers in Genesis''. Retrieved January 4, 2018.

*Snelling, Andrew A. (October 1, 2009). [https://answersingenesis.org/geology/radiometric-dating/radiometric-dating-problems-with-the-assumptions/ Radiometric Dating: Problems with the Assumptions]. ''Answers in Genesis''. Retrieved January 4, 2018.

*Knapp, Alex (May 3, 2011). [https://www.forbes.com/sites/alexknapp/2011/05/03/radioactive-decay-rates-may-not-be-constant-after-all/#4634f095147f Radioactive Decay Rates May Not Be Constant After All]. ''Forbes''. Retrieved January 4, 2018.</ref> While most of these articles accept that the possible discrepancies are nowhere near large enough to refute old-Earth cosmology, the Woodmorappe paper does make that claim.  It uses the phenomenon of ionization, described above, to shut down electron capture decay, which could indeed cause a billion-fold discrepancy.  However, this ionization would not have taken place under real-world circumstances.  The Walker and Knapp articles refer to the noticeable discrepancies in Beryllium-7, described above.

*Knapp, Alex (May 3, 2011). [https://www.forbes.com/sites/alexknapp/2011/05/03/radioactive-decay-rates-may-not-be-constant-after-all/#4634f095147f Radioactive Decay Rates May Not Be Constant After All]. ''Forbes''. Retrieved January 4, 2018.</ref>

As early as of 1673, John Ray, an English naturalist, reckoned with alternative that ''"im the primitive times and soon after the Creation the earth suffered far more concussions and mutations in its superficial part than afterward"''.<ref name="Rappaport1997">{{cite book |title=When Geologists Where Historians, 1665-1750 |author=Rhoda Rappaport |publisher=Cornell University Press |place=Ithaca and London |year=1997 |pages=194 |isbn=978-0801-433863 |url=http://books.google.com/books?id=30U3W2kI7foC |quote=}}</ref> The process of decay is as follows.  Atoms consist of a heavy central core called the [[nucleus]] surrounded by clouds of lightweight particles (electrons), called [[electron shell]]s. The energy locked in the nucleus is enormous, but cannot be released easily. The phenomenon we know as heat is simply the jiggling around of atoms and their components, so in principle a high enough temperature could cause the components of the core to break out. However, the temperature required to do this is in in the millions of degrees, so this cannot be achieved by any natural process that we know about. The second way that a nucleus could be disrupted is by particles striking it. However, the nucleus has a strong positive charge and the electron shells have a strong negative charge. Any incoming negative charge would be deflected by the electron shell and any positive charge that penetrated the electron shells would be deflected by the positive charge of the nucleus itself.

 

As early as of 1673, John Ray, an English naturalist, wrote ''"in the primitive times the Creation of the earth suffered far more concussions and mutations in its superficial part than afterwards"''.<ref>{{cite book |title=Time's Arrows: Scientific Attitudes Toward time|author=Richard Morris|publisher=Simon and Schuster|year=1986|pages=240 pages|isbn=978-0671501587|url=https://books.google.com/books?id=NOZ-r3YZrf0C&printsec=frontcover&dq=Time%27s+arrows&hl=en&sa=X&ved=0ahUKEwiIkL6dqK7ZAhWl2YMKHa0QCAkQ6AEIKTAA#v=onepage&q=Time's%20arrows&f=false}}</ref> He was referring to the geological controversy that would later be dubbed "gradualism" vs. "catastrophism"; this long predated any knowledge of radioactivity.

 

The process of decay is as follows.  Atoms consist of a heavy central core called the [[nucleus]] surrounded by clouds of lightweight particles (electrons), called [[electron shell]]s. The energy locked in the nucleus is enormous, but cannot be released easily. The phenomenon we know as heat is simply the jiggling around of atoms and their components, so in principle a high enough temperature could cause the components of the core to break out. However, the temperature required to do this is in in the millions of degrees, so this cannot be achieved by any natural process that we know about. The second way that a nucleus could be disrupted is by particles striking it. However, the nucleus has a strong positive charge and the electron shells have a strong negative charge. Any incoming negative charge would be deflected by the electron shell and any positive charge that penetrated the electron shells would be deflected by the positive charge of the nucleus itself.

The decay process is as follows.  

The decay process is as follows.  

Atoms themselves consist of a heavy central core called the [[nucleus]] surrounded by arrangements of [[electron shell]]s, wherein there are different probabilities of precisely locating a certain number of electrons (depending on the element). The energy locked in the nucleus is enormous, but cannot be released easily. One way that a nucleus could be disrupted is by particles striking it. However, the nucleus has a strong positive charge and the electron shells have a strong negative charge. Any incoming negative charge would be deflected by the electron shell and any positive charge that penetrated the electron shells would be deflected by the positive charge of the nucleus itself. This interpretation unfortunately fails to consider observed energetic interactions, including that of the strong force, which is stronger the electromagnetic force.

Atoms themselves consist of a heavy central core called the [[nucleus]] surrounded by arrangements of [[electron shell]]s, wherein there are different probabilities of precisely locating a certain number of electrons (depending on the element). The energy locked in the nucleus is enormous, but cannot be released easily. One way that a nucleus could be disrupted is by particles striking it. However, the nucleus has a strong positive charge and the electron shells have a strong negative charge. Any incoming negative charge would be deflected by the electron shell and any positive charge that penetrated the electron shells would be deflected by the positive charge of the nucleus itself. This interpretation unfortunately fails to consider observed energetic interactions, including that of the strong force, which is stronger the electromagnetic force.

=== Outside influences ===

=== Outside influences ===

In order to calibrate radiometric dating methods, the methods need to be checked for accuracy against items with independently-known dates.

In order to calibrate radiometric dating methods, the methods need to be checked for accuracy against items with independently-known dates.

Carbon dating, with its much lower maximum theoretical range, is often used for dating items only hundreds and thousands of years old, so can be calibrated in its lower ranges by comparing results with artifacts whose ages are known from historical records.

Carbon dating, with its much lower maximum theoretical range, is often used for dating items only hundreds and thousands of years old, so can be calibrated in its lower ranges by comparing results with artifacts who's ages are known from historical records.

Scientists have also attempted to extend the calibration range by comparing results to timber which has its age calculated by [[dendrochronology]], but this has also been questioned because carbon dating is used to assist with working out dendrochronological ages.

Scientists have also attempted to extend the calibration range by comparing results to timber which has its age calculated by [[dendrochronology]], but this has also been questioned because carbon dating is used to assist with working out dendrochronological ages.